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Sample records for frequent missense mutation

  1. Functional analysis of HNPCC-related missense mutations in MSH2

    International Nuclear Information System (INIS)

    Luetzen, Anne; Wind, Niels de; Georgijevic, Dubravka; Nielsen, Finn Cilius; Rasmussen, Lene Juel

    2008-01-01

    Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant proportion of MMR mutations found in HNPCC patients are single amino acid substitutions and the functional consequences of many of these mutations in DNA repair are unclear. We have examined the consequences of seven MSH2 missense mutations found in HNPCC families by testing the MSH2 mutant proteins in functional assays as well as by generating equivalent missense mutations in Escherichia coli MutS and analyzing the phenotypes of these mutants. Here we show that two mutant proteins, MSH2-P622L and MSH2-C697F confer multiple biochemical defects, namely in mismatch binding, in vivo interaction with MSH6 and EXO1, and in nuclear localization in the cell. Mutation G674R, located in the ATP-binding region of MSH2, appears to confer resistance to ATP-dependent mismatch release. Mutations D167H and H639R show reduced mismatch binding. Results of in vivo experiments in E. coli with MutS mutants show that one additional mutant, equivalent of MSH2-A834T that do not show any defects in MSH2 assays, is repair deficient. In conclusion, all mutant proteins (except for MSH2-A305T) have defects; either in mismatch binding, ATP-release, mismatch repair activity, subcellular localization or protein-protein interactions

  2. Functional analysis of HNPCC-related missense mutations in MSH2

    Energy Technology Data Exchange (ETDEWEB)

    Luetzen, Anne [Department of Science, Systems and Models, Roskilde University, DK-4000 Roskilde (Denmark); Wind, Niels de; Georgijevic, Dubravka [Department of Toxicogenetics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden (Netherlands); Nielsen, Finn Cilius [Department of Clinical Biochemistry, Rigshospitalet, DK-2100 Copenhagen (Denmark); Rasmussen, Lene Juel [Department of Science, Systems and Models, Roskilde University, DK-4000 Roskilde (Denmark)], E-mail: ljr@ruc.dk

    2008-10-14

    Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant proportion of MMR mutations found in HNPCC patients are single amino acid substitutions and the functional consequences of many of these mutations in DNA repair are unclear. We have examined the consequences of seven MSH2 missense mutations found in HNPCC families by testing the MSH2 mutant proteins in functional assays as well as by generating equivalent missense mutations in Escherichia coli MutS and analyzing the phenotypes of these mutants. Here we show that two mutant proteins, MSH2-P622L and MSH2-C697F confer multiple biochemical defects, namely in mismatch binding, in vivo interaction with MSH6 and EXO1, and in nuclear localization in the cell. Mutation G674R, located in the ATP-binding region of MSH2, appears to confer resistance to ATP-dependent mismatch release. Mutations D167H and H639R show reduced mismatch binding. Results of in vivo experiments in E. coli with MutS mutants show that one additional mutant, equivalent of MSH2-A834T that do not show any defects in MSH2 assays, is repair deficient. In conclusion, all mutant proteins (except for MSH2-A305T) have defects; either in mismatch binding, ATP-release, mismatch repair activity, subcellular localization or protein-protein interactions.

  3. Hotspots of missense mutation identify novel neurodevelopmental disorder genes and functional domains

    Science.gov (United States)

    Geisheker, Madeleine R.; Heymann, Gabriel; Wang, Tianyun; Coe, Bradley P.; Turner, Tychele N.; Stessman, Holly A.F.; Hoekzema, Kendra; Kvarnung, Malin; Shaw, Marie; Friend, Kathryn; Liebelt, Jan; Barnett, Christopher; Thompson, Elizabeth M.; Haan, Eric; Guo, Hui; Anderlid, Britt-Marie; Nordgren, Ann; Lindstrand, Anna; Vandeweyer, Geert; Alberti, Antonino; Avola, Emanuela; Vinci, Mirella; Giusto, Stefania; Pramparo, Tiziano; Pierce, Karen; Nalabolu, Srinivasa; Michaelson, Jacob J.; Sedlacek, Zdenek; Santen, Gijs W.E.; Peeters, Hilde; Hakonarson, Hakon; Courchesne, Eric; Romano, Corrado; Kooy, R. Frank; Bernier, Raphael A.; Nordenskjöld, Magnus; Gecz, Jozef; Xia, Kun; Zweifel, Larry S.; Eichler, Evan E.

    2017-01-01

    Although de novo missense mutations have been predicted to account for more cases of autism than gene-truncating mutations, most research has focused on the latter. We identified the properties of de novo missense mutations in patients with neurodevelopmental disorders (NDDs) and highlight 35 genes with excess missense mutations. Additionally, 40 amino acid sites were recurrently mutated in 36 genes, and targeted sequencing of 20 sites in 17,689 NDD patients identified 21 new patients with identical missense mutations. One recurrent site (p.Ala636Thr) occurs in a glutamate receptor subunit, GRIA1. This same amino acid substitution in the homologous but distinct mouse glutamate receptor subunit Grid2 is associated with Lurcher ataxia. Phenotypic follow-up in five individuals with GRIA1 mutations shows evidence of specific learning disabilities and autism. Overall, we find significant clustering of de novo mutations in 200 genes, highlighting specific functional domains and synaptic candidate genes important in NDD pathology. PMID:28628100

  4. A novel missense mutation of the DDHD1 gene associated with juvenile amyotrophic lateral sclerosis

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    Chujun Wu

    2016-12-01

    Full Text Available Background: Juvenile amyotrophic lateral sclerosis (jALS is a rare form of ALS with an onset age of less than 25 years and is frequently thought to be genetic in origin. DDHD1 gene mutations have been reported to be associated with the SPG28 subtype of autosomal recessive HSP but have never been reported in jALS patients.Methods: Gene screens for the causative genes of ALS, HSP and CMT using next-generation sequencing (NGS technologies were performed on a jALS patient. Sanger sequencing was used to validate identified variants and perform segregation analysis.Results: We identified a novel c.1483A>G (p.Met495Val homozygous missense mutation of the DDHD1 gene in the jALS patient. All of his parents and young bother were heterozygous for this mutation. The mutation was not found in 800 Chinese control subjects or the data of dbSNP, ExAC and 1000G.Conclusion: The novel c.1483A>G (p.Met495Val missense mutation of the DDHD1 gene could be a causative mutation of autosomal recessive jALS.

  5. Dominant missense mutations in ABCC9 cause Cantu syndrome

    NARCIS (Netherlands)

    Harakalova, M.; van Harssel, J.J.; Terhal, P.A.; van Lieshout, S.; Duran, K.; Renkens, I.; Amor, D.J.; Wilson, L.C.; Kirk, E.P.; Turner, C.L.; Shears, D.; Garcia-Minaur, S.; Lees, M.M.; Ross, A.; Venselaar, H.; Vriend, G.; Takanari, H.; Rook, M.B.; van der Heyden, M.A.; Asselbergs, F.W.; Breur, H.M.; Swinkels, M.E.; Scurr, I.J.; Smithson, S.F.; Knoers, N.V.; van der Smagt, J.J.; Nijman, I.J.; Kloosterman, W.P.; van Haelst, M.M.; van Haaften, G.; Cuppen, E.

    2012-01-01

    Cantu syndrome is characterized by congenital hypertrichosis, distinctive facial features, osteochondrodysplasia and cardiac defects. By using family-based exome sequencing, we identified a de novo mutation in ABCC9. Subsequently, we discovered novel dominant missense mutations in ABCC9 in 14 of the

  6. Dominant missense mutations in ABCC9 cause Cantu syndrome.

    NARCIS (Netherlands)

    Harakalova, M.; Harssel, J.J. van; Terhal, P.A.; Lieshout, S. van; Duran, K.; Renkens, I.; Amor, D.J.; Wilson, L.C.; Kirk, E.P.; Turner, C.L.; Shears, D.; Garcia-Minaur, S.; Lees, M.M.; Ross, A.; Venselaar, H.; Vriend, G.; Takanari, H.; Rook, M.B.; Heyden, M.A. van der; Asselbergs, F.W.; Breur, H.M.; Swinkels, M.E.; Scurr, I.J.; Smithson, S.F.; Knoers, N.V.A.M.; Smagt, J.J. van der; Nijman, IJ; Kloosterman, W.P.; Haelst, M.M. van; Haaften, G. van; Cuppen, E.

    2012-01-01

    Cantu syndrome is characterized by congenital hypertrichosis, distinctive facial features, osteochondrodysplasia and cardiac defects. By using family-based exome sequencing, we identified a de novo mutation in ABCC9. Subsequently, we discovered novel dominant missense mutations in ABCC9 in 14 of the

  7. Atypical Clinical Presentation of Xeroderma Pigmentosum in a Patient Harboring a Novel Missense Mutation in the XPC Gene: The Importance of Clinical Suspicion.

    Science.gov (United States)

    Meneses, Marina; Chavez-Bourgeois, Marion; Badenas, Celia; Villablanca, Salvador; Aguilera, Paula; Bennàssar, Antoni; Alos, Llucia; Puig, Susana; Malvehy, Josep; Carrera, Cristina

    2015-01-01

    Xeroderma pigmentosum (XP) is a genodermatosis caused by abnormal DNA repair. XP complementation group C (XPC) is the most frequent type in Mediterranean countries. We describe a case with a novel mutation in the XPC gene. A healthy Caucasian male patient was diagnosed with multiple primary melanomas. Digital follow-up and molecular studies were carried out. During digital follow-up 8 more additional melanomas were diagnosed. Molecular studies did not identify mutations in CDKN2A, CDK4 or MITF genes. Two heterozygous mutations in the XPC gene were detected: c.2287delC (p.Leu763Cysfs*4) frameshift and c.2212A>G (p.Thr738Ala) missense mutations. The p.Thr738Ala missense mutation has not been previously described. Missense mutations in the XPC gene may allow partial functionality that could explain this unusual late onset XP. Atypical clinical presentation of XPC could be misdiagnosed when genetic aberrations allow partial DNA repair capacity. © 2015 S. Karger AG, Basel.

  8. Selected missense mutations impair frataxin processing in Friedreich ataxia.

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    Clark, Elisia; Butler, Jill S; Isaacs, Charles J; Napierala, Marek; Lynch, David R

    2017-08-01

    Frataxin (FXN) is a highly conserved mitochondrial protein. Reduced FXN levels cause Friedreich ataxia, a recessive neurodegenerative disease. Typical patients carry GAA repeat expansions on both alleles, while a subgroup of patients carry a missense mutation on one allele and a GAA repeat expansion on the other. Here, we report that selected disease-related FXN missense mutations impair FXN localization, interaction with mitochondria processing peptidase, and processing. Immunocytochemical studies and subcellular fractionation were performed to study FXN import into the mitochondria and examine the mechanism by which mutations impair FXN processing. Coimmunoprecipitation was performed to study the interaction between FXN and mitochondrial processing peptidase. A proteasome inhibitor was used to model traditional therapeutic strategies. In addition, clinical profiles of subjects with and without point mutations were compared in a large natural history study. FXN I 154F and FXN G 130V missense mutations decrease FXN 81-210 levels compared with FXN WT , FXN R 165C , and FXN W 155R , but do not block its association with mitochondria. FXN I 154F and FXN G 130V also impair FXN maturation and enhance the binding between FXN 42-210 and mitochondria processing peptidase. Furthermore, blocking proteosomal degradation does not increase FXN 81-210 levels. Additionally, impaired FXN processing also occurs in fibroblasts from patients with FXN G 130V . Finally, clinical data from patients with FXN G 130V and FXN I 154F mutations demonstrates a lower severity compared with other individuals with Friedreich ataxia. These data suggest that the effects on processing associated with FXN G 130V and FXN I 154F mutations lead to higher levels of partially processed FXN, which may contribute to the milder clinical phenotypes in these patients.

  9. Prediction of phenotypes of missense mutations in human proteins from biological assemblies.

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    Wei, Qiong; Xu, Qifang; Dunbrack, Roland L

    2013-02-01

    Single nucleotide polymorphisms (SNPs) are the most frequent variation in the human genome. Nonsynonymous SNPs that lead to missense mutations can be neutral or deleterious, and several computational methods have been presented that predict the phenotype of human missense mutations. These methods use sequence-based and structure-based features in various combinations, relying on different statistical distributions of these features for deleterious and neutral mutations. One structure-based feature that has not been studied significantly is the accessible surface area within biologically relevant oligomeric assemblies. These assemblies are different from the crystallographic asymmetric unit for more than half of X-ray crystal structures. We find that mutations in the core of proteins or in the interfaces in biological assemblies are significantly more likely to be disease-associated than those on the surface of the biological assemblies. For structures with more than one protein in the biological assembly (whether the same sequence or different), we find the accessible surface area from biological assemblies provides a statistically significant improvement in prediction over the accessible surface area of monomers from protein crystal structures (P = 6e-5). When adding this information to sequence-based features such as the difference between wildtype and mutant position-specific profile scores, the improvement from biological assemblies is statistically significant but much smaller (P = 0.018). Combining this information with sequence-based features in a support vector machine leads to 82% accuracy on a balanced dataset of 50% disease-associated mutations from SwissVar and 50% neutral mutations from human/primate sequence differences in orthologous proteins. Copyright © 2012 Wiley Periodicals, Inc.

  10. BRCA1/2 missense mutations and the value of in-silico analyses.

    Science.gov (United States)

    Sadowski, Carolin E; Kohlstedt, Daniela; Meisel, Cornelia; Keller, Katja; Becker, Kerstin; Mackenroth, Luisa; Rump, Andreas; Schröck, Evelin; Wimberger, Pauline; Kast, Karin

    2017-11-01

    The clinical implications of genetic variants in BRCA1/2 in healthy and affected individuals are considerable. Variant interpretation, however, is especially challenging for missense variants. The majority of them are classified as variants of unknown clinical significance (VUS). Computational (in-silico) predictive programs are easy to access, but represent only one tool out of a wide range of complemental approaches to classify VUS. With this single-center study, we aimed to evaluate the impact of in-silico analyses in a spectrum of different BRCA1/2 missense variants. We conducted mutation analysis of BRCA1/2 in 523 index patients with suspected hereditary breast and ovarian cancer (HBOC). Classification of the genetic variants was performed according to the German Consortium (GC)-HBOC database. Additionally, all missense variants were classified by the following three in-silico prediction tools: SIFT, Mutation Taster (MT2) and PolyPhen2 (PPH2). Overall 201 different variants, 68 of which constituted missense variants were ranked as pathogenic, neutral, or unknown. The classification of missense variants by in-silico tools resulted in a higher amount of pathogenic mutations (25% vs. 13.2%) compared to the GC-HBOC-classification. Altogether, more than fifty percent (38/68, 55.9%) of missense variants were ranked differently. Sensitivity of in-silico-tools for mutation prediction was 88.9% (PPH2), 100% (SIFT) and 100% (MT2). We found a relevant discrepancy in variant classification by using in-silico prediction tools, resulting in potential overestimation and/or underestimation of cancer risk. More reliable, notably gene-specific, prediction tools and functional tests are needed to improve clinical counseling. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  11. In silico investigation of molecular effects caused by missense mutations in creatine transporter protein

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    Zhang, Zhe; Schwatz, Charles; Alexov, Emil

    2011-03-01

    Creatine transporter (CT) protein, which is encoded by SLC6A8 gene, is essential for taking up the creatine in the cell, which in turn plays a key role in the spatial and temporal maintenance of energy in skeletal and cardiac muscle cells. It was shown that some missense mutations in CT cause mental retardation, while others are harmless non-synonymous single nucleoside polymorphism (nsSNP). Currently fifteen missense mutations in CT are known, among which twelve are disease-causing. Sequence analysis reveals that there is no clear trend distinguishing disease-causing from harmless missense mutations. Because of that, we built 3D model of the CT using highly homologous template and use the model to investigate the effects of mutations of CT stability and hydrogen bond network. It is demonstrated that disease-causing mutations affect the folding free energy and ionization states of titratable group in much greater extend as compared with harmless mutations. Supported by grants from NLM, NIH, grant numbers 1R03LM009748 and 1R03LM009748-S1.

  12. A novel missense HGD gene mutation, K57N, in a patient with alkaptonuria.

    Science.gov (United States)

    Grasko, Jonathan M; Hooper, Amanda J; Brown, Jeffrey W; McKnight, C James; Burnett, John R

    2009-05-01

    Alkaptonuria is a rare recessive disorder of phenylalanine/tyrosine metabolism due to a defect in the enzyme homogentisate 1,2-dioxygenase (HGD) caused by mutations in the HGD gene. We report the case of a 38 year-old male with known alkaptonuria who was referred to an adult metabolic clinic after initially presenting to an emergency department with renal colic and subsequently passing black ureteric calculi. He complained of severe debilitating lower back pain, worsening over the last few years. A CT scan revealed marked degenerative changes and severe narrowing of the disc spaces along the entire lumbar spine. Sequencing of the HGD gene revealed that he was a compound heterozygote for a previously described missense mutation in exon 13 (G360R) and a novel missense mutation in exon 3 (K57N). Lys(57) is conserved among species and mutation of this residue is predicted to affect HGD protein function by interfering with substrate traffic at the active site. In summary, we describe an alkaptonuric patient and report a novel missense HGD mutation, K57N.

  13. Null missense ABCR (ABCA4) mutations in a family with stargardt disease and retinitis pigmentosa.

    Science.gov (United States)

    Shroyer, N F; Lewis, R A; Yatsenko, A N; Lupski, J R

    2001-11-01

    To determine the type of ABCR mutations that segregate in a family that manifests both Stargardt disease (STGD) and retinitis pigmentosa (RP), and the functional consequences of the underlying mutations. Direct sequencing of all 50 exons and flanking intronic regions of ABCR was performed for the STGD- and RP-affected relatives. RNA hybridization, Western blot analysis, and azido-adenosine triphosphate (ATP) labeling was used to determine the effect of disease-associated ABCR mutations in an in vitro assay system. Compound heterozygous missense mutations were identified in patients with STGD and RP. STGD-affected individual AR682-03 was compound heterozygous for the mutation 2588G-->C and a complex allele, [W1408R; R1640W]. RP-affected individuals AR682-04 and-05 were compound heterozygous for the complex allele [W1408R; R1640W] and the missense mutation V767D. Functional analysis of the mutation V767D by Western blot and ATP binding revealed a severe reduction in protein expression. In vitro analysis of ABCR protein with the mutations W1408R and R1640W showed a moderate effect of these individual mutations on expression and ATP-binding; the complex allele [W1408R; R1640W] caused a severe reduction in protein expression. These data reveal that missense ABCR mutations may be associated with RP. Functional analysis reveals that the RP-associated missense ABCR mutations are likely to be functionally null. These studies of the complex allele W1408R; R1640W suggest a synergistic effect of the individual mutations. These data are congruent with a model in which RP is associated with homozygous null mutations and with the notion that severity of retinal disease is inversely related to residual ABCR activity.

  14. Functional consequences and rescue potential of pathogenic missense mutations in tripeptidyl peptidase I.

    Science.gov (United States)

    Walus, Mariusz; Kida, Elizabeth; Golabek, Adam A

    2010-06-01

    There are 35 missense mutations among 68 different mutations in the TPP1 gene, which encodes tripeptidyl peptidase I (TPPI), a lysosomal aminopeptidase associated with classic late-infantile neuronal ceroid lipofuscinosis (CLN2 disease). To elucidate the molecular mechanisms underlying TPPI deficiency in patients carrying missense mutations and to test the amenability of mutant proteins to chemical chaperones and permissive temperature treatment, we introduced individually 14 disease-associated missense mutations into human TPP1 cDNA and analyzed the cell biology of these TPPI variants expressed in Chinese hamster ovary cells. Most TPPI variants displayed obstructed transport to the lysosomes, prolonged half-life of the proenzyme, and residual or no enzymatic activity, indicating folding abnormalities. Protein misfolding was produced by mutations located in both the prosegment (p.Gly77Arg) and throughout the length of the mature enzyme. However, the routes of removal of misfolded proteins by the cells varied, ranging from their efficient degradation by the ubiquitin/proteasome system to abundant secretion. Two TPPI variants demonstrated enhanced processing in response to folding improvement treatment, and the activity of one of them, p.Arg447His, showed a fivefold increase under permissive temperature conditions, which suggests that folding improvement strategies may ameliorate the function of some misfolding TPPI mutant proteins.

  15. Functional characterization of rare missense mutations in MLH1 and MSH2 identified in Danish colorectal cancer patients

    DEFF Research Database (Denmark)

    Christensen, Lise Lotte; Kariola, Reetta; Korhonen, Mari K

    2009-01-01

    Recently, we have performed a population based study to analyse the frequency of colorectal cancer related MLH1 and MSH2 missense mutations in the Danish population. Half of the analyzed mutations were rare and most likely only present in the families where they were identified originally. Some...... of the missense mutations were located in conserved regions in the MLH1 and MSH2 proteins indicating a relation to disease development. In the present study, we functionally characterized 10 rare missense mutations in MLH1 and MSH2 identified in 13 Danish CRC families. To elucidate the pathogenicity...

  16. FATP4 missense and nonsense mutations cause similar features in Ichthyosis Prematurity Syndrome

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    Dahl Niklas

    2011-03-01

    Full Text Available Abstract Background Ichthyosis Prematurity Syndrome (IPS is an autosomal recessive disorder characterized by premature birth, non-scaly ichthyosis and atopic manifestations. The disease was recently shown to be caused by mutations in the gene encoding the fatty acid transport protein 4 (FATP4 and a specific reduction in the incorporation of very long chain fatty acids (VLCFA into cellular lipids. Findings We screened probands from five families segregating IPS for mutations in the FATP4 gene. Four probands were compound heterozygous for four different mutations of which three are novel. Four patients were heterozygous and one patient homozygous for the previously reported non-sense mutation p.C168X (c.504c > a. All patients had clinical characteristics of IPS and a similar clinical course. Conclusions Missense mutations and non-sense mutations in FATP4 are associated with similar clinical features suggesting that missense mutations have a severe impact on FATP4 function. The results broaden the mutational spectrum in FATP4 associated with IPS for molecular diagnosis of and further functional analysis of FATP4.

  17. Nonsense and missense mutation of mitochondrial ND6 gene promotes cell migration and invasion in human lung adenocarcinoma

    International Nuclear Information System (INIS)

    Yuan, Yang; Wang, Weixing; Li, Huizhong; Yu, Yongwei; Tao, Jin; Huang, Shengdong; Zeng, Zhiyong

    2015-01-01

    Previous study showed that mitochondrial ND6 (mitND6) gene missense mutation resulted in NADH dehydrogenase deficiency and was associated with tumor metastasis in several mouse tumor cell lines. In the present study, we investigated the possible role of mitND6 gene nonsense and missense mutations in the metastasis of human lung adenocarcinoma. The presence of mitND6 gene mutations was screened by DNA sequencing of tumor tissues from 87 primary lung adenocarcinoma patients and the correlation of the mutations with the clinical features was analyzed. In addition, we constructed cytoplasmic hybrid cells with denucleared primary lung adenocarcinoma cell as the mitochondria donor and mitochondria depleted lung adenocarcinoma A549 cell as the nuclear donor. Using these cells, we studied the effects of mitND6 gene nonsense and missense mutations on cell migration and invasion through wounding healing and matrigel-coated transwell assay. The effects of mitND6 gene mutations on NADH dehydrogenase activity and ROS production were analyzed by spectrophotometry and flow cytometry. mitND6 gene nonsense and missense mutations were detected in 11 of 87 lung adenocarcinoma specimens and was correlated with the clinical features including age, pathological grade, tumor stage, lymph node metastasis and survival rate. Moreover, A549 cell containing mitND6 gene nonsense and missense mutation exhibited significantly lower activity of NADH dehydrogenase, higher level of ROS, higher capacity of cell migration and invasion, and higher pAKT and pERK1/ERK2 expression level than cells with the wild type mitND6 gene. In addition, NADH dehydrogenase inhibitor rotenone was found to significantly promote the migration and invasion of A549 cells. Our data suggest that mitND6 gene nonsense and missense mutation might promote cell migration and invasion in lung adenocarcinoma, probably by NADH dehydrogenase deficiency induced over-production of ROS

  18. Characterization of cancer-associated missense mutations in MDM2

    OpenAIRE

    Chauhan, Krishna M.; Ramakrishnan, Gopalakrishnan; Kollareddy, Madhusudhan; Martinez, Luis A.

    2015-01-01

    MDM2 is an E3 ubiquitin ligase that binds the N-terminus of p53 and promotes its ubiquitin-dependent degradation. Elevated levels of MDM2 due to overexpression or gene amplification can contribute to tumor development by suppressing p53 activity. Since MDM2 is an oncogene, we explored the possibility that other genetic lesions, namely missense mutations, might alter its activities. We selected mutations in MDM2 that reside in one of the 4 key regions of the protein: p53 binding domain, acidic...

  19. A novel missense Norrie disease mutation associated with a severe ocular phenotype.

    Science.gov (United States)

    Khan, Arif O; Shamsi, Farrukh A; Al-Saif, Amr; Kambouris, Marios

    2004-01-01

    Clinical findings and pedigree analysis led to the diagnosis of severe Norrie disease in two brothers. DNA sequencing demonstrated a novel missense mutation (703G>T) that significantly alters predicted protein structure. Less severe retinal developmental disease may be associated with milder mutations in the Norrie disease gene.

  20. A structural systems biology approach for quantifying the systemic consequences of missense mutations in proteins.

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    Tammy M K Cheng

    Full Text Available Gauging the systemic effects of non-synonymous single nucleotide polymorphisms (nsSNPs is an important topic in the pursuit of personalized medicine. However, it is a non-trivial task to understand how a change at the protein structure level eventually affects a cell's behavior. This is because complex information at both the protein and pathway level has to be integrated. Given that the idea of integrating both protein and pathway dynamics to estimate the systemic impact of missense mutations in proteins remains predominantly unexplored, we investigate the practicality of such an approach by formulating mathematical models and comparing them with experimental data to study missense mutations. We present two case studies: (1 interpreting systemic perturbation for mutations within the cell cycle control mechanisms (G2 to mitosis transition for yeast; (2 phenotypic classification of neuron-related human diseases associated with mutations within the mitogen-activated protein kinase (MAPK pathway. We show that the application of simplified mathematical models is feasible for understanding the effects of small sequence changes on cellular behavior. Furthermore, we show that the systemic impact of missense mutations can be effectively quantified as a combination of protein stability change and pathway perturbation.

  1. A Single Missense Mutation in 77% of Prostate Cancer Bone Metastases: Novel Opportunity for Genetic Biomarker and Novel Therapeutic Mitochondrial Target

    Science.gov (United States)

    2017-10-01

    goal of this application is to identify targets for the treatment of androgen receptor null castration-resistant prostate cancer in in vitro and pre...AWARD NUMBER: W81XWH-16-1-0584 TITLE : A Single Missense Mutation in 77% of Prostate Cancer Bone Metastases: Novel Opportunity for Genetic...Missense Mutation in 77% of Prostate Cancer Bone Metastases: 5a. CONTRACT NUMBER A Single Missense Mutation in 77% of Prostate Cancer Bone Metastases

  2. Common pathogenic effects of missense mutations in the P-type ATPase ATP13A2 (PARK9) associated with early-onset parkinsonism.

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    Podhajska, Agata; Musso, Alessandra; Trancikova, Alzbeta; Stafa, Klodjan; Moser, Roger; Sonnay, Sarah; Glauser, Liliane; Moore, Darren J

    2012-01-01

    Mutations in the ATP13A2 gene (PARK9) cause autosomal recessive, juvenile-onset Kufor-Rakeb syndrome (KRS), a neurodegenerative disease characterized by parkinsonism. KRS mutations produce truncated forms of ATP13A2 with impaired protein stability resulting in a loss-of-function. Recently, homozygous and heterozygous missense mutations in ATP13A2 have been identified in subjects with early-onset parkinsonism. The mechanism(s) by which missense mutations potentially cause parkinsonism are not understood at present. Here, we demonstrate that homozygous F182L, G504R and G877R missense mutations commonly impair the protein stability of ATP13A2 leading to its enhanced degradation by the proteasome. ATP13A2 normally localizes to endosomal and lysosomal membranes in neurons and the F182L and G504R mutations disrupt this vesicular localization and promote the mislocalization of ATP13A2 to the endoplasmic reticulum. Heterozygous T12M, G533R and A746T mutations do not obviously alter protein stability or subcellular localization but instead impair the ATPase activity of microsomal ATP13A2 whereas homozygous missense mutations disrupt the microsomal localization of ATP13A2. The overexpression of ATP13A2 missense mutants in SH-SY5Y neural cells does not compromise cellular viability suggesting that these mutant proteins lack intrinsic toxicity. However, the overexpression of wild-type ATP13A2 may impair neuronal integrity as it causes a trend of reduced neurite outgrowth of primary cortical neurons, whereas the majority of disease-associated missense mutations lack this ability. Finally, ATP13A2 overexpression sensitizes cortical neurons to neurite shortening induced by exposure to cadmium or nickel ions, supporting a functional interaction between ATP13A2 and heavy metals in post-mitotic neurons, whereas missense mutations influence this sensitizing effect. Collectively, our study provides support for common loss-of-function effects of homozygous and heterozygous missense

  3. Epidermal growth factor receptor activation in glioblastoma through novel missense mutations in the extracellular domain.

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    Jeffrey C Lee

    2006-12-01

    Full Text Available Protein tyrosine kinases are important regulators of cellular homeostasis with tightly controlled catalytic activity. Mutations in kinase-encoding genes can relieve the autoinhibitory constraints on kinase activity, can promote malignant transformation, and appear to be a major determinant of response to kinase inhibitor therapy. Missense mutations in the EGFR kinase domain, for example, have recently been identified in patients who showed clinical responses to EGFR kinase inhibitor therapy.Encouraged by the promising clinical activity of epidermal growth factor receptor (EGFR kinase inhibitors in treating glioblastoma in humans, we have sequenced the complete EGFR coding sequence in glioma tumor samples and cell lines. We identified novel missense mutations in the extracellular domain of EGFR in 13.6% (18/132 of glioblastomas and 12.5% (1/8 of glioblastoma cell lines. These EGFR mutations were associated with increased EGFR gene dosage and conferred anchorage-independent growth and tumorigenicity to NIH-3T3 cells. Cells transformed by expression of these EGFR mutants were sensitive to small-molecule EGFR kinase inhibitors.Our results suggest extracellular missense mutations as a novel mechanism for oncogenic EGFR activation and may help identify patients who can benefit from EGFR kinase inhibitors for treatment of glioblastoma.

  4. Structural and functional analysis of rare missense mutations in human chorionic gonadotrophin β-subunit

    DEFF Research Database (Denmark)

    Nagirnaja, Liina; Venclovas, Česlovas; Rull, Kristiina

    2012-01-01

    Heterodimeric hCG is one of the key hormones determining early pregnancy success. We have previously identified rare missense mutations in hCGβ genes with potential pathophysiological importance. The present study assessed the impact of these mutations on the structure and function of hCG by appl...... of intact hCG as also supported by an in silico analysis. In summary, the accumulated data indicate that only mutations with neutral or mild functional consequences might be tolerated in the major hCGβ genes CGB5 and CGB8.......Heterodimeric hCG is one of the key hormones determining early pregnancy success. We have previously identified rare missense mutations in hCGβ genes with potential pathophysiological importance. The present study assessed the impact of these mutations on the structure and function of h......CG by applying a combination of in silico (sequence and structure analysis, molecular dynamics) and in vitro (co-immunoprecipitation, immuno- and bioassays) approaches. The carrier status of each mutation was determined for 1086 North-Europeans [655 patients with recurrent miscarriage (RM)/431 healthy controls...

  5. Two novel missense mutations in bovine ATGL gene and their ...

    African Journals Online (AJOL)

    Adipose triglyceride lipase (ATGL) as a triglyceride-specific lipase, plays a key role in the triglyceride liposis mobilization of fat tissue. In this study, based on the pyrosequencing technology, two novel missense mutations were identified, which were 3289 G>C in exon 6 bringing E277Q and 3514 A>T in exon 7 bringing ...

  6. E-cadherin destabilization accounts for the pathogenicity of missense mutations in hereditary diffuse gastric cancer.

    Directory of Open Access Journals (Sweden)

    Joana Simões-Correia

    Full Text Available E-cadherin is critical for the maintenance of tissue architecture due to its role in cell-cell adhesion. E-cadherin mutations are the genetic cause of Hereditary Diffuse Gastric Cancer (HDGC and missense mutations represent a clinical burden, due to the uncertainty of their pathogenic role. In vitro and in vivo, most mutations lead to loss-of-function, although the causal factor is unknown for the majority. We hypothesized that destabilization could account for the pathogenicity of E-cadherin missense mutations in HDGC, and tested our hypothesis using in silico and in vitro tools. FoldX algorithm was used to calculate the impact of each mutation in E-cadherin native-state stability, and the analysis was complemented with evolutionary conservation, by SIFT. Interestingly, HDGC patients harbouring germline E-cadherin destabilizing mutants present a younger age at diagnosis or death, suggesting that the loss of native-state stability of E-cadherin accounts for the disease phenotype. To elucidate the biological relevance of E-cadherin destabilization in HDGC, we investigated a group of newly identified HDGC-associated mutations (E185V, S232C and L583R, of which L583R is predicted to be destabilizing. We show that this mutation is not functional in vitro, exhibits shorter half-life and is unable to mature, due to premature proteasome-dependent degradation, a phenotype reverted by stabilization with the artificial mutation L583I (structurally tolerated. Herein we report E-cadherin structural models suitable to predict the impact of the majority of cancer-associated missense mutations and we show that E-cadherin destabilization leads to loss-of-function in vitro and increased pathogenicity in vivo.

  7. Hereditary thrombophilia: identification of nonsense and missense mutations in the protein C gene

    International Nuclear Information System (INIS)

    Romeo, G.; Hassan, H.J.; Staempfli, S.

    1987-01-01

    The structure of the gene for protein C, an anticoagulant serine protease, was analyzed in 29 unrelated patients with hereditary thrombophilia and protein C deficiency. Gene deletion(s) or gross rearrangement(s) was not demonstrable by Southern blot hybridization to cDNA probes. However, two unrelated patients showed a variant restriction pattern after Pvu II or BamHi digestion, due to mutations in the last exon: analysis of their pedigrees, including three or seven heterozygotes, respectively, with ∼50% reduction of both enzymatic and antigen level, showed the abnormal restriction pattern in all heterozygous individuals, but not in normal relatives. Cloning of protein C gene and sequencing of the last exon allowed the authors to identify a nonsense and a missense mutation, respectively. In the first case, codon 306 (CGA, arginine) is mutated to an inframe stop codon, thus generating a new Pvu II recognition site. In the second case, a missense mutation in the BamHI palindrome (GGATCC → GCATCC) leads to substitution of a key amino acid (a tryptophan to cysteine substitution at position 402), invariantly conserved in eukaryotic serine proteases. These point mutations may explain the protein C-deficiency phenotype of heterozygotes in the two pedigrees

  8. [Study of gene mutation in 62 hemophilia A children].

    Science.gov (United States)

    Hu, Q; Liu, A G; Zhang, L Q; Zhang, A; Wang, Y Q; Wang, S M; Lu, Y J; Wang, X

    2017-11-02

    Objective: To analyze the mutation type of FⅧ gene in children with hemophilia A and to explore the relationship among hemophilia gene mutation spectrum, gene mutation and clinical phenotype. Method: Sixty-two children with hemophilia A from Department of Pediatric Hematology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology between January 2015 and March 2017 were enrolled. All patients were male, aged from 4 months to 7 years and F Ⅷ activity ranged 0.2%-11.0%. Fifty cases had severe, 10 cases had moderate and 2 cases had mild hemophilia A. DNA was isolated from peripheral blood in hemophilia A children and the target gene fragment was amplified by PCR, in combination with the second generation sequencing, 22 and 1 introns were detected. Negative cases were detected by the second generation sequencing and results were compared with those of the international FⅧ gene mutation database. Result: There were 20 cases (32%) of intron 22 inversion, 2 cases (3%) of intron 1 inversion, 18 cases (29%) of missense mutation, 5 cases (8%) of nonsense mutation, 7 cases (11%) of deletion mutation, 1 case(2%)of splice site mutation, 2 cases (3%) of large fragment deletion and 1 case of insertion mutation (2%). No mutation was detected in 2 cases (3%), and 4 cases (7%) failed to amplify. The correlation between phenotype and genotype showed that the most common gene mutation in severe hemophilia A was intron 22 inversion (20 cases), accounting for 40% of severe patients, followed by 11 cases of missense mutation (22%). The most common mutation in moderate hemophilia A was missense mutation (6 cases), accounting for 60% of moderate patients. Conclusion: The most frequent mutation type in hemophilia A was intron 22 inversion, followed by missense mutation, again for missing mutation. The relationship between phenotype and genotype: the most frequent gene mutation in severe hemophilia A is intron 22 inversion, followed by missense

  9. NDST1 missense mutations in autosomal recessive intellectual disability.

    Science.gov (United States)

    Reuter, Miriam S; Musante, Luciana; Hu, Hao; Diederich, Stefan; Sticht, Heinrich; Ekici, Arif B; Uebe, Steffen; Wienker, Thomas F; Bartsch, Oliver; Zechner, Ulrich; Oppitz, Cornelia; Keleman, Krystyna; Jamra, Rami Abou; Najmabadi, Hossein; Schweiger, Susann; Reis, André; Kahrizi, Kimia

    2014-11-01

    NDST1 was recently proposed as a candidate gene for autosomal recessive intellectual disability in two families. It encodes a bifunctional GlcNAc N-deacetylase/N-sulfotransferase with important functions in heparan sulfate biosynthesis. In mice, Ndst1 is crucial for embryonic development and homozygous null mutations are perinatally lethal. We now report on two additional unrelated families with homozygous missense NDST1 mutations. All mutations described to date predict the substitution of conserved amino acids in the sulfotransferase domain, and mutation modeling predicts drastic alterations in the local protein conformation. Comparing the four families, we noticed significant overlap in the clinical features, including both demonstrated and apparent intellectual disability, muscular hypotonia, epilepsy, and postnatal growth deficiency. Furthermore, in Drosophila, knockdown of sulfateless, the NDST ortholog, impairs long-term memory, highlighting its function in cognition. Our data confirm NDST1 mutations as a cause of autosomal recessive intellectual disability with a distinctive phenotype, and support an important function of NDST1 in human development. © 2014 Wiley Periodicals, Inc.

  10. Effects of missense mutations in sortase A gene on enzyme activity in Streptococcus mutans.

    Science.gov (United States)

    Zhuang, P L; Yu, L X; Tao, Y; Zhou, Y; Zhi, Q H; Lin, H C

    2016-04-11

    Streptococcus mutans (S. mutans) is the major aetiological agent of dental caries, and the transpeptidase Sortase A (SrtA) plays a major role in cariogenicity. The T168G and G470A missense mutations in the srtA gene may be linked to caries susceptibility, as demonstrated in our previous studies. This study aimed to investigate the effects of these missense mutations of the srtA gene on SrtA enzyme activity in S. mutans. The point mutated recombinant S.mutans T168G and G470A sortases were expressed in expression plasmid pET32a. S. mutans UA159 sortase coding gene srtA was used as the template for point mutation. Enzymatic activity was assessed by quantifying increases in the fluorescence intensity generated when a substrate Dabcyl-QALPNTGEE-Edans was cleaved by SrtA. The kinetic constants were calculated based on the curve fit for the Michaelis-Menten equation. SrtA△N40(UA159) and the mutant enzymes, SrtA△N40(D56E) and SrtA△N40(R157H), were expressed and purified. A kinetic analysis showed that the affinity of SrtA△N40(D56E) and SrtA△N40(R157H) remained approximately equal to the affinity of SrtA△N40(UA159), as determined by the Michaelis constant (K m ). However, the catalytic rate constant (k cat ) and catalytic efficiency (k cat /K m ) of SrtA△N40(D56E) were reduced compared with those of SrtA△N40(R157H) and SrtA△N40(UA159), whereas the k cat and k cat /K m values of SrtA△N40(R157H) were slightly lower than those of SrtA△N40(UA159). The findings of this study indicate that the T168G missense mutation of the srtA gene results in a significant reduction in enzymatic activity compared with S. mutans UA159, suggesting that the T168G missense mutation of the srtA gene may be related to low cariogenicity.

  11. In silico analysis of a novel MKRN3 missense mutation in familial central precocious puberty.

    Science.gov (United States)

    Neocleous, Vassos; Shammas, Christos; Phelan, Marie M; Nicolaou, Stella; Phylactou, Leonidas A; Skordis, Nicos

    2016-01-01

    The onset of puberty is influenced by the interplay of stimulating and restraining factors, many of which have a genetic origin. Premature activation of the GnRH secretion in central precocious puberty (CPP) may arise either from gain-of-function mutations of the KISS1 and KISS1R genes or from loss-of-function manner mutations of the MKRN3 gene leading to MKRN3 deficiency. To explore the genetic causes responsible for CPP and the potential role of the RING finger protein 3 (MKRN3) gene. We investigated potential sequence variations in the intronless MKRN3 gene by Sanger sequencing of the entire 507 amino acid coding region of exon 1 in a family with two affected girls presented with CPP at the age of 6 and 5·7 years, respectively. A novel heterozygous g.Gly312Asp missense mutation in the MKRN3 gene was identified in these siblings. The imprinted MKRN3 missense mutation was also identified as expected in the unaffected father and followed as expected an imprinted mode of inheritance. In silico analysis of the altered missense variant using the computational algorithms Polyphen2, SIFT and Mutation Taster predicted a damage and pathogenic alteration causing CPP. The pathogenicity of the alteration at the protein level via an in silico structural model is also explored. A novel mutation in the MKRN3 gene in two sisters with CPP was identified, supporting the fundamental role of this gene in the suppression of the hypothalamic GnRH neurons. © 2015 John Wiley & Sons Ltd.

  12. A case of recurrent encephalopathy with SCN2A missense mutation.

    Science.gov (United States)

    Fukasawa, Tatsuya; Kubota, Tetsuo; Negoro, Tamiko; Saitoh, Makiko; Mizuguchi, Masashi; Ihara, Yukiko; Ishii, Atsushi; Hirose, Shinichi

    2015-06-01

    Voltage-gated sodium channels regulate neuronal excitability, as well as survival and the patterning of neuronal connectivity during development. Mutations in SCN2A, which encodes the Na(+) channel Nav1.2, cause epilepsy syndromes and predispose children to acute encephalopathy. Here, we report the case of a young male with recurrent acute encephalopathy who carried a novel missense mutation in the SCN2A gene. He was born by normal delivery and developed repetitive apneic episodes at 2days of age. Diffusion-weighted imaging revealed high-intensity areas in diffuse subcortical white matter, bilateral thalami, and basal nuclei. His symptoms improved gradually without any specific treatment, but he exhibited a motor milestone delay after the episode. At the age of 10months, he developed acute cerebellopathy associated with a respiratory syncytial viral infection. He received high-dose intravenous gammaglobulin and methylprednisolone pulse therapy and seemed to have no obvious sequelae after the episode. He then developed severe diffuse encephalopathy associated with gastroenteritis at the age of 14months. He received high-dose intravenous gammaglobulin and methylprednisolone pulse therapy but was left with severe neurological sequelae. PCR-based analysis revealed a novel de novo missense mutation, c.4979T>G (p.Leu1660Trp), in the SCN2A gene. This case suggests that SCN2A mutations might predispose children to repetitive encephalopathy with variable clinical and imaging findings. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  13. Genotype-Phenotype Correlations Emerging from the Identification of Missense Mutations in MBTPS2

    NARCIS (Netherlands)

    Bornholdt, D.; Atkinson, T.P.; Bouadjar, B.; Catteau, B.; Cox, H.; Silva, D. De; Fischer, J.; Gunasekera, C.N.; Hadj-Rabia, S.; Happle, R.; Holder-Espinasse, M.; Kaminski, E.; Konig, A.; Megarbane, A.; Megarbane, H.; Neidel, U.; Oeffner, F.; Oji, V.; Theos, A.; Traupe, H.; Vahlquist, A.; Bon, B.W. van; Virtanen, M.; Grzeschik, K.H.

    2013-01-01

    Missense mutations affecting membrane-bound transcription factor protease site 2 (MBTPS2) have been associated with Ichthyosis Follicularis with Atrichia and Photophobia (IFAP) syndrome with or without BRESHECK syndrome, with keratosis follicularis spinulosa decalvans, and Olmsted syndrome. This

  14. Limited importance of the dominant-negative effect of TP53 missense mutations

    International Nuclear Information System (INIS)

    Stoczynska-Fidelus, Ewelina; Liberski, Pawel P; Rieske, Piotr; Szybka, Malgorzata; Piaskowski, Sylwester; Bienkowski, Michal; Hulas-Bigoszewska, Krystyna; Banaszczyk, Mateusz; Zawlik, Izabela; Jesionek-Kupnicka, Dorota; Kordek, Radzislaw

    2011-01-01

    Heterozygosity of TP53 missense mutations is related to the phenomenon of the dominant-negative effect (DNE). To estimate the importance of the DNE of TP53 mutations, we analysed the percentage of cancer cases showing a single heterozygous mutation of TP53 and searched for a cell line with a single heterozygous mutation of this gene. This approach was based on the knowledge that genes with evident DNE, such as EGFR and IDH1, represent nearly 100% of single heterozygous mutations in tumour specimens and cell lines. Genetic analyses (LOH and sequencing) performed for early and late passages of several cell lines originally described as showing single heterozygous TP53 mutations (H-318, G-16, PF-382, MOLT-13, ST-486 and LS-123). Statistical analysis of IARC TP53 and SANGER databases. Genetic analyses of N-RAS, FBXW7, PTEN and STR markers to test cross-contamination and cell line identity. Cell cloning, fluorescence-activated cell sorting and SSCP performed for the PF-382 cell line. A database study revealed TP53 single heterozygous mutations in 35% of in vivo (surgical and biopsy) samples and only 10% of cultured cells (in vitro), although those numbers appeared to be overestimated. We deem that published in vivo TP53 mutation analyses are not as rigorous as studies in vitro, and we did not find any cell line showing a stable, single heterozygous mutation. G16, PF-382 and MOLT-13 cells harboured single heterozygous mutations temporarily. ST-486, H-318 and LS-123 cell lines were misclassified. Specific mutations, such as R175H, R273H, R273L or R273P, which are reported in the literature to exert a DNE, showed the lowest percentage of single heterozygous mutations in vitro (about 5%). We suggest that the currently reported percentage of TP53 single heterozygous mutations in tumour samples and cancer cell lines is overestimated. Thus, the magnitude of the DNE of TP53 mutations is questionable. This scepticism is supported by database investigations showing that retention

  15. Missense mutation in GRN gene affecting RNA splicing and plasma progranulin level in a family affected by frontotemporal lobar degeneration.

    Science.gov (United States)

    Luzzi, Simona; Colleoni, Lara; Corbetta, Paola; Baldinelli, Sara; Fiori, Chiara; Girelli, Francesca; Silvestrini, Mauro; Caroppo, Paola; Giaccone, Giorgio; Tagliavini, Fabrizio; Rossi, Giacomina

    2017-06-01

    Gene coding for progranulin, GRN, is a major gene linked to frontotemporal lobar degeneration. While most of pathogenic GRN mutations are null mutations leading to haploinsufficiency, GRN missense mutations do not have an obvious pathogenicity, and only a few have been revealed to act through different pathogenetic mechanisms, such as cytoplasmic missorting, protein degradation, and abnormal cleavage by elastase. The aim of this study was to disclose the pathogenetic mechanisms of the GRN A199V missense mutation, which was previously reported not to alter physiological progranulin features but was associated with a reduced plasma progranulin level. After investigating the family pedigree, we performed genetic and biochemical analysis on its members and performed RNA expression studies. We found that the mutation segregates with the disease and discovered that its pathogenic feature is the alteration of GRN mRNA splicing, actually leading to haploinsufficiency. Thus, when facing with a missense GRN mutation, its pathogenetic effects should be investigated, especially if associated with low plasma progranulin levels, to determine its nature of either benign polymorphism or pathogenic mutation. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. A novel missense mutation in collagenous domain of EDA gene in a ...

    Indian Academy of Sciences (India)

    Supplementary data: A novel missense mutation in collagenous domain of EDA gene in a. Chinese family with X-linked hypohidrotic ectodermal dysplasia. Daxu Li, Ran Xu, Fumeng Huang, Biyuan Wang, Yu Tao, Zijian Jiang, Hairui Li, Jianfeng Yao,. Peng Xu, Xiaokang Wu, Le Ren, Rui Zhang, John R. Kelsoe and Jie Ma.

  17. Mice with missense and nonsense NF1 mutations display divergent phenotypes compared with human neurofibromatosis type I

    Directory of Open Access Journals (Sweden)

    Kairong Li

    2016-07-01

    Full Text Available Neurofibromatosis type 1 (NF1 is a common genetic disorder characterized by the occurrence of nerve sheath tumors and considerable clinical heterogeneity. Some translational studies have been limited by the lack of animal models available for assessing patient-specific mutations. In order to test therapeutic approaches that might restore function to the mutated gene or gene product, we developed mice harboring NF1 patient-specific mutations including a nonsense mutation (c.2041C>T; p.Arg681* and a missense mutation (c.2542G>C; p.Gly848Arg. The latter is associated with the development of multiple plexiform neurofibromas along spinal nerve roots. We demonstrate that the human nonsense NF1Arg681* and missense NF1Gly848Arg mutations have different effects on neurofibromin expression in the mouse and each recapitulates unique aspects of the NF1 phenotype, depending upon the genetic context when assessed in the homozygous state or when paired with a conditional knockout allele. Whereas the missense Nf1Gly848Arg mutation fails to produce an overt phenotype in the mouse, animals homozygous for the nonsense Nf1Arg681* mutation are not viable. Mice with one Nf1Arg681* allele in combination with a conditional floxed Nf1 allele and the DhhCre transgene (Nf14F/Arg681*; DhhCre display disorganized nonmyelinating axons and neurofibromas along the spinal column, which leads to compression of the spinal cord and paralysis. This model will be valuable for preclinical testing of novel nonsense suppression therapies using drugs to target in-frame point mutations that create premature termination codons in individuals with NF1.

  18. Missense Mutations in CRYAB Are Liable for Recessive Congenital Cataracts.

    Directory of Open Access Journals (Sweden)

    Xiaodong Jiao

    Full Text Available This study was initiated to identify causal mutations responsible for autosomal recessive congenital cataracts in consanguineous familial cases.Affected individuals underwent a detailed ophthalmological and clinical examination, and slit-lamp photographs were ascertained for affected individuals who have not yet been operated for the removal of the cataractous lens. Blood samples were obtained, and genomic DNA was extracted from white blood cells. A genome-wide scan was completed with short tandem repeat (STR markers, and the logarithm of odds (LOD scores were calculated. Protein coding exons of CRYAB were sequenced, bi-directionally. Evolutionary conservation was investigated by aligning CRYAB orthologues, and the expression of Cryab in embryonic and postnatal mice lens was investigated with TaqMan probe.The clinical and ophthalmological examinations suggested that all affected individuals had nuclear cataracts. Genome-wide linkage analysis suggested a potential region on chromosome 11q23 harboring CRYAB. DNA sequencing identified a missense variation: c.34C>T (p.R12C in CRYAB that segregated with the disease phenotype in the family. Subsequent interrogation of our entire cohort of familial cases identified a second familial case localized to chromosome 11q23 harboring a c.31C>T (p.R11C mutation. In silico analyses suggested that the mutations identified in familial cases, p.R11C and p.R12C will not be tolerated by the three-dimensional structure of CRYAB. Real-time PCR analysis identified the expression of Cryab in mouse lens as early as embryonic day 15 (E15 that increased significantly until postnatal day 6 (P6 with steady level of expression thereafter.Here, we report two novel missense mutations, p.R11C and p.R12C, in CRYAB associated with autosomal recessive congenital nuclear cataracts.

  19. Report of a patient with a constitutional missense mutation in SMARCB1, Coffin-Siris phenotype, and schwannomatosis.

    Science.gov (United States)

    Gossai, Nathan; Biegel, Jaclyn A; Messiaen, Ludwine; Berry, Susan A; Moertel, Christopher L

    2015-12-01

    We report a patient with a constitutional missense mutation in SMARCB1, Coffin-Siris Syndrome (CSS), and schwannomatosis. CSS is a rare congenital syndrome with characteristic clinical findings. This thirty-three-year-old man was diagnosed early in life with the constellation of moderate intellectual disability, hypotonia, mild microcephaly, coarse facies, wide mouth with full lips, hypoplasia of the digits, and general hirsutism. At age 26, he was found to have schwannomatosis after presenting with acute spinal cord compression. Blood and tissue analysis of multiple subsequent schwannoma resections revealed a germline missense mutation of SMARCB1, acquired loss of 22q including SMARCB1 and NF2 and mutation of the remaining NF2 wild-type allele-thus completing the four-hit, three-event mechanism associated with schwannomatosis. Variations in five genes have been associated with the Coffin-Siris phenotype: ARID1A, ARID1B, SMARCA4, SMARCB1, and SMARCE1. Of these genes, SMARCB1 has a well-established association with schwannomatosis and malignancy. This is the first report of a patient with a constitutional missense mutation of SMARCB1 resulting in CSS and subsequent development of schwannomatosis. This finding demonstrates that a SMARCB1 mutation may be the initial "hit" (constitutional) for a genetic disorder with subsequent risk of developing schwannomas and other malignancies, and raises the possibility that other patients with switch/sucrose non-fermenting (SWI/SNF) mutations may be at increased risk for tumors. © 2015 Wiley Periodicals, Inc.

  20. RAC1 Missense Mutations in Developmental Disorders with Diverse Phenotypes.

    Science.gov (United States)

    Reijnders, Margot R F; Ansor, Nurhuda M; Kousi, Maria; Yue, Wyatt W; Tan, Perciliz L; Clarkson, Katie; Clayton-Smith, Jill; Corning, Ken; Jones, Julie R; Lam, Wayne W K; Mancini, Grazia M S; Marcelis, Carlo; Mohammed, Shehla; Pfundt, Rolph; Roifman, Maian; Cohn, Ronald; Chitayat, David; Millard, Tom H; Katsanis, Nicholas; Brunner, Han G; Banka, Siddharth

    2017-09-07

    RAC1 is a widely studied Rho GTPase, a class of molecules that modulate numerous cellular functions essential for normal development. RAC1 is highly conserved across species and is under strict mutational constraint. We report seven individuals with distinct de novo missense RAC1 mutations and varying degrees of developmental delay, brain malformations, and additional phenotypes. Four individuals, each harboring one of c.53G>A (p.Cys18Tyr), c.116A>G (p.Asn39Ser), c.218C>T (p.Pro73Leu), and c.470G>A (p.Cys157Tyr) variants, were microcephalic, with head circumferences between -2.5 to -5 SD. In contrast, two individuals with c.151G>A (p.Val51Met) and c.151G>C (p.Val51Leu) alleles were macrocephalic with head circumferences of +4.16 and +4.5 SD. One individual harboring a c.190T>G (p.Tyr64Asp) allele had head circumference in the normal range. Collectively, we observed an extraordinary spread of ∼10 SD of head circumferences orchestrated by distinct mutations in the same gene. In silico modeling, mouse fibroblasts spreading assays, and in vivo overexpression assays using zebrafish as a surrogate model demonstrated that the p.Cys18Tyr and p.Asn39Ser RAC1 variants function as dominant-negative alleles and result in microcephaly, reduced neuronal proliferation, and cerebellar abnormalities in vivo. Conversely, the p.Tyr64Asp substitution is constitutively active. The remaining mutations are probably weakly dominant negative or their effects are context dependent. These findings highlight the importance of RAC1 in neuronal development. Along with TRIO and HACE1, a sub-category of rare developmental disorders is emerging with RAC1 as the central player. We show that ultra-rare disorders caused by private, non-recurrent missense mutations that result in varying phenotypes are challenging to dissect, but can be delineated through focused international collaboration. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  1. Usher syndrome type 1 due to missense mutations on both CDH23 alleles: investigation of mRNA splicing.

    Science.gov (United States)

    Becirovic, Elvir; Ebermann, Inga; Nagy, Ditta; Zrenner, Eberhart; Seeliger, Mathias Wolfgang; Bolz, Hanno Jörn

    2008-03-01

    Usher syndrome (USH) is an autosomal recessive condition characterized by sensorineural hearing loss, vestibular dysfunction, and visual impairment due to retinitis pigmentosa. Truncating mutations in the cadherin-23 gene (CDH23) result in Usher syndrome type 1D (USH1D), whereas missense mutations affecting strongly conserved motifs of the CDH23 protein cause non-syndromic deafness (DFNB12). Four missense mutations constitute an exception from this genotype-phenotype correlation: they have been described in USH1 patients in homozygous state. Using a minigene assay, we have investigated these changes (c.1450G>C, p.A484P; c.3625A>G, p.T1209A; c.4520G>A, p.R1507Q; and c.5237G>A, p.R1746Q) for a possible impact on mRNA splicing which could explain the syndromic phenotype. While in silico analysis suggested impairment of splicing in all four cases, we found aberrant splicing for only one mutation, p.R1746Q. However, splicing was normal in case of p.A484P, p.T1209A and p.R1507Q. These three latter CDH23 missense mutations could interfere with functions of both, the auditory and the visual system. Alternatively, they could represent rare non-pathogenic polymorphisms.

  2. cDNA sequencing improves the detection of P53 missense mutations in colorectal cancer

    International Nuclear Information System (INIS)

    Szybka, Malgorzata; Kordek, Radzislaw; Zakrzewska, Magdalena; Rieske, Piotr; Pasz-Walczak, Grazyna; Kulczycka-Wojdala, Dominika; Zawlik, Izabela; Stawski, Robert; Jesionek-Kupnicka, Dorota; Liberski, Pawel P

    2009-01-01

    Recently published data showed discrepancies beteween P53 cDNA and DNA sequencing in glioblastomas. We hypothesised that similar discrepancies may be observed in other human cancers. To this end, we analyzed 23 colorectal cancers for P53 mutations and gene expression using both DNA and cDNA sequencing, real-time PCR and immunohistochemistry. We found P53 gene mutations in 16 cases (15 missense and 1 nonsense). Two of the 15 cases with missense mutations showed alterations based only on cDNA, and not DNA sequencing. Moreover, in 6 of the 15 cases with a cDNA mutation those mutations were difficult to detect in the DNA sequencing, so the results of DNA analysis alone could be misinterpreted if the cDNA sequencing results had not also been available. In all those 15 cases, we observed a higher ratio of the mutated to the wild type template by cDNA analysis, but not by the DNA analysis. Interestingly, a similar overexpression of P53 mRNA was present in samples with and without P53 mutations. In terms of colorectal cancer, those discrepancies might be explained under three conditions: 1, overexpression of mutated P53 mRNA in cancer cells as compared with normal cells; 2, a higher content of cells without P53 mutation (normal cells and cells showing K-RAS and/or APC but not P53 mutation) in samples presenting P53 mutation; 3, heterozygous or hemizygous mutations of P53 gene. Additionally, for heterozygous mutations unknown mechanism(s) causing selective overproduction of mutated allele should also be considered. Our data offer new clues for studying discrepancy in P53 cDNA and DNA sequencing analysis

  3. Predicting the impact of Lynch syndrome-causing missense mutations from structural calculations

    DEFF Research Database (Denmark)

    Nielsen, Sofie V,; Stein, Amelie; Dinitzen, Alexander B.

    2017-01-01

    selected the human mismatch repair protein, MSH2, where missense variants are known to cause the hereditary cancer predisposition disease, known as Lynch syndrome. We show that the majority of disease-causing MSH2 mutations give rise to folding defects and proteasome-dependent degradation rather than...... and for diagnosis of Lynch syndrome, and perhaps other hereditary diseases....

  4. A Novel Missense Mutation of Doublecortin: Mutation Analysis of Korean Patients with Subcortical Band Heterotopia

    Science.gov (United States)

    Kim, Myeong-Kyu; Park, Man-Seok; Kim, Byeong-Chae; Cho, Ki-Hyun; Kim, Young-Seon; Kim, Jin-Hee; Heo, Tag; Kim, Eun-Young

    2005-01-01

    The neuronal migration disorders, X-linked lissencephaly syndrome (XLIS) and subcortical band heterotopia (SBH), also called "double cortex", have been linked to missense, nonsense, aberrant splicing, deletion, and insertion mutations in doublecortin (DCX) in families and sporadic cases. Most DCX mutations identified to date are located in two evolutionarily conserved domains. We performed mutation analysis of DCX in two Korean patients with SBH. The SBH patients had mild to moderate developmental delays, drug-resistant generalized seizures, and diffuse thick SBH upon brain MRI. Sequence analysis of the DCX coding region in Patient 1 revealed a c.386 C>T change in exon 3. The sequence variation results in a serine to leucine amino acid change at position 129 (S129L), which has not been found in other family members of Patient 1 or in a large panel of 120 control X-chromosomes. We report here a novel c.386 C>T mutation of DCX that is responsible for SBH. PMID:16100463

  5. Severe Clinical Course in a Patient with Congenital Amegakaryocytic Thrombocytopenia Due to a Missense Mutation of the c-MPL Gene.

    Science.gov (United States)

    Ok Bozkaya, İkbal; Yaralı, Neşe; Işık, Pamir; Ünsal Saç, Rukiye; Tavil, Betül; Tunç, Bahattin

    2015-06-01

    Congenital amegakaryocytic thrombocytopenia (CAMT) generally begins at birth with severe thrombocytopenia and progresses to pancytopenia. It is caused by mutations in the thrombopoietin receptor gene, the myeloproliferative leukemia virus oncogene (c-MPL). The association between CAMT and c-MPL mutation type has been reported in the literature. Patients with CAMT have been categorized according to their clinical symptoms caused by different mutations. Missense mutations of c-MPL have been classified as type II and these patients have delayed onset of bone marrow failure compared to type I patients. Here we present a girl with severe clinical course of CAMT II having a missense mutation in exon 4 of the c-MPL gene who was admitted to our hospital with intracranial hemorrhage during the newborn period.

  6. Abnormal fibrinogen Zlín (.gamma.Thr21Ile) with missense mutation causing hypofibrinogenemia

    Czech Academy of Sciences Publication Activity Database

    Riedelová-Reicheltová, Z.; Riedel, Tomáš; Májek, P.; Kotlín, R.; Geierová, V.; Suttnar, J.; Dyr, J. E.

    2014-01-01

    Roč. 132, č. 2 (2014), s. 140-143 ISSN 0001-5792 R&D Projects: GA ČR GBP205/12/G118 Institutional support: RVO:61389013 Keywords : fibrinogen * missense mutation * hypofibrinogenemia Subject RIV: BO - Biophysics Impact factor: 1.116, year: 2014

  7. Structural analysis of eight novel and 112 previously reported missense mutations in the interactive FXI mutation database reveals new insight on FXI deficiency.

    Science.gov (United States)

    Saunders, Rebecca E; Shiltagh, Nuha; Gomez, Keith; Mellars, Gillian; Cooper, Carolyn; Perry, David J; Tuddenham, Edward G; Perkins, Stephen J

    2009-08-01

    Factor XI (FXI) functions in blood coagulation. FXI is composed of four apple (Ap) domains and a serine protease (SP) domain. Deficiency of FXI leads to an injury-related bleeding disorder, which is remarkable for the lack of correlation between bleeding symptoms and FXI coagulant activity (FXI:C). The number of mutations previously reported in our interactive web database (http://www.FactorXI.org) is now significantly increased to 183 through our new patient studies and from literature surveys. Eight novel missense mutations give a total of 120 throughout the FXI gene (F11). The most abundant defects in FXI are revealed to be those from low-protein plasma levels (Type I: CRM-) that originate from protein misfolding, rather than from functional defects (Type II: CRM+). A total of 70 Ap missense mutations were analysed using a consensus Ap domain structure generated from the FXI dimer crystal structure. This showed that all parts of the Ap domain were affected. The 47 SP missense mutations were also distributed throughout the SP domain structure. The periphery of the Ap beta-sheet structure is sensitive to structural perturbation caused by residue changes throughout the Ap domain, yet this beta-sheet is crucial for FXI dimer formation. Residues located at the Ap4:Ap4 interface in the dimer are much less directly involved. We conclude that the abundance of Type I defects in FXI results from the sensitivity of the Ap domain folding to residue changes within this, and discuss how structural knowledge of the mutations improves our understanding of FXI deficiencies.

  8. Involvement of ER Stress in Dysmyelination of Pelizaeus-Merzbacher Disease with PLP1 Missense Mutations Shown by iPSC-Derived Oligodendrocytes

    Directory of Open Access Journals (Sweden)

    Yuko Numasawa-Kuroiwa

    2014-05-01

    Full Text Available Pelizaeus-Merzbacher disease (PMD is a form of X-linked leukodystrophy caused by mutations in the proteolipid protein 1 (PLP1 gene. Although PLP1 proteins with missense mutations have been shown to accumulate in the rough endoplasmic reticulum (ER in disease model animals and cell lines transfected with mutant PLP1 genes, the exact pathogenetic mechanism of PMD has not previously been clarified. In this study, we established induced pluripotent stem cells (iPSCs from two PMD patients carrying missense mutation and differentiated them into oligodendrocytes in vitro. In the PMD iPSC-derived oligodendrocytes, mislocalization of mutant PLP1 proteins to the ER and an association between increased susceptibility to ER stress and increased numbers of apoptotic oligodendrocytes were observed. Moreover, electron microscopic analysis demonstrated drastically reduced myelin formation accompanied by abnormal ER morphology. Thus, this study demonstrates the involvement of ER stress in pathogenic dysmyelination in the oligodendrocytes of PMD patients with the PLP1 missense mutation.

  9. A novel MKRN3 missense mutation causing familial precocious puberty.

    Science.gov (United States)

    de Vries, L; Gat-Yablonski, G; Dror, N; Singer, A; Phillip, M

    2014-12-01

    Central precocious puberty may be familial in about a quarter of the idiopathic cases. However, little is known about the genetic causes responsible for the disorder. In this report we describe a family with central precocious puberty associated with a mutation in the makorin RING-finger protein 3 (MKRN3) gene. A novel missense mutation (p.H420Q) in the imprinted MKRN3 gene was identified in the four affected siblings, in their unaffected father and in his affected mother. An in silico mutant MKRN3 model predicts that the mutation p.H420Q leads to reduced zinc binding and, subsequently, impaired RNA binding. These findings support the fundamental role of the MKRN3 protein in determining pubertal timing. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Identification and functional analysis of SOX10 missense mutations in different subtypes of Waardenburg syndrome.

    Science.gov (United States)

    Chaoui, Asma; Watanabe, Yuli; Touraine, Renaud; Baral, Viviane; Goossens, Michel; Pingault, Veronique; Bondurand, Nadege

    2011-12-01

    Waardenburg syndrome (WS) is a rare disorder characterized by pigmentation defects and sensorineural deafness, classified into four clinical subtypes, WS1-S4. Whereas the absence of additional features characterizes WS2, association with Hirschsprung disease defines WS4. WS is genetically heterogeneous, with six genes already identified, including SOX10. About 50 heterozygous SOX10 mutations have been described in patients presenting with WS2 or WS4, with or without myelination defects of the peripheral and central nervous system (PCWH, Peripheral demyelinating neuropathy-Central dysmyelinating leukodystrophy-Waardenburg syndrome-Hirschsprung disease, or PCW, PCWH without HD). The majority are truncating mutations that most often remove the main functional domains of the protein. Only three missense mutations have been thus far reported. In the present study, novel SOX10 missense mutations were found in 11 patients and were examined for effects on SOX10 characteristics and functions. The mutations were associated with various phenotypes, ranging from WS2 to PCWH. All tested mutations were found to be deleterious. Some mutants presented with partial cytoplasmic redistribution, some lost their DNA-binding and/or transactivation capabilities on various tissue-specific target genes. Intriguingly, several mutants were redistributed in nuclear foci. Whether this phenomenon is a cause or a consequence of mutation-associated pathogenicity remains to be determined, but this observation could help to identify new SOX10 modes of action. © 2011 Wiley-Liss, Inc.

  11. A novel missense mutation of NDP in a Chinese family with X-linked familial exudative vitreoretinopathy.

    Science.gov (United States)

    Liu, Hong Yan; Huang, Jia; Wang, Rui Li; Wang, Yue; Guo, Liang Jie; Li, Tao; Wu, Dong; Wang, Hong Dan; Guo, Qian Nan; Dong, Dao Quan

    2016-11-01

    Familial exudative vitreoretinopathy (FEVR) is a hereditary ocular disorder characterized by a failure of peripheral retinal vascularization. In this report, we describe a novel missense mutation of the Norrie disease gene (NDP) in a Chinese family with X-linked FEVR. Ophthalmologic evaluation was performed on four male patients and seven unaffected individuals after informed consent was obtained. Venous blood was collected from the 11 members of this family, and genomic DNA was extracted using standard methods. The coding exons 2 and 3 and their corresponding exon-intron junctions of NDP were amplified by polymerase chain reaction and then subjected to direct DNA sequencing. A novel missense mutation (c.310A>C) in exon 3, leading to a lysine-to-glutamine substitution at position 104 (p.Lys104Gln), was identified in all four patients with X-linked FEVR. Three unaffected female individuals (III2, IV3, and IV11) were found to be carriers of the mutation. This mutation was not detected in other unaffected individuals. The mutation c.310A>C (p.Lys104Gln) in exon 3 of NDP is associated with FEVR in the studied family. This result further enriches the mutation spectrum of FEVR. Copyright © 2016. Published by Elsevier Taiwan LLC.

  12. A novel missense mutation of NDP in a Chinese family with X-linked familial exudative vitreoretinopathy

    Directory of Open Access Journals (Sweden)

    Hong Yan Liu

    2016-11-01

    Full Text Available Familial exudative vitreoretinopathy (FEVR is a hereditary ocular disorder characterized by a failure of peripheral retinal vascularization. In this report, we describe a novel missense mutation of the Norrie disease gene (NDP in a Chinese family with X-linked FEVR. Ophthalmologic evaluation was performed on four male patients and seven unaffected individuals after informed consent was obtained. Venous blood was collected from the 11 members of this family, and genomic DNA was extracted using standard methods. The coding exons 2 and 3 and their corresponding exon–intron junctions of NDP were amplified by polymerase chain reaction and then subjected to direct DNA sequencing. A novel missense mutation (c.310A>C in exon 3, leading to a lysine-to-glutamine substitution at position 104 (p.Lys104Gln, was identified in all four patients with X-linked FEVR. Three unaffected female individuals (III2, IV3, and IV11 were found to be carriers of the mutation. This mutation was not detected in other unaffected individuals. The mutation c.310A>C (p.Lys104Gln in exon 3 of NDP is associated with FEVR in the studied family. This result further enriches the mutation spectrum of FEVR.

  13. A Novel Homozygous Missense Mutation in HOXC13 Leads to Autosomal Recessive Pure Hair and Nail Ectodermal Dysplasia.

    Science.gov (United States)

    Li, Xiaoxiao; Orseth, Meredith Lee; Smith, J Michael; Brehm, Mary Abigail; Agim, Nnenna Gebechi; Glass, Donald Alexander

    2017-03-01

    Pure hair and nail ectodermal dysplasia (PHNED) is a rare disorder that presents with hypotrichosis and nail dystrophy while sparing other ectodermal structures such as teeth and sweat glands. We describe a homozygous novel missense mutation in the HOXC13 gene that resulted in autosomal recessive PHNED in a Hispanic child. The mutation c.812A>G (p.Gln271Arg) is located within the DNA-binding domain of the HOXC13 gene, cosegregates within the family, and is predicted to be maximally damaging. This is the first reported case of a missense HOXC13 mutation resulting in PHNED and the first reported case of PHNED identified in a North American family. Our findings illustrate the critical role of HOXC13 in human hair and nail development. © 2017 Wiley Periodicals, Inc.

  14. Novel Missense Mitochondrial ND4L Gene Mutations in Friedreich's Ataxia

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Heidari

    2011-05-01

    Full Text Available AbstractObjective(sThe mitochondrial defects in Friedreich's ataxia have been reported in many researches. Mitochondrial DNA is one of the candidates for defects in mitochondrion, and complex I is the first and one of the largest catalytic complexes of oxidative phosphorylation (OXPHOS system. Materials and MethodsWe searched the mitochondrial ND4L gene for mutations by TTGE and sequencing on 30 FRDA patients and 35 healthy controls.ResultsWe found 3 missense mutations [m.10506A>G (T13A, m.10530G>A (V21M, and m.10653G>A (A62T] in four patients whose m.10530G>A and m.10653G>A were not reported previously. In two patients, heteroplasmic m.10530G>A mutation was detected. They showed a very early ataxia syndrome. Our results showed that the number of mutations in FRDA patients was higher than that in the control cases (P= 0.0287.ConclusionAlthough this disease is due to nuclear gene mutation, the presence of these mutations might be responsible for further mitochondrial defects and the increase of the gravity of the disease. Thus, it should be considered in patients with this disorder.

  15. Late-onset Stargardt disease is associated with missense mutations that map outside known functional regions of ABCR (ABCA4).

    Science.gov (United States)

    Yatsenko, A N; Shroyer, N F; Lewis, R A; Lupski, J R

    2001-04-01

    Based on recent studies of the photoreceptor-specific ABC transporter gene ABCR (ABCA4) in Stargardt disease (STGD1) and other retinal dystrophies, we and others have developed a model in which the severity of retinal disease correlates inversely with residual ABCR activity. This model predicts that patients with late-onset STGDI may retain partial ABCR activity attributable to mild missense alleles. To test this hypothesis, we used late-onset STGDI patients (onset: > or =35 years) to provide an in vivo functional analysis of various combinations of mutant alleles. We sequenced directly the entire coding region of ABCR and detected mutations in 33/50 (66%) disease chromosomes, but surprisingly, 11/33 (33%) were truncating alleles. Importantly, all 22 missense mutations were located outside the known functional domains of ABCR (ATP-binding or transmembrane), whereas in our general cohort of STGDI subjects, alterations occurred with equal frequency across the entire protein. We suggest that these missense mutations in regions of unknown function are milder alleles and more susceptible to modifier effects. Thus, we have corroborated a prediction from the model of ABCR pathogenicity that (1) one mutant ABCR allele is always missense in late-onset STGD1 patients, and (2) the age-of-onset is correlated with the amount of ABCR activity of this allele. In addition, we report three new pseudodominant families that now comprise eight of 178 outbred STGD1 families and suggest a carrier frequency of STGD1-associated ABCR mutations of about 4.5% (approximately 1/22).

  16. Molecular evaluation of a novel missense mutation & an insertional truncating mutation in SUMF1 gene

    Directory of Open Access Journals (Sweden)

    Udhaya H Kotecha

    2014-01-01

    Full Text Available Background & objectives: Multiple suphphatase deficiency (MSD is an autosomal recessive disorder affecting the post translational activation of all enzymes of the sulphatase family. To date, approximately 30 different mutations have been identified in the causative gene, sulfatase modifying factor 1 (SUMF1. We describe here the mutation analysis of a case of MSD. Methods: The proband was a four year old boy with developmental delay followed by neuroregression. He had coarse facies, appendicular hypertonia, truncal ataxia and ichthyosis limited to both lower limbs. Radiographs showed dysostosis multiplex. Clinical suspicion of MSD was confirmed by enzyme analysis of four enzymes of the sulphatase group. Results: The patient was compound heterozygote for a c.451A>G (p.K151E substitution in exon 3 and a single base insertion mutation (c.690_691 InsT in exon 5 in the SUMF1 gene. The bioinformatic analysis of the missense mutation revealed no apparent effect on the overall structure. However, the mutated 151-amino acid residue was found to be adjacent to the substrate binding and the active site residues, thereby affecting the substrate binding and/or catalytic activity, resulting in almost complete loss of enzyme function. Conclusions: The two mutations identified in the present case were novel. This is perhaps the first report of an insertion mutation in SUMF1 causing premature truncation of the protein.

  17. Functional characterization of a CRH missense mutation identified in an ADNFLE family.

    Directory of Open Access Journals (Sweden)

    Veronica Sansoni

    Full Text Available Nocturnal frontal lobe epilepsy has been historically considered a channelopathy caused by mutations in subunits of the neuronal nicotinic acetylcholine receptor or in a recently reported potassium channel. However, these mutations account for only a minority of patients, and the existence of at least a new locus for the disease has been demonstrated. In 2005, we detected two nucleotide variations in the promoter of the CRH gene coding for the corticotropin releasing hormone in 7 patients. These variations cosegregated with the disease and were demonstrated to alter the cellular levels of this hormone. Here, we report the identification in an Italian affected family of a novel missense mutation (hpreproCRH p.Pro30Arg located in the region of the CRH coding for the protein pro-sequence. The mutation was detected in heterozygosity in the two affected individuals. In vitro assays demonstrated that this mutation results in reduced levels of protein secretion in the short time thus suggesting that mutated people could present an altered capability to respond immediately to stress agents.

  18. Two microcephaly-associated novel missense mutations in CASK specifically disrupt the CASK-neurexin interaction.

    Science.gov (United States)

    LaConte, Leslie E W; Chavan, Vrushali; Elias, Abdallah F; Hudson, Cynthia; Schwanke, Corbin; Styren, Katie; Shoof, Jonathan; Kok, Fernando; Srivastava, Sarika; Mukherjee, Konark

    2018-03-01

    Deletion and truncation mutations in the X-linked gene CASK are associated with severe intellectual disability (ID), microcephaly and pontine and cerebellar hypoplasia in girls (MICPCH). The molecular origin of CASK-linked MICPCH is presumed to be due to disruption of the CASK-Tbr-1 interaction. This hypothesis, however, has not been directly tested. Missense variants in CASK are typically asymptomatic in girls. We report three severely affected girls with heterozygous CASK missense mutations (M519T (2), G659D (1)) who exhibit ID, microcephaly, and hindbrain hypoplasia. The mutation M519T results in the replacement of an evolutionarily invariant methionine located in the PDZ signaling domain known to be critical for the CASK-neurexin interaction. CASK M519T is incapable of binding to neurexin, suggesting a critically important role for the CASK-neurexin interaction. The mutation G659D is in the SH3 (Src homology 3) domain of CASK, replacing a semi-conserved glycine with aspartate. We demonstrate that the CASK G659D mutation affects the CASK protein in two independent ways: (1) it increases the protein's propensity to aggregate; and (2) it disrupts the interface between CASK's PDZ (PSD95, Dlg, ZO-1) and SH3 domains, inhibiting the CASK-neurexin interaction despite residing outside of the domain deemed critical for neurexin interaction. Since heterozygosity of other aggregation-inducing mutations (e.g., CASK W919R ) does not produce MICPCH, we suggest that the G659D mutation produces microcephaly by disrupting the CASK-neurexin interaction. Our results suggest that disruption of the CASK-neurexin interaction, not the CASK-Tbr-1 interaction, produces microcephaly and cerebellar hypoplasia. These findings underscore the importance of functional validation for variant classification.

  19. Pediatric-type nodal follicular lymphoma: a biologically distinct lymphoma with frequent MAPK pathway mutations.

    Science.gov (United States)

    Louissaint, Abner; Schafernak, Kristian T; Geyer, Julia T; Kovach, Alexandra E; Ghandi, Mahmoud; Gratzinger, Dita; Roth, Christine G; Paxton, Christian N; Kim, Sunhee; Namgyal, Chungdak; Morin, Ryan; Morgan, Elizabeth A; Neuberg, Donna S; South, Sarah T; Harris, Marian H; Hasserjian, Robert P; Hochberg, Ephraim P; Garraway, Levi A; Harris, Nancy Lee; Weinstock, David M

    2016-08-25

    Pediatric-type nodal follicular lymphoma (PTNFL) is a variant of follicular lymphoma (FL) characterized by limited-stage presentation and invariably benign behavior despite often high-grade histological appearance. It is important to distinguish PTNFL from typical FL in order to avoid unnecessary treatment; however, this distinction relies solely on clinical and pathological criteria, which may be variably applied. To define the genetic landscape of PTNFL, we performed copy number analysis and exome and/or targeted sequencing of 26 PTNFLs (16 pediatric and 10 adult). The most commonly mutated gene in PTNFL was MAP2K1, encoding MEK1, with a mutation frequency of 43%. All MAP2K1 mutations were activating missense mutations localized to exons 2 and 3, which encode negative regulatory and catalytic domains, respectively. Missense mutations in MAPK1 (2/22) and RRAS (1/22) were identified in cases that lacked MAP2K1 mutations. The second most commonly mutated gene in PTNFL was TNFRSF14, with a mutation frequency of 29%, similar to that seen in limited-stage typical FL (P = .35). PTNFL was otherwise genomically bland and specifically lacked recurrent mutations in epigenetic modifiers (eg, CREBBP, KMT2D). Copy number aberrations affected a mean of only 0.5% of PTNFL genomes, compared with 10% of limited-stage typical FL genomes (P < .02). Importantly, the mutational profiles of PTNFLs in children and adults were highly similar. Together, these findings define PTNFL as a biologically and clinically distinct indolent lymphoma of children and adults characterized by a high prevalence of MAPK pathway mutations and a near absence of mutations in epigenetic modifiers. © 2016 by The American Society of Hematology.

  20. The first missense mutation of NHS gene in a Tunisian family with clinical features of NHS syndrome including cardiac anomaly.

    Science.gov (United States)

    Chograni, Manèl; Rejeb, Imen; Jemaa, Lamia Ben; Châabouni, Myriam; Bouhamed, Habiba Chaabouni

    2011-08-01

    Nance-Horan Syndrome (NHS) or X-linked cataract-dental syndrome is a disease of unknown gene action mechanism, characterized by congenital cataract, dental anomalies, dysmorphic features and, in some cases, mental retardation. We performed linkage analysis in a Tunisian family with NHS in which affected males and obligate carrier female share a common haplotype in the Xp22.32-p11.21 region that contains the NHS gene. Direct sequencing of NHS coding exons and flanking intronic sequences allowed us to identify the first missense mutation (P551S) and a reported SNP-polymorphism (L1319F) in exon 6, a reported UTR-SNP (c.7422 C>T) and a novel one (c.8239 T>A) in exon 8. Both variations P551S and c.8239 T>A segregate with NHS phenotype in this family. Although truncations, frame-shift and copy number variants have been reported in this gene, no missense mutations have been found to segregate previously. This is the first report of a missense NHS mutation causing NHS phenotype (including cardiac defects). We hypothesize also that the non-reported UTR-SNP of the exon 8 (3'-UTR) is specific to the Tunisian population.

  1. Alzheimer neuropathology without frontotemporal lobar degeneration hallmarks (TAR DNA-binding protein 43 inclusions) in missense progranulin mutation Cys139Arg.

    Science.gov (United States)

    Redaelli, Veronica; Rossi, Giacomina; Maderna, Emanuela; Kovacs, Gabor G; Piccoli, Elena; Caroppo, Paola; Cacciatore, Francesca; Spinello, Sonia; Grisoli, Marina; Sozzi, Giuliano; Salmaggi, Andrea; Tagliavini, Fabrizio; Giaccone, Giorgio

    2018-01-01

    Null mutations in progranulin gene (GRN) reduce the progranulin production resulting in haploinsufficiency and are tightly associated with tau-negative frontotemporal lobar degeneration with TAR DNA-binding protein 43-positive inclusions (FTLD-TDP). Missense mutations of GRN were also identified, but their effects are not completely clear, in particular unanswered is the question of what neuropathology they elicit, also considering that their occurrence has been reported in patients with typical clinical features of Alzheimer disease. They describe two fraternal twins carrying the missense GRN Cys139Arg mutation affected by late-onset dementia and we report the neuropathological study of one of them. Both patients were examined by neuroimaging, neuropsychological assessment and genetic analysis of GRN and other genes associated with dementia. The brain of one was obtained at autopsy and examined neuropathologically. One sister presented clinical and MRI features leading to the diagnosis of Alzheimer disease. The other underwent autopsy and the brain showed neuropathological hallmarks of Alzheimer disease with abundant Aβ-amyloid deposition and Braak stage V of neurofibrillary pathology, in the absence of the hallmark lesions of FTLD-TDP. Their findings may contribute to better clarify the role of progranulin in neurodegenerative diseases indicating that some GRN mutations, in particular missense ones, may act as strong risk factor for Alzheimer disease rather than induce FTLD-TDP. © 2016 International Society of Neuropathology.

  2. Germline Missense Changes in the APC Gene and Their Relationship to Disease.

    Science.gov (United States)

    Scott, Rodney J; Crooks, Renee; Rose, Lindy; Attia, John; Thakkinstian, Ammarin; Thomas, Lesley; Spigelman, Allan D; Meldrum, Cliff J

    2004-05-15

    Familial adenomatous polyposis (FAP) is characterized by the presence of hundreds to thousands of adenomas that carpet the entire colon and rectum. Nonsense and frameshift mutations in the adenomatous polyposis coli (APC) gene account for the majority of mutations identified to date and predispose primarily to the typical disease phenotype. Some APC mutations are associated with a milder form of the disease known as attenuated FAP. Virtually all mutations that have been described in the APC gene result in the formation of a premature stop codon and very little is known about missense mutations apart from a common Ashkenazi Jewish mutation (1307 K) and a British E1317Q missense change. The incidence of missense mutations in the APC gene has been underreported since the APC gene lends itself to analysis using an artificial transcription and translation assay known as the Protein Truncation Test (PTT) or the In Vitro Synthetic Protein assay (IVSP).In this report we have used denaturing high performance liquid chromatography to analyse the entire coding sequence of the APC gene to determine if a cohort of patients adhering to the diagnostic criteria of FAP to assess the frequency of missense mutations in the APC gene. Altogether 112 patients were studied and 22 missense mutations were identified. From the total of 22 missense changes, 13 were silent changes and the remaining 9 resulted in amino acid substitutions. One or more of these changes were identified multiple times in 62.5% of the population under study.The results reveal that missense mutations in the APC gene appear not to radically alter protein function but may be associated with more subtle processing of RNA transcripts which in turn could result in the expression of differentially spliced forms of the APC gene which may interfere with the functional activity of the APC protein.

  3. Germline Missense Changes in the APC Gene and Their Relationship to Disease

    Directory of Open Access Journals (Sweden)

    Scott Rodney J

    2004-05-01

    Full Text Available Abstract Familial adenomatous polyposis (FAP is characterized by the presence of hundreds to thousands of adenomas that carpet the entire colon and rectum. Nonsense and frameshift mutations in the adenomatous polyposis coli (APC gene account for the majority of mutations identified to date and predispose primarily to the typical disease phenotype. Some APC mutations are associated with a milder form of the disease known as attenuated FAP. Virtually all mutations that have been described in the APC gene result in the formation of a premature stop codon and very little is known about missense mutations apart from a common Ashkenazi Jewish mutation (1307 K and a British E1317Q missense change. The incidence of missense mutations in the APC gene has been underreported since the APC gene lends itself to analysis using an artificial transcription and translation assay known as the Protein Truncation Test (PTT or the In Vitro Synthetic Protein assay (IVSP. In this report we have used denaturing high performance liquid chromatography to analyse the entire coding sequence of the APC gene to determine if a cohort of patients adhering to the diagnostic criteria of FAP to assess the frequency of missense mutations in the APC gene. Altogether 112 patients were studied and 22 missense mutations were identified. From the total of 22 missense changes, 13 were silent changes and the remaining 9 resulted in amino acid substitutions. One or more of these changes were identified multiple times in 62.5% of the population under study. The results reveal that missense mutations in the APC gene appear not to radically alter protein function but may be associated with more subtle processing of RNA transcripts which in turn could result in the expression of differentially spliced forms of the APC gene which may interfere with the functional activity of the APC protein.

  4. Mouse models of two missense mutations in actin-binding domain 1 of dystrophin associated with Duchenne or Becker muscular dystrophy.

    Science.gov (United States)

    McCourt, Jackie L; Talsness, Dana M; Lindsay, Angus; Arpke, Robert W; Chatterton, Paul D; Nelson, D'anna M; Chamberlain, Christopher M; Olthoff, John T; Belanto, Joseph J; McCourt, Preston M; Kyba, Michael; Lowe, Dawn A; Ervasti, James M

    2018-02-01

    Missense mutations in the dystrophin protein can cause Duchenne muscular dystrophy (DMD) or Becker muscular dystrophy (BMD) through an undefined pathomechanism. In vitro studies suggest that missense mutations in the N-terminal actin-binding domain (ABD1) cause protein instability, and cultured myoblast studies reveal decreased expression levels that can be restored to wild-type with proteasome inhibitors. To further elucidate the pathophysiology of missense dystrophin in vivo, we generated two transgenic mdx mouse lines expressing L54R or L172H mutant dystrophin, which correspond to missense mutations identified in human patients with DMD or BMD, respectively. Our biochemical, histologic and physiologic analysis of the L54R and L172H mice show decreased levels of dystrophin which are proportional to the phenotypic severity. Proteasome inhibitors were ineffective in both the L54R and L172H mice, yet mice homozygous for the L172H transgene were able to express even higher levels of dystrophin which caused further improvements in muscle histology and physiology. Given that missense dystrophin is likely being degraded by the proteasome but whole body proteasome inhibition was not possible, we screened for ubiquitin-conjugating enzymes involved in targeting dystrophin to the proteasome. A myoblast cell line expressing L54R mutant dystrophin was screened with an siRNA library targeting E1, E2 and E3 ligases which identified Amn1, FBXO33, Zfand5 and Trim75. Our study establishes new mouse models of dystrophinopathy and identifies candidate E3 ligases that may specifically regulate dystrophin protein turnover in vivo. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Two missense mutations in KCNQ1 cause pituitary hormone deficiency and maternally inherited gingival fibromatosis

    DEFF Research Database (Denmark)

    Tommiska, Johanna; Känsäkoski, Johanna; Skibsbye, Lasse

    2017-01-01

    unrelated families harbor either of two missense mutations, c.347G>T p.(Arg116Leu) or c.1106C>T p.(Pro369Leu), in KCNQ1, a gene previously implicated in the long QT interval syndrome. Kcnq1 is expressed in hypothalamic GHRH neurons and pituitary somatotropes. Co-expressing KCNQ1 with the KCNE2 β...

  6. WDR73 missense mutation causes infantile onset intellectual disability and cerebellar hypoplasia in a consanguineous family.

    Science.gov (United States)

    Jiang, Chen; Gai, Nan; Zou, Yongyi; Zheng, Yu; Ma, Ruiyu; Wei, Xianda; Liang, Desheng; Wu, Lingqian

    2017-01-01

    Galloway-Mowat syndrome (GMS) is a very rare autosomal-recessive disorder characterized by nephrotic syndrome associated with microcephaly, and various central nervous system abnormalities, mostly cerebral hypoplasia or cerebellar atrophy, intellectual disability and neural-migration defects. WDR73 is the only gene known to cause GMS, and has never been implicated in other disease. Here we present a Chinese consanguineous family with infantile onset intellectual disability and cerebellar hypoplasia but no microcephaly. Whole exome sequencing identified a WDR73 p.W371G missense mutation. The mutation is confirmed to be segregated in this family by Sanger sequencing according to a recessive inheritance pattern. It is predicted to be deleterious by multiple algorithms and affect highly conserved site. Structural modeling revealed conformational differences between the wild type protein and the p.W371G protein. Real-time PCR and Western blotting revealed altered mRNA and protein levels in mutated samples. Our study indicates the novel WDR73 p.W371G missense mutation causes infantile onset intellectual disability and cerebellar hypoplasia in recessive mode of inheritance. Our findings imply that microcephaly is a variable phenotype in WDR73-related disease, suggest WDR73 to be a candidate gene of severe intellectual disability and cerebellar hypoplasia, and expand the molecular spectrum of WDR73-related disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. A homozygous missense mutation in human KLOTHO causes severe tumoral calcinosis

    Science.gov (United States)

    Ichikawa, Shoji; Imel, Erik A.; Kreiter, Mary L.; Yu, Xijie; Mackenzie, Donald S.; Sorenson, Andrea H.; Goetz, Regina; Mohammadi, Moosa; White, Kenneth E.; Econs, Michael J.

    2007-01-01

    Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia due to inactivating mutations in FGF23 or UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). Herein we report a homozygous missense mutation (H193R) in the KLOTHO (KL) gene of a 13-year-old girl who presented with severe tumoral calcinosis with dural and carotid artery calcifications. This patient exhibited defects in mineral ion homeostasis with marked hyperphosphatemia and hypercalcemia as well as elevated serum levels of parathyroid hormone and FGF23. Mapping of H193R mutation onto the crystal structure of myrosinase, a plant homolog of KL, revealed that this histidine residue was at the base of the deep catalytic cleft and mutation of this histidine to arginine should destabilize the putative glycosidase domain (KL1) of KL, thereby attenuating production of membrane-bound and secreted KL. Indeed, compared with wild-type KL, expression and secretion of H193R KL were markedly reduced in vitro, resulting in diminished ability of FGF23 to signal via its cognate FGF receptors. Taken together, our findings provide what we believe to be the first evidence that loss-of-function mutations in human KL impair FGF23 bioactivity, underscoring the essential role of KL in FGF23-mediated phosphate and vitamin D homeostasis in humans. PMID:17710231

  8. Prefoldin Promotes Proteasomal Degradation of Cytosolic Proteins with Missense Mutations by Maintaining Substrate Solubility.

    Directory of Open Access Journals (Sweden)

    Sophie A Comyn

    2016-07-01

    Full Text Available Misfolded proteins challenge the ability of cells to maintain protein homeostasis and can accumulate into toxic protein aggregates. As a consequence, cells have adopted a number of protein quality control pathways to prevent protein aggregation, promote protein folding, and target terminally misfolded proteins for degradation. In this study, we employed a thermosensitive allele of the yeast Guk1 guanylate kinase as a model misfolded protein to investigate degradative protein quality control pathways. We performed a flow cytometry based screen to identify factors that promote proteasomal degradation of proteins misfolded as the result of missense mutations. In addition to the E3 ubiquitin ligase Ubr1, we identified the prefoldin chaperone subunit Gim3 as an important quality control factor. Whereas the absence of GIM3 did not impair proteasomal function or the ubiquitination of the model substrate, it led to the accumulation of the poorly soluble model substrate in cellular inclusions that was accompanied by delayed degradation. We found that Gim3 interacted with the Guk1 mutant allele and propose that prefoldin promotes the degradation of the unstable model substrate by maintaining the solubility of the misfolded protein. We also demonstrated that in addition to the Guk1 mutant, prefoldin can stabilize other misfolded cytosolic proteins containing missense mutations.

  9. Structure-Function Correlation Analysis of Connexin50 Missense Mutations Causing Congenital Cataract: Electrostatic Potential Alteration Could Determine Intracellular Trafficking Fate of Mutants

    Directory of Open Access Journals (Sweden)

    Devroop Sarkar

    2014-01-01

    Full Text Available Connexin50 (Cx50 mutations are reported to cause congenital cataract probably through the disruption of intercellular transport in the lens. Cx50 mutants that undergo mistrafficking have generally been associated with failure to form functional gap junction channels; however, sometimes even properly trafficked mutants were found to undergo similar consequences. We hereby wanted to elucidate any structural bases of the varied functional consequences of Cx50 missense mutations through in silico approach. Computational studies have been done based on a Cx50 homology model to assess conservation, solvent accessibility, and 3-dimensional localization of mutated residues as well as mutation-induced changes in surface electrostatic potential, H-bonding, and steric clash. This was supplemented with meta-analysis of published literature on the functional properties of connexin missense mutations. Analyses revealed that the mutation-induced critical alterations of surface electrostatic potential in Cx50 mutants could determine their fate in intracellular trafficking. A similar pattern was observed in case of mutations involving corresponding conserved residues in other connexins also. Based on these results the trafficking fates of 10 uncharacterized Cx50 mutations have been predicted. Further experimental analyses are needed to validate the observed correlation.

  10. A novel RUNX2 missense mutation predicted to disrupt DNA binding causes cleidocranial dysplasia in a large Chinese family with hyperplastic nails

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    Wang Xiaoqin

    2007-12-01

    Full Text Available Abstract Background Cleidocranial dysplasia (CCD is a dominantly inherited disease characterized by hypoplastic or absent clavicles, large fontanels, dental dysplasia, and delayed skeletal development. The purpose of this study is to investigate the genetic basis of Chinese family with CCD. Methods Here, a large Chinese family with CCD and hyperplastic nails was recruited. The clinical features displayed a significant intrafamilial variation. We sequenced the coding region of the RUNX2 gene for the mutation and phenotype analysis. Results The family carries a c.T407C (p.L136P mutation in the DNA- and CBFβ-binding Runt domain of RUNX2. Based on the crystal structure, we predict this novel missense mutation is likely to disrupt DNA binding by RUNX2, and at least locally affect the Runt domain structure. Conclusion A novel missense mutation was identified in a large Chinese family with CCD with hyperplastic nails. This report further extends the mutation spectrum and clinical features of CCD. The identification of this mutation will facilitate prenatal diagnosis and preimplantation genetic diagnosis.

  11. A missense mutation in ALDH1A3 causes isolated microphthalmia/anophthalmia in nine individuals from an inbred Muslim kindred.

    Science.gov (United States)

    Mory, Adi; Ruiz, Francesc X; Dagan, Efrat; Yakovtseva, Evgenia A; Kurolap, Alina; Parés, Xavier; Farrés, Jaume; Gershoni-Baruch, Ruth

    2014-03-01

    Nine affected individuals with isolated anophthalmia/microphthalmia from a large Muslim-inbred kindred were investigated. Assuming autosomal-recessive mode of inheritance, whole-genome linkage analysis, on DNA samples from four affected individuals, was undertaken. Homozygosity mapping techniques were employed and a 1.5-Mbp region, homozygous in all affected individuals, was delineated. The region contained nine genes, one of which, aldehyde dehydrogenase 1 (ALDH1A3), was a clear candidate. This gene seems to encode a key enzyme in the formation of a retinoic-acid gradient along the dorsoventral axis during an early eye development and the development of the olfactory system. Sanger sequence analysis revealed a missense mutation, causing a substitution of valine (Val) to methionine (Met) at position 71. Analyzing the p.Val71Met missense mutation using standard open access software (MutationTaster online, PolyPhen, SIFT/PROVEAN) predicts this variant to be damaging. Enzymatic activity, studied in vitro, showed no changes between the mutated and the wild-type ALDH1A3 protein.

  12. Missense Mutation in the USH2A Gene: Association with Recessive Retinitis Pigmentosa without Hearing Loss

    OpenAIRE

    Rivolta, Carlo; Sweklo, Elizabeth A.; Berson, Eliot L.; Dryja, Thaddeus P.

    2000-01-01

    Microdeletions Glu767(1-bp del), Thr967(1-bp del), and Leu1446(2-bp del) in the human USH2A gene have been reported to cause Usher syndrome type II, a disorder characterized by retinitis pigmentosa (RP) and mild-to-severe hearing loss. Each of these three frameshift mutations is predicted to lead to an unstable mRNA transcript that, if translated, would result in a truncated protein lacking the carboxy terminus. Here, we report Cys759Phe, a novel missense mutation in this gene that changes an...

  13. Missense Mutations Allow a Sequence-Blind Mutant of SpoIIIE to Successfully Translocate Chromosomes during Sporulation.

    Science.gov (United States)

    Bose, Baundauna; Reed, Sydney E; Besprozvannaya, Marina; Burton, Briana M

    2016-01-01

    SpoIIIE directionally pumps DNA across membranes during Bacillus subtilis sporulation and vegetative growth. The sequence-reading domain (γ domain) is required for directional DNA transport, and its deletion severely impairs sporulation. We selected suppressors of the spoIIIEΔγ sporulation defect. Unexpectedly, many suppressors were intragenic missense mutants, and some restore sporulation to near-wild-type levels. The mutant proteins are likely not more abundant, faster at translocating DNA, or sequence-sensitive, and rescue does not involve the SpoIIIE homolog SftA. Some mutants behave differently when co-expressed with spoIIIEΔγ, consistent with the idea that some, but not all, variants may form mixed oligomers. In full-length spoIIIE, these mutations do not affect sporulation, and yet the corresponding residues are rarely found in other SpoIIIE/FtsK family members. The suppressors do not rescue chromosome translocation defects during vegetative growth, indicating that the role of the γ domain cannot be fully replaced by these mutations. We present two models consistent with our findings: that the suppressors commit to transport in one arbitrarily-determined direction or delay spore development. It is surprising that missense mutations somehow rescue loss of an entire domain with a complex function, and this raises new questions about the mechanism by which SpoIIIE pumps DNA and the roles SpoIIIE plays in vivo.

  14. Missense Mutations Allow a Sequence-Blind Mutant of SpoIIIE to Successfully Translocate Chromosomes during Sporulation.

    Directory of Open Access Journals (Sweden)

    Baundauna Bose

    Full Text Available SpoIIIE directionally pumps DNA across membranes during Bacillus subtilis sporulation and vegetative growth. The sequence-reading domain (γ domain is required for directional DNA transport, and its deletion severely impairs sporulation. We selected suppressors of the spoIIIEΔγ sporulation defect. Unexpectedly, many suppressors were intragenic missense mutants, and some restore sporulation to near-wild-type levels. The mutant proteins are likely not more abundant, faster at translocating DNA, or sequence-sensitive, and rescue does not involve the SpoIIIE homolog SftA. Some mutants behave differently when co-expressed with spoIIIEΔγ, consistent with the idea that some, but not all, variants may form mixed oligomers. In full-length spoIIIE, these mutations do not affect sporulation, and yet the corresponding residues are rarely found in other SpoIIIE/FtsK family members. The suppressors do not rescue chromosome translocation defects during vegetative growth, indicating that the role of the γ domain cannot be fully replaced by these mutations. We present two models consistent with our findings: that the suppressors commit to transport in one arbitrarily-determined direction or delay spore development. It is surprising that missense mutations somehow rescue loss of an entire domain with a complex function, and this raises new questions about the mechanism by which SpoIIIE pumps DNA and the roles SpoIIIE plays in vivo.

  15. Dyskeratosis congenita--two siblings with a new missense mutation in the DKC1 gene.

    Science.gov (United States)

    Coelho, Joana Dias; Lestre, Sara; Kay, Teresa; Lopes, Maria João Paiva; Fiadeiro, Teresa; Apetato, Margarida

    2011-01-01

    Dyskeratosis congenital is reported in two siblings. They presented with the classic triad of mucocutaneous features: leukoplakia of the tongue, dystrophic nails, and a widespread reticulate pigmentation on the neck and upper chest. A genetic analysis was performed and a new missense mutation S356P, hemizygous, was identified in the DKC1 gene in both patients. Acitretin was started at a low-dose in both patients, resulting in clinical improvement and important, positive psychosocial effects. © 2011 Wiley Periodicals, Inc.

  16. New mutations in APOB100 involved in familial hypobetalipoproteinemia

    DEFF Research Database (Denmark)

    Brusgaard, Klaus; Kjaersgaard, Lars; Hansen, Anne-Birthe Bo

    2011-01-01

    Familial hypolipoproteinemia (FHBL) is characterized by an inherited low plasma level of apolipoprotein B containing lipoproteins. FHBL may be caused by mutations of APOB. Individuals with FHBL typically have intestinal malabsorption and frequently suffer from a deficiency of fat-soluble vitamins....... Most mutations that cause FHBL are APOB truncating mutations. Here we describe a patient with FHBL caused by a novel truncating mutation together with a novel missense mutation....

  17. Missense mutations in the WD40 domain of AHI1 cause non-syndromic retinitis pigmentosa.

    Science.gov (United States)

    Nguyen, Thanh-Minh T; Hull, Sarah; Roepman, Ronald; van den Born, L Ingeborgh; Oud, Machteld M; de Vrieze, Erik; Hetterschijt, Lisette; Letteboer, Stef J F; van Beersum, Sylvia E C; Blokland, Ellen A; Yntema, Helger G; Cremers, Frans P M; van der Zwaag, Paul A; Arno, Gavin; van Wijk, Erwin; Webster, Andrew R; Haer-Wigman, Lonneke

    2017-09-01

    Recent findings suggesting that Abelson helper integration site 1 ( AHI1 ) is involved in non-syndromic retinal disease have been debated, as the functional significance of identified missense variants was uncertain. We assessed whether AHI1 variants cause non-syndromic retinitis pigmentosa (RP). Exome sequencing was performed in three probands with RP. The effects of the identified missense variants in AHI1 were predicted by three-dimensional structure homology modelling. Ciliary parameters were evaluated in patient's fibroblasts, and recombinant mutant proteins were expressed in ciliated retinal pigmented epithelium cells. In the three patients with RP, three sets of compound heterozygous variants were detected in AHI1 (c.2174G>A; p.Trp725* and c.2258A>T; p.Asp753Val, c.660delC; p.Ser221Glnfs*10 and c.2090C>T; p.Pro697Leu, c.2087A>G; p.His696Arg and c.2429C>T; p.Pro810Leu). All four missense variants were present in the conserved WD40 domain of Jouberin, the ciliary protein encoded by AHI1 , with variable predicted implications for the domain structure. No significant changes in the percentage of ciliated cells, nor in cilium length or intraflagellar transport were detected. However, expression of mutant recombinant Jouberin in ciliated cells showed a significantly decreased enrichment at the ciliary base. This report confirms that mutations in AHI1 can underlie autosomal recessive RP. Moreover, it structurally and functionally validates the effect of the RP-associated AHI1 variants on protein function, thus proposing a new genotype-phenotype correlation for AHI1 mutation associated retinal ciliopathies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. Predicting the impact of Lynch syndrome-causing missense mutations from structural calculations.

    Directory of Open Access Journals (Sweden)

    Sofie V Nielsen

    2017-04-01

    Full Text Available Accurate methods to assess the pathogenicity of mutations are needed to fully leverage the possibilities of genome sequencing in diagnosis. Current data-driven and bioinformatics approaches are, however, limited by the large number of new variations found in each newly sequenced genome, and often do not provide direct mechanistic insight. Here we demonstrate, for the first time, that saturation mutagenesis, biophysical modeling and co-variation analysis, performed in silico, can predict the abundance, metabolic stability, and function of proteins inside living cells. As a model system, we selected the human mismatch repair protein, MSH2, where missense variants are known to cause the hereditary cancer predisposition disease, known as Lynch syndrome. We show that the majority of disease-causing MSH2 mutations give rise to folding defects and proteasome-dependent degradation rather than inherent loss of function, and accordingly our in silico modeling data accurately identifies disease-causing mutations and outperforms the traditionally used genetic disease predictors. Thus, in conclusion, in silico biophysical modeling should be considered for making genotype-phenotype predictions and for diagnosis of Lynch syndrome, and perhaps other hereditary diseases.

  19. Functional analysis of HNPCC-related missense mutations in MSH2

    DEFF Research Database (Denmark)

    Lützen, Anne; de Wind, Niels; Georgijevic, Dubravka

    2008-01-01

    Hereditary nonpolyposis colorectal cancer (HNPCC) is associated with germline mutations in the human DNA mismatch repair (MMR) genes, most frequently MSH2 and MLH1. The majority of HNPCC mutations cause truncations and thus loss of function of the affected polypeptide. However, a significant...

  20. Identification of missense mutations in the Norrie disease gene associated with advanced retinopathy of prematurity.

    Science.gov (United States)

    Shastry, B S; Pendergast, S D; Hartzer, M K; Liu, X; Trese, M T

    1997-05-01

    Retinopathy of prematurity (ROP) is a retinal vascular disease occurring in infants with short gestational age and low birth weight and can lead to retinal detachment (ROP stages 4 and 5). X-linked familial exudative vitreoretinopathy is phenotypically similar to ROP and has been associated with mutations in the Norrie disease (ND) gene in some cases. To determine if similar mutations in the ND gene may play a role in the development of advanced ROP. Clinical examination and molecular genetic analysis were performed on 16 children, including 2 dizygotic and 1 monozygotic twin pairs, and their parents from 13 families. Sequencing of the amplified products revealed missense mutations (R121W and L108P) in the third exon of the ND gene in 4 patients. These mutations were not present in an unaffected premature twin, 2 children with regressed stage 3 ROP, the parents, or in 50 unrelated healthy control subjects. These findings suggest that mutations in the ND gene may play a role in the development of severe ROP in premature infants.

  1. Hypomyelinating leukodystrophy-associated missense mutation in HSPD1 blunts mitochondrial dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Yuki [Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535 (Japan); Eguchi, Takahiro [The Institute of Medical Science, The University of Tokyo, Minato, Tokyo 108-8639 (Japan); Kawahara, Kazuko [Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535 (Japan); Hasegawa, Nanami [Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535 (Japan); Faculty of Pharmacy, Keio University, Minato, Tokyo 105-8512 (Japan); Nakamura, Kazuaki [Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535 (Japan); Funakoshi-Tago, Megumi [Faculty of Pharmacy, Keio University, Minato, Tokyo 105-8512 (Japan); Tanoue, Akito [Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535 (Japan); Tamura, Hiroomi [Faculty of Pharmacy, Keio University, Minato, Tokyo 105-8512 (Japan); Yamauchi, Junji, E-mail: yamauchi-j@ncchd.go.jp [Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo 157-8535 (Japan); Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510 (Japan)

    2015-07-03

    Myelin-forming glial cells undergo dynamic morphological changes in order to produce mature myelin sheaths with multiple layers. In the central nervous system (CNS), oligodendrocytes differentiate to insulate neuronal axons with myelin sheaths. Myelin sheaths play a key role in homeostasis of the nervous system, but their related disorders lead not only to dismyelination and repeated demyelination but also to severe neuropathies. Hereditary hypomyelinating leukodystrophies (HLDs) are a group of such diseases affecting oligodendrocytes and are often caused by missense mutations of the respective responsible genes. Despite increasing identification of gene mutations through advanced nucleotide sequencing technology, studies on the relationships between gene mutations and their effects on cellular and subcellular aberrance have not followed at the same rapid pace. In this study, we report that an HLD4-associated (Asp-29-to-Gly) mutant of mitochondrial heat shock 60-kDa protein 1 (HSPD1) causes short-length morphologies and increases the numbers of mitochondria due to their aberrant fission and fusion cycles. In experiments using a fluorescent dye probe, this mutation decreases the mitochondrial membrane potential. Also, mitochondria accumulate in perinuclear regions. HLD4-associated HSPD1 mutant blunts mitochondrial dynamics, probably resulting in oligodendrocyte malfunction. This study constitutes a first finding concerning the relationship between disease-associated HSPD1 mutation and mitochondrial dynamics, which may be similar to the relationship between another disease-associated HSPD1 mutation (MitCHAP-60 disease) and aberrant mitochondrial dynamics. - Highlights: • The HLD4 mutant of HSPD1 decreases mitochondrial fission frequency. • The HLD4 mutant decreases mitochondrial fusion frequency. • Mitochondria harboring the HLD4 mutant exhibit slow motility. • The HLD4 mutant of HSPD1 decreases mitochondrial membrane potential. • HLD4-related diseases may

  2. Hypomyelinating leukodystrophy-associated missense mutation in HSPD1 blunts mitochondrial dynamics

    International Nuclear Information System (INIS)

    Miyamoto, Yuki; Eguchi, Takahiro; Kawahara, Kazuko; Hasegawa, Nanami; Nakamura, Kazuaki; Funakoshi-Tago, Megumi; Tanoue, Akito; Tamura, Hiroomi; Yamauchi, Junji

    2015-01-01

    Myelin-forming glial cells undergo dynamic morphological changes in order to produce mature myelin sheaths with multiple layers. In the central nervous system (CNS), oligodendrocytes differentiate to insulate neuronal axons with myelin sheaths. Myelin sheaths play a key role in homeostasis of the nervous system, but their related disorders lead not only to dismyelination and repeated demyelination but also to severe neuropathies. Hereditary hypomyelinating leukodystrophies (HLDs) are a group of such diseases affecting oligodendrocytes and are often caused by missense mutations of the respective responsible genes. Despite increasing identification of gene mutations through advanced nucleotide sequencing technology, studies on the relationships between gene mutations and their effects on cellular and subcellular aberrance have not followed at the same rapid pace. In this study, we report that an HLD4-associated (Asp-29-to-Gly) mutant of mitochondrial heat shock 60-kDa protein 1 (HSPD1) causes short-length morphologies and increases the numbers of mitochondria due to their aberrant fission and fusion cycles. In experiments using a fluorescent dye probe, this mutation decreases the mitochondrial membrane potential. Also, mitochondria accumulate in perinuclear regions. HLD4-associated HSPD1 mutant blunts mitochondrial dynamics, probably resulting in oligodendrocyte malfunction. This study constitutes a first finding concerning the relationship between disease-associated HSPD1 mutation and mitochondrial dynamics, which may be similar to the relationship between another disease-associated HSPD1 mutation (MitCHAP-60 disease) and aberrant mitochondrial dynamics. - Highlights: • The HLD4 mutant of HSPD1 decreases mitochondrial fission frequency. • The HLD4 mutant decreases mitochondrial fusion frequency. • Mitochondria harboring the HLD4 mutant exhibit slow motility. • The HLD4 mutant of HSPD1 decreases mitochondrial membrane potential. • HLD4-related diseases may

  3. Missense variants in plakophilin-2 in arrhythmogenic right ventricular cardiomyopathy patients--disease-causing or innocent bystanders?

    Science.gov (United States)

    Christensen, Alex Hørby; Benn, Marianne; Tybjaerg-Hansen, Anne; Haunso, Stig; Svendsen, Jesper Hastrup

    2010-01-01

    Mutations in genes encoding desmosomal proteins have been linked to arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). We hypothesized that a Scandinavian ARVC/D population would have a different spectrum of plakophilin-2 (PKP2) mutations and that some of the reported missense mutations may not be pathogenic. We screened 53 unrelated patients fulfilling Task Force criteria for ARVC/D for mutations in PKP2 by direct sequencing. Seven different mutations were identified: two insertion/deletions (E329fsX352, P401fsX406), 1 splice site (2146-2A>T), 1 non-sense (R79X) and 4 missense mutations (Q62K in 2 patients, G489R, G673V) of undeterminable pathogeneity. None of these mutations was present in 650 controls. Five of the mutations were novel. Seven patients carried reported missense mutations (D26N, S140F, V587I); however, these mutations were identified in our healthy controls, although at a lower frequency. Evaluation of all reported missense mutations in PKP2 showed unclear pathogeneity of several reported mutations. Fifteen percent of Danish ARVC/D patients carried PKP2 mutations. Our finding of reported disease-causing mutations at a low frequency among healthy controls suggests that these variants are disease modifying but not directly disease causing. We recommend conservative interpretation of missense variants in PKP2, functional characterization and large-scale sequencing to clarify normal variation in the gene.

  4. Alpha-tubulin missense mutations correlate with antimicrotubule drug resistance in Eleusine indica.

    Science.gov (United States)

    Yamamoto, E; Zeng, L; Baird, W V

    1998-02-01

    Dinitroaniline herbicides are antimicrotubule drugs that bind to tubulins and inhibit polymerization. As a result of repeated application of dinitroaniline herbicides, highly resistant and intermediately resistant biotypes of goosegrass (Eleusine indica) developed in previously wild-type populations. Three alpha-tubulin cDNA classes (designated TUA1, TUA2, and TUA3) were isolated from each biotype. Nucleotide differences between the susceptible and the resistant (R) alpha-tubulins were identified in TUA1 and TUA2. The most significant differences were missense mutations that occurred in TUA1 of the R and intermediately resistant (I) biotypes. Such mutations convert Thr-239 to Ile in the R biotype and Met-268 to Thr in the I biotype. These amino acid substitutions alter hydrophobicity; therefore, they may alter the dinitroaniline binding property of the protein. These mutations were correlated with the dinitroaniline response phenotypes (Drp). Plants homozygous for susceptibility possessed the wild-type TUA1 allele; plants homozygous for resistance possessed the mutant tua1 allele; and plants heterozygous for susceptibility possessed both wild-type and mutant alleles. Thus, we conclude that TUA1 is at the Drp locus. Using polymerase chain reaction primer-introduced restriction analysis, we demonstrated that goosegrass genomic DNA can be diagnosed for Drp alleles. Although not direct proof, these results suggest that a mutation in an alpha-tubulin gene confers resistance to dinitroanilines in goosegrass.

  5. Brittle Cornea Syndrome Associated with a Missense Mutation in the Zinc-Finger 469 Gene

    DEFF Research Database (Denmark)

    Christensen, Anne Elisabeth; Knappskog, Per Morten; Midtbø, Marit

    2010-01-01

    Purpose: To investigate the diverse clinical manifestations, identify the causative mutation and explain the association with red hair in a family with brittle cornea syndrome (BCS). Methods: Eight family members in three generations underwent ophthalmic, dental, and general medical examination...... mapping with SNP markers, DNA sequencing, and MC1R genotyping. Results: At 42 and 48 years of age, respectively, both affected individuals were blind due to retinal detachment and secondary glaucoma. They had extremely thin and bulging corneas, velvety skin, chestnut colored hair, scoliosis, reduced BMD......, dental anomalies, hearing loss and minor cardiac defects. The morphologies of the skin biopsies were normal except that in some areas slightly thinner collagen fibrils were seen in one of the affected individuals. Molecular genetic analysis revealed a novel missense mutation of ZNF469, c.10016G...

  6. Clinical and genetic investigation of a Japanese family with cardiac fabry disease. Identification of a novel α-galactosidase A missense mutation (G195V).

    Science.gov (United States)

    Nakagawa, Naoki; Maruyama, Hiroki; Ishihara, Takayuki; Seino, Utako; Kawabe, Jun-ichi; Takahashi, Fumihiko; Kobayashi, Motoi; Yamauchi, Atsushi; Sasaki, Yukie; Sakamoto, Naka; Ota, Hisanobu; Tanabe, Yasuko; Takeuchi, Toshiharu; Takenaka, Toshihiro; Kikuchi, Kenjiro; Hasebe, Naoyuki

    2011-01-01

    Fabry disease is an X-linked lysosomal storage disorder caused by mutations of the α-galactosidase A gene (GLA), and the disease is a relatively prevalent cause of left ventricular hypertrophy mimicking idiopathic hypertrophic cardiomyopathy. We assessed clinically 5 patients of a three-generation family and also searched for GLA mutations in 10 family members. The proband had left ventricular hypertrophy with localized thinning in the basal posterior wall and late gadolinium enhancement (LGE) in the near-circumferential wall in cardiovascular magnetic resonance images and her sister had vasospastic angina pectoris without organic stenosis of the coronary arteries. LGE notably appeared in parallel with decreased α-galactosidase A activity and increased NT-pro BNP in our patients. We detected a new GLA missense mutation (G195V) in exon 4, resulting in a glycine-to-valine substitution. Of the 10 family members, 5 family members each were positive and negative for this mutation. These new data extend our clinical and molecular knowledge of GLA gene mutations and confirm that a novel missense mutation in the GLA gene is important not only for a precise diagnosis of heterozygous status, but also for confirming relatives who are negative for this mutation.

  7. A novel missense mutation of the paired box 3 gene in a Turkish family with Waardenburg syndrome type 1.

    Science.gov (United States)

    Hazan, Filiz; Ozturk, A Taylan; Adibelli, Hamit; Unal, Nurettin; Tukun, Ajlan

    2013-01-01

    Screening of mutations in the paired box 3 (PAX3) gene in three generations of a Turkish family with Waardenburg syndrome type 1 (WS1). WS1 was diagnosed in a 13-month-old girl according to the WS Consortium criteria. Detailed family history of the proband revealed eight affected members in three generations. Routine clinical and audiological examination and ophthalmologic evaluation were performed on eight affected and five healthy members of the study family. Dystopia canthorum was detected in all affected patients; however, a brilliant blue iris was present in five patients who also had mild retinal hypopigmentation. Genomic DNA was extracted from the peripheral blood of affected and unaffected individuals in the family as well as 50 unrelated healthy volunteers. All coding exons and adjacent intronic regions of PAX3 were sequenced directly. A novel missense heterozygous c.788T>G mutation was identified in eight patients. This nucleotide alteration was not found in unaffected members of the study family or in the 50 unrelated control subjects. The mutation causes V263G amino-acid substitution in the homeodomain of the PAX3 protein, which represents the 45(th) residue of helix 3. We identified a novel missense c.788T>G mutation in PAX3 in a family with Waardenburg syndrome with intrafamilial phenotypic heterogeneity.

  8. Orphan missense mutations in the cystic fibrosis transmembrane conductance regulator: A three-step biological approach to establishing a correlation between genotype and phenotype.

    Science.gov (United States)

    Fresquet, Fleur; Clement, Romain; Norez, Caroline; Sterlin, Adélaïde; Melin, Patricia; Becq, Frédéric; Kitzis, Alain; Thoreau, Vincent; Bilan, Frédéric

    2011-09-01

    More than 1860 mutations have been found within the human cystic fibrosis transmembrane conductance regulator (CFTR) gene sequence. These mutations can be classified according to their degree of severity in CF disease. Although the most common mutations are well characterized, few data are available for rare mutations. Thus, genetic counseling is particularly difficult when fetuses or patients with CF present these orphan variations. We describe a three-step in vitro assay that can evaluate rare missense CFTR mutation consequences to establish a correlation between genotype and phenotype. By using a green fluorescent protein-tagged CFTR construct, we expressed mutated proteins in COS-7 cells. CFTR trafficking was visualized by confocal microscopy, and the cellular localization of CFTR was determined using intracellular markers. We studied the CFTR maturation process using Western blot analysis and evaluated CFTR channel activity by automated iodide efflux assays. Of six rare mutations that we studied, five have been isolated in our laboratory. The cellular and functional impact that we observed in each case was compared with the clinical data concerning the patients in whom we encountered these mutations. In conclusion, we propose that performing this type of analysis for orphan CFTR missense mutations can improve CF genetic counseling. Copyright © 2011 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  9. Brugada syndrome with a novel missense mutation in SCN5A gene: A case report from Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Zahidus Sayeed

    2014-01-01

    Full Text Available Brugada syndrome is an inherited cardiac arrhythmia that follows autosomal dominant transmission and can cause sudden death. We report a case of Brugada syndrome in a 55-year-old male patient presented with recurrent palpitation, atypical chest pain and presyncope. ECG changes were consistent with type 1 Brugada. Gene analysis revealed a novel missense mutation in SCN5A gene with a genetic variation of D785N and a nucleotide change at 2353G-A. One of his children also had the same mutation. To our knowledge this is the first genetically proved case of Brugada syndrome in Bangladesh.

  10. Novel homozygous missense mutation in ALDH7A1 causes neonatal pyridoxine dependent epilepsy.

    Science.gov (United States)

    Coci, Emanuele G; Codutti, Luca; Fink, Christian; Bartsch, Sophie; Grüning, Gunnar; Lücke, Thomas; Kurth, Ingo; Riedel, Joachim

    2017-04-01

    Pyridoxine dependent epilepsy (PDE) (OMIM#266100) is a neonatal form of epilepsy, caused by dysfunction of the enzyme α-aminoadipic semialdehyde dehydrogenase (ALDH7A1 or Antiquitin). This enzyme converts α-aminoadipic semialdehyde (α-AASA) into α-aminoadipate (AAA), a critical step in the lysine metabolism of the brain. ALDH7A1 dysfunction causes an accumulation of α-AASA and δ 1 -piperideine-6-carboxylic acid (P6C), which are in equilibrium with each other. P6C binds and inactivates pyridoxal 5'-phosphate (PLP), the active form of pyridoxine. Individuals affected by ALDH7A1 deficiency show pre-natal and post-natal seizures, which respond to oral pyridoxine but not to other pediatric anti-epileptic drugs. We discovered a novel missense mutation (c.566G > A, p.Gly189Glu) in homozygous state residing in the NAD+ binding domain coding region of exon 6 and affecting an highly conserved amino acid residue. The seizures stopped under post-natal pyridoxine therapy, nevertheless a longer follow-up is needed to evaluate the intellectual development of the child, who is additionally treated with oral l-arginine since the 13th month of life. Developmental delay with or without structural cortex abnormalities were reported in several patients. A brain MRI scan revealed hyperintense white matter in the right cerebellum compatible with cerebellar gliosis. Taken together, our studies enlarge the group of missense pathogenic mutations of ALDH7A1 gene and reveal a novel cerebellar finding within the PDE patients cohort. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. WNT10A missense mutation associated with a complete odonto-onycho-dermal dysplasia syndrome.

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    Nawaz, Sadia; Klar, Joakim; Wajid, Muhammad; Aslam, Muhammad; Tariq, Muhammad; Schuster, Jens; Baig, Shahid Mahmood; Dahl, Niklas

    2009-12-01

    Wnt signalling is one of a few pathways that are crucial for controlling genetic programs during embryonic development as well as in adult tissues. WNT10A is expressed in the skin and epidermis and it has shown to be critical for the development of ectodermal appendages. A nonsense mutation in WNT10A was recently identified in odonto-onycho-dermal dysplasia (OODD; MIM 257980), a rare syndrome characterised by severe hypodontia, nail dystrophy, smooth tongue, dry skin, keratoderma and hyperhydrosis of palms and soles. We identified a large consanguineous Pakistani pedigree comprising six individuals affected by a complete OODD syndrome. Autozygosity mapping using SNP array analysis showed that the affected individuals are homozygous for the WNT10A gene region. Subsequent mutation screening showed a homozygous c.392C>T transition in exon 3 of WNT10A, which predicts a p.A131V substitution in a conserved alpha-helix domain. We report here on the first inherited missense mutation in WNT10A with associated ectodermal features.

  12. A Novel Missense Mutation in SLC5A5 Gene in a Sudanese Family with Congenital Hypothyroidism.

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    Watanabe, Yui; Ebrhim, Reham Shareef; Abdullah, Mohamed A; Weiss, Roy E

    2018-05-15

    Thyroid hormone synthesis requires the presence of iodide. The sodium iodide symporter (NIS) is a glycoprotein which mediates the active uptake of iodide from the blood stream into the thyroid grand. NIS defects due to SLC5A5 gene mutations are known to cause congenital hypothyroidism (CH). The proposita is a 28-year-old female whose origin is the North Sudan where neonatal screening for CH is not available. She presented with severe constipation and a goiter at the age of 40 days. Laboratory testing confirmed CH and she was started on levothyroxine (L-T4). Presumably due to the delayed treatment the patient developed mental retardation. Her younger sister presented with a goiter, tongue protrusion and umbilical hernia and the youngest brother was also diagnosed with CH based on the TSH >100 µIU/mL at the age of 22 days and 8 days, respectively. Two siblings were treated with L-T4 and had normal development. Their consanguineous parents had no history of thyroid disorders. We performed whole exome sequencing (WES) on the proposita. WES identified a novel homozygous missense mutation in the SLC5A5 gene: c.1042T>G, p.Tyr348Asp, which was subsequently confirmed by Sanger sequencing. All affected children were homozygous for the same mutation and their unaffected mother was heterozygous. The NIS protein is composed of 13 transmembrane segments (TMS), an extracellular amino-terminus and an intracellular carboxyl terminus. The mutation is located in the TMS IX which has the most β-OH group-containing amino acids (serine and threonine) which is implicated in Na+ binding and translocation. In conclusion, a novel homozygous missense mutation in the SLC5A5 gene was identified in the Sudanese family with CH. The mutation is located in the TMS IX of the NIS protein which is essential for NIS function. Low iodine intake in Sudan is considered to affect severity of hypothyroidism in the patients.

  13. A Case of Inflammatory Generalized Type of Peeling Skin Syndrome Possibly Caused by a Homozygous Missense Mutation of CDSN

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    Hiroshi Kawakami

    2014-10-01

    Full Text Available A 54-year-old Japanese woman had repetitive superficial skin peeling and ensuing erythematous changes in the sites since infancy. Her parents had a consanguineous marriage, and she was the only individual affected in her family tree. The erythematous changes seemed to worsen in the summer. Histologically, hyperkeratosis and splitting of the epidermis within the stratum corneum was noted, and electron microscopy revealed shedding of corneal cells in the horny layer and normal-looking corneodesmosomes. Gene analysis revealed a homozygous missense mutation at c.1358G>A in CDSN. Electron microscopic examination of the length and number of corneodesmosomes revealed statistically significant shortness and sparsity in the affected individual (mean ± SD 386.2 ± 149.5 nm compared with that of an age- and site-matched control (406.6 ± 182.3 nm. We speculate that this size shrinkage of corneodesmosomes might be the result of a missense mutation of CDSN and that this could be one of the factors contributing to the pathological process of skin peeling.

  14. A Case of Inflammatory Generalized Type of Peeling Skin Syndrome Possibly Caused by a Homozygous Missense Mutation of CDSN.

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    Kawakami, Hiroshi; Uchiyama, Masaki; Maeda, Tatsuo; Tsunoda, Takahiko; Mitsuhashi, Yoshihiko; Tsuboi, Ryoji

    2014-09-01

    A 54-year-old Japanese woman had repetitive superficial skin peeling and ensuing erythematous changes in the sites since infancy. Her parents had a consanguineous marriage, and she was the only individual affected in her family tree. The erythematous changes seemed to worsen in the summer. Histologically, hyperkeratosis and splitting of the epidermis within the stratum corneum was noted, and electron microscopy revealed shedding of corneal cells in the horny layer and normal-looking corneodesmosomes. Gene analysis revealed a homozygous missense mutation at c.1358G>A in CDSN. Electron microscopic examination of the length and number of corneodesmosomes revealed statistically significant shortness and sparsity in the affected individual (mean ± SD 386.2 ± 149.5 nm) compared with that of an age- and site-matched control (406.6 ± 182.3 nm). We speculate that this size shrinkage of corneodesmosomes might be the result of a missense mutation of CDSN and that this could be one of the factors contributing to the pathological process of skin peeling.

  15. Functional Studies of Missense TREM2 Mutations in Human Stem Cell-Derived Microglia

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    Philip W. Brownjohn

    2018-04-01

    Full Text Available Summary: The derivation of microglia from human stem cells provides systems for understanding microglial biology and enables functional studies of disease-causing mutations. We describe a robust method for the derivation of human microglia from stem cells, which are phenotypically and functionally comparable with primary microglia. We used stem cell-derived microglia to study the consequences of missense mutations in the microglial-expressed protein triggering receptor expressed on myeloid cells 2 (TREM2, which are causal for frontotemporal dementia-like syndrome and Nasu-Hakola disease. We find that mutant TREM2 accumulates in its immature form, does not undergo typical proteolysis, and is not trafficked to the plasma membrane. However, in the absence of plasma membrane TREM2, microglia differentiate normally, respond to stimulation with lipopolysaccharide, and are phagocytically competent. These data indicate that dementia-associated TREM2 mutations have subtle effects on microglia biology, consistent with the adult onset of disease in individuals with these mutations. : Brownjohn and colleagues report methods to generate microglia from induced pluripotent human stem cells, which they demonstrate are highly similar to cultured primary human microglia. Microglia differentiated from patient-derived stem cells carrying neurological disease-causing mutations in the TREM2 receptor differentiate normally and respond appropriately to pathogenic stimuli, despite the absence of functional TREM2 receptor on the plasma membrane. Keywords: dementia, microglia, TREM2, Nasu-Hakola disease, frontotemporal dementia, iPSC-microglia, neuroinflammation

  16. Analyses of MMP20 Missense Mutations in Two Families with Hypomaturation Amelogenesis Imperfecta.

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    Kim, Youn Jung; Kang, Jenny; Seymen, Figen; Koruyucu, Mine; Gencay, Koray; Shin, Teo Jeon; Hyun, Hong-Keun; Lee, Zang Hee; Hu, Jan C-C; Simmer, James P; Kim, Jung-Wook

    2017-01-01

    Amelogenesis imperfecta is a group of rare inherited disorders that affect tooth enamel formation, quantitatively and/or qualitatively. The aim of this study was to identify the genetic etiologies of two families presenting with hypomaturation amelogenesis imperfecta. DNA was isolated from peripheral blood samples obtained from participating family members. Whole exome sequencing was performed using DNA samples from the two probands. Sequencing data was aligned to the NCBI human reference genome (NCBI build 37.2, hg19) and sequence variations were annotated with the dbSNP build 138. Mutations in MMP20 were identified in both probands. A homozygous missense mutation (c.678T>A; p.His226Gln) was identified in the consanguineous Family 1. Compound heterozygous MMP20 mutations (c.540T>A, p.Tyr180 * and c.389C>T, p.Thr130Ile) were identified in the non-consanguineous Family 2. Affected persons in Family 1 showed hypomaturation AI with dark brown discoloration, which is similar to the clinical phenotype in a previous report with the same mutation. However, the dentition of the Family 2 proband exhibited slight yellowish discoloration with reduced transparency. Functional analysis showed that the p.Thr130Ile mutant protein had reduced activity of MMP20, while there was no functional MMP20 in the Family 1 proband. These results expand the mutational spectrum of the MMP20 and broaden our understanding of genotype-phenotype correlations in amelogenesis imperfecta.

  17. Analyses of MMP20 Missense Mutations in Two Families with Hypomaturation Amelogenesis Imperfecta

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    Jung-Wook Kim

    2017-04-01

    Full Text Available Amelogenesis imperfecta is a group of rare inherited disorders that affect tooth enamel formation, quantitatively and/or qualitatively. The aim of this study was to identify the genetic etiologies of two families presenting with hypomaturation amelogenesis imperfecta. DNA was isolated from peripheral blood samples obtained from participating family members. Whole exome sequencing was performed using DNA samples from the two probands. Sequencing data was aligned to the NCBI human reference genome (NCBI build 37.2, hg19 and sequence variations were annotated with the dbSNP build 138. Mutations in MMP20 were identified in both probands. A homozygous missense mutation (c.678T>A; p.His226Gln was identified in the consanguineous Family 1. Compound heterozygous MMP20 mutations (c.540T>A, p.Tyr180* and c.389C>T, p.Thr130Ile were identified in the non-consanguineous Family 2. Affected persons in Family 1 showed hypomaturation AI with dark brown discoloration, which is similar to the clinical phenotype in a previous report with the same mutation. However, the dentition of the Family 2 proband exhibited slight yellowish discoloration with reduced transparency. Functional analysis showed that the p.Thr130Ile mutant protein had reduced activity of MMP20, while there was no functional MMP20 in the Family 1 proband. These results expand the mutational spectrum of the MMP20 and broaden our understanding of genotype-phenotype correlations in amelogenesis imperfecta.

  18. Urine screening for patients with developmental disabilities detected a patient with creatine transporter deficiency due to a novel missense mutation in SLC6A8.

    Science.gov (United States)

    Kato, Hidekazu; Miyake, Fuyu; Shimbo, Hiroko; Ohya, Makoto; Sugawara, Hidenori; Aida, Noriko; Anzai, Rie; Takagi, Mariko; Okuda, Mitsuko; Takano, Kyoko; Wada, Takahito; Iai, Mizue; Yamashita, Sumimasa; Osaka, Hitoshi

    2014-08-01

    Creatine transporter deficiency (CTD) is an example of X-linked intellectual disability syndromes, caused by mutations in SLC6A8 on Xq28. Although this is the second most frequent genetic cause of intellectual disabilities in Europe or America after Fragile X syndrome, information on the morbidity of this disease is limited in Japan. Using the HPLC screening method we have established recently, we examined samples of urine of 105 patients (73 males and 32 females) with developmental disabilities at our medical center. And we have found a family with three ID boys with a novel missense mutation in SLC6A8. This is the second report of a Japanese family case of CTD. A systematic diagnostic system of this syndrome should be established in Japan to enable us to estimate its frequency and treatment. Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  19. Massively Parallel Sequencing of a Chinese Family with DFNA9 Identified a Novel Missense Mutation in the LCCL Domain of COCH

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    Xiaodong Gu

    2016-01-01

    Full Text Available DFNA9 is a late-onset, progressive, autosomal dominantly inherited sensorineural hearing loss with vestibular dysfunction, which is caused by mutations in the COCH (coagulation factor C homology gene. In this study, we investigated a Chinese family segregating autosomal dominant nonsyndromic sensorineural hearing loss. We identified a missense mutation c.T275A p.V92D in the LCCL domain of COCH cosegregating with the disease and absent in 100 normal hearing controls. This mutation leads to substitution of the hydrophobic valine to an acidic amino acid aspartic acid. Our data enriched the mutation spectrum of DFNA9 and implied the importance for mutation screening of COCH in age related hearing loss with vestibular dysfunctions.

  20. A Novel Missense Mutation in Oncostatin M Receptor Beta Causing Primary Localized Cutaneous Amyloidosis

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    Marjan Saeedi

    2014-01-01

    Full Text Available Primary localized cutaneous amyloidosis (PLCA is a chronic skin disorder, caused by amyloid material deposition in the upper dermis. Autosomal dominant PLCA has been mapped earlier to pathogenic missense mutations in the OSMR gene, which encodes the oncostatin M receptor ß subunit (OSMRß. OSMRß is interleukin-6 family cytokine receptors and possesses two ligands, oncostatin M and interleukin-31, which both have biologic roles in inflammation and keratinocyte cell proliferation, differentiation, and apoptosis. Here, we identified a new OSMR mutation in a Kurdish family for the first time. Blood samples were taken from all the affected individuals in the family. DNA extraction was performed using salting out technique. Primers were designed for intron flanking individual exons of OSMR gene which were subjected to direct sequencing after PCR amplification for each sample. Sequencing showed a C/T substitution at position 613 in the proband. This mutation results in an L613S (leucine 613 to serine amino acid change. The identified mutation was observed in all affected family members but not in 100 ethnically matched healthy controls. Elucidating the molecular basis of familial PLCA provides new insight into mechanisms of itch in human skin and may lead to new therapeutic targets for pruritus.

  1. Determining the role of missense mutations in the POU domain of HNF1A that reduce the DNA-binding affinity: A computational approach.

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    Sneha P

    Full Text Available Maturity-onset diabetes of the young type 3 (MODY3 is a non-ketotic form of diabetes associated with poor insulin secretion. Over the past years, several studies have reported the association of missense mutations in the Hepatocyte Nuclear Factor 1 Alpha (HNF1A with MODY3. Missense mutations in the POU homeodomain (POUH of HNF1A hinder binding to the DNA, thereby leading to a dysfunctional protein. Missense mutations of the HNF1A were retrieved from public databases and subjected to a three-step computational mutational analysis to identify the underlying mechanism. First, the pathogenicity and stability of the mutations were analyzed to determine whether they alter protein structure and function. Second, the sequence conservation and DNA-binding sites of the mutant positions were assessed; as HNF1A protein is a transcription factor. Finally, the biochemical properties of the biological system were validated using molecular dynamic simulations in Gromacs 4.6.3 package. Two arginine residues (131 and 203 in the HNF1A protein are highly conserved residues and contribute to the function of the protein. Furthermore, the R131W, R131Q, and R203C mutations were predicted to be highly deleterious by in silico tools and showed lower binding affinity with DNA when compared to the native protein using the molecular docking analysis. Triplicate runs of molecular dynamic (MD simulations (50ns revealed smaller changes in patterns of deviation, fluctuation, and compactness, in complexes containing the R131Q and R131W mutations, compared to complexes containing the R203C mutant complex. We observed reduction in the number of intermolecular hydrogen bonds, compactness, and electrostatic potential, as well as the loss of salt bridges, in the R203C mutant complex. Substitution of arginine with cysteine at position 203 decreases the affinity of the protein for DNA, thereby destabilizing the protein. Based on our current findings, the MD approach is an important

  2. A novel COL11A1 missense mutation in siblings with non-ocular Stickler syndrome.

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    Kohmoto, Tomohiro; Tsuji, Atsumi; Morita, Kei-Ichi; Naruto, Takuya; Masuda, Kiyoshi; Kashimada, Kenichi; Enomoto, Keisuke; Morio, Tomohiro; Harada, Hiroyuki; Imoto, Issei

    2016-01-01

    Stickler syndrome (STL) is an autosomal, dominantly inherited, clinically variable and genetically heterogeneous connective tissue disorder characterized by ocular, auditory, orofacial and skeletal abnormalities. We conducted targeted resequencing using a next-generation sequencer for molecular diagnosis of a 2-year-old girl who was clinically suspected of having STL with Pierre Robin sequence. We detected a novel heterozygous missense mutation, NM_001854.3:n.4838G>A [NM_001854.3 (COL11A1_v001):c.4520G>A], in COL11A1, resulting in a Gly to Asp substitution at position 1507 [NM_001854.3(COL11A1_i001)] within one of the collagen-like domains of the triple helical region. The same mutation was detected in her 4-year-old brother with cleft palate and high-frequency sensorineural hearing loss.

  3. Mutation spectrum of Chinese patients with Bartter syndrome.

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    Han, Yue; Lin, Yi; Sun, Qing; Wang, Shujuan; Gao, Yanxia; Shao, Leping

    2017-11-24

    Bartter syndrome (BS) has been rarely reported in Chinese population except for a few case reports. This investigation was aimed to analyze the mutations of the causal genes in sixteen Chinese patients with BS, and review their followup and treatment. Identify mutations by the next generation sequencing and the multiplex ligation-dependent probe amplification (MLPA). Clinical characteristics and biochemical findings at the first presentation as well as follow-up were reviewed. 15 different CLCNKB gene mutations were identified in fourteen patients with BS, including 11 novel ones. A novel missense mutation and a novel small deletion were found from SLC12A1 gene. A novel gross deletion was found in CLCNKA gene. A recurrent missense mutation was identified from BSND gene. We found that the whole gene deletion mutation of CLCNKB gene was the most frequent mutation (32%), and the rate of gross deletion was up to 50 percent in this group of Chinese patients. The present study has found 19 mutations, including 14 novel ones, which would enrich the human gene mutation database (HGMD) and provide valuable references to the genetic counseling and diagnosis of the Chinese population.

  4. Missense mutation in the USH2A gene: association with recessive retinitis pigmentosa without hearing loss.

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    Rivolta, C; Sweklo, E A; Berson, E L; Dryja, T P

    2000-06-01

    Microdeletions Glu767(1-bp del), Thr967(1-bp del), and Leu1446(2-bp del) in the human USH2A gene have been reported to cause Usher syndrome type II, a disorder characterized by retinitis pigmentosa (RP) and mild-to-severe hearing loss. Each of these three frameshift mutations is predicted to lead to an unstable mRNA transcript that, if translated, would result in a truncated protein lacking the carboxy terminus. Here, we report Cys759Phe, a novel missense mutation in this gene that changes an amino-acid residue within the fifth laminin-epidermal growth factor-like domain of the USH2A gene and that is associated with recessive RP without hearing loss. This single mutation was found in 4.5% of 224 patients with recessive RP, suggesting that USH2A could cause more cases of nonsyndromic recessive RP than does any other gene identified to date.

  5. A de novo missense mutation of FGFR2 causes facial dysplasia syndrome in Holstein cattle.

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    Agerholm, Jørgen S; McEvoy, Fintan J; Heegaard, Steffen; Charlier, Carole; Jagannathan, Vidhya; Drögemüller, Cord

    2017-08-02

    Surveillance for bovine genetic diseases in Denmark identified a hitherto unreported congenital syndrome occurring among progeny of a Holstein sire used for artificial breeding. A genetic aetiology due to a dominant inheritance with incomplete penetrance or a mosaic germline mutation was suspected as all recorded cases were progeny of the same sire. Detailed investigations were performed to characterize the syndrome and to reveal its cause. Seven malformed calves were submitted examination. All cases shared a common morphology with the most striking lesions being severe facial dysplasia and complete prolapse of the eyes. Consequently the syndrome was named facial dysplasia syndrome (FDS). Furthermore, extensive brain malformations, including microencephaly, hydrocephalus, lobation of the cerebral hemispheres and compression of the brain were present. Subsequent data analysis of progeny of the sire revealed that around 0.5% of his offspring suffered from FDS. High density single nucleotide polymorphism (SNP) genotyping data of the seven cases and their parents were used to map the defect in the bovine genome. Significant genetic linkage was obtained for three regions, including chromosome 26 where whole genome sequencing of a case-parent trio revealed two de novo variants perfectly associated with the disease: an intronic SNP in the DMBT1 gene and a single non-synonymous variant in the FGFR2 gene. This FGFR2 missense variant (c.927G>T) affects a gene encoding a member of the fibroblast growth factor receptor family, where amino acid sequence is highly conserved between members and across species. It is predicted to change an evolutionary conserved tryptophan into a cysteine residue (p.Trp309Cys). Both variant alleles were proven to result from de novo mutation events in the germline of the sire. FDS is a novel genetic disorder of Holstein cattle. Mutations in the human FGFR2 gene are associated with various dominant inherited craniofacial dysostosis syndromes. Given

  6. A novel missense mutation in the CLCN7 gene linked to benign autosomal dominant osteopetrosis: a case series

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    Rashid Ban Mousa

    2013-01-01

    Full Text Available Abstract Introduction Osteopetrosis is a rare inherited genetic disease characterized by sclerosis of the skeleton. The absence or malfunction of osteoclasts is found to be strongly associated with the disease evolution. Currently, four clinically distinct forms of the disease have been recognized: the infantile autosomal recessive osteopetrosis, the malignant and the intermediate forms, and autosomal dominant osteopetrosis, type I and type II forms. The autosomal recessive types are the most severe forms with symptoms in very early childhood, whereas the autosomal dominant classes exhibit a heterogeneous trait with milder symptoms, often at later childhood or adulthood. Case presentation Case 1 is the 12-year-old daughter (index patient of an Iraqi-Kurdish family who, at the age of eight years, was diagnosed clinically to have mild autosomal dominant osteopetrosis. Presently, at 12-years old, she has severe complications due to the disease progression. In addition, the same family previously experienced the death of a female child in her late childhood. The deceased child had been misdiagnosed, at that time, with thalassemia major. In this report, we extended our investigation to identify the type of the inheritance patterns of osteopetrosis using molecular techniques, because consanguineous marriages exist within the family history. We have detected one heterozygous mutation in exon 15 of the Chloride Channel 7 gene in the index patient (Case 1, whereas other mutations were not detected in the associated genes TCIRG1, OSTM1, RANK, and RANKL. The missense mutation (CGG>TGG located in exon 15 (c.1225C>T of the Chloride Channel 7 gene changed the amino acid position 409 from arginine to tryptophan (p.R409W, c.1225C>T. Case 2 is the 16-year-old son (brother of the index patient of the same family who was diagnosed clinically with mild autosomal dominant osteopetrosis. We have identified the same heterozygous mutation in exon 15 of the Chloride

  7. A novel missense mutation in the CLCN7 gene linked to benign autosomal dominant osteopetrosis: a case series.

    Science.gov (United States)

    Rashid, Ban Mousa; Rashid, Nawshirwan Gafoor; Schulz, Ansgar; Lahr, Georgia; Nore, Beston Faiek

    2013-01-09

    Osteopetrosis is a rare inherited genetic disease characterized by sclerosis of the skeleton. The absence or malfunction of osteoclasts is found to be strongly associated with the disease evolution. Currently, four clinically distinct forms of the disease have been recognized: the infantile autosomal recessive osteopetrosis, the malignant and the intermediate forms, and autosomal dominant osteopetrosis, type I and type II forms. The autosomal recessive types are the most severe forms with symptoms in very early childhood, whereas the autosomal dominant classes exhibit a heterogeneous trait with milder symptoms, often at later childhood or adulthood. Case 1 is the 12-year-old daughter (index patient) of an Iraqi-Kurdish family who, at the age of eight years, was diagnosed clinically to have mild autosomal dominant osteopetrosis. Presently, at 12-years old, she has severe complications due to the disease progression. In addition, the same family previously experienced the death of a female child in her late childhood. The deceased child had been misdiagnosed, at that time, with thalassemia major. In this report, we extended our investigation to identify the type of the inheritance patterns of osteopetrosis using molecular techniques, because consanguineous marriages exist within the family history. We have detected one heterozygous mutation in exon 15 of the Chloride Channel 7 gene in the index patient (Case 1), whereas other mutations were not detected in the associated genes TCIRG1, OSTM1, RANK, and RANKL. The missense mutation (CGG>TGG) located in exon 15 (c.1225C>T) of the Chloride Channel 7 gene changed the amino acid position 409 from arginine to tryptophan (p.R409W, c.1225C>T).Case 2 is the 16-year-old son (brother of the index patient) of the same family who was diagnosed clinically with mild autosomal dominant osteopetrosis. We have identified the same heterozygous mutation in exon 15 of the Chloride channel 7 gene in this patient (Case 2). The missense

  8. Profound, prelingual nonsyndromic deafness maps to chromosome 10q21 and is caused by a novel missense mutation in the Usher syndrome type IF gene PCDH15.

    Science.gov (United States)

    Doucette, Lance; Merner, Nancy D; Cooke, Sandra; Ives, Elizabeth; Galutira, Dante; Walsh, Vanessa; Walsh, Tom; MacLaren, Linda; Cater, Tracey; Fernandez, Bridget; Green, Jane S; Wilcox, Edward R; Shotland, Lawrence I; Shotland, Larry; Li, Xiaoyan Cindy; Li, X C; Lee, Ming; King, Mary-Claire; Young, Terry-Lynn

    2009-05-01

    We studied a consanguineous family (Family A) from the island of Newfoundland with an autosomal recessive form of prelingual, profound, nonsyndromic sensorineural hearing loss. A genome-wide scan mapped the deafness trait to 10q21-22 (max LOD score of 4.0; D10S196) and fine mapping revealed a 16 Mb ancestral haplotype in deaf relatives. The PCDH15 gene was mapped within the critical region and was an interesting candidate because truncating mutations cause Usher syndrome type IF (USH1F) and two missense mutations have been previously associated with isolated deafness (DFNB23). Sequencing of the PCDH15 gene revealed 33 sequencing variants. Three of these variants were homozygous exclusively in deaf siblings but only one of them was not seen in ethnically matched controls. This novel c.1583 T>A transversion predicts an amino-acid substitution of a valine with an aspartic acid at codon 528 (V528D). Like the two DFNB23 mutations, the V528D mutation in Family A occurs in a highly conserved extracellular cadherin (EC) domain of PCDH15 and is predicted to be more deleterious than the previously identified DFNB23 missense mutations (R134G and G262D). Physical assessment, vestibular and visual function testing in deaf adults ruled out syndromic deafness because of Usher syndrome. This study validates the DFNB23 designation and supports the hypothesis that missense mutations in conserved motifs of PCDH15 cause nonsyndromic hearing loss. This emerging genotype-phenotype correlation in USH1F is similar to that in several other USH1 genes and cautions against a prognosis of a dual sensory loss in deaf children found to be homozygous for hypomorphic mutations at the USH1F locus.

  9. In Silico Analysis of FMR1 Gene Missense SNPs.

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    Tekcan, Akin

    2016-06-01

    The FMR1 gene, a member of the fragile X-related gene family, is responsible for fragile X syndrome (FXS). Missense single-nucleotide polymorphisms (SNPs) are responsible for many complex diseases. The effect of FMR1 gene missense SNPs is unknown. The aim of this study, using in silico techniques, was to analyze all known missense mutations that can affect the functionality of the FMR1 gene, leading to mental retardation (MR) and FXS. Data on the human FMR1 gene were collected from the Ensembl database (release 81), National Centre for Biological Information dbSNP Short Genetic Variations database, 1000 Genomes Browser, and NHLBI Exome Sequencing Project Exome Variant Server. In silico analysis was then performed. One hundred-twenty different missense SNPs of the FMR1 gene were determined. Of these, 11.66 % of the FMR1 gene missense SNPs were in highly conserved domains, and 83.33 % were in domains with high variety. The results of the in silico prediction analysis showed that 31.66 % of the FMR1 gene SNPs were disease related and that 50 % of SNPs had a pathogenic effect. The results of the structural and functional analysis revealed that although the R138Q mutation did not seem to have a damaging effect on the protein, the G266E and I304N SNPs appeared to disturb the interaction between the domains and affect the function of the protein. This is the first study to analyze all missense SNPs of the FMR1 gene. The results indicate the applicability of a bioinformatics approach to FXS and other FMR1-related diseases. I think that the analysis of FMR1 gene missense SNPs using bioinformatics methods would help diagnosis of FXS and other FMR1-related diseases.

  10. A rat model of hypohidrotic ectodermal dysplasia carries a missense mutation in the Edaradd gene

    Science.gov (United States)

    2011-01-01

    Background Hypohidrotic ectodermal dysplasia (HED) is a congenital disorder characterized by sparse hair, oligodontia, and inability to sweat. It is caused by mutations in any of three Eda pathway genes: ectodysplasin (Eda), Eda receptor (Edar), and Edar-associated death domain (Edaradd), which encode ligand, receptor, and intracellular adaptor molecule, respectively. The Eda signaling pathway activates NF-κB, which is central to ectodermal differentiation. Although the causative genes and the molecular pathway affecting HED have been identified, no curative treatment for HED has been established. Previously, we found a rat spontaneous mutation that caused defects in hair follicles and named it sparse-and-wavy (swh). Here, we have established the swh rat as the first rat model of HED and successfully identified the swh mutation. Results The swh/swh rat showed sparse hair, abnormal morphology of teeth, and absence of sweat glands. The ectoderm-derived glands, meibomian, preputial, and tongue glands, were absent. We mapped the swh mutation to the most telomeric part of rat Chr 7 and found a Pro153Ser missense mutation in the Edaradd gene. This mutation was located in the death domain of EDARADD, which is crucial for signal transduction and resulted in failure to activate NF-κB. Conclusions These findings suggest that swh is a loss-of-function mutation in the rat Edaradd and indicate that the swh/swh rat would be an excellent animal model of HED that could be used to investigate the pathological basis of the disease and the development of new therapies. PMID:22013926

  11. Eight novel F13A1 gene missense mutations in patients with mild FXIII deficiency: in silico analysis suggests changes in FXIII-A subunit structure/function.

    Science.gov (United States)

    Biswas, Arijit; Ivaskevicius, Vytautas; Thomas, Anne; Varvenne, Michael; Brand, Brigitte; Rott, Hannelore; Haussels, Iris; Ruehl, Heiko; Scholz, Ute; Klamroth, Robert; Oldenburg, Johannes

    2014-10-01

    Mild FXIII deficiency is an under-diagnosed disorder because the carriers of this deficiency are often asymptomatic and reveal a phenotype only under special circumstances like surgery or induced trauma. Mutational reports from this type of deficiency have been rare. In this study, we present the phenotypic and genotypic data of nine patients showing mild FXIII-A deficiency caused by eight novel heterozygous missense mutations (Pro166Leu, Arg171Gln, His342Tyr, Gln415Arg, Leu529Pro, Gln601Lys, Arg703Gln and Arg715Gly) in the F13A1 gene. None of these variants were seen in 200 healthy controls. In silico structural analysis of the local wild-type protein structures (activated and non-activated) from X-ray crystallographic models downloaded from the protein databank identified potential structural/functional effects for the identified mutations. The missense mutations in the core domain are suggested to be directly influencing the catalytic triad. Mutations on other domains might influence other critical factors such as activation peptide cleavage or the barrel domain integrity. In vitro expression and subsequent biochemical studies in the future will be able to confirm the pathophysiological mechanisms proposed for the mutations in this article.

  12. A novel missense mutation in the gene EDARADD associated with an unusual phenotype of hypohidrotic ectodermal dysplasia.

    Science.gov (United States)

    Wohlfart, Sigrun; Söder, Stephan; Smahi, Asma; Schneider, Holm

    2016-01-01

    Hypohidrotic ectodermal dysplasia (HED) is a rare disorder characterized by deficient development of structures derived from the ectoderm including hair, nails, eccrine glands, and teeth. HED forms that are caused by mutations in the genes EDA, EDAR, or EDARADD may show almost identical phenotypes, explained by a common signaling pathway. Proper interaction of the proteins encoded by these three genes is important for the activation of the NF-κB signaling pathway and subsequent transcription of the target genes. Mutations in the gene EDARADD are most rarely implicated in HED. Here we describe a novel missense mutation, c.367G>A (p.Asp123Asn), in this gene which did not appear to influence the interaction between EDAR and EDARADD proteins, but led to an impaired ability to activate NF-κB signaling. Female members of the affected family showed either unilateral or bilateral amazia. In addition, an affected girl developed bilateral ovarian teratomas, possibly associated with her genetic condition. © 2015 Wiley Periodicals, Inc.

  13. Genotype-Phenotype Correlation in NF1: Evidence for a More Severe Phenotype Associated with Missense Mutations Affecting NF1 Codons 844–848

    NARCIS (Netherlands)

    Koczkowska, M. (Magdalena); Chen, Y. (Yunjia); Callens, T. (Tom); Gomes, A. (Alicia); Sharp, A. (Angela); Johnson, S. (Sherrell); Hsiao, M.-C. (Meng-Chang); Chen, Z. (Zhenbin); Balasubramanian, M. (Meena); Barnett, C.P. (Christopher P.); Becker, T.A. (Troy A.); Ben-Shachar, S. (Shay); D.R. Bertola (Débora Romeo); J.O. Blakeley (Jaishri O.); Burkitt-Wright, E.M.M. (Emma M.M.); Callaway, A. (Alison); Crenshaw, M. (Melissa); Cunha, K.S. (Karin S.); Cunningham, M. (Mitch); M.D. D'Agostino (Maria Daniela); K. Dahan (Karin); De Luca, A. (Alessandro); A. Destrée (Anne); Dhamija, R. (Radhika); Eoli, M. (Marica); Evans, D.G.R. (D. Gareth R.); Galvin-Parton, P. (Patricia); George-Abraham, J.K. (Jaya K.); K.W. Gripp (Karen); Guevara-Campos, J. (Jose); Hanchard, N.A. (Neil A.); Hernández-Chico, C. (Concepcion); Immken, L. (LaDonna); S. Janssens (Sandra); K.J. Jones (Kristi); Keena, B.A. (Beth A.); Kochhar, A. (Aaina); Liebelt, J. (Jan); Martir-Negron, A. (Arelis); Mahoney, M.J. (Maurice J.); I. Maystadt (Isabelle); McDougall, C. (Carey); M. McEntagart (Meriel); N.J. Mendelsohn; Miller, D.T. (David T.); G. Mortier (Geert); J. Morton (Jenny); Pappas, J. (John); S.R. Plotkin (Scott R.); Pond, D. (Dinel); Rosenbaum, K. (Kenneth); Rubin, K. (Karol); Russell, L. (Laura); Rutledge, L.S. (Lane S.); Saletti, V. (Veronica); Schonberg, R. (Rhonda); Schreiber, A. (Allison); Seidel, M. (Meredith); Siqveland, E. (Elizabeth); D.W. Stockton (David); Trevisson, E. (Eva); N.J. Ullrich (Nicole J.); M. Upadhyaya (Meena); A.S. Thornton (Andrew); H. Verhelst (H.); M.R. Wallace (Margaret); Yap, Y.-S. (Yoon-Sim); Zackai, E. (Elaine); Zonana, J. (Jonathan); Zurcher, V. (Vickie); K. Claes (Kathleen); Martin, Y. (Yolanda); B. Korf (Bruce); E. Legius (Eric); L.M. Messiaen (Ludwine)

    2018-01-01

    textabstractNeurofibromatosis type 1 (NF1), a common genetic disorder with a birth incidence of 1:2,000–3,000, is characterized by a highly variable clinical presentation. To date, only two clinically relevant intragenic genotype-phenotype correlations have been reported for NF1 missense mutations

  14. Classification of rare missense substitutions, using risk surfaces, with genetic- and molecular-epidemiology applications.

    Science.gov (United States)

    Tavtigian, Sean V; Byrnes, Graham B; Goldgar, David E; Thomas, Alun

    2008-11-01

    Many individually rare missense substitutions are encountered during deep resequencing of candidate susceptibility genes and clinical mutation screening of known susceptibility genes. BRCA1 and BRCA2 are among the most resequenced of all genes, and clinical mutation screening of these genes provides an extensive data set for analysis of rare missense substitutions. Align-GVGD is a mathematically simple missense substitution analysis algorithm, based on the Grantham difference, which has already contributed to classification of missense substitutions in BRCA1, BRCA2, and CHEK2. However, the distribution of genetic risk as a function of Align-GVGD's output variables Grantham variation (GV) and Grantham deviation (GD) has not been well characterized. Here, we used data from the Myriad Genetic Laboratories database of nearly 70,000 full-sequence tests plus two risk estimates, one approximating the odds ratio and the other reflecting strength of selection, to display the distribution of risk in the GV-GD plane as a series of surfaces. We abstracted contours from the surfaces and used the contours to define a sequence of missense substitution grades ordered from greatest risk to least risk. The grades were validated internally using a third, personal and family history-based, measure of risk. The Align-GVGD grades defined here are applicable to both the genetic epidemiology problem of classifying rare missense substitutions observed in known susceptibility genes and the molecular epidemiology problem of analyzing rare missense substitutions observed during case-control mutation screening studies of candidate susceptibility genes. (c) 2008 Wiley-Liss, Inc.

  15. Frequent genes in rare diseases: panel-based next generation sequencing to disclose causal mutations in hereditary neuropathies.

    Science.gov (United States)

    Dohrn, Maike F; Glöckle, Nicola; Mulahasanovic, Lejla; Heller, Corina; Mohr, Julia; Bauer, Christine; Riesch, Erik; Becker, Andrea; Battke, Florian; Hörtnagel, Konstanze; Hornemann, Thorsten; Suriyanarayanan, Saranya; Blankenburg, Markus; Schulz, Jörg B; Claeys, Kristl G; Gess, Burkhard; Katona, Istvan; Ferbert, Andreas; Vittore, Debora; Grimm, Alexander; Wolking, Stefan; Schöls, Ludger; Lerche, Holger; Korenke, G Christoph; Fischer, Dirk; Schrank, Bertold; Kotzaeridou, Urania; Kurlemann, Gerhard; Dräger, Bianca; Schirmacher, Anja; Young, Peter; Schlotter-Weigel, Beate; Biskup, Saskia

    2017-12-01

    Hereditary neuropathies comprise a wide variety of chronic diseases associated to more than 80 genes identified to date. We herein examined 612 index patients with either a Charcot-Marie-Tooth phenotype, hereditary sensory neuropathy, familial amyloid neuropathy, or small fiber neuropathy using a customized multigene panel based on the next generation sequencing technique. In 121 cases (19.8%), we identified at least one putative pathogenic mutation. Of these, 54.4% showed an autosomal dominant, 33.9% an autosomal recessive, and 11.6% an X-linked inheritance. The most frequently affected genes were PMP22 (16.4%), GJB1 (10.7%), MPZ, and SH3TC2 (both 9.9%), and MFN2 (8.3%). We further detected likely or known pathogenic variants in HINT1, HSPB1, NEFL, PRX, IGHMBP2, NDRG1, TTR, EGR2, FIG4, GDAP1, LMNA, LRSAM1, POLG, TRPV4, AARS, BIC2, DHTKD1, FGD4, HK1, INF2, KIF5A, PDK3, REEP1, SBF1, SBF2, SCN9A, and SPTLC2 with a declining frequency. Thirty-four novel variants were considered likely pathogenic not having previously been described in association with any disorder in the literature. In one patient, two homozygous mutations in HK1 were detected in the multigene panel, but not by whole exome sequencing. A novel missense mutation in KIF5A was considered pathogenic because of the highly compatible phenotype. In one patient, the plasma sphingolipid profile could functionally prove the pathogenicity of a mutation in SPTLC2. One pathogenic mutation in MPZ was identified after being previously missed by Sanger sequencing. We conclude that panel based next generation sequencing is a useful, time- and cost-effective approach to assist clinicians in identifying the correct diagnosis and enable causative treatment considerations. © 2017 International Society for Neurochemistry.

  16. Phenotypic variability in 49 cases of ESCO2 mutations, including novel missense and codon deletion in the acetyltransferase domain, correlates with ESCO2 expression and establishes the clinical criteria for Roberts syndrome

    DEFF Research Database (Denmark)

    Vega, H; Trainer, A H; Gordillo, M

    2010-01-01

    Roberts syndrome (RBS) and SC phocomelia are caused by mutations in ESCO2, which codes for an acetyltransferase involved in the regulation of sister chromatid cohesion. Of 26 mutations described to date, only one missense mutation has been reported and all others are predicted to be truncating...

  17. Phenotypic variability in 49 cases of ESCO2 mutations, including novel missense and codon deletion in the acetyltransferase domain, correlates with ESCO2 expression and establishes the clinical criteria for Roberts syndrome

    NARCIS (Netherlands)

    Vega, H.; Trainer, A.H.; Gordillo, M.; Crosier, M.; Kayserili, H.; Skovby, F.; Uzielli, M.L.G.; Schnur, R.E.; Manouvrier, S.; Blair, E.; Hurst, J.A.; Forzano, F.; Meins, M.; Simola, K.O.J.; Raas-Rothschild, A; Hennekam, R.C.M.; Jabs, E.W.

    2010-01-01

    Background Roberts syndrome (RBS) and SC phocomelia are caused by mutations in ESCO2, which codes for an acetyltransferase involved in the regulation of sister chromatid cohesion. Of 26 mutations described to date, only one missense mutation has been reported and all others are predicted to be

  18. A missense mutation in the alpha-actinin 1 gene (ACTN1 is the cause of autosomal dominant macrothrombocytopenia in a large French family.

    Directory of Open Access Journals (Sweden)

    Paul Guéguen

    Full Text Available Inherited thrombocytopenia is a heterogeneous group of disorders characterized by a reduced number of blood platelets. Despite the identification of nearly 20 causative genes in the past decade, approximately half of all subjects with inherited thrombocytopenia still remain unexplained in terms of the underlying pathogenic mechanisms. Here we report a six-generation French pedigree with an autosomal dominant mode of inheritance and the identification of its genetic basis. Of the 55 subjects available for analysis, 26 were diagnosed with isolated macrothrombocytopenia. Genome-wide linkage analysis mapped a 10.9 Mb locus to chromosome 14 (14q22 with a LOD score of 7.6. Candidate gene analysis complemented by targeted next-generation sequencing identified a missense mutation (c.137GA; p.Arg46Gln in the alpha-actinin 1 gene (ACTN1 that segregated with macrothrombocytopenia in this large pedigree. The missense mutation occurred within actin-binding domain of alpha-actinin 1, a functionally critical domain that crosslinks actin filaments into bundles. The evaluation of cultured mutation-harboring megakaryocytes by electron microscopy and the immunofluorescence examination of transfected COS-7 cells suggested that the mutation causes disorganization of the cellular cytoplasm. Our study concurred with a recently published whole-exome sequence analysis of six small Japanese families with congenital macrothrombocytopenia, adding ACTN1 to the growing list of thrombocytopenia genes.

  19. A pathogenic S250F missense mutation results in a mouse model of mild aromatic l-amino acid decarboxylase (AADC) deficiency.

    Science.gov (United States)

    Caine, Charlotte; Shohat, Meytal; Kim, Jeong-Ki; Nakanishi, Koki; Homma, Shunichi; Mosharov, Eugene V; Monani, Umrao R

    2017-11-15

    Homozygous mutations in the aromatic l-amino acid decarboxylase (AADC) gene result in a severe depletion of its namesake protein, triggering a debilitating and often fatal form of infantile Parkinsonism known as AADC deficiency. AADC deficient patients fail to produce normal levels of the monoamine neurotransmitters dopamine and serotonin, and suffer a multi-systemic disorder characterized by movement abnormalities, developmental delay and autonomic dysfunction; an absolute loss of dopamine is generally considered incompatible with life. There is no optimal treatment for AADC deficiency and few truly good models in which to investigate disease mechanisms or develop and refine therapeutic strategies. In this study, we introduced a relatively frequently reported but mildly pathogenic S250F missense mutation into the murine Aadc gene. We show that mutants homozygous for the mutation are viable and express a stable but minimally active form of the AADC protein. Although the low enzymatic activity of the protein resulted in only modestly reduced concentrations of brain dopamine, serotonin levels were markedly diminished, and this perturbed behavior as well as autonomic function in mutant mice. Still, we found no evidence of morphologic abnormalities of the dopaminergic cells in mutant brains. The striatum as well as substantia nigra appeared normal and no loss of dopamine expressing cells in the latter was detected. We conclude that even minute levels of active AADC are sufficient to allow for substantial amounts of dopamine to be produced in model mice harboring the S250F mutation. Such mutants represent a novel, mild model of human AADC deficiency. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. A novel common large genomic deletion and two new missense mutations identified in the Romanian phenylketonuria population.

    Science.gov (United States)

    Gemperle-Britschgi, Corinne; Iorgulescu, Daniela; Mager, Monica Alina; Anton-Paduraru, Dana; Vulturar, Romana; Thöny, Beat

    2016-01-15

    The mutation spectrum for the phenylalanine hydroxylase (PAH) gene was investigated in a cohort of 84 hyperphenylalaninemia (HPA) patients from Romania identified through newborn screening or neurometabolic investigations. Differential diagnosis identified 81 patients with classic PAH deficiency while 3 had tetrahydropterin-cofactor deficiency and/or remained uncertain due to insufficient specimen. PAH-genetic analysis included a combination of Sanger sequencing of exons and exon–intron boundaries, MLPA and NGS with genomic DNA, and cDNA analysis from immortalized lymphoblasts. A diagnostic efficiency of 99.4% was achieved, as for one allele (out of a total of 162 alleles) no mutation could be identified. The most prevalent mutation was p.Arg408Trp which was found in ~ 38% of all PKU alleles. Three novel mutations were identified, including the two missense mutations p.Gln226Lys and p.Tyr268Cys that were both disease causing by prediction algorithms, and the large genomic deletion EX6del7831 (c.509 + 4140_706 + 510del7831) that resulted in skipping of exon 6 based on PAH-cDNA analysis in immortalized lymphocytes. The genomic deletion was present in a heterozygous state in 12 patients, i.e. in ~ 8% of all the analyzed PKU alleles, and might have originated from a Romanian founder.

  1. Risk of cancer by ATM missense mutations in the general population

    DEFF Research Database (Denmark)

    Dombernowsky, Sarah Louise; Weischer, Maren; Allin, Kristine Højgaard

    2008-01-01

    PURPOSE: Truncating and missense mutations in the ATM gene, which cause insufficient DNA damage surveillance, allow damaged cells to proceed into mitosis, which eventually results in increased cancer susceptibility. We tested the hypotheses that ATM Ser49Cys and ATM Ser707Pro heterozygosity......: Multifactorially adjusted hazard ratios for ATM Ser49Cys heterozygotes versus noncarriers were 1.2 (95% CI, 0.9 to 1.5) for cancer overall, 0.8 (95% CI, 0.3 to 2.0) for breast cancer, 4.8 (95% CI, 2.2 to 11) for melanoma, 2.3 (95% CI, 1.1 to 5.0) for prostate cancer, and 3.4 (95% CI, 1.1 to 11) for cancer...... of the oral cavity/pharynx. Multifactorially adjusted hazard ratios for ATM Ser707Pro heterozygotes versus noncarriers were 0.8 (95% CI, 0.6 to 1.2) for cancer overall, 0.6 (95% CI, 0.2 to 1.6) for breast cancer, 10 (95% CI, 1.1 to 93) for thyroid/other endocrine tumors, and 2.7 (95% CI, 1.0 to 7...

  2. A novel rasopathy caused by recurrent de novo missense mutations in PPP1CB closely resembles Noonan syndrome with loose anagen hair.

    Science.gov (United States)

    Gripp, Karen W; Aldinger, Kimberly A; Bennett, James T; Baker, Laura; Tusi, Jessica; Powell-Hamilton, Nina; Stabley, Deborah; Sol-Church, Katia; Timms, Andrew E; Dobyns, William B

    2016-09-01

    Noonan syndrome is a rasopathy caused by mutations in multiple genes encoding components of the RAS/MAPK pathway. Despite its variable phenotype, limited genotype-phenotype correlations exist. Noonan syndrome with loose anagen hair (NS-LAH) is characterized by its distinctive hair anomalies, developmental differences, and structural brain abnormalities and is caused by a single recurrent missense SHOC2 mutation. SHOC2 forms a complex with protein phosphatase 1 (PP1C). Protein phosphatases counterbalance kinases and control activation of signaling proteins, such as the mitogen-activated protein kinases of the RAS/MAPK pathway. Here we report four patients with de novo missense mutations in protein phosphatase one catalytic subunit beta (PPP1CB), sharing a recognizable phenotype. Three individuals had the recurrent PPP1CB c.146G>C, p.Pro49Arg mutation, the fourth had a c.166G>C, p.Ala56Pro change. All had relative or absolute macrocephaly, low-set and posteriorly angulated ears, and developmental delay. Slow growing and/or sparse hair and/or an unruly hair texture was present in all. Three individuals had feeding difficulties requiring feeding tubes. One of two males had cryptorchidism, another had pectus excavatum. Short stature was present in three. A female with the recurrent mutation had a Dandy-Walker malformation and optic nerve hypoplasia. Mild ventriculomegaly occurred in all, cerebellar tonsillar ectopia was seen in two and progressed to Chiari 1 malformation in one individual. Based on the combination of phenotypic findings and PPP1CB's effect on RAF dephosphorylation within the RAS/MAPK pathway, this novel condition can be considered a rasopathy, most similar to NS-LAH. Collectively, these mutations meet the standardized criteria for pathogenicity. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Frequent beneficial mutations during single-colony serial transfer of Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Kathleen E Stevens

    2011-08-01

    Full Text Available The appearance of new mutations within a population provides the raw material for evolution. The consistent decline in fitness observed in classical mutation accumulation studies has provided support for the long-held view that deleterious mutations are more common than beneficial mutations. Here we present results of a study using a mutation accumulation design with the bacterium Streptococcus pneumoniae in which the fitness of the derived populations increased. This rise in fitness was associated specifically with adaptation to survival during brief stationary phase periods between single-colony population bottlenecks. To understand better the population dynamics behind this unanticipated adaptation, we developed a maximum likelihood model describing the processes of mutation and stationary-phase selection in the context of frequent population bottlenecks. Using this model, we estimate that the rate of beneficial mutations may be as high as 4.8×10(-4 events per genome for each time interval corresponding to the pneumococcal generation time. This rate is several orders of magnitude higher than earlier estimates of beneficial mutation rates in bacteria but supports recent results obtained through the propagation of small populations of Escherichia coli. Our findings indicate that beneficial mutations may be relatively frequent in bacteria and suggest that in S. pneumoniae, which develops natural competence for transformation, a steady supply of such mutations may be available for sampling by recombination.

  4. Two Thai families with Norrie disease (ND): association of two novel missense mutations with severe ND phenotype, seizures, and a manifesting carrier.

    Science.gov (United States)

    Yamada, K; Limprasert, P; Ratanasukon, M; Tengtrisorn, S; Yingchareonpukdee, J; Vasiknanonte, P; Kitaoka, T; Ghadami, M; Niikawa, N; Kishino, T

    2001-04-15

    We describe two Thai families with Norrie disease (ND) in three generations, including 10 affected males and one manifesting female. All affected males in each family had severely defective eye development with complete loss of vision. In addition, three male patients (one from family 1 and two from family 2) suffered from epilepsy, and one female carrier from one family manifested blindness with phthisis bulbi in her right eye. Mutation analysis of the ND gene (NDP) revealed two different novel missense mutations (L16P and S75P) that co-segregated with ND in each family, suggesting that the newly appearing proline at codon 16 or codon 75 alters the conformation of the ND protein and contributes to the severe phenotype of ND in each family. Other studies suggest that epileptic seizures or growth retardation that is associated with ND is the consequence of loss of contiguous genes, because most such patients had deletions extending beyond the Norrie locus. Our finding that the three affected males in the two families with the missense mutations had epilepsy does not support a contiguous gene effect, but favors the pleiotropism of NDP, at least as far as the epileptic manifestation is concerned. The unilateral blindness in the female carrier may have been due to non-random X-inactivation. Copyright 2001 Wiley-Liss, Inc.

  5. E2-EPF UCP regulates stability and functions of missense mutant pVHL via ubiquitin mediated proteolysis.

    Science.gov (United States)

    Park, Kyeong-Su; Kim, Ju Hee; Shin, Hee Won; Chung, Kyung-Sook; Im, Dong-Soo; Lim, Jung Hwa; Jung, Cho-Rok

    2015-10-26

    Missense mutation of VHL gene is frequently detected in type 2 VHL diseases and linked to a wide range of pVHL functions and stability. Certain mutant pVHLs retain ability to regulate HIFs but lose their function by instability. In this case, regulating of degradation of mutant pVHLs, can be postulated as therapeutic method. The stability and cellular function of missense mutant pVHLs were determine in HEK293T transient expressing cell and 786-O stable cell line. Ubiquitination assay of mutant VHL proteins was performed in vitro system. Anticancer effect of adenovirus mediated shUCP expressing was evaluated using ex vivo mouse xenograft assay. Three VHL missense mutants (V155A, L158Q, and Q164R) are directly ubiquitinated by E2-EPF UCP (UCP) in vitro. Mutant pVHLs are more unstable than wild type in cell. Missense mutant pVHLs interact with UCP directly in both in vitro and cellular systems. Lacking all of lysine residues of pVHL result in resistance to ubiquitination thereby increase its stability. Missense mutant pVHLs maintained the function of E3 ligase to ubiquitinate HIF-1α in vitro. In cells expressing mutant pVHLs, Glut-1 and VEGF were relatively upregulated compared to their levels in cells expressing wild-type. Depletion of UCP restored missense mutant pVHLs levels and inhibited cell growth. Adenovirus-mediated shUCP RNA delivery inhibited tumor growth in ex vivo mouse xenograft model. These data suggest that targeting of UCP can be one of therapeutic method in type 2 VHL disease caused by unstable but functional missense mutant pVHL.

  6. Spectrum of MECP2 gene mutations in a cohort of Indian patients with Rett syndrome: report of two novel mutations.

    Science.gov (United States)

    Das, Dhanjit Kumar; Raha, Sarbani; Sanghavi, Daksha; Maitra, Anurupa; Udani, Vrajesh

    2013-02-15

    Rett syndrome (RTT) is an X-linked neurodevelopmental disorder, primarily affecting females and characterized by developmental regression, epilepsy, stereotypical hand movements, and motor abnormalities. Its prevalence is about 1 in 10,000 female births. Rett syndrome is caused by mutations within methyl CpG-binding protein 2 (MECP2) gene. Over 270 individual nucleotide changes which cause pathogenic mutations have been reported. However, eight most commonly occurring missense and nonsense mutations account for almost 70% of all patients. We screened 90 individuals with Rett syndrome phenotype. A total of 19 different MECP2 mutations and polymorphisms were identified in 27 patients. Of the 19 mutations, we identified 7 (37%) frameshift, 6 (31%) nonsense, 14 (74%) missense mutations and one duplication (5%). The most frequent pathogenic changes were: missense p.T158M (11%), p.R133C (7.4%), and p.R306C (7.4%) and nonsense p.R168X (11%), p.R255X (7.4%) mutations. We have identified two novel mutations namely p.385-388delPLPP present in atypical patients and p.Glu290AlafsX38 present in a classical patient of Rett syndrome. Sequence homology for p.385-388delPLPP mutation revealed that these 4 amino acids were conserved across mammalian species. This indicated the importance of these 4 amino acids in structure and function of the protein. A novel variant p.T479T has also been identified in a patient with atypical Rett syndrome. A total of 62 (69%) patients remained without molecular genetics diagnosis that necessitates further search for mutations in other genes like CDKL5 and FOXG1 that are known to cause Rett phenotype. The majority of mutations are detected in exon 4 and only one mutation was present in exon 3. Therefore, our study suggests the need for screening exon 4 of MECP2 as first line of diagnosis in these patients. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Spliceosomal gene aberrations are rare, coexist with oncogenic mutations, and are unlikely to exert a driver effect in childhood MDS and JMML

    NARCIS (Netherlands)

    S. Hirabayashi (Shinsuke); C. Flotho (Christian); J. Moetter (Jessica); M. Heuser (Michael); H. Hasle (Henrik); B. Gruhn (Bernd); T. Klingebiel (Thomas); F. Thol (Felicitas); B. Schlegelberger (Brigitte); I. Baumann (Irith); B. Strahm (Brigitte); J. Stary (Jan); F. Locatelli (Franco); M. Zecca (Marco); E. Bergstraesser (Eva); M.N. Dworzak (Michael); M.M. van den Heuvel-Eibrink (Marry); B. de Moerloose (Barbara); S. Ogawa (Susumu); C.M. Niemeyer (Charlotte); M. Wlodarski (Marcin)

    2012-01-01

    textabstractSomatic mutations of the spliceosomal machinery occur frequently in adult patients with myelodysplastic syndrome (MDS). We resequenced SF3B1, U2AF35, and SRSF2 in 371 children with MDS or juvenile myelomonocytic leukemia. We found missense mutations in 2 juvenile myelomonocytic leukemia

  8. Familial Mediterranean fever, Inflammation and Nephrotic Syndrome: Fibrillary Glomerulopathy and the M680I Missense Mutation

    Directory of Open Access Journals (Sweden)

    Semerdjian Ronald J

    2003-08-01

    Full Text Available Abstract Background Familial Mediterranean fever (FMF is an autosomal recessive disease characterized by inflammatory serositis (fever, peritonitis, synovitis and pleuritis. The gene locus responsible for FMF was identified in 1992 and localized to the short arm of chromosome 16. In 1997, a specific FMF gene locus, MEFV, was discovered to encode for a protein, pyrin that mediates inflammation. To date, more than forty missense mutations are known to exist. The diversity of mutations identified has provided insight into the variability of clinical presentation and disease progression. Case Report We report an individual heterozygous for the M680I gene mutation with a clinical diagnosis of FMF using the Tel-Hashomer criteria. Subsequently, the patient developed nephrotic syndrome with biopsy-confirmed fibrillary glomerulonephritis (FGN. Further diagnostic studies were unremarkable with clinical workup negative for amyloidosis or other secondary causes of nephrotic syndrome. Discussion Individuals with FMF are at greater risk for developing nephrotic syndrome. The most serious etiology is amyloidosis (AA variant with renal involvement, ultimately progressing to end-stage renal disease. Other known renal diseases in the FMF population include IgA nephropathy, IgM nephropathy, Henoch-Schönlein purpura as well as polyarteritis nodosa. Conclusion To our knowledge, this is the first association between FMF and the M680I mutation later complicated by nephrotic syndrome and fibrillary glomerulonephritis.

  9. Identification of a Novel Heterozygous Missense Mutation in the CACNA1F Gene in a Chinese Family with Retinitis Pigmentosa by Next Generation Sequencing

    Directory of Open Access Journals (Sweden)

    Qi Zhou

    2015-01-01

    Full Text Available Background. Retinitis pigmentosa (RP is an inherited retinal degenerative disease, which is clinically and genetically heterogeneous, and the inheritance pattern is complex. In this study, we have intended to study the possible association of certain genes with X-linked RP (XLRP in a Chinese family. Methods. A Chinese family with RP was recruited, and a total of seven individuals were enrolled in this genetic study. Genomic DNA was isolated from peripheral leukocytes, and used for the next generation sequencing (NGS. Results. The affected individual presented the clinical signs of XLRP. A heterozygous missense mutation (c.1555C>T, p.R519W was identified by NGS in exon 13 of the CACNA1F gene on X chromosome, and was confirmed by Sanger sequencing. It showed perfect cosegregation with the disease in the family. The mutation at this position in the CACNA1F gene of RP was found novel by database searching. Conclusion. By using NGS, we have found a novel heterozygous missense mutation (c.1555C>T, p.R519W in CACNA1F gene, which is probably associated with XLRP. The findings might provide new insights into the cause and diagnosis of RP, and have implications for genetic counseling and clinical management in this family.

  10. Contribution of novel ATGL missense mutations to the clinical phenotype of NLSD-M: a strikingly low amount of lipase activity may preserve cardiac function.

    Science.gov (United States)

    Tavian, Daniela; Missaglia, Sara; Redaelli, Chiara; Pennisi, Elena M; Invernici, Gloria; Wessalowski, Ruediger; Maiwald, Robert; Arca, Marcello; Coleman, Rosalind A

    2012-12-15

    The lack of adipose triglyceride lipase (ATGL), a patatin-like phospholipase domain-containing enzyme that hydrolyzes fatty acids from triacylglycerol (TAG) stored in multiple tissues, causes the autosomal recessive disorder neutral lipid storage disease with myopathy (NLSD-M). In two families of Lebanese and Italian origin presenting with NLSD-M, we identified two new missense mutations in highly conserved regions of ATGL (p.Arg221Pro and p.Asn172Lys) and a novel nonsense mutation (p.Trp8X). The Lebanese patients harbor homozygous p.Arg221Pro, whereas the Italian patients are heterozygotes for p.Asn172Lys and the p.Trp8X mutation. The p.Trp8X mutation results in a complete absence of ATGL protein, while the p.Arg221Pro and p.Asn172Lys mutations result in proteins with minimal lipolytic activity. Although these mutations did not affect putative catalytic residues or the lipid droplet (LD)-binding domain of ATGL, cytosolic LDs accumulated in cultured skin fibroblasts from the patients. The missense mutations might destabilize a random coil (p.Asn172Lys) or a helix (p.Arg221Pro) structure within or proximal to the patatin domain of the lipase, thereby interfering with the enzyme activity, while leaving intact the residues required to localize the protein to LDs. Overexpressing wild-type ATGL in one patient's fibroblasts corrected the metabolic defect and effectively reduced the number and area of cellular LDs. Despite the poor lipase activity in vitro, the Lebanese siblings have a mild myopathy and not clinically evident myocardial dysfunction. The patients of Italian origin show a late-onset and slowly progressive skeletal myopathy. These findings suggest that a small amount of correctly localized lipase activity preserves cardiac function in NLSD-M.

  11. Significance of somatic mutations and content alteration of mitochondrial DNA in esophageal cancer

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    Wang Yu-Fen

    2006-04-01

    Full Text Available Abstract Background The roles of mitochondria in energy metabolism, the generation of ROS, aging, and the initiation of apoptosis have implicated their importance in tumorigenesis. In this study we aim to establish the mutation spectrum and to understand the role of somatic mtDNA mutations in esophageal cancer. Methods The entire mitochondrial genome was screened for somatic mutations in 20 pairs (18 esophageal squamous cell carcinomas, one adenosquamous carcinoma and one adenocarcinoma of tumor/surrounding normal tissue of esophageal cancers, using temporal temperature gradient gel electrophoresis (TTGE, followed by direct DNA sequencing to identify the mutations. Results Fourteen somatic mtDNA mutations were identified in 55% (11/20 of tumors analyzed, including 2 novel missense mutations and a frameshift mutation in ND4L, ATP6 subunit, and ND4 genes respectively. Nine mutations (64% were in the D-loop region. Numerous germline variations were found, at least 10 of them were novel and five were missense mutations, some of them occurred in evolutionarily conserved domains. Using real-time quantitative PCR analysis, the mtDNA content was found to increase in some tumors and decrease in others. Analysis of molecular and other clinicopathological findings does not reveal significant correlation between somatic mtDNA mutations and mtDNA content, or between mtDNA content and metastatic status. Conclusion Our results demonstrate that somatic mtDNA mutations in esophageal cancers are frequent. Some missense and frameshift mutations may play an important role in the tumorigenesis of esophageal carcinoma. More extensive biochemical and molecular studies will be necessary to determine the pathological significance of these somatic mutations.

  12. Familial tumoral calcinosis and hyperostosis-hyperphosphataemia syndrome are different manifestations of the same disease: novel missense mutations in GALNT3

    International Nuclear Information System (INIS)

    Joseph, Leo; Joseph, Selvanayagam; Hing, Sandra N.; Idowu, Bernadine D.; Delaney, David; Presneau, Nadege; O'Donnell, Paul; Diss, Tim; Flanagan, Adrienne Margaret

    2010-01-01

    To report on the biochemistry and clinical and genetic findings of two siblings, the younger sister presenting with recurrent bone pain of the radius and ulna, and medullary sclerosis, and the older brother with soft tissue calcific deposits (tumoral calcinosis) but who later developed bone pain. Both were found to be hyperphosphaturic. The index family comprised four individuals (father, mother, brother, sister). The affected siblings were the offspring of a non-consanguineous Indian family of Tamil origin. Bidirectional sequencing was performed on the DNA from the index family and on 160 alleles from a population of 80 unrelated unaffected control individuals of Tamil extraction and 72 alleles from individuals of non-Tamil origin. Two symptomatic siblings were found to harbour previously unreported compound heterozygous missense UDP-N-acetyl-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase 3 (GalNAc-transferase; GALNT3) mutations in exon 4 c.842A>G and exon 5 c.1097T>G. This sequence variation was not detected in the control DNA. This is the first report of siblings exhibiting stigmata of familial tumoral calcinosis and hyperostosis-hyperphosphataemia syndrome with documented evidence of autosomal recessive missense GALNT3 mutations. The findings from this family add further evidence to the literature that familial tumoral calcinosis and hyperostosis-hyperphosphataemia syndrome are manifestations of the same disease and highlight the importance of appropriate metabolic and genetic investigations. (orig.)

  13. Familial tumoral calcinosis and hyperostosis-hyperphosphataemia syndrome are different manifestations of the same disease: novel missense mutations in GALNT3

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Leo; Joseph, Selvanayagam [Vinodhagan Memorial Hospital and Dr. Joseph' s Ortho Clinic, Department of Orthopaedic Surgery, Thanjavur (India); Hing, Sandra N.; Idowu, Bernadine D.; Delaney, David [Royal National Orthopaedic Hospital NHS Trust, Department of Histopathology, Stanmore, Middlesex (United Kingdom); Presneau, Nadege [University College London (UCL), Cancer Institute, London (United Kingdom); O' Donnell, Paul [Royal National Orthopaedic Hospital NHS Trust, Department of Radiology, Stanmore, Middlesex (United Kingdom); University College London (UCL), Institute of Orthopaedics and Musculoskeletal Science, Stanmore (United Kingdom); University College London (UCL), The Institute of Orthopaedics and Musculoskeletal Science, London (United Kingdom); Diss, Tim [University College London Hospital (UCLH) NHS Trust, Rockefeller Building, Department of Histopathology, London (United Kingdom); Flanagan, Adrienne Margaret [Royal National Orthopaedic Hospital NHS Trust, Department of Histopathology, Stanmore, Middlesex (United Kingdom); University College London (UCL), Cancer Institute, London (United Kingdom); University College London Hospital (UCLH) NHS Trust, Rockefeller Building, Department of Histopathology, London (United Kingdom); University College London (UCL), Institute of Orthopaedics and Musculoskeletal Science, Stanmore (United Kingdom); Institute of Orthopaedics and Musculoskeletal Science, Stanmore, Middlesex (United Kingdom)

    2010-01-15

    To report on the biochemistry and clinical and genetic findings of two siblings, the younger sister presenting with recurrent bone pain of the radius and ulna, and medullary sclerosis, and the older brother with soft tissue calcific deposits (tumoral calcinosis) but who later developed bone pain. Both were found to be hyperphosphaturic. The index family comprised four individuals (father, mother, brother, sister). The affected siblings were the offspring of a non-consanguineous Indian family of Tamil origin. Bidirectional sequencing was performed on the DNA from the index family and on 160 alleles from a population of 80 unrelated unaffected control individuals of Tamil extraction and 72 alleles from individuals of non-Tamil origin. Two symptomatic siblings were found to harbour previously unreported compound heterozygous missense UDP-N-acetyl-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase 3 (GalNAc-transferase; GALNT3) mutations in exon 4 c.842A>G and exon 5 c.1097T>G. This sequence variation was not detected in the control DNA. This is the first report of siblings exhibiting stigmata of familial tumoral calcinosis and hyperostosis-hyperphosphataemia syndrome with documented evidence of autosomal recessive missense GALNT3 mutations. The findings from this family add further evidence to the literature that familial tumoral calcinosis and hyperostosis-hyperphosphataemia syndrome are manifestations of the same disease and highlight the importance of appropriate metabolic and genetic investigations. (orig.)

  14. Homozygous missense mutation (G56R in glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPI-HBP1 in two siblings with fasting chylomicronemia (MIM 144650

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    Hegele Robert A

    2007-09-01

    Full Text Available Abstract Background Mice with a deleted Gpihbp1 gene encoding glycosylphosphatidylinositol-anchored high-density lipoprotein-binding protein 1 (GPI-HBP1 develop severe chylomicronemia. We screened the coding regions of the human homologue – GPIHBP1 – from the genomic DNA of 160 unrelated adults with fasting chylomicronemia and plasma triglycerides >10 mmol/L, each of whom had normal sequence of the LPL and APOC2 genes. Results One patient with severe type 5 hyperlipoproteinemia (MIM 144650, fasting chylomicronemia and relapsing pancreatitis resistant to standard therapy was found to be homozygous for a novel GPIHBP1 missense variant, namely G56R. This mutation was absent from the genomes of 600 control subjects and 610 patients with hyperlipidemia. The GPIHBP1 G56 residue has been conserved throughout evolution and the G56R mutation was predicted to have compromised function. Her homozygous brother also had refractory chylomicronemia and relapsing pancreatitis together with early coronary heart disease. G56R heterozygotes in the family had fasting mild hypertriglyceridemia. Conclusion Thus, a very rare GPIHBP1 missense mutation appears to be associated with severe hypertriglyceridemia and chylomicronemia.

  15. A missense mutation in the CRBN gene that segregates with intellectual disability and self-mutilating behaviour in a consanguineous Saudi family.

    Science.gov (United States)

    Sheereen, Atia; Alaamery, Manal; Bawazeer, Shahad; Al Yafee, Yusra; Massadeh, Salam; Eyaid, Wafaa

    2017-04-01

    Autosomal-recessive non-syndromic intellectual disability (ARNS-ID) is an aetiologically heterogeneous disorder. Although little is known about the function of human cereblon (CRBN), its relationship to mild cognitive deficits suggests that it is involved in the basic processes of human memory and learning. We aim to identify the genetic cause of intellectual disability and self-mutilation in a consanguineous Saudi family with five affected members. Clinical whole-exome sequencing was performed on the proband patient, and Sanger sequencing was done to validate and confirm segregation in other family members. A missense variant (c. 1171T>C) in the CRBN gene was identified in five individuals with severe intellectual disability (ID) in a consanguineous Saudi family. The homozygous variant was co-segregating in the family with the phenotype of severe ID, seizures and self-mutilating behaviour. The missense mutation (p.C391R) reported here results in the replacement of a conserved cysteine residue by an arginine in the CULT (cereblon domain of unknown activity, binding cellular ligands and thalidomide) domain of CRBN, which contains a zinc-binding site. These findings thus contribute to a growing list of ID disorders caused by CRBN mutations, broaden the spectrum of phenotypes attributable to ARNS-ID and provide new insight into genotype-phenotype correlations between CRBN mutations and the aetiology of ARNS-ID. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  16. PIK3CA mutations frequently coexist with RAS and BRAF mutations in patients with advanced cancers.

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    Filip Janku

    Full Text Available Oncogenic mutations of PIK3CA, RAS (KRAS, NRAS, and BRAF have been identified in various malignancies, and activate the PI3K/AKT/mTOR and RAS/RAF/MEK pathways, respectively. Both pathways are critical drivers of tumorigenesis.Tumor tissues from 504 patients with diverse cancers referred to the Clinical Center for Targeted Therapy at MD Anderson Cancer Center starting in October 2008 were analyzed for PIK3CA, RAS (KRAS, NRAS, and BRAF mutations using polymerase chain reaction-based DNA sequencing.PIK3CA mutations were found in 54 (11% of 504 patients tested; KRAS in 69 (19% of 367; NRAS in 19 (8% of 225; and BRAF in 31 (9% of 361 patients. PIK3CA mutations were most frequent in squamous cervical (5/14, 36%, uterine (7/28, 25%, breast (6/29, 21%, and colorectal cancers (18/105, 17%; KRAS in pancreatic (5/9, 56%, colorectal (49/97, 51%, and uterine cancers (3/20, 15%; NRAS in melanoma (12/40, 30%, and uterine cancer (2/11, 18%; BRAF in melanoma (23/52, 44%, and colorectal cancer (5/88, 6%. Regardless of histology, KRAS mutations were found in 38% of patients with PIK3CA mutations compared to 16% of patients with wild-type (wtPIK3CA (p = 0.001. In total, RAS (KRAS, NRAS or BRAF mutations were found in 47% of patients with PIK3CA mutations vs. 24% of patients wtPIK3CA (p = 0.001. PIK3CA mutations were found in 28% of patients with KRAS mutations compared to 10% with wtKRAS (p = 0.001 and in 20% of patients with RAS (KRAS, NRAS or BRAF mutations compared to 8% with wtRAS (KRAS, NRAS or wtBRAF (p = 0.001.PIK3CA, RAS (KRAS, NRAS, and BRAF mutations are frequent in diverse tumors. In a wide variety of tumors, PIK3CA mutations coexist with RAS (KRAS, NRAS and BRAF mutations.

  17. Geographical Distribution of the Most Frequent Mutations of Familial Mediterranean fever in the World

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    Soraya Hadi

    2016-09-01

    Full Text Available Background and objectives: Familial Mediterranean Fever (FMF is an autosomal recessive disease. Generally, the Mediterranean basin is the region where the first cases of FMF have been identified. The gene responsible for FMF is gene MEFV. Disease occurs due to mutations in the gene MEFV. Our aim was to determine the geographical distribution of the most frequent mutations in Familial Mediterranean Fever Disease in the world. Material and Methods: In this study, databases including Google Scholar, PubMed, Medline, Ovid, IranMedex, Irandoc, SID, Magiran and published papers were searched with no limitation in time. Then, all collected studies without any limitation were assessed to determine relevant studies. At the end, world map of the most frequent mutations of FMF was generated by Geographical Information System (GIS software. Results: Although more than 290 mutations of the MEFV gene have been described, only four mutations (M694V, M694I, V726A, and E148Q were prevalent among patients with FMF. Conclusion: The most frequent mutation associated with FMF mutation is M694V all over the world. E148Q mutation was found to be with mild clinical relevance.

  18. Identification of rare heterozygous missense mutations in FANCA in esophageal atresia patients using next-generation sequencing.

    Science.gov (United States)

    Feng, Yu; Chen, Runsen; Da, Min; Qian, Bo; Mo, Xuming

    2018-06-30

    Esophageal atresia and tracheoesophageal fistula (EA/TEF) are relatively common malformations in newborns, but the etiology of EA/TEF remains unknown. Fanconi anemia (FA) complementation group A (FANCA) is a key component of the FA core complex and is essential for the activation of the DNA repair pathway. The middle region (amino acids 674-1208) of FANCA is required for its interaction with FAAP20. We performed targeted sequencing of this binding region of FANCA (exons 23-36) in 40 EA/TEF patients. We also investigated the effect of the p.A958V mutation on the protein-protein interaction between FANCA and FAAP20 using an in vitro binding assay and co-immunoprecipitation. Immunolocalization analysis was performed to investigate the subcellular localization of FANCA, and tissue sections and immunohistochemistry were used to explore the expression of FANCA. We identified four rare missense variants in the FANCA binding region. FANCA mutations were significantly overrepresented in EA/TEF patients compared with 4300 control subjects from the NHLBI-ESP project (Fisher's exact p = 2.17 × 10 -5 , odds ratio = 31.75). p.A958V, a novel de novo mutation in the FANCA gene, was identified in one patient with EA/TEF. We provide further evidence that the p.A958V mutation reduces the binding affinity of FANCA for FAAP20. Interestingly, the p.A958V mutation impaired the nuclear localization of the FANCA protein expressed in HeLa cells. We found that FANCA was more highly expressed in stratified squamous epithelium than in smooth muscle. In conclusion, mutations in the FANCA gene are associated with EA/TEF in humans. Copyright © 2018. Published by Elsevier B.V.

  19. A novel missense mutation in the NDP gene in a child with Norrie disease and severe neurological involvement including infantile spasms.

    Science.gov (United States)

    Lev, Dorit; Weigl, Yuval; Hasan, Mariana; Gak, Eva; Davidovich, Michael; Vinkler, Chana; Leshinsky-Silver, Esther; Lerman-Sagie, Tally; Watemberg, Nathan

    2007-05-01

    Norrie disease (ND) is a rare X-linked recessive disorder characterized by congenital blindness and in some cases, mental retardation and deafness. Other neurological complications, particularly epilepsy, are rare. We report on a novel mutation identified in a patient with ND and profound mental retardation. The patient was diagnosed at the age of 6 months due to congenital blindness. At the age of 8 months he developed infantile spasms, which were diagnosed at 11 months as his EEG demonstrated hypsarrhythmia. Mutation analysis of the ND gene (NDP) of the affected child and his mother revealed a novel missense mutation at position c.134T > A resulting in amino acid change at codon V45E. To the best of our knowledge, such severe neurological involvement has not been previously reported in ND patients. The severity of the phenotype may suggest the functional importance of this site of the NDP gene.

  20. Recurrent missense mutations in TMEM43 (ARVD5) due to founder effects cause arrhythmogenic cardiomyopathies in the UK and Canada

    KAUST Repository

    Haywood, Annika; Merner, Nancy D.; Hodgkinson, Kathy A.; Houston, Jim; Syrris, Petros; Booth, Valerie; Connors, Sean; Pantazis, Antonios; Quarta, Giovanni; Elliott, Perry; McKenna, William; Young, Terry Lynn

    2012-01-01

    AimsAutosomal dominant arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) (in the group of arrhythmogenic cardiomyopathies) is a common cause of sudden cardiac death in young adults. It is both clinically and genetically heterogeneous, with 12 loci (ARVC/D1-12) and eight genes identified, the majority of which encode structural proteins of cardiac desmosomes. The most recent gene identified, TMEM43, causes disease due to a missense mutation in a non-desmosomal gene (p.S358L) in 15 extended families from Newfoundland, Canada. To determine whether mutations in TMEM43 cause ARVC/D and arrhythmogenic cardiomyopathy in other populations, we fully re-sequenced TMEM43 on 143 ARVC/D probands (families) from the UK and 55 probands (from 55 families) from Newfoundland.Methods and resultsBidirectional sequencing of TMEM43 including intron-exon boundaries revealed 33 variants, the majority located in non-coding regions of TMEM43. For the purpose of validation, families of probands with rare, potentially deleterious coding variants were subjected to clinical and molecular follow-up. Three missense variants of uncertain significance (p.R28W, p.E142K, p.R312W) were located in highly conserved regions of the TMEM43 protein. One variant (p.R312W) also co-segregated with relatives showing clinical signs of disease. Genotyping and expansion of the disease-associated haplotype in subjects with the p.R312W variant from Newfoundland, Canada, and the UK suggest common ancestry.ConclusionAlthough the p.R312W variant was found in controls (3/378), identification of an ancestral disease p R312W haplotype suggests that the p.R312W variant is a pathogenic founder mutation. © 2012 The Author.

  1. Recurrent missense mutations in TMEM43 (ARVD5) due to founder effects cause arrhythmogenic cardiomyopathies in the UK and Canada

    KAUST Repository

    Haywood, Annika

    2012-11-15

    AimsAutosomal dominant arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) (in the group of arrhythmogenic cardiomyopathies) is a common cause of sudden cardiac death in young adults. It is both clinically and genetically heterogeneous, with 12 loci (ARVC/D1-12) and eight genes identified, the majority of which encode structural proteins of cardiac desmosomes. The most recent gene identified, TMEM43, causes disease due to a missense mutation in a non-desmosomal gene (p.S358L) in 15 extended families from Newfoundland, Canada. To determine whether mutations in TMEM43 cause ARVC/D and arrhythmogenic cardiomyopathy in other populations, we fully re-sequenced TMEM43 on 143 ARVC/D probands (families) from the UK and 55 probands (from 55 families) from Newfoundland.Methods and resultsBidirectional sequencing of TMEM43 including intron-exon boundaries revealed 33 variants, the majority located in non-coding regions of TMEM43. For the purpose of validation, families of probands with rare, potentially deleterious coding variants were subjected to clinical and molecular follow-up. Three missense variants of uncertain significance (p.R28W, p.E142K, p.R312W) were located in highly conserved regions of the TMEM43 protein. One variant (p.R312W) also co-segregated with relatives showing clinical signs of disease. Genotyping and expansion of the disease-associated haplotype in subjects with the p.R312W variant from Newfoundland, Canada, and the UK suggest common ancestry.ConclusionAlthough the p.R312W variant was found in controls (3/378), identification of an ancestral disease p R312W haplotype suggests that the p.R312W variant is a pathogenic founder mutation. © 2012 The Author.

  2. CBL is frequently altered in lung cancers: its relationship to mutations in MET and EGFR tyrosine kinases.

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    Yi-Hung Carol Tan

    2010-01-01

    Full Text Available Non-small cell lung cancer (NSCLC is a heterogeneous group of disorders with a number of genetic and proteomic alterations. c-CBL is an E3 ubiquitin ligase and adaptor molecule important in normal homeostasis and cancer. We determined the genetic variations of c-CBL, relationship to receptor tyrosine kinases (EGFR and MET, and functionality in NSCLC.Using archival formalin-fixed paraffin embedded (FFPE extracted genomic DNA, we show that c-CBL mutations occur in somatic fashion for lung cancers. c-CBL mutations were not mutually exclusive of MET or EGFR mutations; however they were independent of p53 and KRAS mutations. In normal/tumor pairwise analysis, there was significant loss of heterozygosity (LOH for the c-CBL locus (22%, n = 8/37 and none of these samples revealed any mutation in the remaining copy of c-CBL. The c-CBL LOH also positively correlated with EGFR and MET mutations observed in the same samples. Using select c-CBL somatic mutations such as S80N/H94Y, Q249E and W802* (obtained from Caucasian, Taiwanese and African-American samples, respectively transfected in NSCLC cell lines, there was increased cell viability and cell motility.Taking the overall mutation rate of c-CBL to be a combination as somatic missense mutation and LOH, it is clear that c-CBL is highly mutated in lung cancers and may play an essential role in lung tumorigenesis and metastasis.

  3. Missense mutations located in structural p53 DNA-binding motifs are associated with extremely poor survival in chronic lymphocytic leukemia.

    Science.gov (United States)

    Trbusek, Martin; Smardova, Jana; Malcikova, Jitka; Sebejova, Ludmila; Dobes, Petr; Svitakova, Miluse; Vranova, Vladimira; Mraz, Marek; Francova, Hana Skuhrova; Doubek, Michael; Brychtova, Yvona; Kuglik, Petr; Pospisilova, Sarka; Mayer, Jiri

    2011-07-01

    There is a distinct connection between TP53 defects and poor prognosis in chronic lymphocytic leukemia (CLL). It remains unclear whether patients harboring TP53 mutations represent a homogenous prognostic group. We evaluated the survival of patients with CLL and p53 defects identified at our institution by p53 yeast functional assay and complementary interphase fluorescence in situ hybridization analysis detecting del(17p) from 2003 to 2010. A defect of the TP53 gene was identified in 100 of 550 patients. p53 mutations were strongly associated with the deletion of 17p and the unmutated IgVH locus (both P DBMs), structurally well-defined parts of the DNA-binding domain, manifested a clearly shorter median survival (12 months) compared with patients having missense mutations outside DBMs (41 months; P = .002) or nonmissense alterations (36 months; P = .005). The difference in survival was similar in the analysis limited to patients harboring mutation accompanied by del(17p) and was also confirmed in a subgroup harboring TP53 defect at diagnosis. The patients with p53 DBMs mutation (at diagnosis) also manifested a short median time to first therapy (TTFT; 1 month). The substantially worse survival and the short TTFT suggest a strong mutated p53 gain-of-function phenotype in patients with CLL with DBMs mutations. The impact of p53 DBMs mutations on prognosis and response to therapy should be analyzed in investigative clinical trials.

  4. A missense mutation in ALDH18A1, encoding Delta1-pyrroline-5-carboxylate synthase (P5CS), causes an autosomal recessive neurocutaneous syndrome.

    Science.gov (United States)

    Bicknell, Louise S; Pitt, James; Aftimos, Salim; Ramadas, Ram; Maw, Marion A; Robertson, Stephen P

    2008-10-01

    There are several rare syndromes combining wrinkled, redundant skin and neurological abnormalities. Although phenotypic overlap between conditions has suggested that some might be allelic to one another, the aetiology for many of them remains unknown. A consanguineous New Zealand Maori family has been characterised that segregates an autosomal recessive connective tissue disorder (joint dislocations, lax skin) associated with neurological abnormalities (severe global developmental delay, choreoathetosis) without metabolic abnormalities in four affected children. A genome-screen performed under a hypothesis of homozygosity by descent for an ancestral mutation, identified a locus at 10q23 (Z = 3.63). One gene within the candidate interval, ALDH18A1, encoding Delta1-pyrroline-5-carboxylate synthase (P5CS), was considered a plausible disease gene since a missense mutation had previously been shown to cause progressive neurodegeneration, cataracts, skin laxity, joint dislocations and metabolic derangement in a consanguineous Algerian family. A missense mutation, 2350C>T, was identified in ALDH18A1, which predicts the substitution H784Y. H784 is invariant across all phyla and lies within a previously unrecognised, conserved C-terminal motif in P5CS. In an in vivo assay of flux through this metabolic pathway using dermal fibroblasts obtained from an affected individual, proline and ornithine biosynthetic activity of P5CS was not affected by the H784Y substitution. These data suggest that P5CS may possess additional uncharacterised functions that affect connective tissue and central nervous system function.

  5. Missense mutations in ITPR1 cause autosomal dominant congenital nonprogressive spinocerebellar ataxia

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    Huang Lijia

    2012-09-01

    Full Text Available Abstract Background Congenital nonprogressive spinocerebellar ataxia is characterized by early gross motor delay, hypotonia, gait ataxia, mild dysarthria and dysmetria. The clinical presentation remains fairly stable and may be associated with cerebellar atrophy. To date, only a few families with autosomal dominant congenital nonprogressive spinocerebellar ataxia have been reported. Linkage to 3pter was demonstrated in one large Australian family and this locus was designated spinocerebellar ataxia type 29. The objective of this study is to describe an unreported Canadian family with autosomal dominant congenital nonprogressive spinocerebellar ataxia and to identify the underlying genetic causes in this family and the original Australian family. Methods and Results Exome sequencing was performed for the Australian family, resulting in the identification of a heterozygous mutation in the ITPR1 gene. For the Canadian family, genotyping with microsatellite markers and Sanger sequencing of ITPR1 gene were performed; a heterozygous missense mutation in ITPR1 was identified. Conclusions ITPR1 encodes inositol 1,4,5-trisphosphate receptor, type 1, a ligand-gated ion channel that mediates calcium release from the endoplasmic reticulum. Deletions of ITPR1 are known to cause spinocerebellar ataxia type 15, a distinct and very slowly progressive form of cerebellar ataxia with onset in adulthood. Our study demonstrates for the first time that, in addition to spinocerebellar ataxia type 15, alteration of ITPR1 function can cause a distinct congenital nonprogressive ataxia; highlighting important clinical heterogeneity associated with the ITPR1 gene and a significant role of the ITPR1-related pathway in the development and maintenance of the normal functions of the cerebellum.

  6. A Comprehensive Functional Analysis of NTRK1 Missense Mutations Causing Hereditary Sensory and Autonomic Neuropathy Type IV (HSAN IV).

    Science.gov (United States)

    Shaikh, Samiha S; Chen, Ya-Chun; Halsall, Sally-Anne; Nahorski, Michael S; Omoto, Kiyoyuki; Young, Gareth T; Phelan, Anne; Woods, Christopher Geoffrey

    2017-01-01

    Hereditary sensory and autonomic neuropathy type IV (HSAN IV) is an autosomal recessive disorder characterized by a complete lack of pain perception and anhidrosis. Here, we studied a cohort of seven patients with HSAN IV and describe a comprehensive functional analysis of seven novel NTRK1 missense mutations, c.1550G >A, c.1565G >A, c.1970T >C, c.2096T >C, c.2254T >A, c.2288G >C, and c.2311C >T, corresponding to p.G517E, p.G522E, p.L657P, p.I699T, p.C752S, p.C763S, and p.R771C, all of which were predicted pathogenic by in silico analysis. The results allowed us to assess the pathogenicity of each mutation and to gain novel insights into tropomyosin receptor kinase A (TRKA) downstream signaling. Each mutation was systematically analyzed for TRKA glycosylation states, intracellular and cell membrane expression patterns, nerve growth factor stimulated TRKA autophosphorylation, TRKA-Y496 phosphorylation, PLCγ activity, and neurite outgrowth. We showed a diverse range of functional effects: one mutation appeared fully functional, another had partial activity in all assays, one mutation affected only the PLCγ pathway and four mutations were proved null in all assays. Thus, we conclude that complete abolition of TRKA kinase activity is not the only pathogenic mechanism underlying HSAN IV. By corollary, the assessment of the clinical pathogenicity of HSAN IV mutations is more complex than initially predicted and requires a multifaceted approach. © 2016 WILEY PERIODICALS, INC.

  7. Neonatal High Bone Mass With First Mutation of the NF-κB Complex: Heterozygous De Novo Missense (p.Asp512Ser) RELA (Rela/p65).

    Science.gov (United States)

    Frederiksen, Anja L; Larsen, Martin J; Brusgaard, Klaus; Novack, Deborah V; Knudsen, Peter Juel Thiis; Schrøder, Henrik Daa; Qiu, Weimin; Eckhardt, Christina; McAlister, William H; Kassem, Moustapha; Mumm, Steven; Frost, Morten; Whyte, Michael P

    2016-01-01

    Heritable disorders that feature high bone mass (HBM) are rare. The etiology is typically a mutation(s) within a gene that regulates the differentiation and function of osteoblasts (OBs) or osteoclasts (OCs). Nevertheless, the molecular basis is unknown for approximately one-fifth of such entities. NF-κB signaling is a key regulator of bone remodeling and acts by enhancing OC survival while impairing OB maturation and function. The NF-κB transcription complex comprises five subunits. In mice, deletion of the p50 and p52 subunits together causes osteopetrosis (OPT). In humans, however, mutations within the genes that encode the NF-κB complex, including the Rela/p65 subunit, have not been reported. We describe a neonate who died suddenly and unexpectedly and was found at postmortem to have HBM documented radiographically and by skeletal histopathology. Serum was not available for study. Radiographic changes resembled malignant OPT, but histopathological investigation showed morphologically normal OCs and evidence of intact bone resorption excluding OPT. Furthermore, mutation analysis was negative for eight genes associated with OPT or HBM. Instead, accelerated bone formation appeared to account for the HBM. Subsequently, trio-based whole exome sequencing revealed a heterozygous de novo missense mutation (c.1534_1535delinsAG, p.Asp512Ser) in exon 11 of RELA encoding Rela/p65. The mutation was then verified using bidirectional Sanger sequencing. Lipopolysaccharide stimulation of patient fibroblasts elicited impaired NF-κB responses compared with healthy control fibroblasts. Five unrelated patients with unexplained HBM did not show a RELA defect. Ours is apparently the first report of a mutation within the NF-κB complex in humans. The missense change is associated with neonatal osteosclerosis from in utero increased OB function rather than failed OC action. These findings demonstrate the importance of the Rela/p65 subunit within the NF-κB pathway for human

  8. A de novo missense mutation of FGFR2 causes facial dysplasia syndrome in Holstein cattle

    DEFF Research Database (Denmark)

    Agerholm, Jørgen Steen; McEvoy, Fintan; Heegaard, Steffen

    2017-01-01

    was suspected as all recorded cases were progeny of the same sire. Detailed investigations were performed to characterize the syndrome and to reveal its cause. Results Seven malformed calves were submitted examination. All cases shared a common morphology with the most striking lesions being severe facial...... chromosome 26 where whole genome sequencing of a case-parent trio revealed two de novo variants perfectly associated with the disease: an intronic SNP in the DMBT1 gene and a single non-synonymous variant in the FGFR2 gene. This FGFR2 missense variant (c.927G>T) affects a gene encoding a member...... of the fibroblast growth factor receptor family, where amino acid sequence is highly conserved between members and across species. It is predicted to change an evolutionary conserved tryptophan into a cysteine residue (p.Trp309Cys). Both variant alleles were proven to result from de novo mutation events...

  9. BRCA1 and BRCA2 missense variants of high and low clinical significance influence lymphoblastoid cell line post-irradiation gene expression.

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    Nic Waddell

    2008-05-01

    Full Text Available The functional consequences of missense variants in disease genes are difficult to predict. We assessed if gene expression profiles could distinguish between BRCA1 or BRCA2 pathogenic truncating and missense mutation carriers and familial breast cancer cases whose disease was not attributable to BRCA1 or BRCA2 mutations (BRCAX cases. 72 cell lines from affected women in high-risk breast ovarian families were assayed after exposure to ionising irradiation, including 23 BRCA1 carriers, 22 BRCA2 carriers, and 27 BRCAX individuals. A subset of 10 BRCAX individuals carried rare BRCA1/2 sequence variants considered to be of low clinical significance (LCS. BRCA1 and BRCA2 mutation carriers had similar expression profiles, with some subclustering of missense mutation carriers. The majority of BRCAX individuals formed a distinct cluster, but BRCAX individuals with LCS variants had expression profiles similar to BRCA1/2 mutation carriers. Gaussian Process Classifier predicted BRCA1, BRCA2 and BRCAX status, with a maximum of 62% accuracy, and prediction accuracy decreased with inclusion of BRCAX samples carrying an LCS variant, and inclusion of pathogenic missense carriers. Similarly, prediction of mutation status with gene lists derived using Support Vector Machines was good for BRCAX samples without an LCS variant (82-94%, poor for BRCAX with an LCS (40-50%, and improved for pathogenic BRCA1/2 mutation carriers when the gene list used for prediction was appropriate to mutation effect being tested (71-100%. This study indicates that mutation effect, and presence of rare variants possibly associated with a low risk of cancer, must be considered in the development of array-based assays of variant pathogenicity.

  10. Mutation Spectrum and Phenotypic Features in Noonan Syndrome with PTPN11 Mutations: Definition of Two Novel Mutations.

    Science.gov (United States)

    Atik, Tahir; Aykut, Ayca; Hazan, Filiz; Onay, Huseyin; Goksen, Damla; Darcan, Sukran; Tukun, Ajlan; Ozkinay, Ferda

    2016-06-01

    To evaluate the spectrum of PTPN11 gene mutations in Noonan syndrome patients and to study the genotype-phenotype associations. In this study, twenty Noonan syndrome patients with PTPN11 mutations were included. The patients underwent a detailed clinical and physical evaluation. To identify inherited cases, parents of all mutation positive patients were analyzed. Thirteen different PTPN11 mutations, two of them being novel, were detected in the study group. These mutations included eleven missense mutations: p.G60A, p.D61N, p.Y62D, p.Y63C, p.E69Q, p.Q79R, p.Y279C,p.N308D, p.N308S, p.M504V, p.Q510R and two novel missense mutations: p.I56V and p.I282M. The frequency of cardiac abnormalities and short stature were found to be 80 % and 80 %, respectively. Mental retardation was not observed in patients having exon 8 mutations. No significant correlations were detected between other phenotypic features and genotypes. By identifying genotype-phenotype correlations, this study provides information on phenotypes observed in NS patients with different PTPN11 mutations.

  11. Compound heterozygosity for two GHR missense mutations in a patient affected by Laron Syndrome: a case report.

    Science.gov (United States)

    Moia, Stefania; Tessaris, Daniele; Einaudi, Silvia; de Sanctis, Luisa; Bona, Gianni; Bellone, Simonetta; Prodam, Flavia

    2017-10-12

    Mutations localized in the Growth Hormone Receptor (GHR) gene are often associated with the pathogenesis of Laron Syndrome, an autosomal recessive hereditary disorder characterized by severe growth retardation. Biochemically, patients present normal to high circulating GH levels, in presence of very low or undetectable IGF-I levels, which do not rise after rhGH treatment. We describe the case of a 3.8 years old girl with symmetrical short stature (-3.76 SDS), low IGF-1 and IGFBP-3, in presence of normal GH levels. Parents were not relatives and there was no family history of short stature. During the second day of birth, she developed severe hypoglycaemia that required glucose infusion. She presented frontal bossing and depressed nasal bridge. IGF-1 generation test showed no response, suggesting a GH resistance evidence. In the hypothesis of Laron Syndrome, we decided to perform a molecular analysis of Growth Hormone Receptor (GHR) gene. This analysis demonstrated that the patient was compound heterozygote for two missense mutations. GHR gene mutations are a well demonstrated cause of GH insensitivity. In heterozygous patients, probably the normal stature may be achieved by a compensatory mechanism of GH secretion or signalling. On the contrary, in homozygous or compound heterozygous patients these compensatory mechanisms are inadequate, and short stature may be the consequence.

  12. Missense Variants in ATM in 26,101 Breast Cancer Cases and 29,842 Controls

    DEFF Research Database (Denmark)

    Fletcher, O.; Johnson, N.; Silva, Andreá Lema Da

    2010-01-01

    Background: Truncating mutations in ATM have been shown to increase the risk of breast cancer but the effect of missense variants remains contentious. Methods: We have genotyped five polymorphic (minor allele frequency, 0.9-2.6%) missense single nucleotide polymorphisms (SNP) in ATM (S49C, S707P, F...... for any of the SNPs with an overall trend OR of 1.06 (P-trend = 0.04). The trend OR among bilateral and familial cases was 1.12 (95% confidence interval, 1.02-1.23; P-trend = 0.02). Conclusions: In this large combined analysis, these five missense ATM SNPs were associated with a small increased risk...

  13. Genetic and bioinformatics analysis of four novel GCK missense variants detected in Caucasian families with GCK-MODY phenotype.

    Science.gov (United States)

    Costantini, S; Malerba, G; Contreas, G; Corradi, M; Marin Vargas, S P; Giorgetti, A; Maffeis, C

    2015-05-01

    Heterozygous loss-of-function mutations in the glucokinase (GCK) gene cause maturity-onset diabetes of the young (MODY) subtype GCK (GCK-MODY/MODY2). GCK sequencing revealed 16 distinct mutations (13 missense, 1 nonsense, 1 splice site, and 1 frameshift-deletion) co-segregating with hyperglycaemia in 23 GCK-MODY families. Four missense substitutions (c.718A>G/p.Asn240Asp, c.757G>T/p.Val253Phe, c.872A>C/p.Lys291Thr, and c.1151C>T/p.Ala384Val) were novel and a founder effect for the nonsense mutation (c.76C>T/p.Gln26*) was supposed. We tested whether an accurate bioinformatics approach could strengthen family-genetic evidence for missense variant pathogenicity in routine diagnostics, where wet-lab functional assays are generally unviable. In silico analyses of the novel missense variants, including orthologous sequence conservation, amino acid substitution (AAS)-pathogenicity predictors, structural modeling and splicing predictors, suggested that the AASs and/or the underlying nucleotide changes are likely to be pathogenic. This study shows how a careful bioinformatics analysis could provide effective suggestions to help molecular-genetic diagnosis in absence of wet-lab validations. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. The Chemical Chaperone, PBA, Reduces ER Stress and Autophagy and Increases Collagen IV α5 Expression in Cultured Fibroblasts From Men With X-Linked Alport Syndrome and Missense Mutations

    Directory of Open Access Journals (Sweden)

    Dongmao Wang

    2017-07-01

    Discussion: Sodium 4-phenylbutyrate increases collagen IV α5 mRNA levels, reduces ER stress and autophagy, and possibly facilitates collagen IV α5 extracellular transport. Whether these actions delay end-stage renal failure in men with X-linked Alport syndrome and missense mutations will only be determined with clinical trials.

  15. Splice, insertion-deletion and nonsense mutations that perturb the phenylalanine hydroxylase transcript cause phenylketonuria in India.

    Science.gov (United States)

    Bashyam, Murali D; Chaudhary, Ajay K; Kiran, Manjari; Nagarajaram, Hampapathalu A; Devi, Radha Rama; Ranganath, Prajnya; Dalal, Ashwin; Bashyam, Leena; Gupta, Neerja; Kabra, Madhulika; Muranjan, Mamta; Puri, Ratna D; Verma, Ishwar C; Nampoothiri, Sheela; Kadandale, Jayarama S

    2014-03-01

    Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by mutational inactivation of the phenylalanine hydroxylase (PAH) gene. Missense mutations are the most common PAH mutation type detected in PKU patients worldwide. We performed PAH mutation analysis in 27 suspected Indian PKU families (including 7 from our previous study) followed by structure and function analysis of specific missense and splice/insertion-deletion/nonsense mutations, respectively. Of the 27 families, disease-causing mutations were detected in 25. A total of 20 different mutations were identified of which 7 "unique" mutations accounted for 13 of 25 mutation positive families. The unique mutations detected exclusively in Indian PKU patients included three recurrent mutations detected in three families each. The 20 mutations included only 5 missense mutations in addition to 5 splice, 4 each nonsense and insertion-deletion mutations, a silent variant in coding region and a 3'UTR mutation. One deletion and two nonsense mutations were characterized to confirm significant reduction in mutant transcript levels possibly through activation of nonsense mediated decay. All missense mutations affected conserved amino acid residues and sequence and structure analysis suggested significant perturbations in the enzyme activity of respective mutant proteins. This is probably the first report of identification of a significantly low proportion of missense PAH mutations from PKU families and together with the presence of a high proportion of splice, insertion-deletion, and nonsense mutations, points to a unique PAH mutation profile in Indian PKU patients. © 2013 Wiley Periodicals, Inc.

  16. Ubiquitin ligases of the N-end rule pathway: assessment of mutations in UBR1 that cause the Johanson-Blizzard syndrome.

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    Cheol-Sang Hwang

    Full Text Available Johanson-Blizzard syndrome (JBS; OMIM 243800 is an autosomal recessive disorder that includes congenital exocrine pancreatic insufficiency, facial dysmorphism with the characteristic nasal wing hypoplasia, multiple malformations, and frequent mental retardation. Our previous work has shown that JBS is caused by mutations in human UBR1, which encodes one of the E3 ubiquitin ligases of the N-end rule pathway. The N-end rule relates the regulation of the in vivo half-life of a protein to the identity of its N-terminal residue. One class of degradation signals (degrons recognized by UBR1 are destabilizing N-terminal residues of protein substrates.Most JBS-causing alterations of UBR1 are nonsense, frameshift or splice-site mutations that abolish UBR1 activity. We report here missense mutations of human UBR1 in patients with milder variants of JBS. These single-residue changes, including a previously reported missense mutation, involve positions in the RING-H2 and UBR domains of UBR1 that are conserved among eukaryotes. Taking advantage of this conservation, we constructed alleles of the yeast Saccharomyces cerevisiae UBR1 that were counterparts of missense JBS-UBR1 alleles. Among these yeast Ubr1 mutants, one of them (H160R was inactive in yeast-based activity assays, the other one (Q1224E had a detectable but weak activity, and the third one (V146L exhibited a decreased but significant activity, in agreement with manifestations of JBS in the corresponding JBS patients.These results, made possible by modeling defects of a human ubiquitin ligase in its yeast counterpart, verified and confirmed the relevance of specific missense UBR1 alleles to JBS, and suggested that a residual activity of a missense allele is causally associated with milder variants of JBS.

  17. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

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    Matei Irina

    2001-08-01

    Full Text Available Abstract Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP positive and negative gastric carcinomas (GCs. Methods We analyzed 50 gastric carcinomas (GCs for mutations in the BLM poly(A tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases but not in any of the MMP negative GCs (0/35 cases. The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %, BAX (27%, hMSH6 (20%,hMSH3 (13%, CBL (13%, IGFIIR (7%, RECQL (0% and WRN (0%. Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors.

  18. Somatic frameshift mutations in the Bloom syndrome BLM gene are frequent in sporadic gastric carcinomas with microsatellite mutator phenotype

    Science.gov (United States)

    Calin, George; Ranzani, Guglielmina N; Amadori, Dino; Herlea, Vlad; Matei, Irina; Barbanti-Brodano, Giuseppe; Negrini, Massimo

    2001-01-01

    Background Genomic instability has been reported at microsatellite tracts in few coding sequences. We have shown that the Bloom syndrome BLM gene may be a target of microsatelliteinstability (MSI) in a short poly-adenine repeat located in its coding region. To further characterize the involvement of BLM in tumorigenesis, we have investigated mutations in nine genes containing coding microsatellites in microsatellite mutator phenotype (MMP) positive and negative gastric carcinomas (GCs). Methods We analyzed 50 gastric carcinomas (GCs) for mutations in the BLM poly(A) tract aswell as in the coding microsatellites of the TGFβ1-RII, IGFIIR, hMSH3, hMSH6, BAX, WRN, RECQL and CBL genes. Results BLM mutations were found in 27% of MMP+ GCs (4/15 cases) but not in any of the MMP negative GCs (0/35 cases). The frequency of mutations in the other eight coding regions microsatellite was the following: TGFβ1-RII (60 %), BAX (27%), hMSH6 (20%),hMSH3 (13%), CBL (13%), IGFIIR (7%), RECQL (0%) and WRN (0%). Mutations in BLM appear to be more frequently associated with frameshifts in BAX and in hMSH6and/or hMSH3. Tumors with BLM alterations present a higher frequency of unstable mono- and trinucleotide repeats located in coding regions as compared with mutator phenotype tumors without BLM frameshifts. Conclusions BLM frameshifts are frequent alterations in GCs specifically associated with MMP+tumors. We suggest that BLM loss of function by MSI may increase the genetic instability of a pre-existent unstable genotype in gastric tumors. PMID:11532193

  19. Frequent mutations in EGFR, KRAS and TP53 genes in human lung cancer tumors detected by ion torrent DNA sequencing.

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    Xin Cai

    Full Text Available Lung cancer is the most common malignancy and the leading cause of cancer deaths worldwide. While smoking is by far the leading cause of lung cancer, other environmental and genetic factors influence the development and progression of the cancer. Since unique mutations patterns have been observed in individual cancer samples, identification and characterization of the distinctive lung cancer molecular profile is essential for developing more effective, tailored therapies. Until recently, personalized DNA sequencing to identify genetic mutations in cancer was impractical and expensive. The recent technological advancements in next-generation DNA sequencing, such as the semiconductor-based Ion Torrent sequencing platform, has made DNA sequencing cost and time effective with more reliable results. Using the Ion Torrent Ampliseq Cancer Panel, we sequenced 737 loci from 45 cancer-related genes to identify genetic mutations in 76 human lung cancer samples. The sequencing analysis revealed missense mutations in KRAS, EGFR, and TP53 genes in the breast cancer samples of various histologic types. Thus, this study demonstrates the necessity of sequencing individual human cancers in order to develop personalized drugs or combination therapies to effectively target individual, breast cancer-specific mutations.

  20. A missense mutation in the agouti signaling protein gene (ASIP) is associated with the no light points coat phenotype in donkeys.

    Science.gov (United States)

    Abitbol, Marie; Legrand, Romain; Tiret, Laurent

    2015-04-08

    Seven donkey breeds are recognized by the French studbook and are characterized by a black, bay or grey coat colour including light cream-to-white points (LP). Occasionally, Normand bay donkeys give birth to dark foals that lack LP and display the no light points (NLP) pattern. This pattern is more frequent and officially recognized in American miniature donkeys. The LP (or pangare) phenotype resembles that of the light bellied agouti pattern in mouse, while the NLP pattern resembles that of the mammalian recessive black phenotype; both phenotypes are associated with the agouti signaling protein gene (ASIP). We used a panel of 127 donkeys to identify a recessive missense c.349 T > C variant in ASIP that was shown to be in complete association with the NLP phenotype. This variant results in a cysteine to arginine substitution at position 117 in the ASIP protein. This cysteine is highly-conserved among vertebrate ASIP proteins and was previously shown by mutagenesis experiments to lie within a functional site. Altogether, our results strongly support that the identified mutation is causative of the NLP phenotype. Thus, we propose to name the c.[349 T > C] allele in donkeys, the a(nlp) allele, which enlarges the panel of coat colour alleles in donkeys and ASIP recessive loss-of-function alleles in animals.

  1. Allele frequencies of hemojuvelin gene (HJV I222N and G320V missense mutations in white and African American subjects from the general Alabama population

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    Bohannon Sean B

    2004-12-01

    Full Text Available Abstract Background Homozygosity or compound heterozygosity for coding region mutations of the hemojuvelin gene (HJV in whites is a cause of early age-of-onset iron overload (juvenile hemochromatosis, and of hemochromatosis phenotypes in some young or middle-aged adults. HJV coding region mutations have also been identified recently in African American primary iron overload and control subjects. Primary iron overload unexplained by typical hemochromatosis-associated HFE genotypes is common in white and black adults in Alabama, and HJV I222N and G320V were detected in a white Alabama juvenile hemochromatosis index patient. Thus, we estimated the frequency of the HJV missense mutations I222N and G320V in adult whites and African Americans from Alabama general population convenience samples. Methods We evaluated the genomic DNA of 241 Alabama white and 124 African American adults who reported no history of hemochromatosis or iron overload to detect HJV missense mutations I222N and G320V using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP technique. Analysis for HJV I222N was performed in 240 whites and 124 African Americans. Analysis for HJV G320V was performed in 241 whites and 118 African Americans. Results One of 240 white control subjects was heterozygous for HJV I222N; she was also heterozygous for HFE C282Y, but had normal serum iron measures and bone marrow iron stores. HJV I222N was not detected in 124 African American subjects. HJV G320V was not detected in 241 white or 118 African American subjects. Conclusions HJV I222N and G320V are probably uncommon causes or modifiers of primary iron overload in adult whites and African Americans in Alabama. Double heterozygosity for HJV I222N and HFE C282Y may not promote increased iron absorption.

  2. MED12 exon 2 mutations in phyllodes tumors of the breast

    International Nuclear Information System (INIS)

    Nagasawa, Satoi; Maeda, Ichiro; Fukuda, Takayo; Wu, Wenwen; Hayami, Ryosuke; Kojima, Yasuyuki; Tsugawa, Ko-ichiro; Ohta, Tomohiko

    2015-01-01

    Exon 2 of MED12, a subunit of the transcriptional mediator complex, has been frequently mutated in uterine leiomyomas and breast fibroadenomas; however, it has been rarely mutated in other tumors. Although the mutations were also found in uterine leiomyosarcomas, the frequency was significantly lower than in uterine leiomyomas. Here, we examined the MED12 mutation in phyllodes tumors, another biphasic tumor with epithelial and stromal components related to breast fibroadenomas. Mutations in MED12 exon 2 were analyzed in nine fibroadenomas and eleven phyllodes tumors via Sanger sequencing. A panel of cancer- and sarcoma-related genes was also analyzed using Ion Torrent next-generation sequencing. Six mutations in fibroadenomas, including those previously reported (6/9, 67%), and five mutations in phyllodes tumors (5/11, 45%) were observed. Three mutations in the phyllodes tumors were missense mutations at Gly44, which is common in uterine leiomyomas and breast fibroadenomas. In addition, two deletion mutations (in-frame c.133-144del12 and loss of splice acceptor c.100-68-137del106) were observed in the phyllodes tumors. No other recurrent mutation was observed with next-generation sequencing. Frequent mutations in MED12 exon 2 in the phyllodes tumors suggest that it may share genetic etiology with uterine leiomyoma, a subgroup of uterine leiomyosarcomas and breast fibroadenoma

  3. A novel missense mutation in the HECT domain of NEDD4L identified in a girl with periventricular nodular heterotopia, polymicrogyria and cleft palate.

    Science.gov (United States)

    Kato, Koji; Miya, Fuyuki; Hori, Ikumi; Ieda, Daisuke; Ohashi, Kei; Negishi, Yutaka; Hattori, Ayako; Okamoto, Nobuhiko; Kato, Mitsuhiro; Tsunoda, Tatsuhiko; Yamasaki, Mami; Kanemura, Yonehiro; Kosaki, Kenjiro; Saitoh, Shinji

    2017-09-01

    We identified a novel de novo heterozygous missense mutation in the NEDD4L gene (NM_015277: c.2617G>A; p.Glu873Lys) through whole-exome sequencing in a 3-year-old girl showing severe global developmental delay, infantile spasms, cleft palate, periventricular nodular heterotopia and polymicrogyria. Mutations in the HECT domain of NEDD4L have been reported in patients with a neurodevelopmental disorder along with similar brain malformations. All patients reported with NEDD4L HECT domain mutations showed periventricular nodular heterotopia, and most had seizures, cortex anomalies, cleft palate and syndactyly. The unique constellation of clinical features in patients with NEDD4L mutations might help clinically distinguish them from patients with other genetic mutations including FLNA, which is a well-known causative gene of periventricular nodular heterotopia. Although mutations in the HECT domain of NEDD4L that lead to AKT-mTOR pathway deregulation in forced expression system were reported, our western blot analysis did not show an increased level of AKT-mTOR activity in lymphoblastoid cell lines (LCLs) derived from the patient. In contrast to the forced overexpression system, AKT-mTOR pathway deregulation in LCLs derived from our patient seems to be subtle.

  4. A Novel Missense Mutation of the NSD1 Gene Associated with Overgrowth in Three Generations of an Italian Family: Case Report, Differential Diagnosis, and Review of Mutations of NSD1 Gene in Familial Sotos Syndrome

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    Gianluigi Laccetta

    2017-11-01

    Full Text Available Sotos syndrome (SoS is characterized by overgrowth of prenatal onset, learning disability, and characteristic facial appearance; it is usually due to haploinsufficiency of NSD1 gene at chromosome 5q35. An Italian child was born at 37 weeks of gestation (weight 2,910 g, 25th–50th centiles; length 50 cm, 75th centile; head circumference 36 cm, 97th centile showing cryptorchidism on the right side, hypertelorism, dolichocephaly, broad and prominent forehead, and narrow jaw; the pregnancy was worsened by maternal preeclampsia and gestational diabetes, and his mother had a previous history of four early miscarriages. The patient showed neonatal jaundice, hypotonia, feeding difficulties, frequent vomiting, and gastroesophageal reflux. After the age of 6 months, his weight, length, and head circumference were above the 97th centile; psychomotor development was delayed. At the age of 9 years, the patient showed also joint laxity and scoliosis. DNA sequence analysis of NSD1 gene detected a novel heterozygous mutation (c.521T>A, p.Val174Asp in exon 2. The same mutant allele was also found in the mother and in the maternal grandfather of the proband; both the mother and the maternal grandfather of the proband showed isolated overgrowth with height above the 97th centile in absence of other features of SoS. At present 23 familial cases of SoS have been described (two cases with mutation in exon 2 of NSD1 gene; no familial cases of SoS with mutation of NSD1 gene and isolated overgrowth have been reported. Probably, point mutations of NSD1 gene, and particularly mutations between exon 20 and exon 23, are not likely to affect reproductive fitness. Epigenetic mechanisms and intrauterine environment may influence phenotypes, therefore genetic tests are not useful to predict the phenotype but they are indispensable for the diagnosis of SoS. This is the first Italian familial case of SoS with genetic confirmation and the third report in which a

  5. A Missense Mutation of G257A at Exon 3 in PEX7 CDS Was Responsible for the Incidence of Rhizomelic Chondrodysplasia Punctata Type 1

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    Marziyeh Alamatsaz

    2018-02-01

    Full Text Available Background Rhizomelic chondrodysplasia punctata (RCDP type 1 is among of the rare autosomal recessive peroxisome biogenesis disorders caused by mutations in the PEX7 gene. RCDP patients with the classic form of RCDP1 do not live more than 10- year. Materials and Methods In the present study, a two-year-old girl with skeletal abnormalities and dysmorphic facial appearance is reported to be suffered from RCDP. The patient's parents were second cousins and healthy and there was no similar case in the parents’ family. PEX7 gene was sequenced in the patient and her parents. Results A homozygous mutation, G257A, was identified PEX7 in the genome of patient while the parents were compound heterozygous. Conclusion Taken together, clinical presentation and peroxisome profile of the patient suggested a missense mutation led to formation of a pathogenic PEX7, responsible for incidence of RCDP.

  6. Mutational analysis of GALT gene in Greek patients with galactosaemia: identification of two novel mutations and clinical evaluation.

    Science.gov (United States)

    Schulpis, Kleopatra H; Thodi, Georgia; Iakovou, Konstantinos; Chatzidaki, Maria; Dotsikas, Yannis; Molou, Elina; Triantafylli, Olga; Loukas, Yannis L

    2017-10-01

    Classical galactosaemia is an inborn error of metabolism due to the deficiency of the enzyme galactose-1-phosphate uridylyltransferase (GALT). The aim of the study was to identify the underlying mutations in Greek patients with GALT deficiency and evaluate their psychomotor and speech development. Patients with GALT deficiency (n = 17) were picked up through neonatal screening. Mutational analysis was conducted via Sanger sequencing, while in silico analysis was used in the cases of novel missense mutations. Psychomotor speech development tests were utilized for the clinical evaluation of the patients. Eleven different mutations in the GALT gene were detected in the patient cohort, including two novel ones. The most frequent mutation was p.Q188R (c.563 A > G). As for the novel mutations, p.M298I (c.894 G > A) was identified in four out of 32 independent alleles, while p.P115S (c.343 C > T) was identified once. Psychomotor evaluation revealed that most of the patients were found in the borderline area (Peabody test), while only two had speech delay problems. The WISK test revealed three patients at borderline limits and two were at lower than normal limits. The mutational spectrum of the GALT gene in Greek patients is presented for the first time. The mutation p.Q188R is the most frequent among Greek patients. Two novel mutations were identified and their potential pathogenicity was estimated. Regarding the phenotypic characteristics, psychomotor disturbances and speech delay were mainly observed among GALT-deficient patients.

  7. Rescue of sarcoglycan mutations by inhibition of endoplasmic reticulum quality control is associated with minimal structural modifications.

    Science.gov (United States)

    Soheili, Tayebeh; Gicquel, Evelyne; Poupiot, Jérôme; N'Guyen, Luu; Le Roy, Florence; Bartoli, Marc; Richard, Isabelle

    2012-02-01

    Sarcoglycanopathies (SGP) are a group of autosomal recessive muscle disorders caused by primary mutations in one of the four sarcoglycan genes. The sarcoglycans (α-, β-, γ-, and δ-sarcoglycan) form a tetrameric complex at the muscle membrane that is part of the dystrophin-glycoprotein complex and plays an essential role for membrane integrity during muscle contractions. We previously showed that the most frequent missense mutation in α-sarcoglycan (p.R77C) leads to the absence of the protein at the cell membrane due to its blockade by the endoplasmic reticulum (ER) quality control. Moreover, we demonstrated that inhibition of the ER α-mannosidase I activity using kifunensine could rescue the mutant protein localization at the cell membrane. Here, we investigate 25 additional disease-causing missense mutations in the sarcoglycan genes with respect to intracellular fate and localization rescue of the mutated proteins by kifunensine. Our studies demonstrate that, similarly to p.R77C, 22 of 25 of the selected mutations lead to defective intracellular trafficking of the SGs proteins. Six of these were saved from ER retention upon kifunensine treatment. The trafficking of SGs mutants rescued by kifunensine was associated with mutations that have moderate structural impact on the protein. © 2011 Wiley Periodicals, Inc.

  8. Novel Mutations in the PC Gene in Patients with Type B Pyruvate Carboxylase Deficiency

    DEFF Research Database (Denmark)

    Ostergaard, Elsebet; Duno, Morten; Møller, Lisbeth Birk

    2013-01-01

    We have investigated seven patients with the type B form of pyruvate carboxylase (PC) deficiency. Mutation analysis revealed eight mutations, all novel. In a patient with exon skipping on cDNA analysis, we identified a homozygous mutation located in a potential branch point sequence, the first...... possible branch point mutation in PC. Two patients were homozygous for missense mutations (with normal protein amounts on western blot analysis), and two patients were homozygous for nonsense mutations. In addition, a duplication of one base pair was found in a patient who also harboured a splice site...... mutation. Another splice site mutation led to the activation of a cryptic splice site, shown by cDNA analysis.All patients reported until now with at least one missense mutation have had the milder type A form of PC deficiency. We thus report for the first time two patients with homozygous missense...

  9. A Homozygous Missense Mutation in TGM5 Abolishes Epidermal Transglutaminase 5 Activity and Causes Acral Peeling Skin Syndrome

    Science.gov (United States)

    Cassidy, Andrew J.; van Steensel, Maurice A. M.; Steijlen, Peter M.; van Geel, Michel; Velden, Jaap van der; Morley, Susan M.; Terrinoni, Alessandro; Melino, Gerry; Candi, Eleonora; McLean, W. H. Irwin

    2005-01-01

    Peeling skin syndrome is an autosomal recessive genodermatosis characterized by the shedding of the outer epidermis. In the acral form, the dorsa of the hands and feet are predominantly affected. Ultrastructural analysis has revealed tissue separation at the junction between the granular cells and the stratum corneum in the outer epidermis. Genomewide linkage analysis in a consanguineous Dutch kindred mapped the gene to 15q15.2 in the interval between markers D15S1040 and D15S1016. Two homozygous missense mutations, T109M and G113C, were found in TGM5, which encodes transglutaminase 5 (TG5), in all affected persons in two unrelated families. The mutation was present on the same haplotype in both kindreds, indicating a probable ancestral mutation. TG5 is strongly expressed in the epidermal granular cells, where it cross-links a variety of structural proteins in the terminal differentiation of the epidermis to form the cornified cell envelope. An established, in vitro, biochemical cross-linking assay revealed that, although T109M is not pathogenic, G113C completely abolishes TG5 activity. Three-dimensional modeling of TG5 showed that G113C lies close to the catalytic domain, and, furthermore, that this glycine residue is conserved in all known transglutaminases, which is consistent with pathogenicity. Other families with more-widespread peeling skin phenotypes lacked TGM5 mutations. This study identifies the first causative gene in this heterogeneous group of skin disorders and demonstrates that the protein cross-linking function performed by TG5 is vital for maintaining cell-cell adhesion between the outermost layers of the epidermis. PMID:16380904

  10. Spectrum of rhodopsin mutations in Korean patients with retinitis pigmentosa

    Science.gov (United States)

    Kim, Kwang Joong; Kim, Cinoo; Bok, Jeong; Kim, Kyung-Seon; Lee, Eun-Ju; Park, Sung Pyo; Chung, Hum; Han, Bok-Ghee; Kim, Hyung-Lae; Kimm, Kuchan; Yu, Hyeong Gon

    2011-01-01

    Purpose To determine the spectrum and frequency of rhodopsin gene (RHO) mutations in Korean patients with retinitis pigmentosa (RP) and to characterize genotype–phenotype correlations in patients with mutations. Methods The RHO mutations were screened by direct sequencing, and mutation prevalence was measured in patients and controls. The impact of missense mutations to RP was predicted by segregation analysis, peptide sequence alignment, and in silico analysis. The severity of disease in patients with the missense mutations was compared by visual acuity, electroretinography, optical coherence tomography, and kinetic visual field testing. Results Five heterozygous mutations were identified in six of 302 probands with RP, including a novel mutation (c.893C>A, p.A298D) and four known mutations (c.50C>T, p.T17M; c.533A>G, p.Y178C; c.888G>T, p.K296N; and c.1040C>T, p.P347L). The allele frequency of missense mutations was measured in 114 ethnically matched controls. p.A298D, newly identified in a sporadic patient, had never been found in controls and was predicted to be pathogenic. Among the patients with the missense mutations, we observed the most severe phenotype in patients with p.P347L, less severe phenotypes in patients with p.Y178C or p.A298D, and a relatively moderate phenotype in a patient with p.T17M. Conclusions The results reveal the spectrum of RHO mutations in Korean RP patients and clinical features that vary according to mutations. Our findings will be useful for understanding these genetic spectra and the genotype–phenotype correlations and will therefore help with predicting disease prognosis and facilitating the development of gene therapy. PMID:21677794

  11. Avoiding dangerous missense: thermophiles display especially low mutation rates.

    Directory of Open Access Journals (Sweden)

    John W Drake

    2009-06-01

    Full Text Available Rates of spontaneous mutation have been estimated under optimal growth conditions for a variety of DNA-based microbes, including viruses, bacteria, and eukaryotes. When expressed as genomic mutation rates, most of the values were in the vicinity of 0.003-0.004 with a range of less than two-fold. Because the genome sizes varied by roughly 10(4-fold, the mutation rates per average base pair varied inversely by a similar factor. Even though the commonality of the observed genomic rates remains unexplained, it implies that mutation rates in unstressed microbes reach values that can be finely tuned by evolution. An insight originating in the 1920s and maturing in the 1960s proposed that the genomic mutation rate would reflect a balance between the deleterious effect of the average mutation and the cost of further reducing the mutation rate. If this view is correct, then increasing the deleterious impact of the average mutation should be countered by reducing the genomic mutation rate. It is a common observation that many neutral or nearly neutral mutations become strongly deleterious at higher temperatures, in which case they are called temperature-sensitive mutations. Recently, the kinds and rates of spontaneous mutations were described for two microbial thermophiles, a bacterium and an archaeon. Using an updated method to extrapolate from mutation-reporter genes to whole genomes reveals that the rate of base substitutions is substantially lower in these two thermophiles than in mesophiles. This result provides the first experimental support for the concept of an evolved balance between the total genomic impact of mutations and the cost of further reducing the basal mutation rate.

  12. TOX3 mutations in breast cancer.

    Directory of Open Access Journals (Sweden)

    James Owain Jones

    Full Text Available TOX3 maps to 16q12, a region commonly lost in breast cancers and recently implicated in the risk of developing breast cancer. However, not much is known of the role of TOX3 itself in breast cancer biology. This is the first study to determine the importance of TOX3 mutations in breast cancers. We screened TOX3 for mutations in 133 breast tumours and identified four mutations (three missense, one in-frame deletion of 30 base pairs in six primary tumours, corresponding to an overall mutation frequency of 4.5%. One potentially deleterious missense mutation in exon 3 (Leu129Phe was identified in one tumour (genomic DNA and cDNA. Whilst copy number changes of 16q12 are common in breast cancer, our data show that mutations of TOX3 are present at low frequency in tumours. Our results support that TOX3 should be further investigated to elucidate its role in breast cancer biology.

  13. Identification of a missense mutation in the tyrosinase gene in a Chinese family with oculocutaneous albinism type 1.

    Science.gov (United States)

    Lu, Qian; Yuan, Lamei; Xu, Hongbo; Huang, Xiangjun; Yang, Zhijian; Yi, Junhui; Ni, Bin; Chen, Yong; Deng, Hao

    2017-03-01

    Oculocutaneous albinism (OCA) is a group of heterogeneous and autosomal recessive disorders characterized by a reduction or complete loss of melanin biosynthesis in melanocytes. OCA type 1 (OCA1) is the most severe and common form of OCA, and is caused by mutations in the tyrosinase gene (TYR). The present study aimed to identify the genetic cause of OCA1 in a four‑generation consanguineous Chinese Han family. Complete physical examinations were performed and blood samples were collected from five members of the family and 100 unrelated healthy controls. Exome sequencing was conducted in the proband, followed by verification in other family members, using Sanger sequencing. Patients in the family presented with typical OCA1 features, including hypopigmentation of the skin and hair, and distinctive ocular changes. A homozygous missense variant, c.896G>A (p.R299H), in the TYR gene was identified in two patients, which co‑segregated with disease in the family. This variant was not present in the 100 healthy controls. These results expand the number of mutations identified to be responsible for OCA1 in the Chinese Han population, and may have implications for genetic counseling and clinical management of the disease.

  14. Clinical Expression and New SPINK5 Splicing Defects in Netherton Syndrome: Unmasking a Frequent Founder Synonymous Mutation and Unconventional Intronic Mutations

    DEFF Research Database (Denmark)

    Lacroix, Matthieu; Lacaze-Buzy, Laetitia; Furio, Laetitia

    2012-01-01

    a clinical triad suggestive of NS with variations in inter- and intra-familial disease expression. We identified a new and frequent synonymous mutation c.891C>T (p.Cys297Cys) in exon 11 of the 12 NS patients. This mutation disrupts an exonic splicing enhancer sequence and causes out-of-frame skipping of exon...

  15. Targeted next-generation sequencing extends the phenotypic and mutational spectrums for EYS mutations.

    Science.gov (United States)

    Gu, Shun; Tian, Yuanyuan; Chen, Xue; Zhao, Chen

    2016-01-01

    We aim to determine genetic lesions with a phenotypic correlation in four Chinese families with autosomal recessive retinitis pigmentosa (RP). Medical histories were carefully reviewed. All patients received comprehensive ophthalmic evaluations. The next-generation sequencing (NGS) approach targeting a panel of 205 retinal disease-relevant genes and 15 candidate genes was selectively performed on probands from the four recruited families for mutation detection. Online predictive software and crystal structure modeling were also applied to test the potential pathogenic effects of identified mutations. Of the four families, two were diagnosed with RP sino pigmento (RPSP). Patients with RPSP claimed to have earlier RP age of onset but slower disease progression. Five mutations in the eyes shut homolog (EYS) gene, involving two novel (c.7228+1G>A and c.9248G>A) and three recurrent mutations (c.4957dupA, c.6416G>A and c.6557G>A), were found as RP causative in the four families. The missense variant c.5093T>C was determined to be a variant of unknown significance (VUS) due to the variant's colocalization in the same allele with the reported pathogenic mutation c.6416G>A. The two novel variants were further confirmed absent in 100 unrelated healthy controls. Online predictive software indicated potential pathogenicity of the three missense mutations. Further, crystal structural modeling suggested generation of two abnormal hydrogen bonds by the missense mutation p.G2186E (c.6557G>A) and elongation of its neighboring β-sheet induced by p.G3083D (c.9248G>A), which could alter the tertiary structure of the eys protein and thus interrupt its physicochemical properties. Taken together, with the targeted NGS approach, we reveal novel EYS mutations and prove the efficiency of targeted NGS in the genetic diagnoses of RP. We also first report the correlation between EYS mutations and RPSP. The genotypic-phenotypic relationship in all Chinese patients carrying mutations in the EYS

  16. Disease-associated mutations disrupt functionally important regions of intrinsic protein disorder.

    Directory of Open Access Journals (Sweden)

    Vladimir Vacic

    Full Text Available The effects of disease mutations on protein structure and function have been extensively investigated, and many predictors of the functional impact of single amino acid substitutions are publicly available. The majority of these predictors are based on protein structure and evolutionary conservation, following the assumption that disease mutations predominantly affect folded and conserved protein regions. However, the prevalence of the intrinsically disordered proteins (IDPs and regions (IDRs in the human proteome together with their lack of fixed structure and low sequence conservation raise a question about the impact of disease mutations in IDRs. Here, we investigate annotated missense disease mutations and show that 21.7% of them are located within such intrinsically disordered regions. We further demonstrate that 20% of disease mutations in IDRs cause local disorder-to-order transitions, which represents a 1.7-2.7 fold increase compared to annotated polymorphisms and neutral evolutionary substitutions, respectively. Secondary structure predictions show elevated rates of transition from helices and strands into loops and vice versa in the disease mutations dataset. Disease disorder-to-order mutations also influence predicted molecular recognition features (MoRFs more often than the control mutations. The repertoire of disorder-to-order transition mutations is limited, with five most frequent mutations (R→W, R→C, E→K, R→H, R→Q collectively accounting for 44% of all deleterious disorder-to-order transitions. As a proof of concept, we performed accelerated molecular dynamics simulations on a deleterious disorder-to-order transition mutation of tumor protein p63 and, in agreement with our predictions, observed an increased α-helical propensity of the region harboring the mutation. Our findings highlight the importance of mutations in IDRs and refine the traditional structure-centric view of disease mutations. The results of this study

  17. Novel Homozygous Missense Mutation in RYR1 Leads to Severe Congenital Ptosis, Ophthalmoplegia, and Scoliosis in the Absence of Myopathy.

    Science.gov (United States)

    Dilaver, Nafi; Mazaheri, Neda; Maroofian, Reza; Zeighami, Jawaher; Seifi, Tahere; Zamani, Mina; Sedaghat, Alireza; Shariati, Gholam Reza; Galehdari, Hamid

    2017-12-01

    Ryanodine receptor 1 ( RYR1 ) is an intracellular calcium receptor primarily expressed in skeletal muscle with a role in excitation contraction. Both dominant and recessive mutations in the RYR1 gene cause a range of RYR1 -related myopathies and/or susceptibility to malignant hyperthermia (MH). Recently, an atypical manifestation of ptosis, variably presenting with ophthalmoplegia, facial paralysis, and scoliosis but without significant muscle weakness, has been reported in 9 cases from 4 families with bialleic variants in RYR1 . Two affected children from a consanguineous family with severe congenital ptosis, ophthalmoplegia, scoliosis, and distinctive long faces but without skeletal myopathy were studied. To identify the cause of the hereditary condition, DNA from the proband was subjected to whole exome sequencing (WES). WES revealed a novel homozygous missense variant in RYR1 (c.14066T>A; p.IIe4689Asn), which segregated within the family. Although the phenotype of the affected siblings in this study was similar to previously described cases, the clinical features were more severely expressed. Our findings contribute to the expansion of phenotypes related to RYR1 dysfunction. Additionally, it supports a new RYR1 -related clinical presentation without musculoskeletal involvement. It is important that individuals with RYR1 mutations are considered susceptible to MH, as 70% of the MH cases are caused by mutations in the RYR1 gene.

  18. Identification of A Novel Missense Mutation in The Norrie Disease Gene: The First Molecular Genetic Analysis and Prenatal Diagnosis of Norrie Disease in An Iranian Family.

    Science.gov (United States)

    Talebi, Farah; Ghanbari Mardasi, Farideh; Mohammadi Asl, Javad; Lashgari, Ali; Farhadi, Freidoon

    2018-07-01

    Norrie disease (ND) is a rare X-linked recessive disorder, which is characterized by congenital blindness and, in several cases, accompanied with mental retardation and deafness. ND is caused by mutations in NDP, located on the proximal short arm of the X chromosome (Xp11.3). The disease has been observed in many ethnic groups worldwide, however, no such case has been reported from Iran. In this study, we present the molecular analysis of two patients with ND and the subsequent prenatal diagnosis. Screening of NDP identified a hemizygous missense mutation (p.Ser133Cys) in the affected male siblings of the family. The mother was the carrier for the mutation (p.Ser133Cys). In a subsequent chorionic amniotic pregnancy, we carried out prenatal diagnosis by sequencing NDP in the chorionic villi sample at 11 weeks of gestation. The fetus was carrying the mutation and thus unaffected. This is the first mutation report and prenatal diagnosis of an Iranian family with ND, and highlights the importance of prenatal diagnostic screening of this congenital disorder and relevant genetic counseling. Copyright© by Royan Institute. All rights reserved.

  19. Performance of in silico prediction tools for the classification of rare BRCA1/2 missense variants in clinical diagnostics.

    Science.gov (United States)

    Ernst, Corinna; Hahnen, Eric; Engel, Christoph; Nothnagel, Michael; Weber, Jonas; Schmutzler, Rita K; Hauke, Jan

    2018-03-27

    The use of next-generation sequencing approaches in clinical diagnostics has led to a tremendous increase in data and a vast number of variants of uncertain significance that require interpretation. Therefore, prediction of the effects of missense mutations using in silico tools has become a frequently used approach. Aim of this study was to assess the reliability of in silico prediction as a basis for clinical decision making in the context of hereditary breast and/or ovarian cancer. We tested the performance of four prediction tools (Align-GVGD, SIFT, PolyPhen-2, MutationTaster2) using a set of 236 BRCA1/2 missense variants that had previously been classified by expert committees. However, a major pitfall in the creation of a reliable evaluation set for our purpose is the generally accepted classification of BRCA1/2 missense variants using the multifactorial likelihood model, which is partially based on Align-GVGD results. To overcome this drawback we identified 161 variants whose classification is independent of any previous in silico prediction. In addition to the performance as stand-alone tools we examined the sensitivity, specificity, accuracy and Matthews correlation coefficient (MCC) of combined approaches. PolyPhen-2 achieved the lowest sensitivity (0.67), specificity (0.67), accuracy (0.67) and MCC (0.39). Align-GVGD achieved the highest values of specificity (0.92), accuracy (0.92) and MCC (0.73), but was outperformed regarding its sensitivity (0.90) by SIFT (1.00) and MutationTaster2 (1.00). All tools suffered from poor specificities, resulting in an unacceptable proportion of false positive results in a clinical setting. This shortcoming could not be bypassed by combination of these tools. In the best case scenario, 138 families would be affected by the misclassification of neutral variants within the cohort of patients of the German Consortium for Hereditary Breast and Ovarian Cancer. We show that due to low specificities state-of-the-art in silico

  20. Missense variants in plakophilin-2 in arrhythmogenic right ventricular cardiomyopathy patients - disease - causing or innocent bystanders?

    DEFF Research Database (Denmark)

    Christensen, A.H.; Benn, M.; Tybjaerg-Hansen, A.

    2009-01-01

    Objectives: Mutations in genes encoding desmosomal proteins have been linked to arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). We hypothesized that a Scandinavian ARVC/D population would have a different spectrum of plakophilin-2 (PKP2) mutations and that some of the reported...... missense mutations may not be pathogenic. Methods: We screened 53 unrelated patients fulfilling Task Force criteria for ARVC/D for mutations in PKP2 by direct sequencing. Results: Seven different mutations were identified: two insertion/deletions (E329fsX352, P401fsX406), 1 splice site (2146-2A>T), 1 non...

  1. Missense variants in plakophilin-2 in arrhythmogenic right ventricular cardiomyopathy patients--disease-causing or innocent bystanders?

    DEFF Research Database (Denmark)

    Christensen, Alex Hørby; Benn, Marianne; Tybjaerg-Hansen, Anne

    2010-01-01

    Objectives: Mutations in genes encoding desmosomal proteins have been linked to arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). We hypothesized that a Scandinavian ARVC/D population would have a different spectrum of plakophilin-2 (PKP2) mutations and that some of the reported...... missense mutations may not be pathogenic. Methods: We screened 53 unrelated patients fulfilling Task Force criteria for ARVC/D for mutations in PKP2 by direct sequencing. Results: Seven different mutations were identified: two insertion/deletions (E329fsX352, P401fsX406), 1 splice site (2146-2A>T), 1 non...

  2. Spectrum of mutations in CRM-positive and CRM-reduced hemophilia A

    Energy Technology Data Exchange (ETDEWEB)

    McGinniss, M.J.; Kazazian, H.H. Jr.; Bi, L.; Antonarakis, S.E. (John Hopkins Univ., Baltimore, MD (United States)); Hoyer, L.W. (American Red Cross Blood Services, Rockville, MD (United States)); Inaba, H. (Tokyo Medical College (Japan))

    1993-02-01

    Hemophilia A is due to the functional deficiency of factor VIII (FVIII, gene locus F8C). Although half the patients have no detectable FVIII protein in their plasma, the more rare patients ([approximately]5%) have normal levels of a dysfunctional FVIII and are termed cross-reacting material (CRM)-positive. More commonly ([approximately]45%), patients have plasma FVIII protein reduced to an extent roughly comparable to the level of FVIII activity and are designated CRM-reduced. We used denaturing gradient gel electrophoresis to screen for mutations within the F8C gene of 11 patients (6CRM-positive, 5 CRM-reduced) and identified 9 different mutations in 9 patients after analyses of all 26 exons, the promoter region, and the polyadenylation site. Six mutations have not been described previously. Five weree missense (Ser289Leu, Ser558Phe, Val634Ala, Val634Met, Asn1441Lys), and the sixth was a 3-bp deletion ([Delta]Phe652). A review of the literature and the assay of FVIII antigen in 5 hemophilia A patients with previously identified missense mutations from this laboratory yielded a total of 20 other unique CRM-reduced and CRM-positive mutations. Almost all CRM-positive/reduced mutations (24/26) were missense, and many (12/26) occurred at CpG dinucleotides. We examined 19 missense mutation for evolutionary conservation using the portions of the porcine and murine F8C sequences that are known, and 18/19 amino acid residue altered by mutation in these patients wer conserved. Almost 50% of mutations (11/26) clustered in the A2 domain, suggesting that this region is critical for the function of FVIII. The results indicate a nonrandom distribution of mutations and suggest that mutations in a limited number of FVIII regions may cause CRM-positive and CRM-reduced heomphilia A. 48 refs., 1 fig., 1 tab.

  3. Whole exome analysis identifies frequent CNGA1 mutations in Japanese population with autosomal recessive retinitis pigmentosa.

    Directory of Open Access Journals (Sweden)

    Satoshi Katagiri

    Full Text Available OBJECTIVE: The purpose of this study was to investigate frequent disease-causing gene mutations in autosomal recessive retinitis pigmentosa (arRP in the Japanese population. METHODS: In total, 99 Japanese patients with non-syndromic and unrelated arRP or sporadic RP (spRP were recruited in this study and ophthalmic examinations were conducted for the diagnosis of RP. Among these patients, whole exome sequencing analysis of 30 RP patients and direct sequencing screening of all CNGA1 exons of the other 69 RP patients were performed. RESULTS: Whole exome sequencing of 30 arRP/spRP patients identified disease-causing gene mutations of CNGA1 (four patients, EYS (three patients and SAG (one patient in eight patients and potential disease-causing gene variants of USH2A (two patients, EYS (one patient, TULP1 (one patient and C2orf71 (one patient in five patients. Screening of an additional 69 arRP/spRP patients for the CNGA1 gene mutation revealed one patient with a homozygous mutation. CONCLUSIONS: This is the first identification of CNGA1 mutations in arRP Japanese patients. The frequency of CNGA1 gene mutation was 5.1% (5/99 patients. CNGA1 mutations are one of the most frequent arRP-causing mutations in Japanese patients.

  4. Frequent POLE1 p.S297F mutation in Chinese patients with ovarian endometrioid carcinoma

    International Nuclear Information System (INIS)

    Zou, Yang; Liu, Fa-Ying; Liu, Huai; Wang, Feng; Li, Wei; Huang, Mei-Zhen; Huang, Yan; Yuan, Xiao-Qun; Xu, Xiao-Yun; Huang, Ou-Ping; He, Ming

    2014-01-01

    The catalytic subunit of DNA polymerase epsilon (POLE1) functions primarily in nuclear DNA replication and repair. Recently, POLE1 mutations were detected frequently in colorectal and endometrial carcinomas while with lower frequency in several other types of cancer, and the p.P286R and p.V411L mutations were the potential mutation hotspots in human cancers. Nevertheless, the mutation frequency of POLE1 in ovarian cancer still remains largely unknown. Here, we screened a total of 251 Chinese samples with distinct subtypes of ovarian carcinoma for the presence of POLE1 hotspot mutations by direct sequencing. A heterozygous somatic POLE1 mutation, p.S297F (c.890C>T), but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was identified in 3 out of 37 (8.1%) patients with ovarian endometrioid carcinoma; this mutation was evolutionarily highly conserved from Homo sapiens to Schizosaccharomyces. Of note, the POLE1 mutation coexisted with mutation in the ovarian cancer-associated PPP2R1A (protein phosphatase 2, regulatory subunit A, α) gene in a 46-year-old patient, who was also diagnosed with ectopic endometriosis in the benign ovary. In addition, a 45-year-old POLE1-mutated ovarian endometrioid carcinoma patient was also diagnosed with uterine leiomyoma while the remaining 52-year-old POLE1-mutated patient showed no additional distinctive clinical manifestation. In contrast to high frequency of POLE1 mutations in ovarian endometrioid carcinoma, no POLE1 mutations were identified in patients with other subtypes of ovarian carcinoma. Our results showed for the first time that the POLE1 p.S297F mutation, but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was frequent in Chinese ovarian endometrioid carcinoma, but absent in other subtypes of ovarian carcinoma. These results implicated that POLE1 p.S297F mutation might be actively involved in the pathogenesis of ovarian endometrioid carcinoma, but might not be actively

  5. Frequent POLE1 p.S297F mutation in Chinese patients with ovarian endometrioid carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Yang; Liu, Fa-Ying; Liu, Huai; Wang, Feng [Key Laboratory of Women' s Reproductive Health of Jiangxi Province, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Central Laboratory, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Li, Wei [Key Laboratory of Women' s Reproductive Health of Jiangxi Province, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Central Laboratory, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Huang, Mei-Zhen [Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Jiangxi Provincial Cancer Institute, Jiangxi Provincial Cancer Hospital, Nanchang, Jiangxi 330029 (China); Huang, Yan; Yuan, Xiao-Qun [Key Laboratory of Women' s Reproductive Health of Jiangxi Province, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Central Laboratory, Jiangxi Provincial Maternal and Child Health Hospital, Nanchang, Jiangxi 330006 (China); Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Xu, Xiao-Yun [Graduate School of Nanchang University, Nanchang, Jiangxi 330031 (China); Jiangxi Provincial Cancer Institute, Jiangxi Provincial Cancer Hospital, Nanchang, Jiangxi 330029 (China); Huang, Ou-Ping, E-mail: huangouping@gmail.com [Jiangxi Provincial Cancer Institute, Jiangxi Provincial Cancer Hospital, Nanchang, Jiangxi 330029 (China); He, Ming, E-mail: jxhm56@hotmail.com [Department of Pharmacology and Molecular Therapeutics, Nanchang University School of Pharmaceutical Science, Nanchang 330006 (China)

    2014-03-15

    The catalytic subunit of DNA polymerase epsilon (POLE1) functions primarily in nuclear DNA replication and repair. Recently, POLE1 mutations were detected frequently in colorectal and endometrial carcinomas while with lower frequency in several other types of cancer, and the p.P286R and p.V411L mutations were the potential mutation hotspots in human cancers. Nevertheless, the mutation frequency of POLE1 in ovarian cancer still remains largely unknown. Here, we screened a total of 251 Chinese samples with distinct subtypes of ovarian carcinoma for the presence of POLE1 hotspot mutations by direct sequencing. A heterozygous somatic POLE1 mutation, p.S297F (c.890C>T), but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was identified in 3 out of 37 (8.1%) patients with ovarian endometrioid carcinoma; this mutation was evolutionarily highly conserved from Homo sapiens to Schizosaccharomyces. Of note, the POLE1 mutation coexisted with mutation in the ovarian cancer-associated PPP2R1A (protein phosphatase 2, regulatory subunit A, α) gene in a 46-year-old patient, who was also diagnosed with ectopic endometriosis in the benign ovary. In addition, a 45-year-old POLE1-mutated ovarian endometrioid carcinoma patient was also diagnosed with uterine leiomyoma while the remaining 52-year-old POLE1-mutated patient showed no additional distinctive clinical manifestation. In contrast to high frequency of POLE1 mutations in ovarian endometrioid carcinoma, no POLE1 mutations were identified in patients with other subtypes of ovarian carcinoma. Our results showed for the first time that the POLE1 p.S297F mutation, but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was frequent in Chinese ovarian endometrioid carcinoma, but absent in other subtypes of ovarian carcinoma. These results implicated that POLE1 p.S297F mutation might be actively involved in the pathogenesis of ovarian endometrioid carcinoma, but might not be actively

  6. Compared effects of missense mutations in Very-Long-Chain Acyl-CoA Dehydrogenase deficiency: Combined analysis by structural, functional and pharmacological approaches.

    Science.gov (United States)

    Gobin-Limballe, Stéphanie; McAndrew, Ryan P; Djouadi, Fatima; Kim, Jung-Ja; Bastin, Jean

    2010-05-01

    Very-Long-Chain Acyl-CoA Dehydrogenase deficiency (VLCADD) is an autosomal recessive disorder considered as one of the more common ss-oxidation defects, possibly associated with neonatal cardiomyopathy, infantile hepatic coma, or adult-onset myopathy. Numerous gene missense mutations have been described in these VLCADD phenotypes, but only few of them have been structurally and functionally analyzed, and the molecular basis of disease variability is still poorly understood. To address this question, we first analyzed fourteen disease-causing amino acid changes using the recently described crystal structure of VLCAD. The predicted effects varied from the replacement of amino acid residues lining the substrate binding cavity, involved in holoenzyme-FAD interactions or in enzyme dimerisation, predicted to have severe functional consequences, up to amino acid substitutions outside key enzyme domains or lying on near enzyme surface, with predicted milder consequences. These data were combined with functional analysis of residual fatty acid oxidation (FAO) and VLCAD protein levels in patient cells harboring these mutations, before and after pharmacological stimulation by bezafibrate. Mutations identified as detrimental to the protein structure in the 3-D model were generally associated to profound FAO and VLCAD protein deficiencies in the patient cells, however, some mutations affecting FAD binding or monomer-monomer interactions allowed a partial response to bezafibrate. On the other hand, bezafibrate restored near-normal FAO rates in some mutations predicted to have milder consequences on enzyme structure. Overall, combination of structural, biochemical, and pharmacological analysis allowed assessment of the relative severity of individual mutations, with possible applications for disease management and therapeutic approach. Copyright 2010 Elsevier B.V. All rights reserved.

  7. Intrafamilial variability of the ocular phenotype in a Polish family with a missense mutation (A63D) in the Norrie disease gene.

    Science.gov (United States)

    Zaremba, J; Feil, S; Juszko, J; Myga, W; van Duijnhoven, G; Berger, W

    1998-09-01

    To describe the phenotypic variability in a Polish Norrie disease (ND) family associated with the missense mutation A63D. A patient with spared vision from a Polish ND family underwent detailed ophthalmological examinations including slit-lamp biomicroscopy, ultrasound (USG), angiography, Goldmann kinetic visual field, and electroretinography (ERG). Mutation screening was carried out using the single-strand conformation polymorphism (SSCP) technique and subsequent DNA sequencing of the coding part of the ND gene. A mutation was detected (exon 3, A63D) in a large Polish family with 12 affected males, all but one presenting with classical ND symptoms. In one male, partially preserved vision was observed up to 40 years of age (distance acuity of the right eye 1/50 and left eye 2/50). Slit-lamp examination revealed remnants of a persistent primary vitreous and hyaloid artery. Upon angiography, the retina was vascularized within the posterior pole but not in the periphery. The ERG revealed pathological changes characteristic for chorioretinal degenerations. Within one family, individuals with identical sequence alterations in the ND gene can show remarkable phenotypic variability of the ocular symptoms. These findings indicate the involvement of additional factors (epigenetic or genetic) in ocular pathogenesis of ND.

  8. Genetic Mutations in Cancer

    Science.gov (United States)

    Many different types of genetic mutations are found in cancer cells. This infographic outlines certain types of alterations that are present in cancer, such as missense, nonsense, frameshift, and chromosome rearrangements.

  9. Structural implications of mutations in the pea SYM8 symbiosis gene, the DMI1 ortholog, encoding a predicted ion channel

    DEFF Research Database (Denmark)

    Edwards, Anne; Heckmann, Anne Birgitte Lau; Yousafzai, Faridoon

    2007-01-01

    the aspartate to valine and identified a missense mutation (changing alanine to valine adjacent to the aspartate residues) in this predicted filter region; both mutations caused a loss of function. We also identified a loss-of-function missense mutation (changing arginine to isoleucine) in a domain proposed...

  10. six novel mutations in the TSC1 and TSC2 genes

    Indian Academy of Sciences (India)

    M. GLUSHKOVA

    2018-04-30

    Apr 30, 2018 ... RESEARCH ARTICLE ... nant disorder caused by inactivating TSC1 or TSC2 gene variants (Van ... premature protein truncation, while missense mutations are rare ..... TSC2 variants in our cohort are missense, frame-shift.

  11. De novo mutations in ARID1B associated with both syndromic and non-syndromic short stature.

    Science.gov (United States)

    Yu, Yongguo; Yao, RuEn; Wang, Lili; Fan, Yanjie; Huang, Xiaodong; Hirschhorn, Joel; Dauber, Andrew; Shen, Yiping

    2015-09-16

    Human height is a complex trait with a strong genetic basis. Recently, a significant association between rare copy number variations (CNVs) and short stature has been identified, and candidate genes in these rare CNVs are being explored. This study aims to evaluate the association between mutations in ARID1B gene and short stature, both the syndromic and non-syndromic form. Based on a case-control study of whole genome chromosome microarray analysis (CMA), three overlapping CNVs were identified in patients with developmental disorders who exhibited short stature. ARID1B, a causal gene for Coffin Siris syndrome, is the only gene encompassed by all three CNVs. A following retrospective genotype-phenotype analysis based on a literature review confirmed that short stature is a frequent feature in those Coffin-Siris syndrome patients with ARID1B mutations. Mutation screening of ARID1B coding regions was further conducted in a cohort of 48 non-syndromic short stature patients,andfour novel missense variants including two de novo mutations were found. These results suggest that haploinsufficient mutations of ARID1B are associated with syndromic short stature including Coffin-Siris syndrome and intellectual disability, while rare missense variants in ARID1B are associated with non-syndromic short stature. This study supports the notion that mutations in genes related to syndromic short stature may exert milder effect and contribute to short stature in the general population.

  12. Frequent mutations of genes encoding ubiquitin-mediated proteolysis pathway components in clear cell renal cell carcinoma

    DEFF Research Database (Denmark)

    Guo, Guangwu; Gui, Yaoting; Gao, Shengjie

    2012-01-01

    We sequenced whole exomes of ten clear cell renal cell carcinomas (ccRCCs) and performed a screen of similar to 1,100 genes in 88 additional ccRCCs, from which we discovered 12 previously unidentified genes mutated at elevated frequencies in ccRCC. Notably, we detected frequent mutations in the u...

  13. Analysis of Hungarian patients with Rett syndrome phenotype for MECP2, CDKL5 and FOXG1 gene mutations.

    Science.gov (United States)

    Hadzsiev, Kinga; Polgar, Noemi; Bene, Judit; Komlosi, Katalin; Karteszi, Judit; Hollody, Katalin; Kosztolanyi, Gyorgy; Renieri, Alessandra; Melegh, Bela

    2011-03-01

    Rett syndrome (RTT) is characterized by a relatively specific clinical phenotype. We screened 152 individuals with RTT phenotype. A total of 22 different known MECP2 mutations were identified in 42 subjects (27.6%). Of the 22 mutations, we identified 7 (31.8%) frameshift-causing deletions, 4 (18.2%) nonsense, 10 (45.5%) missense mutations and one insertion (4.5%). The most frequent pathologic changes were: p.Thr158Met (14.2%) and p.Arg133Cys (11.9%) missense, and p.Arg255Stop (9.5%) and p.Arg294Stop (9.5%) nonsense mutations. We also detected the c.925C >T (p.Arg309Trp) mutation in an affected patient, whose role in RTT pathogenesis is still unknown. Patients without detectable MECP2 defects were screened for mutations of cyclin-dependent kinase-like 5 (CDKL5) gene, responsible for the early-onset variant of RTT. We discovered two novel mutations: c.607G >T resulting in a termination codon at aa203, disrupting the catalytic domain, and c.1708G >T leading to a stop at aa570 of the C terminus. Both patients with CDKL5 mutation presented therapy-resistant epilepsy and a phenotype fitting with the diagnosis of early-onset variant of RTT. No FOXG1 mutation was detected in any of the remaining patients. A total of 110 (72.5%) patients remained without molecular genetic diagnosis that necessitates further search for novel gene mutations in this phenotype. Our results also suggest the need of screening for CDKL5 mutations in patients with Rett phenotype tested negative for MECP2 mutations.

  14. Spectrum of CREBBP mutations in Indian patients with Rubinstein ...

    Indian Academy of Sciences (India)

    Prakash

    Rubinstein–Taybi syndrome. NEETI SHARMA, AVINASH M MALI and SHARMILA A BAPAT ..... Supplementary table 4. Exon mutations in RSTS patients in the Indian population. S.No. Gene Position Sense /. Missense. Patient. Exon. Amino acid change. Novel/de novo/SNP. Domain. 1 g.3276G>C missense. RSTS13a. 32 p.

  15. Novel missense mutations in PNPLA2 causing late onset and clinical heterogeneity of neutral lipid storage disease with myopathy in three siblings.

    Science.gov (United States)

    Missaglia, Sara; Tasca, Elisabetta; Angelini, Corrado; Moro, Laura; Tavian, Daniela

    2015-01-01

    Neutral lipid storage disease with myopathy (NLSD-M) is a rare autosomal recessive disorder characterised by an abnormal accumulation of triacylglycerol into cytoplasmic lipid droplets (LDs). NLSD-M patients are mainly affected by progressive myopathy, cardiomyopathy and hepatomegaly. Mutations in the PNPLA2 gene cause variable phenotypes of NLSD-M. PNPLA2 codes for adipose triglyceride lipase (ATGL), an enzyme that hydrolyses fatty acids from triacylglycerol. This report outlines the clinical and genetic findings in a NLSD-M Italian family with three affected members. In our patients, we identified two novel PNPLA2 missense mutations (p.L56R and p.I193F). Functional data analysis demonstrated that these mutations caused the production of ATGL proteins able to bind to LDs, but with decreased lipase activity. The oldest brother, at the age of 38, had weakness and atrophy of the right upper arm and kyphosis. Now he is 61 years old and is unable to raise arms in the horizontal position. The second brother, from the age of 44, had exercise intolerance, cramps and pain in lower limbs. He is currently 50 years old and has an asymmetric distal amyotrophy. One of the two sisters, 58 years old, presents the same PNPLA2 mutations, but she is still oligo-symptomatic on neuromuscular examination with slight triceps muscle involvement. She suffered from diabetes and liver steatosis. This NLSD-M family shows a wide range of intra-familial phenotypic variability in subjects carrying the same mutations, both in terms of target-organs and in terms of rate of disease progression. Copyright © 2015. Published by Elsevier Inc.

  16. Identification of novel FBN1 and TGFBR2 mutations in 65 probands with Marfan syndrome or Marfan-like phenotypes.

    Science.gov (United States)

    Chung, Brian Hon-Yin; Lam, Stephen Tak-Sum; Tong, Tony Ming-For; Li, Susanna Yuk-Han; Lun, Kin-Shing; Chan, Daniel Hon-Chuen; Fok, Susanna Fung-Shan; Or, June Siu-Fong; Smith, David Keith; Yang, Wanling; Lau, Yu-Lung

    2009-07-01

    Marfan syndrome is an autosomal dominant connective tissue disorder, and mutations in the FBN1 and TGFBR2 genes have been identified in probands with MFS and related phenotypes. Using DHPLC and sequencing, we studied the mutation spectrum in 65 probands with Marfan syndrome and related phenotypes. A total of 24 mutations in FBN1 were identified, of which 19 (nine missense, six frameshift, two nonsense and two affecting splice junctions) were novel. In the remaining 41 probands, six were identified to have novel TGFBR2 mutations (one frameshift and five missense mutations). All novel mutations found in this study were confirmed to be absent in 50 unrelated normal individuals of the same ethnic background. In probands who fulfilled the Ghent criteria (n = 16), mutations in FBN1 were found in 81% of cases. None of those with TGFBR2 mutations fulfilled the Ghent criteria. Novel missense mutations of unknown significance were classified according to the latest ACMG guidelines and their likelihood to be causative was evaluated.

  17. The IARC TP53 mutation database: a resource for studying the significance of TP53 mutations in human cancers

    Directory of Open Access Journals (Sweden)

    Magali Olivier

    2007-02-01

    Full Text Available

    The tumor suppressor gene TP53 is frequently inactivated by gene mutations in many types of human sporadic cancers, and inherited TP53 mutations predispose to a wide spectrum of early-onset tumors (Li-Fraumeni et Li-Fraumenilike Syndromes. All TP53 gene variations (somatic and germline mutations, as well as polymorphisms that are reported in the scientific literature or in SNP databases are compiled in the IARC TP53 Database. This database provides structured data and analysis tools to study mutation patterns in human cancers and cell-lines and to investigate the clinical impact of mutations. It contains annotations related to the clinical and pathological characteristics of tumors, as well as the demographics and carcinogen exposure of patients. The IARC TP53 web site (http://www-p53.iarc.fr/ provides a search interface for the core database and includes a comprehensive user guide, a slideshow on TP53 mutations in human cancer, protocols and references for sequencing TP53 gene, and links to relevant publications and bioinformatics databases. The database interface allows download of entire data sets and propose various tools for the selection, analysis and downloads of specific sets of data according to user's query.

    Recently, new annotations on the functional properties of mutant p53 proteins have been integrated in this database. Indeed, the most frequent TP53 alterations observed in cancers (75% are missense mutations that result in the production of a mutant protein that differ from the wildtype by one single amino-acid. The characterization of the biological activities of these mutant proteins is thus very important. Over the last ten years, a great amount of systematic data has been generated from experimental assays performed in

  18. [A young boy with elevated aminotransferases in physical examination--Two novel missense mutations associated with Wilson's disease were found].

    Science.gov (United States)

    Zhu, Yu; Deng, Si-Yan; Wan, Chao-Min

    2015-07-01

    A 3-year-old boy had abnormal liver function, which was found in physical examination, for 5 months before admission. He had no symptoms such as anorexia, poor appetite, and jaundice, had normal growth and development, and showed no hepatosplenomegaly. Laboratory examination revealed significantly reduced ceruloplasmin (35 mg/L), as well as negative hepatotropic virus, cytomegalovirus, and Epstein-Barr virus. There were normal muscle enzymes, blood glucose, and blood ammonia and negative liver-specific autoantibodies. The boy had negative K-F ring and normal 24-hour urine copper (0.56 μmol/L). The ATP7B gene testing for the boy, his sister, and their parents detected two novel missense mutations in the boy and his sister, i.e., compound heterozygous mutations in exon 7 (c.2075T>C, p.L692P) and exon 13 (c.3044T>C, p.L1015P), which were inherited from their father and mother, respectively. Wilson's disease was confirmed by genetic diagnosis in the boy and his sister. The boy and his sister were given a low-copper diet. The boy was administered with penicillamine for decoppering and zinc supplement against copper uptake. His sister received zinc supplement alone because no clinical symptoms were observed. The boy showed normal liver function in the reexamination after 3 months of treatment.

  19. MEK inhibitors block growth of lung tumours with mutations in ataxia-telangiectasia mutated

    Czech Academy of Sciences Publication Activity Database

    Smida, M.; de la Cruz, F.F.; Kerzendorfer, C.; Uras, I.Z.; Mair, B.; Mazouzi, A.; Suchánková, Tereza; Konopka, T.; Katz, A.M.; Paz, K.; Nagy-Bojarszky, K.; Muellner, M.K.; Bago-Horvath, Z.; Haura, E.B.; Loizou, J.I.; Nijman, S.M.B.

    2016-01-01

    Roč. 7, DEC2016 (2016), č. článku 13701. ISSN 2041-1723 Institutional support: RVO:68081707 Keywords : breast-cancer * insulin -resistance * missense mutations Subject RIV: BO - Biophysics Impact factor: 12.124, year: 2016

  20. Alternative splicing of exon 17 and a missense mutation in exon 20 of the insulin receptor gene in two brothers with a novel syndrome of insulin resistance (congenital fiber-type disproportion myopathy)

    DEFF Research Database (Denmark)

    Vorwerk, P; Christoffersen, C T; Müller, J

    1999-01-01

    to be compound heterozygotes for mutations in the IR gene. The maternal allele was alternatively spliced in exon 17 due to a point mutation in the -1 donor splice site of the exon. The abnormal skipping of exon 17 shifts the amino acid reading frame and leads to a truncated IR, missing the entire tyrosine kinase......The insulin receptor (IR) in two brothers with a rare syndrome of congenital muscle fiber type disproportion myopathy (CFTDM) associated with diabetes and severe insulin resistance was studied. By direct sequencing of Epstein-Barr virus-transformed lymphocytes both patients were found...... domain. In the correct spliced variant, the point mutation is silent and results in a normally translated IR. The paternal allele carries a missense mutation in the tyrosine kinase domain. All three cDNA variants were present in the lymphocytes of the patients. Purified IR from 293 cells overexpressing...

  1. Identification of Mutations Underlying 20 Inborn Errors of Metabolism in the United Arab Emirates Population

    Science.gov (United States)

    Ben-Rebeh, Imen; Hertecant, Jozef L.; Al-Jasmi, Fatma A.; Aburawi, Hanan E.; Al-Yahyaee, Said A.; Al-Gazali, Lihadh

    2012-01-01

    Inborn errors of metabolism (IEM) are frequently encountered by physicians in the United Arab Emirates (UAE). However, the mutations underlying a large number of these disorders have not yet been determined. Therefore, the objective of this study was to identify the mutations underlying a number of IEM disorders among UAE residents from both national and expatriate families. A case series of patients from 34 families attending the metabolic clinic at Tawam Hospital were clinically evaluated, and molecular testing was carried out to determine their causative mutations. The mutation analysis was carried out at molecular genetics diagnostic laboratories. Thirty-eight mutations have been identified as responsible for twenty IEM disorders, including in the metabolism of amino acids, lipids, steroids, metal transport and mitochondrial energy metabolism, and lysosomal storage disorders. Nine of the identified mutations are novel, including two missense mutations, three premature stop codons and four splice site mutations. Mutation analysis of IEM disorders in the UAE population has an important impact on molecular diagnosis and genetic counseling for families affected by these disorders. PMID:22106832

  2. A novel missense NDP mutation [p.(Cys93Arg)] with a manifesting carrier in an austrian family with Norrie disease.

    Science.gov (United States)

    Parzefall, Thomas; Lucas, Trevor; Ritter, Markus; Ludwig, Martin; Ramsebner, Reinhard; Frohne, Alexandra; Schöfer, Christian; Hengstschläger, Markus; Frei, Klemens

    2014-01-01

    Norrie disease is a rare, X-linked genetic syndrome characterized by combined congenital blindness and progressive hearing impairment. Norrie disease is caused by alterations in the NDP gene encoding the growth factor norrin that plays a key role in vascular development and stabilization of the eye, inner ear and brain. We identified a family with 3 affected deafblind males and a single female carrier presenting with a serous retinal detachment but normal hearing. Genetic analysis revealed a novel c.277T>C missense mutation causing the substitution of a hydrophobic cysteine to a hydrophilic arginine [p.(Cys93Arg)] within the highly conserved cysteine knot domain of the norrin protein. These results should expand the scope for amniocentesis and genetic testing for Norrie disease which is gaining in importance due to novel postnatal therapeutic concepts to alleviate the devastating retinal symptoms of Norrie disease. © 2014 S. Karger AG, Basel.

  3. Missense mutation in DISC1 C-terminal coiled-coil has GSK3β signaling and sex-dependent behavioral effects in mice

    Science.gov (United States)

    Dachtler, James; Elliott, Christina; Rodgers, R. John; Baillie, George S.; Clapcote, Steven J.

    2016-01-01

    Disrupted-in-Schizophrenia 1 (DISC1) is a risk factor for schizophrenia and affective disorders. The full-length DISC1 protein consists of an N-terminal ‘head’ domain and a C-terminal tail domain that contains several predicted coiled-coils, structural motifs involved in protein-protein interactions. To probe the in vivo effects of missense mutation of DISC1’s C-terminal tail, we tested mice carrying mutation D453G within a predicted α-helical coiled-coil region. We report that, relative to wild-type littermates, female DISC1D453G mice exhibited novelty-induced hyperlocomotion, an anxiogenic profile in the elevated plus-maze and open field tests, and reduced social exploration of unfamiliar mice. Male DISC1D453G mice displayed a deficit in passive avoidance, while neither males nor females exhibited any impairment in startle reactivity or prepulse inhibition. Whole brain homogenates showed normal levels of DISC1 protein, but decreased binding of DISC1 to GSK3β, decreased phospho-inhibition of GSK3β at serine 9, and decreased levels of β-catenin in DISC1D453G mice of either sex. Interrupted GSK3β signaling may thus be part of the mechanism underlying the behavioral phenotype associated with D453G, in common with the previously described N-terminal domain mutations Q31L and L100P in mice, and the schizophrenia risk-conferring variant R264Q in humans. PMID:26728762

  4. Integrating population variation and protein structural analysis to improve clinical interpretation of missense variation: application to the WD40 domain.

    Science.gov (United States)

    Laskowski, Roman A; Tyagi, Nidhi; Johnson, Diana; Joss, Shelagh; Kinning, Esther; McWilliam, Catherine; Splitt, Miranda; Thornton, Janet M; Firth, Helen V; Wright, Caroline F

    2016-03-01

    We present a generic, multidisciplinary approach for improving our understanding of novel missense variants in recently discovered disease genes exhibiting genetic heterogeneity, by combining clinical and population genetics with protein structural analysis. Using six new de novo missense diagnoses in TBL1XR1 from the Deciphering Developmental Disorders study, together with population variation data, we show that the β-propeller structure of the ubiquitous WD40 domain provides a convincing way to discriminate between pathogenic and benign variation. Children with likely pathogenic mutations in this gene have severely delayed language development, often accompanied by intellectual disability, autism, dysmorphology and gastrointestinal problems. Amino acids affected by likely pathogenic missense mutations are either crucial for the stability of the fold, forming part of a highly conserved symmetrically repeating hydrogen-bonded tetrad, or located at the top face of the β-propeller, where 'hotspot' residues affect the binding of β-catenin to the TBLR1 protein. In contrast, those altered by population variation are significantly less likely to be spatially clustered towards the top face or to be at buried or highly conserved residues. This result is useful not only for interpreting benign and pathogenic missense variants in this gene, but also in other WD40 domains, many of which are associated with disease. © The Author 2016. Published by Oxford University Press.

  5. Most of rare missense alleles in humans are deleterious:implications for evolution of complex disease and associationstudies

    Energy Technology Data Exchange (ETDEWEB)

    Kryukov, Gregory V.; Pennacchio, Len A.; Sunyaev, Shamil R.

    2006-10-24

    The accumulation of mildly deleterious missense mutations inindividual human genomes has been proposed to be a genetic basis forcomplex diseases. The plausibility of this hypothesis depends onquantitative estimates of the prevalence of mildly deleterious de novomutations and polymorphic variants in humans and on the intensity ofselective pressure against them. We combined analysis of mutationscausing human Mendelian diseases, human-chimpanzee divergence andsystematic data on human SNPs and found that about 20 percent of newmissense mutations in humans result in a loss of function, while about 27percent are effectively neutral. Thus, more than half of new missensemutations have mildly deleterious effects. These mutations give rise tomany low frequency deleterious allelic variants in the human populationas evident from a new dataset of 37 genes sequenced in over 1,500individual human chromosomes. Surprisingly, up to 70 percent of lowfrequency missense alleles are mildly deleterious and associated with aheterozygous fitness loss in the range 0.001-0.003. Thus, the low allelefrequency of an amino acid variant can by itself serve as a predictor ofits functional significance. Several recent studies have reported asignificant excess of rare missense variants in disease populationscompared to controls in candidate genes or pathways. These studies wouldbe unlikely to work if most rare variants were neutral or if rarevariants were not a significant contributor to the genetic component ofphenotypic inheritance. Our results provide a justification for thesetypes of candidate gene (pathway) association studies and imply thatmutation-selection balance may be a feasible mechanism for evolution ofsome common diseases.

  6. Nonketotic hyperglycinemia: Functional assessment of missense variants in GLDC to understand phenotypes of the disease.

    Science.gov (United States)

    Bravo-Alonso, Irene; Navarrete, Rosa; Arribas-Carreira, Laura; Perona, Almudena; Abia, David; Couce, María Luz; García-Cazorla, Angels; Morais, Ana; Domingo, Rosario; Ramos, María Antonia; Swanson, Michael A; Van Hove, Johan L K; Ugarte, Magdalena; Pérez, Belén; Pérez-Cerdá, Celia; Rodríguez-Pombo, Pilar

    2017-06-01

    The rapid analysis of genomic data is providing effective mutational confirmation in patients with clinical and biochemical hallmarks of a specific disease. This is the case for nonketotic hyperglycinemia (NKH), a Mendelian disorder causing seizures in neonates and early-infants, primarily due to mutations in the GLDC gene. However, understanding the impact of missense variants identified in this gene is a major challenge for the application of genomics into clinical practice. Herein, a comprehensive functional and structural analysis of 19 GLDC missense variants identified in a cohort of 26 NKH patients was performed. Mutant cDNA constructs were expressed in COS7 cells followed by enzymatic assays and Western blot analysis of the GCS P-protein to assess the residual activity and mutant protein stability. Structural analysis, based on molecular modeling of the 3D structure of GCS P-protein, was also performed. We identify hypomorphic variants that produce attenuated phenotypes with improved prognosis of the disease. Structural analysis allows us to interpret the effects of mutations on protein stability and catalytic activity, providing molecular evidence for clinical outcome and disease severity. Moreover, we identify an important number of mutants whose loss-of-functionality is associated with instability and, thus, are potential targets for rescue using folding therapeutic approaches. © 2017 Wiley Periodicals, Inc.

  7. Case report: a novel KERA mutation associated with cornea plana and its predicted effect on protein function

    DEFF Research Database (Denmark)

    Roos, Laura; Bertelsen, Birgitte; Harris, Pernille

    2015-01-01

    individuals, hypotrichosis was found. KERA was screened for mutations using Sanger sequencing. We detected a novel KERA variant, p.(Ile225Thr), that segregates with the disease in the homozygous form. The three-dimensional structure of keratocan protein was modelled, and we showed that this missense variation...... of the keratocan gene (KERA) on chromosome 12q22. To date, only nine different disease-associated KERA mutations, including four missense mutations, have been described. Case presentation: In this report, we present clinical data from a Turkish family with autosomal recessive cornea plana. In some of the affected...... are predicted to result in destabilization of the protein. Conclusion: We present the 10th pathogenic KERA mutation identified so far. Protein modelling is a useful tool in predicting the effect of missense mutations. This case underline the importance of the leucin rich repeat domain for the protein function...

  8. A missense mutation in melanocortin 1 receptor is associated with the red coat colour in donkeys.

    Science.gov (United States)

    Abitbol, M; Legrand, R; Tiret, L

    2014-12-01

    The seven donkey breeds recognised by the French studbook are characterised by few coat colours: black, bay and grey. Normand bay donkeys seldom give birth to red foals, a colour more commonly seen and recognised in American miniature donkeys. Red resembles the equine chestnut colour, previously attributed to a mutation in the melanocortin 1 receptor gene (MC1R). We used a panel of 124 donkeys to identify a recessive missense c.629T>C variant in MC1R that showed a perfect association with the red coat colour. This variant leads to a methionine to threonine substitution at position 210 in the protein. We showed that methionine 210 is highly conserved among vertebrate melanocortin receptors. Previous in silico and in vitro analyses predicted this residue to lie within a functional site. Our in vivo results emphasised the pivotal role played by this residue, the alteration of which yielded a phenotype fully compatible with a loss of function of MC1R. We thus propose to name the c.629T>C allele in donkeys the e allele, which further enlarges the panel of recessive MC1R loss-of-function alleles described in animals and humans. © 2014 Stichting International Foundation for Animal Genetics.

  9. Simultaneous Occurence of an Autosomal Dominant Inherited MSX1 Mutation and an X-linked Recessive Inherited EDA Mutation in One Chinese Family with Non-syndromic Oligodontia.

    Science.gov (United States)

    Zhang, Xiao Xia; Wong, Sing Wai; Han, Dong; Feng, Hai Lan

    2015-01-01

    To describe the simultaneous occurence of an autosomal dominant inherited MSX1 mutation and an X-linked recessive inherited EDA mutation in one Chinese family with nonsyndromic oligodontia. Clinical data of characteristics of tooth agenesis were collected. MSX1 and EDA gene mutations were detected in a Chinese family of non-syndromic oligodontia. Mild hypodontia in the parents and severe oligodontia in the son was recorded. A novel missense heterozygous mutation c.517C>A (p.Arg173Ser) was detected in the MSX1 gene in the boy and the father. A homozygous missense mutation c.1001G>A (p.Arg334His) was detected in the EDA gene in the boy and the same mutant occurred heterozygously in the mother. Simultaneous occurence of two different gene mutations with different inheritence patterns, which both caused oligodontia, which occurred in one subject and in one family, was reported.

  10. Germline mutations of regulator of telomere elongation helicase 1, RTEL1, in Dyskeratosis congenita.

    Science.gov (United States)

    Ballew, Bari J; Yeager, Meredith; Jacobs, Kevin; Giri, Neelam; Boland, Joseph; Burdett, Laurie; Alter, Blanche P; Savage, Sharon A

    2013-04-01

    Dyskeratosis congenita (DC) is an inherited bone marrow failure and cancer predisposition syndrome caused by aberrant telomere biology. The classic triad of dysplastic nails, abnormal skin pigmentation, and oral leukoplakia is diagnostic of DC, but substantial clinical heterogeneity exists; the clinically severe variant Hoyeraal Hreidarsson syndrome (HH) also includes cerebellar hypoplasia, severe immunodeficiency, enteropathy, and intrauterine growth retardation. Germline mutations in telomere biology genes account for approximately one-half of known DC families. Using exome sequencing, we identified mutations in RTEL1, a helicase with critical telomeric functions, in two families with HH. In the first family, two siblings with HH and very short telomeres inherited a premature stop codon from their mother who has short telomeres. The proband from the second family has HH and inherited a premature stop codon in RTEL1 from his father and a missense mutation from his mother, who also has short telomeres. In addition, inheritance of only the missense mutation led to very short telomeres in the proband's brother. Targeted sequencing identified a different RTEL1 missense mutation in one additional DC proband who has bone marrow failure and short telomeres. Both missense mutations affect the helicase domain of RTEL1, and three in silico prediction algorithms suggest that they are likely deleterious. The nonsense mutations both cause truncation of the RTEL1 protein, resulting in loss of the PIP box; this may abrogate an important protein-protein interaction. These findings implicate a new telomere biology gene, RTEL1, in the etiology of DC.

  11. AR mutations in 28 patients with androgen insensitivity syndrome (Prader grade 0-3).

    Science.gov (United States)

    Wang, Yi; Gong, Chunxiu; Wang, Xiou; Qin, Miao

    2017-07-01

    We investigated the androgen receptor (AR) gene mutation profiles of Chinese patients exhibiting severe androgen insensitivity syndrome (AIS) phenotypes. The present study enrolled 28 patients with genetically diagnosed AIS, who presented with severe phenotypes (Prader grade 0-3). Patients and some family members were screened via amplification and sequencing of their AR exons 1-8, including the corresponding intronic flanking regions. Luteinizing (LH), follicle-stimulating (FSH), and testosterone (T) hormone levels were found to be slightly, but not significantly, higher in patients with complete androgen insensitivity syndrome (CAIS) than in patients with partial androgen insensitivity syndrome (PAIS) (P>0.05). We identified 24 different AR mutations, including 12 that were novel. Ten patients (cases 2, 3, 10, 28, 11, 12, 19, 20, 24, and 25) were found to carry five recurrent mutations (p.Y572S, p.P914S, p.S176R, p.Y782N, and p.R841H); of these, p.Y572S, p.S176R, and p.Y782N were novel. Among the mutations identified in patients with CAIS, six (66.7%) were characterized as single-nucleotide missense mutations, and six (66.7%) were found to be located in the AR ligand-binding domain (LBD). Among the mutations identified in patients with PAIS, 15 (93.8%) were found to be missense, and 11 (68.8%) were found to be located in the LBD. Patients 10 and 28 were determined to harbor the same missense mutation (p.P914S), but were diagnosed with CAIS and PAIS, respectively. Sex hormone levels were slightly, but not significantly, elevated in patients with CAIS compared to those with PAIS. Missense mutations spanning AR exons 1-8 were the predominant form of identified mutations, and these were mostly located in the AR LBD. Approximately 50% of the identified mutations were novel, and have enriched the AR gene-mutation database. Patients harboring identical mutations were in some instances found to exhibit divergent phenotypes.

  12. Origin, functional role, and clinical impact of Fanconi anemia FANCA mutations.

    Science.gov (United States)

    Castella, Maria; Pujol, Roser; Callén, Elsa; Trujillo, Juan P; Casado, José A; Gille, Hans; Lach, Francis P; Auerbach, Arleen D; Schindler, Detlev; Benítez, Javier; Porto, Beatriz; Ferro, Teresa; Muñoz, Arturo; Sevilla, Julián; Madero, Luis; Cela, Elena; Beléndez, Cristina; de Heredia, Cristina Díaz; Olivé, Teresa; de Toledo, José Sánchez; Badell, Isabel; Torrent, Montserrat; Estella, Jesús; Dasí, Angeles; Rodríguez-Villa, Antonia; Gómez, Pedro; Barbot, José; Tapia, María; Molinés, Antonio; Figuera, Angela; Bueren, Juan A; Surrallés, Jordi

    2011-04-07

    Fanconi anemia is characterized by congenital abnormalities, bone marrow failure, and cancer predisposition. To investigate the origin, functional role, and clinical impact of FANCA mutations, we determined a FANCA mutational spectrum with 130 pathogenic alleles. Some of these mutations were further characterized for their distribution in populations, mode of emergence, or functional consequences at cellular and clinical level. The world most frequent FANCA mutation is not the result of a mutational "hot-spot" but results from worldwide dissemination of an ancestral Indo-European mutation. We provide molecular evidence that total absence of FANCA in humans does not reduce embryonic viability, as the observed frequency of mutation carriers in the Gypsy population equals the expected by Hardy-Weinberg equilibrium. We also prove that long distance Alu-Alu recombination can cause Fanconi anemia by originating large interstitial deletions involving FANCA and 2 adjacent genes. Finally, we show that all missense mutations studied lead to an altered FANCA protein that is unable to relocate to the nucleus and activate the FA/BRCA pathway. This may explain the observed lack of correlation between type of FANCA mutation and cellular phenotype or clinical severity in terms of age of onset of hematologic disease or number of malformations.

  13. Mutation analysis of the WFS1 gene in seven Danish Wolfram syndrome families; four new mutations identified

    DEFF Research Database (Denmark)

    Hansen, Lars; Eiberg, Hans Rudolf Lytchoff; Barrett, Timothy

    2005-01-01

    loss (LFSNHL). WFS1 variants were identified in eight subjects from seven families with WS, leading to the identification of four novel mutations, Q194X (nonsense), H313Y (missense), L313fsX360 (duplication frame shift) and F883fsX951 (deletion frame shift), and four previously reported mutations, A133...

  14. Mutation spectrum of homogentisic acid oxidase (HGD) in alkaptonuria.

    Science.gov (United States)

    Vilboux, Thierry; Kayser, Michael; Introne, Wendy; Suwannarat, Pim; Bernardini, Isa; Fischer, Roxanne; O'Brien, Kevin; Kleta, Robert; Huizing, Marjan; Gahl, William A

    2009-12-01

    Alkaptonuria (AKU) is a rare autosomal recessive metabolic disorder, characterized by accumulation of homogentisic acid, leading to darkened urine, pigmentation of connective tissue (ochronosis), joint and spine arthritis, and destruction of cardiac valves. AKU is due to mutations in the homogentisate dioxygenase gene (HGD) that converts homogentisic acid to maleylacetoacetic acid in the tyrosine catabolic pathway. Here we report a comprehensive mutation analysis of 93 patients enrolled in our study, as well as an extensive update of all previously published HGD mutations associated with AKU. Within our patient cohort, we identified 52 HGD variants, of which 22 were novel. This yields a total of 91 identified HGD variations associated with AKU to date, including 62 missense, 13 splice site, 10 frameshift, 5 nonsense, and 1 no-stop mutation. Most HGD variants reside in exons 3, 6, 8, and 13. We assessed the potential effect of all missense variations on protein function, using five bioinformatic tools specifically designed for interpretation of missense variants (SIFT, POLYPHEN, PANTHER, PMUT, and SNAP). We also analyzed the potential effect of splice-site variants using two different tools (BDGP and NetGene2). This study provides valuable resources for molecular analysis of alkaptonuria and expands our knowledge of the molecular basis of this disease.

  15. Novel mutations underlying argininosuccinic aciduria in Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Rashed Mohamed S

    2010-03-01

    Full Text Available Abstract Background Argininosuccinic aciduria (ASAuria is an autosomal recessive disorder of the urea cycle relatively common in Saudi Arabia as a consequence of extensive consanguinity. It is the most common urea cycle disorder identified in the Saudi population, which therefore prioritizes the need to delineate the underlying molecular defects leading to disease. Findings We utilized Whole Genome Amplification (WGA, PCR and direct sequencing to identify mutations underlying ASAuria cases diagnosed by our institution. A missense mutation that accounts for 50% of Saudi ASAuria patients was recently reported by our laboratory. In this study we report a further six novel mutations (and one previously reported found in Saudi patients with ASAuria. The novel four missense, one nonsense and one splice-site mutation were confirmed by their absence in >300 chromosomes from the normal population. Pathogenicity of the novel splice-site mutation was also confirmed using reverse transcriptase-PCR analysis. Cross species amino acid conservation at the substituted residues described were observed in some but not all instances. Conclusions Together, the eight mutations described by our laboratory, encompass >90% of ASAuria patients in Saudi Arabia and add to about 45 other ASAuria mutations reported worldwide.

  16. A novel missense KIT mutation causing piebaldism in one Chinese family associated with café-au-lait macules and intertriginous freckling

    Directory of Open Access Journals (Sweden)

    Jia WX

    2015-04-01

    Full Text Available Wei-Xue Jia,1,2 Xue-Min Xiao,1,2 Jian-Bing Wu,1,2 Yi-Ping Ma,1,2 Yi-Ping Ge,1,2 Qi Li,1,2 Qiu-Xia Mao,1,2 Cheng-Rang Li1,2 1Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, Jiangsu, China; 2Jiangsu Key Laboratory of Molecular Biology for Skin Diseases and STIs, Nanjing, Jiangsu, China Abstract: Piebaldism is a rare autosomal dominant genodermatosis, manifesting as congenital and stable depigmentation of the skin and white forelock. It has been found to be associated with mutations in the KIT or SLUG genes. We report a Chinese piebaldism family including a 28-year-old woman and her 3-year-old son with characteristics of white patches and forelock associated with numerous brown macules and patches. Genomic DNA samples of the proband and her son were extracted from their peripheral blood. One hundred unrelated healthy individuals were used as controls. All coding regions of KIT, SLUG, and NF1 genes were amplified by polymerase chain reaction using exon flanking intronic primers and Sanger sequencings were performed. DNA sequencing revealed heterozygous missense c.2431T>G mutation in exon 17 of the KIT gene in the proband and the affected son. No potentially pathogenic variant was identified in SLUG or NF1 genes. The nucleotide substitution was not found in 100 unrelated control individuals. This study reveals a novel KIT mutation in piebaldism, and it further supports that café-au-lait macules and intertriginous freckling of piebaldism are parts of pigmented anomaly in piebaldism, which does not necessarily represent coexistence of neurofibromatosis type 1 (NF1. Keywords: novel mutation, KIT gene, neurofibromatosis type 1 

  17. Severe fluoropyrimidine toxicity due to novel and rare DPYD missense mutations, deletion and genomic amplification affecting DPD activity and mRNA splicing

    DEFF Research Database (Denmark)

    van Kuilenburg, André B P; Meijer, Judith; Maurer, Dirk

    2017-01-01

    Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme in the catabolism of 5-fluorouracil (5FU). Genetic variations in DPD have emerged as predictive risk factors for severe fluoropyrimidine toxicity. Here, we report novel and rare genetic variants underlying DPD deficiency...... in 9 cancer patients presenting with severe fluoropyrimidine-associated toxicity. All patients possessed a strongly reduced DPD activity, ranging from 9 to 53% of controls. Analysis of the DPD gene (DPYD) showed the presence of 21 variable sites including 4 novel and 4 very rare aberrations: 3 missense...... of exon 4 immediately upstream of the mutated splice-donor site in the process of DPD pre-mRNA splicing. A lethal toxicity in two DPD patients suggests that fluoropyrimidines combined with other therapies such as radiotherapy might be particularly toxic for DPD deficient patients. Our study advocates...

  18. Quantitative Missense Variant Effect Prediction Using Large-Scale Mutagenesis Data.

    Science.gov (United States)

    Gray, Vanessa E; Hause, Ronald J; Luebeck, Jens; Shendure, Jay; Fowler, Douglas M

    2018-01-24

    Large datasets describing the quantitative effects of mutations on protein function are becoming increasingly available. Here, we leverage these datasets to develop Envision, which predicts the magnitude of a missense variant's molecular effect. Envision combines 21,026 variant effect measurements from nine large-scale experimental mutagenesis datasets, a hitherto untapped training resource, with a supervised, stochastic gradient boosting learning algorithm. Envision outperforms other missense variant effect predictors both on large-scale mutagenesis data and on an independent test dataset comprising 2,312 TP53 variants whose effects were measured using a low-throughput approach. This dataset was never used for hyperparameter tuning or model training and thus serves as an independent validation set. Envision prediction accuracy is also more consistent across amino acids than other predictors. Finally, we demonstrate that Envision's performance improves as more large-scale mutagenesis data are incorporated. We precompute Envision predictions for every possible single amino acid variant in human, mouse, frog, zebrafish, fruit fly, worm, and yeast proteomes (https://envision.gs.washington.edu/). Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Annotating Mutational Effects on Proteins and Protein Interactions: Designing Novel and Revisiting Existing Protocols.

    Science.gov (United States)

    Li, Minghui; Goncearenco, Alexander; Panchenko, Anna R

    2017-01-01

    In this review we describe a protocol to annotate the effects of missense mutations on proteins, their functions, stability, and binding. For this purpose we present a collection of the most comprehensive databases which store different types of sequencing data on missense mutations, we discuss their relationships, possible intersections, and unique features. Next, we suggest an annotation workflow using the state-of-the art methods and highlight their usability, advantages, and limitations for different cases. Finally, we address a particularly difficult problem of deciphering the molecular mechanisms of mutations on proteins and protein complexes to understand the origins and mechanisms of diseases.

  20. Distinct mutations in STXBP2 are associated with variable clinical presentations in patients with familial hemophagocytic lymphohistiocytosis type 5 (FHL5)

    DEFF Research Database (Denmark)

    Pagel, Julia; Beutel, Karin; Lehmberg, Kai

    2012-01-01

    the genetic and clinical spectrum of FHL5, we analyzed a cohort of 185 patients with suspected FHL for mutations in STXBP2. We detected biallelic mutations in 37 patients from 28 families of various ethnic origins. Missense mutations and mutations affecting 1 of the exon 15 splice sites were the predominant...... changes detectable in this cohort. Patients with exon 15 splice-site mutations (n = 13) developed clinical manifestations significantly later than patients with other mutations (median age, 4.1 year vs 2 months) and showed less severe impairment of degranulation and cytotoxic function of NK cells and CTLs....... Patients with FHL5 showed several atypical features, including sensorineural hearing deficit, abnormal bleeding, and, most frequently, severe diarrhea that was only present in early-onset disease. In conclusion, we report the largest cohort of patients with FHL5 so far, describe an extended disease...

  1. [beta]-hexosaminidase isozymes from cells cotransfected with [alpha] and [beta] cDNA constructs: Analysis of the [alpha]-subunit missense mutation associated with the adult form of Tay-Sachs disease

    Energy Technology Data Exchange (ETDEWEB)

    Brown, C.A.; Mahuran, D.J. (Univ. of Toronto (Canada))

    1993-08-01

    In vitro mutagenesis and transient expression in COS cells has been used to associate a missense mutation with a clinical or biochemical phenotype. Mutations affecting the [alpha]-subunit of [beta]-hexosaminidase A ([alpha][beta]) (E.C.3.2.1.52) result in Tay-Sachs disease. Because hexosaminidase A is heterodimeric, analysis of [alpha]-chain mutations is not straightforward. The authors examine three approaches utilizing previously identified mutations affecting [alpha]-chain folding. These involve transfection of (1) the [alpha] cDNA alone; (2) a [beta] cDNA construct encoding a [beta]-subunit substituted at a position homologous to that of the [alpha]-subunit, and (3) both [alpha] and [beta] cDNAs. The latter two procedures amplified residual activity levels over that of patient samples, an effect not previously found with mutations affecting an [open quotes]active[close quotes] [alpha]Arg residue. This effect may help to discriminate between protein-folding and active-site mutations. The authors conclude that, with proper controls, the latter method of cotransfection can be used to evaluate the effects and perhaps to predict the clinical course of some [alpha]-chain mutations. Using this technique, they demonstrate that the adult-onset Tay-Sachs mutation, [alpha]Gly[yields]Ser[sup 269], does not directly affect [alpha][beta] dimerization but exerts an indirect effect on the dimer through destabilizing the folded [alpha]-subunit at physiological temperatures. Two other [alpha] mutations linked to more severe phenotypes appear to inhibit the initial folding of the subunit. 36 refs., 2 figs., 5 tabs.

  2. Autosomal recessive mutations in THOC6 cause intellectual disability: syndrome delineation requiring forward and reverse phenotyping.

    Science.gov (United States)

    Amos, J S; Huang, L; Thevenon, J; Kariminedjad, A; Beaulieu, C L; Masurel-Paulet, A; Najmabadi, H; Fattahi, Z; Beheshtian, M; Tonekaboni, S H; Tang, S; Helbig, K L; Alcaraz, W; Rivière, J-B; Faivre, L; Innes, A M; Lebel, R R; Boycott, K M

    2017-01-01

    THOC6 is a part of the THO complex, which is involved in coordinating mRNA processing with export. The THO complex interacts with additional components to form the larger TREX complex (transcription export complex). Previously, a homozygous missense mutation in THOC6 in the Hutterite population was reported in association with syndromic intellectual disability. Using exome sequencing, we identified three unrelated patients with bi-allelic mutations in THOC6 associated with intellectual disability and additional clinical features. Two of the patients were compound heterozygous for a stop and a missense mutation, and the third was homozygous for a missense mutation; the missense mutations were predicted to be pathogenic by in silico analysis and modeling. Clinical features of the three newly identified patients and those previously reported are reviewed; intellectual disability is moderate to severe, and malformations are variable including renal and heart defects, cleft palate, microcephaly, and corpus callosum dysgenesis. Facial features are variable and include tall forehead, short upslanting palpebral fissures +/- deep set eyes, and a long nose with overhanging columella. These subtle facial features render the diagnosis difficult to make in isolation with certainty. Our results expand the mutational and clinical spectrum of this rare disease, confirm that THOC6 is an intellectual disability causing gene, while providing insight into the importance of the THO complex in neurodevelopment. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Whole Exome Sequencing Leading to the Diagnosis of Dysferlinopathy with a Novel Missense Mutation (c.959G>C

    Directory of Open Access Journals (Sweden)

    Abhisek Swaika

    2016-01-01

    Full Text Available Dysferlinopathy is an uncommon, progressive muscular dystrophy that has a wide phenotypic variability and primarily supportive management (Nguyen et al., 2007; Narayanaswami et al., 2014. Amyloid myopathy is a distinct, rare disorder that can present similarly to inflammatory myopathies and requires a high clinical suspicion for early intervention to prolong survival. Amyloid myopathy is typically associated with other systemic manifestations of amyloidosis, but rare cases of isolated amyloid myopathy have been described (Mandl et al., 2000; Hull et al., 2001. Positive Congo red stains on tissue biopsy remain the gold standard for diagnosis (Spuler et al., 1998; Karacostas et al., 2005. A high clinical suspicion and meticulous diagnostic workup that includes novel techniques are necessary for identifying these rare disorders. We report a middle-aged man with progressive leg muscle weakness who was initially treated as having amyloid myopathy but was later diagnosed as having dysferlinopathy by Whole Exome Sequencing (WES analysis. We also report a novel missense mutation (c.959G>C to help correlate in any patient with presumed dysferlinopathy and to add to the already known genotype of this disorder.

  4. Novel USH2A mutations in Israeli patients with retinitis pigmentosa and Usher syndrome type 2.

    Science.gov (United States)

    Kaiserman, Nadia; Obolensky, Alexey; Banin, Eyal; Sharon, Dror

    2007-02-01

    To identify USH2A mutations in Israeli patients with autosomal-recessive Usher syndrome type 2 (USH2) and retinitis pigmentosa (RP). Patients from 95 families with RP and 4 with USH2 were clinically evaluated. USH2A exons 2-72 were scanned for mutations using single-strand conformation and sequencing analyses. The frequency of novel missense changes was determined in patients and controls using restriction endonucleases. The analysis revealed 3 USH2A mutations, 2 of which are novel, in 2 families with USH2 and a large family (MOL0051) with both USH2 and RP. Compound heterozygotes for 2 null mutations (Thr80fs and Arg737stop) in MOL0051 suffered from USH2 while compound heterozygotes for 1 of the null mutations and a novel missense mutation (Gly4674Arg) had nonsyndromic RP. Our results support the involvement of USH2A in nonsyndromic RP and we report here of a second, novel, missense mutation in this gene causing autosomal-recessive RP. Possible involvement of USH2A should be considered in the molecular genetic evaluation of patients with autosomal-recessive RP. Understanding the mechanism by which different USH2A mutations cause either USH2 or RP may assist in the development of novel therapeutic approaches.

  5. Novel splice-site and missense mutations in the ALDH1A3 gene underlying autosomal recessive anophthalmia/microphthalmia.

    Science.gov (United States)

    Semerci, C Nur; Kalay, Ersan; Yıldırım, Cem; Dinçer, Tuba; Olmez, Akgün; Toraman, Bayram; Koçyiğit, Ali; Bulgu, Yunus; Okur, Volkan; Satıroğlu-Tufan, Lale; Akarsu, Nurten A

    2014-06-01

    This study aimed to identify the underlying genetic defect responsible for anophthalmia/microphthalmia. In total, two Turkish families with a total of nine affected individuals were included in the study. Affymetrix 250 K single nucleotide polymorphism genotyping and homozygosity mapping were used to identify the localisation of the genetic defect in question. Coding region of the ALDH1A3 gene was screened via direct sequencing. cDNA samples were generated from primary fibroblast cell cultures for expression analysis. Reverse transcriptase PCR (RT-PCR) analysis was performed using direct sequencing of the obtained fragments. The causative genetic defect was mapped to chromosome 15q26.3. A homozygous G>A substitution (c.666G>A) at the last nucleotide of exon 6 in the ALDH1A3 gene was identified in the first family. Further cDNA sequencing of ALDH1A3 showed that the c.666G>A mutation caused skipping of exon 6, which predicted in-frame loss of 43 amino acids (p.Trp180_Glu222del). A novel missense c.1398C>A mutation in exon 12 of ALDH1A3 that causes the substitution of a conserved asparagine by lysine at amino acid position 466 (p.Asn466Lys) was observed in the second family. No extraocular findings-except for nevus flammeus in one affected individual and a variant of Dandy-Walker malformation in another affected individual-were observed. Autistic-like behaviour and mental retardation were observed in three cases. In conclusion, novel ALDH1A3 mutations identified in the present study confirm the pivotal role of ALDH1A3 in human eye development. Autistic features, previously reported as an associated finding, were considered to be the result of social deprivation and inadequate parenting during early infancy in the presented families. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. A novel homozygous Arg222Trp missense mutation in WNT7A in two sisters with severe Al-Awadi/Raas-Rothschild/Schinzel phocomelia syndrome.

    Science.gov (United States)

    Kantaputra, Piranit N; Mundlos, Stefan; Sripathomsawat, Warissara

    2010-11-01

    Al-Awadi/Raas-Rothschild/Schinzel phocomelia (AARRS) syndrome, a rare autosomal recessive disorder, comprises malformations of upper and lower limbs with severely hypoplastic pelvis and abnormal genitalia. Mutations in WNT7A have been reported as cause of the syndrome. We report on two sisters in a Thai family with short and malformed long bones, absent fibulae, flexion contracture of digits, and a/hypoplastic nails. Fusion between severely malformed femora and slender tibiae has never been reported in patients with WNT7A mutations. Lower limbs were more severely malformed than the upper ones and the pelvis was also severely affected. Multiple fusions of long bones and of the femoral heads to the acetabula were evident. A novel homozygous missense mutation in coding exon 4 of the WNT7A was detected in both affected daughters (c.664C > T) leading to an amino acid exchange from arginine to tryptophan (p.Arg222Trp; R222W). The phenotype is likely to result from an abnormality of all three signaling centers in the developing limb resulting in ventralization with a loss of dorsal structures (aplasia/hypoplasia of nails) a loss of anterior-posterior identity (single distal bones in lower limb without polarity) and an outgrowth defect resulting in distal truncations. © 2010 Wiley-Liss, Inc.

  7. CDH23 mutation and phenotype heterogeneity: a profile of 107 diverse families with Usher syndrome and nonsyndromic deafness.

    Science.gov (United States)

    Astuto, L M; Bork, J M; Weston, M D; Askew, J W; Fields, R R; Orten, D J; Ohliger, S J; Riazuddin, S; Morell, R J; Khan, S; Riazuddin, S; Kremer, H; van Hauwe, P; Moller, C G; Cremers, C W R J; Ayuso, C; Heckenlively, J R; Rohrschneider, K; Spandau, U; Greenberg, J; Ramesar, R; Reardon, W; Bitoun, P; Millan, J; Legge, R; Friedman, T B; Kimberling, W J

    2002-08-01

    Usher syndrome type I is characterized by congenital hearing loss, retinitis pigmentosa (RP), and variable vestibular areflexia. Usher syndrome type ID, one of seven Usher syndrome type I genetic localizations, have been mapped to a chromosomal interval that overlaps with a nonsyndromic-deafness localization, DFNB12. Mutations in CDH23, a gene that encodes a putative cell-adhesion protein with multiple cadherin-like domains, are responsible for both Usher syndrome and DFNB12 nonsyndromic deafness. Specific CDH23 mutational defects have been identified that differentiate these two phenotypes. Only missense mutations of CDH23 have been observed in families with nonsyndromic deafness, whereas nonsense, frameshift, splice-site, and missense mutations have been identified in families with Usher syndrome. In the present study, a panel of 69 probands with Usher syndrome and 38 probands with recessive nonsyndromic deafness were screened for the presence of mutations in the entire coding region of CDH23, by heteroduplex, single-strand conformation polymorphism, and direct sequence analyses. A total of 36 different CDH23 mutations were detected in 45 families; 33 of these mutations were novel, including 18 missense, 3 nonsense, 5 splicing defects, 5 microdeletions, and 2 insertions. A total of seven mutations were common to more than one family. Numerous exonic and intronic polymorphisms also were detected. Results of ophthalmologic examinations of the patients with nonsyndromic deafness have found asymptomatic RP-like manifestations, indicating that missense mutations may have a subtle effect in the retina. Furthermore, patients with mutations in CDH23 display a wide range of hearing loss and RP phenotypes, differing in severity, age at onset, type, and the presence or absence of vestibular areflexia.

  8. CDH23 Mutation and Phenotype Heterogeneity: A Profile of 107 Diverse Families with Usher Syndrome and Nonsyndromic Deafness

    Science.gov (United States)

    Astuto, L. M.; Bork, J. M.; Weston, M. D.; Askew, J. W.; Fields, R. R.; Orten, D. J.; Ohliger, S. J.; Riazuddin, S.; Morell, R. J.; Khan, S.; Riazuddin, S.; Kremer, H.; van Hauwe, P.; Moller, C. G.; Cremers, C. W. R. J.; Ayuso, C.; Heckenlively, J. R.; Rohrschneider, K.; Spandau, U.; Greenberg, J.; Ramesar, R.; Reardon, W.; Bitoun, P.; Millan, J.; Legge, R.; Friedman, T. B.; Kimberling, W. J.

    2002-01-01

    Usher syndrome type I is characterized by congenital hearing loss, retinitis pigmentosa (RP), and variable vestibular areflexia. Usher syndrome type ID, one of seven Usher syndrome type I genetic localizations, have been mapped to a chromosomal interval that overlaps with a nonsyndromic-deafness localization, DFNB12. Mutations in CDH23, a gene that encodes a putative cell-adhesion protein with multiple cadherin-like domains, are responsible for both Usher syndrome and DFNB12 nonsyndromic deafness. Specific CDH23 mutational defects have been identified that differentiate these two phenotypes. Only missense mutations of CDH23 have been observed in families with nonsyndromic deafness, whereas nonsense, frameshift, splice-site, and missense mutations have been identified in families with Usher syndrome. In the present study, a panel of 69 probands with Usher syndrome and 38 probands with recessive nonsyndromic deafness were screened for the presence of mutations in the entire coding region of CDH23, by heteroduplex, single-strand conformation polymorphism, and direct sequence analyses. A total of 36 different CDH23 mutations were detected in 45 families; 33 of these mutations were novel, including 18 missense, 3 nonsense, 5 splicing defects, 5 microdeletions, and 2 insertions. A total of seven mutations were common to more than one family. Numerous exonic and intronic polymorphisms also were detected. Results of ophthalmologic examinations of the patients with nonsyndromic deafness have found asymptomatic RP–like manifestations, indicating that missense mutations may have a subtle effect in the retina. Furthermore, patients with mutations in CDH23 display a wide range of hearing loss and RP phenotypes, differing in severity, age at onset, type, and the presence or absence of vestibular areflexia. PMID:12075507

  9. Mucinous Cystic Neoplasms Lined by Abundant Mucinous Epithelium Frequently Involve KRAS Mutations and Malignant Progression.

    Science.gov (United States)

    Shibata, Hideki; Ohike, Nobuyuki; Norose, Tomoko; Isobe, Tomohide; Suzuki, Reika; Imai, Hideyuki; Shiokawa, Akira; Aoki, Takeshi; Murakami, Masahiko; Mizukami, Hiroki; Tanaka, Jun-Ichi; Takimoto, Masafumi

    2017-12-01

    Pancreatic and hepatic mucinous cyst neoplasms (MCNs) have a malignant potential, but indolent MCNs are not uncommon. The pathological and genetic characteristics of resected MCNs (n=15) categorized by the amount of mucin of the lining epithelium were investigated. MCNs were divided into two groups: (i) a rich (r)-MCN group (n=6), in which more than half of the epithelium was lined by abundant mucinous epithelium; and (ii) a poor (p)-MCN group (n=9), which consisted of the remaining cases. Three patients in the r-MCN group showed invasive carcinoma or high-grade dysplasia, whereas all patients in the p-MCN group showed low-grade dysplasia. Mutations of Kirsten rat sarcoma viral oncogene homolog (KRAS) were more frequent in the r-MCN group (83%) (p-MCN; 11%, p<0.05). Mucinous MCNs more frequently have KRAS mutations and higher risk of malignant progression. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  10. A novel AMELX mutation causes hypoplastic amelogenesis imperfecta.

    Science.gov (United States)

    Kim, Young-Jae; Kim, Youn Jung; Kang, Jenny; Shin, Teo Jeon; Hyun, Hong-Keun; Lee, Sang-Hoon; Lee, Zang Hee; Kim, Jung-Wook

    2017-04-01

    Amelogenesis imperfecta (AI) is a hereditary genetic defect affecting tooth enamel. AI is heterogeneous in clinical phenotype as well as in genetic etiology. To date, more than 10 genes have been associated with the etiology of AI. Amelogenin is the most abundant enamel matrix protein, most of which is encoded by the amelogenin gene in the X-chromosome (AMELX). More than 16 alternative splicing transcripts have been identified in the murine Amelx gene. The purpose of this study was to identify the genetic cause of an AI family. We recruited a family with hypoplastic AI and performed mutational analysis on the candidate gene based on the clinical phenotype. Mutational analysis revealed a missense mutation in exon 6 (NM_182680.1; c.242C > T), which changes a sequence in a highly conserved amino acid (NP_872621.1; p.Pro81Leu). Furthermore, a splicing assay using a minigene displayed that the mutation changed the mRNA splicing repertory. In this study, we identified a novel AMELX missense mutation causing hypoplastic AI, and this mutation also resulted in altered mRNA splicing. These results will not only expand the mutation spectrum causing AI but also broaden our understanding of the biological mechanism of enamel formation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The first USH2A mutation analysis of Japanese autosomal recessive retinitis pigmentosa patients: a totally different mutation profile with the lack of frequent mutations found in Caucasian patients.

    Science.gov (United States)

    Zhao, Yang; Hosono, Katsuhiro; Suto, Kimiko; Ishigami, Chie; Arai, Yuuki; Hikoya, Akiko; Hirami, Yasuhiko; Ohtsubo, Masafumi; Ueno, Shinji; Terasaki, Hiroko; Sato, Miho; Nakanishi, Hiroshi; Endo, Shiori; Mizuta, Kunihiro; Mineta, Hiroyuki; Kondo, Mineo; Takahashi, Masayo; Minoshima, Shinsei; Hotta, Yoshihiro

    2014-09-01

    Retinitis pigmentosa (RP) is a highly heterogeneous genetic disease. The USH2A gene, which accounts for approximately 74-90% of Usher syndrome type 2 (USH2) cases, is also one of the major autosomal recessive RP (arRP) causative genes among Caucasian populations. To identify disease-causing USH2A gene mutations in Japanese RP patients, all 73 exons were screened for mutations by direct sequencing. In total, 100 unrelated Japanese RP patients with no systemic manifestations were identified, excluding families with obvious autosomal dominant inheritance. Of these 100 patients, 82 were included in this present study after 18 RP patients with very likely pathogenic EYS (eyes shut homolog) mutations were excluded. The mutation analysis of the USH2A revealed five very likely pathogenic mutations in four patients. A patient had only one very likely pathogenic mutation and the others had two of them. Caucasian frequent mutations p.C759F in arRP and p.E767fs in USH2 were not found. All the four patients exhibited typical clinical features of RP. The observed prevalence of USH2A gene mutations was approximately 4% among Japanese arRP patients, and the profile of the USH2A gene mutations differed largely between Japanese patients and previously reported Caucasian populations.

  12. Mutations in the newly identified RAX regulatory sequence are not a frequent cause of micro/anophthalmia.

    Science.gov (United States)

    Chassaing, Nicolas; Vigouroux, Adeline; Calvas, Patrick

    2009-06-01

    Microphthalmia and anophthalmia are at the severe end of the spectrum of abnormalities in ocular development. A few genes (SOX2, OTX2, RAX, and CHX10) have been implicated in isolated micro/anophthalmia, but causative mutations of these genes explain less than a quarter of these developmental defects. A specifically conserved SOX2/OTX2-mediated RAX expression regulatory sequence has recently been identified. We postulated that mutations in this sequence could lead to micro/anophthalmia, and thus we performed molecular screening of this regulatory element in patients suffering from micro/anophthalmia. Fifty-one patients suffering from nonsyndromic microphthalmia (n = 40) or anophthalmia (n = 11) were included in this study after negative molecular screening for SOX2, OTX2, RAX, and CHX10 mutations. Mutation screening of the RAX regulatory sequence was performed by direct sequencing for these patients. No mutations were identified in the highly conserved RAX regulatory sequence in any of the 51 patients. Mutations in the newly identified RAX regulatory sequence do not represent a frequent cause of nonsyndromic micro/anophthalmia.

  13. Increased missense mutation burden of Fatty Acid metabolism related genes in nunavik inuit population.

    Science.gov (United States)

    Zhou, Sirui; Xiong, Lan; Xie, Pingxing; Ambalavanan, Amirthagowri; Bourassa, Cynthia V; Dionne-Laporte, Alexandre; Spiegelman, Dan; Turcotte Gauthier, Maude; Henrion, Edouard; Diallo, Ousmane; Dion, Patrick A; Rouleau, Guy A

    2015-01-01

    Nunavik Inuit (northern Quebec, Canada) reside along the arctic coastline where for generations their daily energy intake has mainly been derived from animal fat. Given this particular diet it has been hypothesized that natural selection would lead to population specific allele frequency differences and unique variants in genes related to fatty acid metabolism. A group of genes, namely CPT1A, CPT1B, CPT1C, CPT2, CRAT and CROT, encode for three carnitine acyltransferases that are important for the oxidation of fatty acids, a critical step in their metabolism. Exome sequencing and SNP array genotyping were used to examine the genetic variations in the six genes encoding for the carnitine acyltransferases in 113 Nunavik Inuit individuals. Altogether ten missense variants were found in genes CPT1A, CPT1B, CPT1C, CPT2 and CRAT, including three novel variants and one Inuit specific variant CPT1A p.P479L (rs80356779). The latter has the highest frequency (0.955) compared to other Inuit populations. We found that by comparison to Asians or Europeans, the Nunavik Inuit have an increased mutation burden in CPT1A, CPT2 and CRAT; there is also a high level of population differentiation based on carnitine acyltransferase gene variations between Nunavik Inuit and Asians. The increased number and frequency of deleterious variants in these fatty acid metabolism genes in Nunavik Inuit may be the result of genetic adaptation to their diet and/or the extremely cold climate. In addition, the identification of these variants may help to understand some of the specific health risks of Nunavik Inuit.

  14. EDNRB mutations cause Waardenburg syndrome type II in the heterozygous state.

    Science.gov (United States)

    Issa, Sarah; Bondurand, Nadege; Faubert, Emmanuelle; Poisson, Sylvain; Lecerf, Laure; Nitschke, Patrick; Deggouj, Naima; Loundon, Natalie; Jonard, Laurence; David, Albert; Sznajer, Yves; Blanchet, Patricia; Marlin, Sandrine; Pingault, Veronique

    2017-05-01

    Waardenburg syndrome (WS) is a genetic disorder characterized by sensorineural hearing loss and pigmentation anomalies. The clinical definition of four WS types is based on additional features due to defects in structures mostly arising from the neural crest, with type I and type II being the most frequent. While type I is tightly associated to PAX3 mutations, WS type II (WS2) remains partly enigmatic with mutations in known genes (MITF, SOX10) accounting for only 30% of the cases. We performed exome sequencing in a WS2 index case and identified a heterozygous missense variation in EDNRB. Interestingly, homozygous (and very rare heterozygous) EDNRB mutations are already described in type IV WS (i.e., in association with Hirschsprung disease [HD]) and heterozygous mutations in isolated HD. Screening of a WS2 cohort led to the identification of an overall of six heterozygous EDNRB variations. Clinical phenotypes, pedigrees and molecular segregation investigations unraveled a dominant mode of inheritance with incomplete penetrance. In parallel, cellular and functional studies showed that each of the mutations impairs the subcellular localization of the receptor or induces a defective downstream signaling pathway. Based on our results, we now estimate EDNRB mutations to be responsible for 5%-6% of WS2. © 2017 Wiley Periodicals, Inc.

  15. Frequent alteration of MLL3 frameshift mutations in microsatellite deficient colorectal cancer.

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    Yoshiyuki Watanabe

    Full Text Available MLL3 is a histone 3-lysine 4 methyltransferase with tumor-suppressor properties that belongs to a family of chromatin regulator genes potentially altered in neoplasia. Mutations in MLL3 were found in a whole genome analysis of colorectal cancer but have not been confirmed by a separate study.We analyzed mutations of coding region and promoter methylation in MLL3 using 126 cases of colorectal cancer. We found two isoforms of MLL3 and DNA sequencing revealed frameshift and other mutations affecting both isoforms of MLL3 in colorectal cancer cells and 19 of 134 (14% primary colorectal samples analyzed. Moreover, frameshift mutations were more common in cases with microsatellite instability (31% both in CRC cell lines and primary tumors. The largest isoform of MLL3 is transcribed from a CpG island-associated promoter that has highly homology with a pseudo-gene on chromosome 22 (psiTPTE22. Using an assay which measured both loci simultaneously we found prominent age related methylation in normal colon (from 21% in individuals less than 25 years old to 56% in individuals older than 70, R = 0.88, p<0.001 and frequent hypermethylation (83% in both CRC cell lines and primary tumors. We next studied the two loci separately and found that age and cancer related methylation was solely a property of the pseudogene CpG island and that the MLL3 loci was unmethylated.We found that frameshift mutations of MLL3 in both CRC cells and primary tumor that were more common in cases with microsatellite instability. Moreover, we have shown CpG island-associated promoter of MLL3 gene has no DNA methylation in CRC cells but also primary tumor and normal colon, and this region has a highly homologous of pseudo gene (psiTPTE22 that was age relate DNA methylation.

  16. Infection-triggered familial or recurrent cases of acute necrotizing encephalopathy caused by mutations in a component of the nuclear pore, RANBP2

    DEFF Research Database (Denmark)

    Neilson, Derek E; Adams, Mark D; Orr, Caitlin M D

    2009-01-01

    a susceptibility locus (ANE1) in a family segregating recurrent ANE as an incompletely penetrant, autosomal-dominant trait. We now report that all affected individuals and obligate carriers in this family are heterozygous for a missense mutation (c.1880C-->T, p.Thr585Met) in the gene encoding the nuclear pore...... protein Ran Binding Protein 2 (RANBP2). To determine whether this mutation is the susceptibility allele, we screened controls and other patients with ANE who are unrelated to the index family. Patients from 9 of 15 additional kindreds with familial or recurrent ANE had the identical mutation. It arose de...... novo in two families and independently in several other families. Two other patients with familial ANE had different RANBP2 missense mutations that altered conserved residues. None of the three RANBP2 missense mutations were found in 19 patients with isolated ANE or in unaffected controls. We conclude...

  17. Mutational status of EGFR and KIT in thymoma and thymic carcinoma.

    Science.gov (United States)

    Yoh, Kiyotaka; Nishiwaki, Yutaka; Ishii, Genichiro; Goto, Koichi; Kubota, Kaoru; Ohmatsu, Hironobu; Niho, Seiji; Nagai, Kanji; Saijo, Nagahiro

    2008-12-01

    This study was conducted to evaluate the prevalence of EGFR and KIT mutations in thymomas and thymic carcinomas as a means of exploring the potential for molecularly targeted therapy with tyrosine kinase inhibitors. Genomic DNA was isolated from 41 paraffin-embedded tumor samples obtained from 24 thymomas and 17 thymic carcinomas. EGFR exons 18, 19, and 21, and KIT exons 9, 11, 13, and 17, were analyzed for mutations by PCR and direct sequencing. Protein expression of EGFR and KIT was evaluated immunohistochemically. EGFR mutations were detected in 2 of 20 thymomas, but not in any of the thymic carcinomas. All of the EGFR mutations detected were missense mutations (L858R and G863D) in exon 21. EGFR protein was expressed in 71% of the thymomas and 53% of the thymic carcinomas. The mutational analysis of KIT revealed only a missense mutation (L576P) in exon 11 of one thymic carcinoma. KIT protein was expressed in 88% of the thymic carcinomas and 0% of the thymomas. The results of this study indicate that EGFR and KIT mutations in thymomas and thymic carcinomas are rare, but that many of the tumors express EGFR or KIT protein.

  18. Homozygous STIL mutation causes holoprosencephaly and microcephaly in two siblings.

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    Charlotte Mouden

    Full Text Available Holoprosencephaly (HPE is a frequent congenital malformation of the brain characterized by impaired forebrain cleavage and midline facial anomalies. Heterozygous mutations in 14 genes have been identified in HPE patients that account for only 30% of HPE cases, suggesting the existence of other HPE genes. Data from homozygosity mapping and whole-exome sequencing in a consanguineous Turkish family were combined to identify a homozygous missense mutation (c.2150G>A; p.Gly717Glu in STIL, common to the two affected children. STIL has a role in centriole formation and has previously been described in rare cases of microcephaly. Rescue experiments in U2OS cells showed that the STIL p.Gly717Glu mutation was not able to fully restore the centriole duplication failure following depletion of endogenous STIL protein indicating the deleterious role of the mutation. In situ hybridization experiments using chick embryos demonstrated that expression of Stil was in accordance with a function during early patterning of the forebrain. It is only the second time that a STIL homozygous mutation causing a recessive form of HPE was reported. This result also supports the genetic heterogeneity of HPE and increases the panel of genes to be tested for HPE diagnosis.

  19. Mutational Analysis of PTPN11 Gene in Taiwanese Children with Noonan Syndrome

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    Chia-Sui Hung

    2007-01-01

    Full Text Available Noonan syndrome (NS is an autosomal dominant disorder presenting with characteristic facies, short stature, skeletal anomalies, and congenital heart defects. Mutations in protein-tyrosine phosphatase, nonreceptor-type 11 (PTPN11, encoding SHP-2, account for 33-50% of NS. This study screened for mutations in the PTPN11 gene in 34 Taiwanese patients with NS. Mutation analysis of the 15 coding exons and exon/intron boundaries was performed by polymerase chain reaction and direct sequencing of the PTPN11 gene. We identified 10 different missense mutations in 13 (38% patients, including a novel missense mutation (855T > G, F285L. These mutations were clustered in exon 3 (n = 6 encoding the N-SH2 domain, exon 4 (n = 2 encoding the C-SH2 domain, and in exons 8 (n = 2 and 13 (n = 3 encoding the PTP domain. In conclusion, this study provides further support that PTPN11 mutations are responsible for Noonan syndrome in Taiwanese patients. [J Formos Med Assoc 2007;106(2:169-172

  20. Case reports of juvenile GM1 gangliosidosisis type II caused by mutation in GLB1 gene.

    Science.gov (United States)

    Karimzadeh, Parvaneh; Naderi, Samaneh; Modarresi, Farzaneh; Dastsooz, Hassan; Nemati, Hamid; Farokhashtiani, Tayebeh; Shamsian, Bibi Shahin; Inaloo, Soroor; Faghihi, Mohammad Ali

    2017-07-17

    Type II or juvenile GM1-gangliosidosis is an autosomal recessive lysosomal storage disorder, which is clinically distinct from infantile form of the disease by the lack of characteristic cherry-red spot and hepatosplenomegaly. The disease is characterized by slowly progressive neurodegeneration and mild skeletal changes. Due to the later age of onset and uncharacteristic presentation, diagnosis is frequently puzzled with other ataxic and purely neurological disorders. Up to now, 3-4 types of GM1-gangliosidosis have been reported and among them type I is the most common phenotype with the age of onset around 6 months. Various forms of GM1-gangliosidosis are caused by GLB1 gene mutations but severity of the disease and age of onset are directly related to the position and the nature of deleterious mutations. However, due to its unique genetic cause and overlapping clinical features, some researchers believe that GM1 gangliosidosis represents an overlapped disease spectrum instead of four distinct types. Here, we report a less frequent type of autosomal recessive GM1 gangliosidosis with perplexing clinical presentation in three families in the southwest part of Iran, who are unrelated but all from "Lurs" ethnic background. To identify disease-causing mutations, Whole Exome Sequencing (WES) utilizing next generation sequencing was performed. Four patients from three families were investigated with the age of onset around 3 years old. Clinical presentations were ataxia, gate disturbances and dystonia leading to wheelchair-dependent disability, regression of intellectual abilities, and general developmental regression. They all were born in consanguineous families with no previous documented similar disease in their parents. A homozygote missense mutation in GLB1 gene (c. 601 G > A, p.R201C) was found in all patients. Using Sanger sequencing this identified mutation was confirmed in the proband, their parents, grandparents, and extended family members, confirming

  1. Parkinson disease: α-synuclein mutational screening and new clinical insight into the p.E46K mutation.

    Science.gov (United States)

    Pimentel, Márcia M G; Rodrigues, Fabíola C; Leite, Marco Antônio A; Campos Júnior, Mário; Rosso, Ana Lucia; Nicaretta, Denise H; Pereira, João S; Silva, Delson José; Della Coletta, Marcus V; Vasconcellos, Luiz Felipe R; Abreu, Gabriella M; Dos Santos, Jussara M; Santos-Rebouças, Cíntia B

    2015-06-01

    Amongst Parkinson's disease-causing genetic factors, missense mutations and genomic multiplications in the gene encoding α-synuclein are well established causes of the disease, although genetic data in populations with a high degree of admixture, such as the Brazilian one, are still scarce. In this study, we conducted a molecular screening of α-synuclein point mutations and copy number variation in the largest cohort of Brazilian patients with Parkinson's disease (n = 549) and also in twelve Portuguese and one Bolivian immigrants. Genomic DNA was isolated from peripheral blood leukocytes or saliva, and the mutational screening was performed by quantitative and qualitative real-time PCR. The only alteration identified was the p.E46K mutation in a 60-year-old man, born in Bolivia, with a familial history of autosomal dominant Parkinson's disease. This is the second family ever reported, in which this rare pathogenic mutation is segregating. The same mutation was firstly described ten years ago in a Spanish family with a neurodegenerative syndrome combining parkinsonism, dementia and visual hallucinations. The clinical condition of our proband reveals a less aggressive phenotype than previously described and reinforces that marked phenotypic heterogeneity is common among patients with Parkinson's disease, even among those carriers sharing the same mutation. Our findings add new insight into the preexisting information about α-synuclein p.E46K, improving our understanding about the endophenotypes associated to this mutation and corroborate that missense alterations and multiplications in α-synuclein are uncommon among Brazilian patients with Parkinson's disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Rapid identification of HEXA mutations in Tay-Sachs patients.

    Science.gov (United States)

    Giraud, Carole; Dussau, Jeanne; Azouguene, Emilie; Feillet, François; Puech, Jean-Philippe; Caillaud, Catherine

    2010-02-19

    Tay-Sachs disease (TSD) is a recessively inherited neurodegenerative disorder due to mutations in the HEXA gene resulting in a beta-hexosaminidase A (Hex A) deficiency. The purpose of this study was to characterize the molecular abnormalities in patients with infantile or later-onset forms of the disease. The complete sequencing of the 14 exons and flanking regions of the HEXA gene was performed with a unique technical condition in 10 unrelated TSD patients. Eleven mutations were identified, including five splice mutations, one insertion, two deletions and three single-base substitutions. Four mutations were novel: two splice mutations (IVS8+5G>A, IVS2+4delAGTA), one missense mutation in exon 6 (c.621T>G (p.D207E)) and one small deletion (c.1211-1212delTG) in exon 11 resulting in a premature stop codon at residue 429. The c.621T>G missense mutation was found in a patient presenting an infantile form. Its putative role in the pathogenesis of TSD is suspected as residue 207 is highly conserved in human, mouse and rat. Moreover, structural modelling predicted changes likely to affect substrate binding and catalytic activity of the enzyme. The time-saving procedure reported here could be useful for the characterization of Tay-Sachs-causing mutations, in particular in non-Ashkenazi patients mainly exhibiting rare mutations. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  3. Effects of near-ultraviolet light on mutations, intragenic and intergenic recombinations in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Machida, Isamu; Saeki, Tetsuya; Nakai, Sayaka

    1986-01-01

    The effects of far and near ultraviolet light on mutations, intragenic and intergenic recombinations were compared in diploid strains of Saccharomyces cerevisiae. At equivalent survival levels there was not much difference in the induction of nonsense and missense mutations between far- and near-UV radiations. However, frameshift mutations were induced more frequently by near-UV than by far-UV radiation. Near-UV radiation induced intragenic recombination as efficiently as far-UV radiation. A strikingly higher frequency was observed for the intergenic recombination induced by near-UV radiation than by far-UV radiation when compared at equivalent survival levels. Photoreactivation reduced the frequency only slightly in far-UV induced intergenic recombination and not at all in near-UV induction. These results indicate that near-UV damage involves strand breakage in addition to pyrimidine dimers and other lesions induced, whereas far-UV damage consists largely of photoreactivable lesions, pyrimidine dimers, and near-UV induced damage is more efficient for the induction of crossing-over. (Auth.)

  4. Lamb–Shaffer syndrome, deferred outside not described by SOX5 mutation

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    I. V. Sharkova

    2018-01-01

    Full Text Available Clinical and genetic characteristics of a patient with Lamb–Shaffer syndrome due to the newly discovered heterozygous missense mutation p.1868A>C in the 14 exon of the SOX5 gene are presented in the next generation sequencing of exom. It is shown that, in contrast to the previously described patients due to the presence of a deletion in the region of the gene or segment of chromosome 12p12.1, in the presence of missense mutation, the intellectual deficit and the dysmorphic features of the structure are not pronounced sharply and there is no anomaly in the development of other organs and systems.

  5. Rats with a missense mutation in Atm display neuroinflammation and neurodegeneration subsequent to accumulation of cytosolic DNA following unrepaired DNA damage.

    Science.gov (United States)

    Quek, Hazel; Luff, John; Cheung, KaGeen; Kozlov, Sergei; Gatei, Magtouf; Lee, C Soon; Bellingham, Mark C; Noakes, Peter G; Lim, Yi Chieh; Barnett, Nigel L; Dingwall, Steven; Wolvetang, Ernst; Mashimo, Tomoji; Roberts, Tara L; Lavin, Martin F

    2017-04-01

    Mutations in the ataxia-telangiectasia (A-T)-mutated ( ATM ) gene give rise to the human genetic disorder A-T, characterized by immunodeficiency, cancer predisposition, and neurodegeneration. Whereas a series of animal models recapitulate much of the A-T phenotype, they fail to present with ataxia or neurodegeneration. We describe here the generation of an Atm missense mutant [amino acid change of leucine (L) to proline (P) at position 2262 (L2262P)] rat by intracytoplasmic injection (ICSI) of mutant sperm into oocytes. Atm -mutant rats ( Atm L2262P/L2262P ) expressed low levels of ATM protein, suggesting a destabilizing effect of the mutation, and had a significantly reduced lifespan compared with Atm +/+ Whereas these rats did not show cerebellar atrophy, they succumbed to hind-limb paralysis (45%), and the remainder developed tumors. Closer examination revealed the presence of both dsDNA and ssDNA in the cytoplasm of cells in the hippocampus, cerebellum, and spinal cord of Atm L2262P/L2262P rats. Significantly increased levels of IFN-β and IL-1β in all 3 tissues were indicative of DNA damage induction of the type 1 IFN response. This was further supported by NF-κB activation, as evidenced by p65 phosphorylation (P65) and translocation to the nucleus in the spinal cord and parahippocampus. Other evidence of neuroinflammation in the brain and spinal cord was the loss of motor neurons and the presence of increased activation of microglia. These data provide support for a proinflammatory phenotype that is manifested in the Atm mutant rat as hind-limb paralysis. This mutant represents a useful model to investigate the importance of neuroinflammation in A-T. © Society for Leukocyte Biology.

  6. Alternating hemiplegia of childhood-related neural and behavioural phenotypes in Na+,K+-ATPase α3 missense mutant mice.

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    Greer S Kirshenbaum

    Full Text Available Missense mutations in ATP1A3 encoding Na(+,K(+-ATPase α3 have been identified as the primary cause of alternating hemiplegia of childhood (AHC, a motor disorder with onset typically before the age of 6 months. Affected children tend to be of short stature and can also have epilepsy, ataxia and learning disability. The Na(+,K(+-ATPase has a well-known role in maintaining electrochemical gradients across cell membranes, but our understanding of how the mutations cause AHC is limited. Myshkin mutant mice carry an amino acid change (I810N that affects the same position in Na(+,K(+-ATPase α3 as I810S found in AHC. Using molecular modelling, we show that the Myshkin and AHC mutations display similarly severe structural impacts on Na(+,K(+-ATPase α3, including upon the K(+ pore and predicted K(+ binding sites. Behavioural analysis of Myshkin mice revealed phenotypic abnormalities similar to symptoms of AHC, including motor dysfunction and cognitive impairment. 2-DG imaging of Myshkin mice identified compromised thalamocortical functioning that includes a deficit in frontal cortex functioning (hypofrontality, directly mirroring that reported in AHC, along with reduced thalamocortical functional connectivity. Our results thus provide validation for missense mutations in Na(+,K(+-ATPase α3 as a cause of AHC, and highlight Myshkin mice as a starting point for the exploration of disease mechanisms and novel treatments in AHC.

  7. Dominant Red Coat Color in Holstein Cattle Is Associated with a Missense Mutation in the Coatomer Protein Complex, Subunit Alpha (COPA Gene.

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    Ben Dorshorst

    Full Text Available Coat color in Holstein dairy cattle is primarily controlled by the melanocortin 1 receptor (MC1R gene, a central determinant of black (eumelanin vs. red/brown pheomelanin synthesis across animal species. The major MC1R alleles in Holsteins are Dominant Black (MC1RD and Recessive Red (MC1Re. A novel form of dominant red coat color was first observed in an animal born in 1980. The mutation underlying this phenotype was named Dominant Red and is epistatic to the constitutively activated MC1RD. Here we show that a missense mutation in the coatomer protein complex, subunit alpha (COPA, a gene with previously no known role in pigmentation synthesis, is completely associated with Dominant Red in Holstein dairy cattle. The mutation results in an arginine to cysteine substitution at an amino acid residue completely conserved across eukaryotes. Despite this high level of conservation we show that both heterozygotes and homozygotes are healthy and viable. Analysis of hair pigment composition shows that the Dominant Red phenotype is similar to the MC1R Recessive Red phenotype, although less effective at reducing eumelanin synthesis. RNA-seq data similarly show that Dominant Red animals achieve predominantly pheomelanin synthesis by downregulating genes normally required for eumelanin synthesis. COPA is a component of the coat protein I seven subunit complex that is involved with retrograde and cis-Golgi intracellular coated vesicle transport of both protein and RNA cargo. This suggests that Dominant Red may be caused by aberrant MC1R protein or mRNA trafficking within the highly compartmentalized melanocyte, mimicking the effect of the Recessive Red loss of function MC1R allele.

  8. [Analysis of gene mutation in a Chinese family with Norrie disease].

    Science.gov (United States)

    Zhang, Tian-xiao; Zhao, Xiu-li; Hua, Rui; Zhang, Jin-song; Zhang, Xue

    2012-09-01

    To detect the pathogenic mutation in a Chinese family with Norrie disease. Clinical diagnosis was based on familial history, clinical sign and B ultrasonic examination. Peripheral blood samples were obtained from all available members in a Chinese family with Norrie disease. Genomic DNA was extracted from lymphocytes by the standard SDS-proteinase K-phenol/chloroform method. Two coding exons and all intron-exon boundaries of the NDP gene were PCR amplified using three pairs of primers and subjected to automatic DNA sequence. The causative mutation was confirmed by restriction enzyme analysis and genotyping analysis in all members. Sequence analysis of NDP gene revealed a missense mutation c.220C > T (p.Arg74Cys) in the proband and his mother. Further mutation identification by restriction enzyme analysis and genotyping analysis showed that the proband was homozygote of this mutation. His mother and other four unaffected members (III3, IV4, III5 and II2) were carriers of this mutation. The mutant amino acid located in the C-terminal cystine knot-like domain, which was critical motif for the structure and function of NDP. A NDP missense mutation was identified in a Chinese family with Norrie disease.

  9. ATM (ataxia-telangiectasia mutated) abnormality and diseases

    International Nuclear Information System (INIS)

    Takagi, Masatoshi; Nakata, Shinichiro; Mizutani, Shuki

    2007-01-01

    Ataxia-Telangiectasia (A-T) is an autosomal recessive inherited disease due to mutation of ATM gene on chromosome 11q22.3, with major symptoms of ataxia, telangiectasia, immunodeficiency and frequent complication of cancer, and the cells have characters of chromosomal break, high sensitivity to radiation and inappropriate continuation of DNA synthesis after radiation. This review describes past and present studies of ATM functions with clinical features in the following order: Clinical symptoms and epidemiology; ATM gene mutation in A-T patients, mainly by frame-shift (80-90%); ATM, whose gene consisted from 66 exons (150 kb), functions in phosphoinositide-3-kinase related kinase family which protecting cells from stress and integrating their system, at response to DNA double strand break, and in the cell cycle checkpoints at G1/S, S and G2/M phases; ATM nonsense/missense mutations in embryonic cells leading to carcinogenesis and role of ATM in the suppression of carcinogenesis in somatic cells; Chromosomal translocation which relating to carcinogenesis, by functional defect of ATM; and Other functions of ATM in neuronal growth, immunodeficiency, carbohydrate and lipid metabolism, early senescence, and virus infection. ATM is thus an essential molecule to maintain growth and homeostasis. (T.I.)

  10. Novel and recurrent mutations of WISP3 in two Chinese families with progressive pseudorheumatoid dysplasia.

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    Jing Sun

    Full Text Available BACKGROUND: The WNT1-inducible signaling pathway protein 3 (WISP3, which belongs to the CCN (cysteine-rich protein 61, connective tissue growth factor, nephroblastoma overexpressed family, is a secreted cysteine-rich matricellular protein that is involved in chondrogenesis, osteogenesis and tumorigenesis. WISP3 gene mutations are associated with progressive pseudorheumatoid dysplasia (PPD, OMIM208230, an autosomal recessive genetic disease that is characterized by the swelling of multiple joints and disproportionate dwarfism. METHODOLOGY/PRINCIPAL FINDINGS: Four PPD patients from two unrelated Chinese families were recruited for this study. The clinical diagnosis was confirmed by medical history, physical examinations, laboratory results and radiological abnormalities. WISP3 mutations were detected by direct DNA sequence analysis. In total, four different mutations were identified, which consisted of two missense mutations, one deletion and one insertion that spanned exons 3, 5 and 6 of the WISP3 gene. One of the missense mutations (c.342T>G/p.C114W and a seven-base pair frameshift deletion (c.716_722del/p.E239fs*16 were novel. The other missense mutation (c.1000T>C/p. S334P and the insertion mutation (c.866_867insA/p.Q289fs*31 had previously been identified in Chinese patients. All four cases had a compound heterozygous status, and their parents were heterozygous carriers of these mutations. CONCLUSIONS/SIGNIFICANCE: The results of our study expand the spectrum of WISP3 mutations that are associated with PPD and further elucidate the function of WISP3.

  11. Making Sense of Missense in the Lynch Syndrome: The Clinical Perspective

    Science.gov (United States)

    Lynch, Henry T.; Jascur, Thomas; Lanspa, Stephen; Boland, C. Richard

    2010-01-01

    The DNA mismatch repair system provides critical genetic housekeeping, and its failure is associated with tumorigenesis. Through distinct domains on the DNA mismatch repair proteins, the system recognizes and repairs errors occurring during DNA synthesis, but signals apoptosis when the DNA damage cannot be repaired. Certain missense mutations in the mismatch repair genes can selectively alter just one of these functions. This impacts the clinical features of tumors associated with defective DNA mismatch repair activity. New work reported by Xie et al. in this issue of the journal (beginning on page XXX) adds to the understanding of DNA mismatch repair. PMID:20978117

  12. The effect of the pathological V72I, D109N and T190M missense mutations on the molecular structure of α-dystroglycan.

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    Sonia Covaceuszach

    Full Text Available Dystroglycan (DG is a highly glycosylated protein complex that links the cytoskeleton with the extracellular matrix, mediating fundamental physiological functions such as mechanical stability of tissues, matrix organization and cell polarity. A crucial role in the glycosylation of the DG α subunit is played by its own N-terminal region that is required by the glycosyltransferase LARGE. Alteration in this O-glycosylation deeply impairs the high affinity binding to other extracellular matrix proteins such as laminins. Recently, three missense mutations in the gene encoding DG, mapped in the α-DG N-terminal region, were found to be responsible for hypoglycosylated states, causing congenital diseases of different severity referred as primary dystroglycanopaties.To gain insight on the molecular basis of these disorders, we investigated the crystallographic and solution structures of these pathological point mutants, namely V72I, D109N and T190M. Small Angle X-ray Scattering analysis reveals that these mutations affect the structures in solution, altering the distribution between compact and more elongated conformations. These results, supported by biochemical and biophysical assays, point to an altered structural flexibility of the mutant α-DG N-terminal region that may have repercussions on its interaction with LARGE and/or other DG-modifying enzymes, eventually reducing their catalytic efficiency.

  13. Mutational analysis of FLASH and PTPN13 genes in colorectal carcinomas.

    Science.gov (United States)

    Jeong, Eun Goo; Lee, Sung Hak; Yoo, Nam Jin; Lee, Sug Hyung

    2008-01-01

    The Fas-Fas ligand system is considered a major pathway for induction of apoptosis in cells and tissues. FLASH was identified as a pro-apoptotic protein that transmits apoptosis signal during Fas-mediated apoptosis. PTPN13 interacts with Fas and functions as both suppressor and inducer of Fas-mediated apoptosis. There are polyadenine tracts in both FLASH (A8 and A9 in exon 8) and PTPN13 (A8 in exon 7) genes that could be frameshift mutation targets in colorectal carcinomas. Because genes encoding proteins in Fas-mediated apoptosis frequently harbor somatic mutations in cancers, we explored the possibility as to whether mutations of FLASH and PTPN13 are a feature of colorectal carcinomas. We analysed human FLASH in exon 8 and PTPN13 in exon 7 for the detection of somatic mutations in 103 colorectal carcinomas by a polymerase chain reaction (PCR)- based single-strand conformation polymorphism (SSCP). We detected two mutations in FLASH gene, but none in PTPN13 gene. However, the two mutations were not frameshift (deletion or insertion) mutations in the polyadenine tracts of FLASH. The two mutations consisted of a deletion mutation (c.3734-3737delAGAA) and a missense mutation (c.3703A>C). These data indicate that frameshift mutation in the polyadenine tracts in both FLASH and PTPN13 genes is rare in colorectal carcinomas. Also, the data suggest that both FLASH and PTPN13 mutations in the polyadenine tracts may not have a crucial role in the pathogenesis of colorectal carcinomas.

  14. Screening of 1331 Danish breast and/or ovarian cancer families identified 40 novel BRCA1 and BRCA2 mutations

    DEFF Research Database (Denmark)

    Hansen, Thomas V O; Jønson, Lars; Steffensen, Ane Y

    2011-01-01

    Germ-line mutations in the tumour suppressor genes BRCA1 and BRCA2 predispose to breast and ovarian cancer. Since 1999 we have performed mutational screening of breast and/or ovarian cancer patients in East Denmark. During this period we have identified 40 novel sequence variations in BRCA1...... and BRCA2 in high risk breast and/or ovarian cancer families. The mutations were detected via pre-screening using dHPLC or high-resolution melting and direct sequencing. We identified 16 variants in BRCA1, including 9 deleterious frame-shift mutations, 2 intronic variants, 4 missense mutations, and 1......, the presumed significance of the missense mutations was predicted in silico using the align GVGD algorithm. In conclusion, the mutation screening identified 40 novel variants in the BRCA1 and BRCA2 genes and thereby extends the knowledge of the BRCA1/BRCA2 mutation spectrum. Nineteen of the mutations were...

  15. Structural Effects of Some Relevant Missense Mutations on the MECP2-DNA Binding: A MD Study Analyzed by Rescore+, a Versatile Rescoring Tool of the VEGA ZZ Program.

    Science.gov (United States)

    Pedretti, Alessandro; Granito, Cinzia; Mazzolari, Angelica; Vistoli, Giulio

    2016-09-01

    DNA methylation plays key roles in mammalian cells and is modulated by a set of proteins which recognize symmetrically methylated nucleotides. Among them, the protein MECP2 shows multifunctional roles repressing and/or activating genes by binding to both methylated and unmethylated regions of the genome. The interest for this protein markedly increased from the observation that its mutations are the primary cause of Rett syndrome, a neurodevelopmental disorder which causes mental retardation in young females. Thus, the present study is aimed to investigate the effects of some of these known pathogenic missense mutations (i.e. R106Q, R106W, R111G, R133C and R133H) on the MECP2 folding and DNA binding by molecular dynamics simulations. The effects of the simulated mutations are also parameterized by using a here proposed new tool, named Rescore+, implemented in the VEGA ZZ suite of programs, which calculates a set of scoring functions on all frames of a trajectory or on all complexes contained in a database thus allowing an easy rescoring of results coming from MD or docking simulations. The obtained results revealed that the reported loss of the MECP2 function induced by the simulated mutations can be ascribed to both stabilizing and destabilizing effect on DNA binding. The study confirms that MD simulations are particularly useful to rationalize and predict the mutation effects offering insightful information for diagnostics and drug design. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Hereditary 1,25-dihydroxyvitamin D-resistant rickets with alopecia resulting from a novel missense mutation in the DNA-binding domain of the vitamin D receptor

    Science.gov (United States)

    Malloy, Peter J.; Wang, Jining; Srivastava, Tarak; Feldman, David

    2009-01-01

    The rare genetic recessive disease, hereditary vitamin D resistant rickets (HVDRR), is caused by mutations in the vitamin D receptor (VDR) that result in resistance to the active hormone 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3 or calcitriol). In this study, we examined the VDR from a young boy with clinical features of HVDRR including severe rickets, hypocalcemia, hypophosphatemia and partial alopecia. The pattern of alopecia was very unusual with areas of total baldness, adjacent to normal hair and regions of scant hair. The child failed to improve on oral calcium and vitamin D therapy but his abnormal chemistries and his bone x-rays normalized with intravenous calcium therapy. We found that the child was homozygous for a unique missense mutation in the VDR gene that converted valine to methionine at amino acid 26 (V26M) in the VDR DNA-binding domain (DBD). The mutant VDR was studied in the patient’s cultured skin fibroblasts and found to exhibit normal [3H]1,25-(OH)2D3 binding and protein expression. However, the fibroblasts were unresponsive to treatment with high concentrations of 1,25(OH)2D3 as demonstrated by their failure to induce CYP24A1 gene expression, a marker of 1,25(OH)2D3 responsiveness. We recreated the V26M mutation in the WT VDR and showed that in transfected COS-7 cells the mutation abolished 1,25(OH)2D3-mediated transactivation. The mutant VDR exhibited normal ligand-induced binding to RXRα and to the coactivator DRIP205. However, the V26M mutation inhibited VDR binding to a consensus vitamin D response element (VDRE). In summary, we have identified a novel V26M mutation in the VDR DBD as the molecular defect in a patient with HVDRR and an unusual pattern of alopecia. PMID:19815438

  17. High frequency of potentially pathogenic SORL1 mutations in autosomal dominant early-onset Alzheimer disease.

    Science.gov (United States)

    Pottier, C; Hannequin, D; Coutant, S; Rovelet-Lecrux, A; Wallon, D; Rousseau, S; Legallic, S; Paquet, C; Bombois, S; Pariente, J; Thomas-Anterion, C; Michon, A; Croisile, B; Etcharry-Bouyx, F; Berr, C; Dartigues, J-F; Amouyel, P; Dauchel, H; Boutoleau-Bretonnière, C; Thauvin, C; Frebourg, T; Lambert, J-C; Campion, D

    2012-09-01

    Performing exome sequencing in 14 autosomal dominant early-onset Alzheimer disease (ADEOAD) index cases without mutation on known genes (amyloid precursor protein (APP), presenilin1 (PSEN1) and presenilin2 (PSEN2)), we found that in five patients, the SORL1 gene harbored unknown nonsense (n=1) or missense (n=4) mutations. These mutations were not retrieved in 1500 controls of same ethnic origin. In a replication sample, including 15 ADEOAD cases, 2 unknown non-synonymous mutations (1 missense, 1 nonsense) were retrieved, thus yielding to a total of 7/29 unknown mutations in the combined sample. Using in silico predictions, we conclude that these seven private mutations are likely to have a pathogenic effect. SORL1 encodes the Sortilin-related receptor LR11/SorLA, a protein involved in the control of amyloid beta peptide production. Our results suggest that besides the involvement of the APP and PSEN genes, further genetic heterogeneity, involving another gene of the same pathway is present in ADEOAD.

  18. Phenotype/genotype correlation in a case series of Stargardt's patients identifies novel mutations in the ABCA4 gene.

    Science.gov (United States)

    Gemenetzi, M; Lotery, A J

    2013-11-01

    To investigate phenotypic variability in terms of best-corrected visual acuity (BCVA) in patients with Stargardt disease (STGD) and confirmed ABCA4 mutations. Entire coding region analysis of the ABCA4 gene by direct sequencing of seven patients with clinical findings of STGD seen in the Retina Clinics of Southampton Eye Unit between 2002 and 2011.Phenotypic variables recorded were BCVA, fluorescein angiographic appearance, electrophysiology, and visual fields. All patients had heterozygous amino acid-changing variants (missense mutations) in the ABCA4 gene. A splice sequence change was found in a 30-year-old patient with severly affected vision. Two novel sequence changes were identified: a missense mutation in a mildly affected 44-year-old patient and a frameshift mutation in a severly affected 34-year-old patient. The identified ABCA4 mutations were compatible with the resulting phenotypes in terms of BCVA. Higher BCVAs were recorded in patients with missense mutations. Sequence changes, predicted to have more deleterious effect on protein function, resulted in a more severe phenotype. This case series of STGD patients demonstrates novel genotype/phenotype correlations, which may be useful to counselling of patients. This information may prove useful in selection of candidates for clinical trials in ABCA4 disease.

  19. A mutation in KIF7 is responsible for the autosomal recessive syndrome of macrocephaly, multiple epiphyseal dysplasia and distinctive facial appearance

    Directory of Open Access Journals (Sweden)

    Ali Bassam R

    2012-05-01

    Full Text Available Abstract Background We previously reported the existence of a unique autosomal recessive syndrome consisting of macrocephaly, multiple epiphyseal dysplasia and distinctive facial appearance mapping to chromosome 15q26. Methods In this manuscript, we have used whole exome sequencing on two affected members of a consanguineous family with this condition and carried out detailed bioinformatics analysis to elucidate the causative mutation. Results Our analysis resulted in the identification of a homozygous p.N1060S missense mutation in a highly conserved residue in KIF7, a regulator of Hedgehog signaling that has been recently found to be causing Joubert syndrome, fetal hydrolethalus and acrocallosal syndromes. The phenotype in our patients partially overlaps with the phenotypes associated with those syndromes but they also exhibit some distinctive features including multiple epiphyseal dysplasia. Conclusions We report the first missense homozygous disease-causing mutation in KIF7 and expand the clinical spectrum associated with mutations in this gene to include multiple epiphyseal dysplasia. The missense nature of the mutation might account for the unique presentation in our patients.

  20. Frequent mutations of chromatin remodeling genes in transitional cell carcinoma of the bladder

    DEFF Research Database (Denmark)

    Gui, Yaoting; Guo, Guangwu; Huang, Yi

    2011-01-01

    frequently in tumors of low stages and grades, highlighting its potential role in the classification and diagnosis of bladder cancer. Our results provide an overview of the genetic basis of TCC and suggest that aberration of chromatin regulation might be a hallmark of bladder cancer.......Transitional cell carcinoma (TCC) is the most common type of bladder cancer. Here we sequenced the exomes of nine individuals with TCC and screened all the somatically mutated genes in a prevalence set of 88 additional individuals with TCC with different tumor stages and grades. In our study, we...

  1. BRCA1 and BRCA2 Gene Mutations Screening In Sporadic Breast Cancer Patients In Kazakhstan.

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    Ainur R. Akilzhanova

    2013-05-01

    Full Text Available Background: A large number of distinct mutations in the BRCA1 and BRCA2 genes have been reported worldwide, but little is known regarding the role of these inherited susceptibility genes in breast cancer risk among Kazakhstan women. Aim: To evaluate the role of BRCA1/2 mutations in Kazakhstan women presenting with sporadic breast cancer. Methods: We investigated the distribution and nature of polymorphisms in BRCA1 and BRCA2 entire coding regions in 156 Kazakhstan sporadic breast cancer cases and 112 age-matched controls using automatic direct sequencing. Results: We identified 22 distinct variants, including 16 missense mutations and 6 polymorphisms in BRCA1/2 genes. In BRCA1, 9 missense mutations and 3 synonymous polymorphisms were observed. In BRCA2, 7 missense mutations and 3 polymorphisms were detected. There was a higher prevalence of observed mutations in Caucasian breast cancer cases compared to Asian cases (p<0.05; higher frequencies of sequence variants were observed in Asian controls. No recurrent or founder mutations were observed in BRCA1/2 genes. There were no statistically significant differences in age at diagnosis, tumor histology, size of tumor, and lymph node involvement between women with breast cancer with or without the BRCA sequence alterations. Conclusions: Considering the majority of breast cancer cases are sporadic, the present study will be helpful in the evaluation of the need for the genetic screening of BRCA1/2 mutations and reliable genetic counseling for Kazakhstan sporadic breast cancer patients. Evaluation of common polymorphisms and mutations and breast cancer risk in families with genetic predisposition to breast cancer is ongoing in another current investigation. 

  2. Novel glucokinase mutation in a boy with maturity-onset diabetes of the young

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    Milenković Tatjana

    2008-01-01

    Full Text Available INTRODUCTION Maturity-onset diabetes of the young (MODY is a heterogenous group of disorders characterized by an early onset of insulin-independent diabetes mellitus, an autosomal dominant mode of inheritance and a primary defect in beta-cell. There are six subtypes of MODY. MODY2 and MODY3 are the most frequent. CASE OUTLINE We present a nine-year-old boy with intermittent hyperglycaemia. According to family history, the diagnosis of MODY2 was suspected. Molecular analysis revealed novel missense mutation R250c in exon 7 of glucokinase gene. Mutation (c.748 C>T is the result of substitution of aminoacid cysteine by arginine (p.Arg250Cys. This is the first pediatric patient with MODY2 in Serbia whose diagnosis is established at molecular level. CONCLUSION Molecular diagnosis of MODY has important consequences in terms of prognosis, therapy and family screening of the disorder. Investigation of other patients with MODY2 in our country is important to establish prevalence and nature of mutations in glucokinase gene.

  3. Normosmic congenital hypogonadotropic hypogonadism due to TAC3/TACR3 mutations: characterization of neuroendocrine phenotypes and novel mutations.

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    Bruno Francou

    Full Text Available CONTEXT: TAC3/TACR3 mutations have been reported in normosmic congenital hypogonadotropic hypogonadism (nCHH (OMIM #146110. In the absence of animal models, studies of human neuroendocrine phenotypes associated with neurokinin B and NK3R receptor dysfunction can help to decipher the pathophysiology of this signaling pathway. OBJECTIVE: To evaluate the prevalence of TAC3/TACR3 mutations, characterize novel TACR3 mutations and to analyze neuroendocrine profiles in nCHH caused by deleterious TAC3/TACR3 biallelic mutations. RESULTS: From a cohort of 352 CHH, we selected 173 nCHH patients and identified nine patients carrying TAC3 or TACR3 variants (5.2%. We describe here 7 of these TACR3 variants (1 frameshift and 2 nonsense deleterious mutations and 4 missense variants found in 5 subjects. Modeling and functional studies of the latter demonstrated the deleterious consequence of one missense mutation (Tyr267Asn probably caused by the misfolding of the mutated NK3R protein. We found a statistically significant (p<0.0001 higher mean FSH/LH ratio in 11 nCHH patients with TAC3/TACR3 biallelic mutations than in 47 nCHH patients with either biallelic mutations in KISS1R, GNRHR, or with no identified mutations and than in 50 Kallmann patients with mutations in KAL1, FGFR1 or PROK2/PROKR2. Three patients with TAC3/TACR3 biallelic mutations had an apulsatile LH profile but low-frequency alpha-subunit pulses. Pulsatile GnRH administration increased alpha-subunit pulsatile frequency and reduced the FSH/LH ratio. CONCLUSION: The gonadotropin axis dysfunction associated with nCHH due to TAC3/TACR3 mutations is related to a low GnRH pulsatile frequency leading to a low frequency of alpha-subunit pulses and to an elevated FSH/LH ratio. This ratio might be useful for pre-screening nCHH patients for TAC3/TACR3 mutations.

  4. Four Novel Mutations in the ALPL Gene in Chinese patients with Odonto, Childhood and Adult Hypophosphatasia.

    Science.gov (United States)

    Xu, Lijun; Pang, Qianqian; Jiang, Yan; Wang, Ou; Li, Mei; Xing, Xiaoping; Xia, Weibo

    2018-05-03

    Background and purpose: Hypophosphatasiais (HPP) is a rare inherited disorder characterized by defective bone and/or dental mineralization, and decreased serum alkaline phosphatase activity. ALPL , the only gene related with HPP, encodes tissue non-specific alkaline phosphatase (TNSALP). Few studies were carried out in ALPL gene mutations in the Chinese population with HPP. The purpose of this study is to elucidate the clinical and genetic characteristics of HPP in 5 unrelated Chinese families and 2 sporadic patients. Methods : 10 clinically diagnosed HPP patients from 5 unrelated Chinese families and 2 sporadic patients and 50 healthy controls were genetic investigated. All 12 exons and exon-intron boundaries of the ALPL gene were amplified by polymerase chain reaction and directly sequenced. The laboratory and radiological investigations were conducted simultaneously in these 10 HPP patients. A three-dimensional model of the TNSALP was used to predict the dominant negative effect of identified missense mutations. Results : 3 odonto, 3 childhood and 4 adult types of HPP were clinically diagnosed. 10 mutations were identified in 5 unrelated Chinese families and 2 sporadic patients, including 8 missense mutations and 2 frameshift mutations. Of which, 4 were novel: 1 frameshift mutation (p.R138Pfsx45); 3 missense mutations (p.C201R, p.V459A, p.C497S). No identical mutations and any other new ALPL mutations were found in unrelated 50 healthy controls. Conclusions : Our study demonstrated that the ALPL  gene mutations are responsible for HPP in these Chinese families. These findings will be useful for clinicians to improve understanding of this heritable bone disorder. ©2018 The Author(s).

  5. Whole Genome Sequencing Identifies a Missense Mutation in HES7 Associated with Short Tails in Asian Domestic Cats.

    Science.gov (United States)

    Xu, Xiao; Sun, Xin; Hu, Xue-Song; Zhuang, Yan; Liu, Yue-Chen; Meng, Hao; Miao, Lin; Yu, He; Luo, Shu-Jin

    2016-08-25

    Domestic cats exhibit abundant variations in tail morphology and serve as an excellent model to study the development and evolution of vertebrate tails. Cats with shortened and kinked tails were first recorded in the Malayan archipelago by Charles Darwin in 1868 and remain quite common today in Southeast and East Asia. To elucidate the genetic basis of short tails in Asian cats, we built a pedigree of 13 cats segregating at the trait with a founder from southern China and performed linkage mapping based on whole genome sequencing data from the pedigree. The short-tailed trait was mapped to a 5.6 Mb region of Chr E1, within which the substitution c. 5T > C in the somite segmentation-related gene HES7 was identified as the causal mutation resulting in a missense change (p.V2A). Validation in 245 unrelated cats confirmed the correlation between HES7-c. 5T > C and Chinese short-tailed feral cats as well as the Japanese Bobtail breed, indicating a common genetic basis of the two. In addition, some of our sampled kinked-tailed cats could not be explained by either HES7 or the Manx-related T-box, suggesting at least three independent events in the evolution of domestic cats giving rise to short-tailed traits.

  6. Recurrent mutations in the CDKL5 gene: genotype-phenotype relationships.

    Science.gov (United States)

    Bahi-Buisson, Nadia; Villeneuve, Nathalie; Caietta, Emilie; Jacquette, Aurélia; Maurey, Helene; Matthijs, Gert; Van Esch, Hilde; Delahaye, Andrée; Moncla, Anne; Milh, Mathieu; Zufferey, Flore; Diebold, Bertrand; Bienvenu, Thierry

    2012-07-01

    Mutations in the cyclin-dependent kinase-like 5 gene (CDKL5) have been described in epileptic encephalopathies in females with infantile spasms with features that overlap with Rett syndrome. With more than 80 reported patients, the phenotype of CDKL5-related encephalopathy is well-defined. The main features consist of seizures starting before 6 months of age, severe intellectual disability with absent speech and hand stereotypies and deceleration of head growth, which resembles Rett syndrome. However, some clinical discrepancies suggested the influence of genetics and/or environmental factors. No genotype-phenotype correlation has been defined and thus there is a need to examine individual mutations. In this study, we analyzed eight recurrent CDKL5 mutations to test whether the clinical phenotype of patients with the same mutation is similar and whether patients with specific CDKL5 mutations have a milder phenotype than those with other CDKL5 mutations. Patients bearing missense mutations in the ATP binding site such as the p.Ala40Val mutation typically walked unaided, had normocephaly, better hand use ability, and less frequent refractory epilepsy when compared to girls with other CDKL5 mutations. In contrast, patients with mutations in the kinase domain (such as p.Arg59X, p.Arg134X, p.Arg178Trp/Pro/Gln, or c.145 + 2T > C) and frameshift mutations in the C-terminal region (such as c.2635_2636delCT) had a more severe phenotype with infantile spasms, refractory epileptic encephalopathy, absolute microcephaly, and inability to walk. It is important for clinicians to have this information when such patients are diagnosed. Copyright © 2012 Wiley Periodicals, Inc.

  7. CDKL5 mutations in boys with severe encephalopathy and early-onset intractable epilepsy.

    Science.gov (United States)

    Elia, M; Falco, M; Ferri, R; Spalletta, A; Bottitta, M; Calabrese, G; Carotenuto, M; Musumeci, S A; Lo Giudice, M; Fichera, M

    2008-09-23

    To search for CDKL5 gene mutations in boys presenting with severe early-onset encephalopathy and intractable epilepsy, a clinical picture very similar to that already described in girls with CDKL5 mutations. Eight boys (age range 3-16 years, mean age 8.5 years, SD 4.38) with severe or profound mental retardation and early-onset intractable seizures were selected for CDKL5 gene mutation screening by denaturing high-performance liquid chromatography analysis. We found three unrelated boys carrying three different missense mutations of the CDKL5 gene: c.872G>A (p.C291Y), c.863C>T (p.T288I), and c.533G>C (p.R178P). They presented early-onset, polymorphous, and drug-resistant seizures, mostly myoclonic and tonic or spasms. EEG showed epileptiform abnormalities which were multifocal during wakefulness, and pseudoperiodic bisynchronous during sleep. This study describes three boys carrying CDKL5 missense mutations and their detailed clinical and EEG data, and indicates that CDKL5 gene mutations may represent a cause of severe or profound mental retardation and early-onset intractable seizures, also in boys. Screening for CDKL5 mutations is strongly recommended in individuals with these clinical features.

  8. Missense mutation Lys18Asn in dystrophin that triggers X-linked dilated cardiomyopathy decreases protein stability, increases protein unfolding, and perturbs protein structure, but does not affect protein function.

    Directory of Open Access Journals (Sweden)

    Surinder M Singh

    Full Text Available Genetic mutations in a vital muscle protein dystrophin trigger X-linked dilated cardiomyopathy (XLDCM. However, disease mechanisms at the fundamental protein level are not understood. Such molecular knowledge is essential for developing therapies for XLDCM. Our main objective is to understand the effect of disease-causing mutations on the structure and function of dystrophin. This study is on a missense mutation K18N. The K18N mutation occurs in the N-terminal actin binding domain (N-ABD. We created and expressed the wild-type (WT N-ABD and its K18N mutant, and purified to homogeneity. Reversible folding experiments demonstrated that both mutant and WT did not aggregate upon refolding. Mutation did not affect the protein's overall secondary structure, as indicated by no changes in circular dichroism of the protein. However, the mutant is thermodynamically less stable than the WT (denaturant melts, and unfolds faster than the WT (stopped-flow kinetics. Despite having global secondary structure similar to that of the WT, mutant showed significant local structural changes at many amino acids when compared with the WT (heteronuclear NMR experiments. These structural changes indicate that the effect of mutation is propagated over long distances in the protein structure. Contrary to these structural and stability changes, the mutant had no significant effect on the actin-binding function as evident from co-sedimentation and depolymerization assays. These results summarize that the K18N mutation decreases thermodynamic stability, accelerates unfolding, perturbs protein structure, but does not affect the function. Therefore, K18N is a stability defect rather than a functional defect. Decrease in stability and increase in unfolding decrease the net population of dystrophin molecules available for function, which might trigger XLDCM. Consistently, XLDCM patients have decreased levels of dystrophin in cardiac muscle.

  9. The albinism of the feral Asinara white donkeys (Equus asinus) is determined by a missense mutation in a highly conserved position of the tyrosinase (TYR) gene deduced protein.

    Science.gov (United States)

    Utzeri, V J; Bertolini, F; Ribani, A; Schiavo, G; Dall'Olio, S; Fontanesi, L

    2016-02-01

    A feral donkey population (Equus asinus), living in the Asinara National Park (an island north-west of Sardinia, Italy), includes a unique white albino donkey subpopulation or colour morph that is a major attraction of this park. Disrupting mutations in the tyrosinase (TYR) gene are known to cause recessive albinisms in humans (oculocutaneous albinism Type 1; OCA1) and other species. In this study, we analysed the donkey TYR gene as a strong candidate to identify the causative mutation of the albinism of these donkeys. The TYR gene was sequenced from 13 donkeys (seven Asinara white albino and six coloured animals). Seven single nucleotide polymorphisms were identified. A missense mutation (c.604C>G; p.His202Asp) in a highly conserved amino acid position (even across kingdoms), which disrupts the first copper-binding site (CuA) of functional protein, was identified in the homozygous condition (G/G or D/D) in all Asinara white albino donkeys and in the albino son of a trio (the grey parents had genotype C/G or H/D), supporting the recessive mode of inheritance of this mutation. Genotyping 82 donkeys confirmed that Asinara albino donkeys had genotype G/G whereas all other coloured donkeys had genotype C/C or C/G. Across-population association between the c.604C>G genotypes and the albino coat colour was highly significant (P = 6.17E-18). The identification of the causative mutation of the albinism in the Asinara white donkeys might open new perspectives to study the dynamics of this putative deleterious allele in a feral population and to manage this interesting animal genetic resource. © 2015 Stichting International Foundation for Animal Genetics.

  10. Frequent Nuclear/Cytoplasmic Localization of β-Catenin without Exon 3 Mutations in Malignant Melanoma

    Science.gov (United States)

    Rimm, David L.; Caca, Karel; Hu, Gang; Harrison, Frank B.; Fearon, Eric R.

    1999-01-01

    β-Catenin has a critical role in E-cadherin-mediated cell-cell adhesion, and it also functions as a downstream signaling molecule in the wnt pathway. Mutations in the putative glycogen synthase kinase 3β phosphorylation sites near the β-catenin amino terminus have been found in some cancers and cancer cell lines. The mutations render β-catenin resistant to regulation by a complex containing the glycogen synthase kinase 3β, adenomatous polyposis coli, and axin proteins. As a result, β-catenin accumulates in the cytosol and nucleus and activates T-cell factor/lymphoid enhancing factor transcription factors. Previously, 6 of 27 melanoma cell lines were found to have β-catenin exon 3 mutations affecting the N-terminal phosphorylation sites (Rubinfeld B, Robbins P, Elgamil M, Albert I, Porfiri E, Polakis P: Stabilization of beta-catenin by genetic defects in melanoma cell lines. Science 1997, 275:1790–1792). To assess the role of β-catenin defects in primary melanomas, we undertook immunohistochemical and DNA sequencing studies in 65 melanoma specimens. Nuclear and/or cytoplasmic localization of β-catenin, a potential indicator of wnt pathway activation, was seen focally within roughly one third of the tumors, though a clonal somatic mutation in β-catenin was found in only one case (codon 45 Ser→Pro). Our findings demonstrate that β-catenin mutations are rare in primary melanoma, in contrast to the situation in melanoma cell lines. Nonetheless, activation of β-catenin, as indicated by its nuclear and/or cytoplasmic localization, appears to be frequent in melanoma, and in some cases, it may reflect focal and transient activation of the wnt pathway within the tumor. PMID:10027390

  11. Mutations in REEP6 Cause Autosomal-Recessive Retinitis Pigmentosa.

    Science.gov (United States)

    Arno, Gavin; Agrawal, Smriti A; Eblimit, Aiden; Bellingham, James; Xu, Mingchu; Wang, Feng; Chakarova, Christina; Parfitt, David A; Lane, Amelia; Burgoyne, Thomas; Hull, Sarah; Carss, Keren J; Fiorentino, Alessia; Hayes, Matthew J; Munro, Peter M; Nicols, Ralph; Pontikos, Nikolas; Holder, Graham E; Asomugha, Chinwe; Raymond, F Lucy; Moore, Anthony T; Plagnol, Vincent; Michaelides, Michel; Hardcastle, Alison J; Li, Yumei; Cukras, Catherine; Webster, Andrew R; Cheetham, Michael E; Chen, Rui

    2016-12-01

    Retinitis pigmentosa (RP) is the most frequent form of inherited retinal dystrophy. RP is genetically heterogeneous and the genes identified to date encode proteins involved in a wide range of functional pathways, including photoreceptor development, phototransduction, the retinoid cycle, cilia, and outer segment development. Here we report the identification of biallelic mutations in Receptor Expression Enhancer Protein 6 (REEP6) in seven individuals with autosomal-recessive RP from five unrelated families. REEP6 is a member of the REEP/Yop1 family of proteins that influence the structure of the endoplasmic reticulum but is relatively unstudied. The six variants identified include three frameshift variants, two missense variants, and a genomic rearrangement that disrupts exon 1. Human 3D organoid optic cups were used to investigate REEP6 expression and confirmed the expression of a retina-specific isoform REEP6.1, which is specifically affected by one of the frameshift mutations. Expression of the two missense variants (c.383C>T [p.Pro128Leu] and c.404T>C [p.Leu135Pro]) and the REEP6.1 frameshift mutant in cultured cells suggest that these changes destabilize the protein. Furthermore, CRISPR-Cas9-mediated gene editing was used to produce Reep6 knock-in mice with the p.Leu135Pro RP-associated variant identified in one RP-affected individual. The homozygous knock-in mice mimic the clinical phenotypes of RP, including progressive photoreceptor degeneration and dysfunction of the rod photoreceptors. Therefore, our study implicates REEP6 in retinal homeostasis and highlights a pathway previously uncharacterized in retinal dystrophy. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Identification of a novel mutation in WFS1 in a family affected by low-frequency hearing impairment

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    Kunz, Juergen; Marquez-Klaka, Ben; Uebe, Steffen; Volz-Peters, Anja; Berger, Roswitha; Rausch, Peter

    2003-04-09

    Previously we confirmed linkage of autosomal dominantly inherited low-frequency sensorineural hearing impairment (LFSNHI) in a German family to the genetic locus DFNA6/DFNA14 on chromosome 4p16.3 close to the markers D4S432 and D4S431. Analysis of data from the Human Genome Project, showed that WFS1 is located in this region. Mutations in WFS1 are known to be responsible for Wolfram syndrome (DIDMOAD, MIM no. 606201), which follows an autosomal recessive trait. Studies in low-frequency hearing loss families showed that mutations in WFS1 were responsible for the phenotype. In all affected family members analysed, we detected a missense mutation in WFS1 (K705N) and therefore confirm the finding that the majority of mutations responsible for LFSNHI are missense mutations which localise to the C-terminal domain of the protein.

  13. Identification of a novel mutation in WFS1 in a family affected by low-frequency hearing impairment

    International Nuclear Information System (INIS)

    Kunz, Juergen; Marquez-Klaka, Ben; Uebe, Steffen; Volz-Peters, Anja; Berger, Roswitha; Rausch, Peter

    2003-01-01

    Previously we confirmed linkage of autosomal dominantly inherited low-frequency sensorineural hearing impairment (LFSNHI) in a German family to the genetic locus DFNA6/DFNA14 on chromosome 4p16.3 close to the markers D4S432 and D4S431. Analysis of data from the Human Genome Project, showed that WFS1 is located in this region. Mutations in WFS1 are known to be responsible for Wolfram syndrome (DIDMOAD, MIM no. 606201), which follows an autosomal recessive trait. Studies in low-frequency hearing loss families showed that mutations in WFS1 were responsible for the phenotype. In all affected family members analysed, we detected a missense mutation in WFS1 (K705N) and therefore confirm the finding that the majority of mutations responsible for LFSNHI are missense mutations which localise to the C-terminal domain of the protein

  14. A novel missense mutation in CCDC88C activates the JNK pathway and causes a dominant form of spinocerebellar ataxia.

    Science.gov (United States)

    Tsoi, Ho; Yu, Allen C S; Chen, Zhefan S; Ng, Nelson K N; Chan, Anne Y Y; Yuen, Liz Y P; Abrigo, Jill M; Tsang, Suk Ying; Tsui, Stephen K W; Tong, Tony M F; Lo, Ivan F M; Lam, Stephen T S; Mok, Vincent C T; Wong, Lawrence K S; Ngo, Jacky C K; Lau, Kwok-Fai; Chan, Ting-Fung; Chan, H Y Edwin

    2014-09-01

    Spinocerebellar ataxias (SCAs) are a group of clinically and genetically diverse and autosomal-dominant disorders characterised by neurological deficits in the cerebellum. At present, there is no cure for SCAs. Of the different distinct subtypes of autosomal-dominant SCAs identified to date, causative genes for only a fraction of them are currently known. In this study, we investigated the cause of an autosomal-dominant SCA phenotype in a family that exhibits cerebellar ataxia and pontocerebellar atrophy along with a global reduction in brain volume. Whole-exome analysis revealed a missense mutation c.G1391A (p.R464H) in the coding region of the coiled-coil domain containing 88C (CCDC88C) gene in all affected individuals. Functional studies showed that the mutant form of CCDC88C activates the c-Jun N-terminal kinase (JNK) pathway, induces caspase 3 cleavage and triggers apoptosis. This study expands our understanding of the cause of autosomal-dominant SCAs, a group of heterogeneous congenital neurological conditions in humans, and unveils a link between the JNK stress pathway and cerebellar atrophy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. Two novel mutations of CLCN7 gene in Chinese families with autosomal dominant osteopetrosis (type II).

    Science.gov (United States)

    Zheng, Hui; Shao, Chong; Zheng, Yan; He, Jin-Wei; Fu, Wen-Zhen; Wang, Chun; Zhang, Zhen-Lin

    2016-07-01

    Autosomal dominant osteopetrosis type II (ADO-II) is a heritable bone disorder characterized by osteosclerosis, predominantly involving the spine (vertebral end-plate thickening, or rugger-jersey spine), the pelvis ("bone-within-bone" structures) and the skull base. Chloride channel 7 (CLCN7) has been reported to be the causative gene. In this study, we aimed to identify the pathogenic mutation in four Chinese families with ADO-II. All 25 exons of the CLCN7 gene, including the exon-intron boundaries, were amplified and sequenced directly in four probands from the Chinese families with ADO-II. The mutation site was then identified in other family members and 250 healthy controls. In family 1, a known missense mutation c.296A>G in exon 4 of CLCN7 was identified in the proband, resulting in a tyrosine (UAU) to cysteine (UGU) substitution at p.99 (Y99C); the mutation was also identified in his affected father. In family 2, a novel missense mutation c.865G>C in exon 10 was identified in the proband, resulting in a valine (GUC) to leucine (CUC) substitution at p.289 (V289L); the mutation was also identified in her healthy mother and sister. In family 3, a novel missense mutation c.1625C>T in exon 17 of CLCN7 was identified in the proband, resulting in an alanine (GCG) to valine (GUG) substitution at p.542 (A542V); the mutation was also identified in her father. In family 4, a hot spot, R767W (c.2299C>T, CGG>TGG), in exon 24 was found in the proband which once again proved the susceptibility of the site or the similar genetic background in different races. Moreover, two novel mutations, V289L and A542V, occurred at a highly conserved position, found by a comparison of the protein sequences from eight vertebrates, and were predicted to have a pathogenic effect by PolyPhen-2 software, which showed "probably damaging" with a score of approximately 1. These mutation sites were not identified in 250 healthy controls. Our present findings suggest that the novel missense

  16. Insights into the Molecular Mechanisms of Alzheimer’s and Parkinson’s Diseases with Molecular Simulations: Understanding the Roles of Artificial and Pathological Missense Mutations in Intrinsically Disordered Proteins Related to Pathology

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    Orkid Coskuner-Weber

    2018-01-01

    Full Text Available Amyloid-β and α-synuclein are intrinsically disordered proteins (IDPs, which are at the center of Alzheimer’s and Parkinson’s disease pathologies, respectively. These IDPs are extremely flexible and do not adopt stable structures. Furthermore, both amyloid-β and α-synuclein can form toxic oligomers, amyloid fibrils and other type of aggregates in Alzheimer’s and Parkinson’s diseases. Experimentalists face challenges in investigating the structures and thermodynamic properties of these IDPs in their monomeric and oligomeric forms due to the rapid conformational changes, fast aggregation processes and strong solvent effects. Classical molecular dynamics simulations complement experiments and provide structural information at the atomic level with dynamics without facing the same experimental limitations. Artificial missense mutations are employed experimentally and computationally for providing insights into the structure-function relationships of amyloid-β and α-synuclein in relation to the pathologies of Alzheimer’s and Parkinson’s diseases. Furthermore, there are several natural genetic variations that play a role in the pathogenesis of familial cases of Alzheimer’s and Parkinson’s diseases, which are related to specific genetic defects inherited in dominant or recessive patterns. The present review summarizes the current understanding of monomeric and oligomeric forms of amyloid-β and α-synuclein, as well as the impacts of artificial and pathological missense mutations on the structural ensembles of these IDPs using molecular dynamics simulations. We also emphasize the recent investigations on residual secondary structure formation in dynamic conformational ensembles of amyloid-β and α-synuclein, such as β-structure linked to the oligomerization and fibrillation mechanisms related to the pathologies of Alzheimer’s and Parkinson’s diseases. This information represents an important foundation for the successful and

  17. [Analysis of genetic polymorphisms and mutations of 20 frequently used STR loci among ethnic Hans from Henan].

    Science.gov (United States)

    Wang, Hongdan; Kang, Bing; Gao, Yue; Huo, Xiaodong; Li, Tao; Guo, Qiannan; Zhu, Bofeng; Liao, Shixiu

    2017-04-10

    To study the genetic polymorphisms and mutations of 20 frequently used autosomal microsatellites among ethnic Hans from Henan. Peripheral blood samples of 2604 individuals were collected. DNA was amplified and genotyped using a PowerPlex(TM) 21 system. The frequencies, forensic parameters and mutation rates of the 20 short tandem repeat (STR) loci were analyzed. A total of 323 alleles were found in this population and the allelic frequencies have ranged from 0.0003 to 0.5144. Except for D3S1358, TH01 and TPOX, mutations have been found in all of the remaining 17 STR loci, which totaled 47, with mutation rates ranging from 0 to 3.46 × 10 -3 . The 20 STR loci selected by the PowerPlex(TM) 21 system are highly polymorphic among ethnic Hans from Henan, and may be of great value in forensic and human population studies. As no similar study has been carried out previously, above results may be of great value for individual discrimination and paternal testing.

  18. Guanine holes are prominent targets for mutation in cancer and inherited disease.

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    Albino Bacolla

    Full Text Available Single base substitutions constitute the most frequent type of human gene mutation and are a leading cause of cancer and inherited disease. These alterations occur non-randomly in DNA, being strongly influenced by the local nucleotide sequence context. However, the molecular mechanisms underlying such sequence context-dependent mutagenesis are not fully understood. Using bioinformatics, computational and molecular modeling analyses, we have determined the frequencies of mutation at G • C bp in the context of all 64 5'-NGNN-3' motifs that contain the mutation at the second position. Twenty-four datasets were employed, comprising >530,000 somatic single base substitutions from 21 cancer genomes, >77,000 germline single-base substitutions causing or associated with human inherited disease and 16.7 million benign germline single-nucleotide variants. In several cancer types, the number of mutated motifs correlated both with the free energies of base stacking and the energies required for abstracting an electron from the target guanines (ionization potentials. Similar correlations were also evident for the pathological missense and nonsense germline mutations, but only when the target guanines were located on the non-transcribed DNA strand. Likewise, pathogenic splicing mutations predominantly affected positions in which a purine was located on the non-transcribed DNA strand. Novel candidate driver mutations and tissue-specific mutational patterns were also identified in the cancer datasets. We conclude that electron transfer reactions within the DNA molecule contribute to sequence context-dependent mutagenesis, involving both somatic driver and passenger mutations in cancer, as well as germline alterations causing or associated with inherited disease.

  19. RNF43 is mutated less frequently in Lynch Syndrome compared with sporadic microsatellite unstable colorectal cancers.

    Science.gov (United States)

    Fennell, Lochlan J; Clendenning, Mark; McKeone, Diane M; Jamieson, Saara H; Balachandran, Samanthy; Borowsky, Jennifer; Liu, John; Kawamata, Futoshi; Bond, Catherine E; Rosty, Christophe; Burge, Matthew E; Buchanan, Daniel D; Leggett, Barbara A; Whitehall, Vicki L J

    2018-01-01

    The WNT signaling pathway is commonly altered during colorectal cancer development. The E3 ubiquitin ligase, RNF43, negatively regulates the WNT signal through increased ubiquitination and subsequent degradation of the Frizzled receptor. RNF43 has recently been reported to harbor frequent truncating frameshift mutations in sporadic microsatellite unstable (MSI) colorectal cancers. This study assesses the relative frequency of RNF43 mutations in hereditary colorectal cancers arising in the setting of Lynch syndrome. The entire coding region of RNF43 was Sanger sequenced in 24 colorectal cancers from 23 patients who either (i) carried a germline mutation in one of the DNA mismatch repair genes (MLH1, MSH6, MSH2, PMS2), or (ii) showed immunohistochemical loss of expression of one or more of the DNA mismatch repair proteins, was BRAF wild type at V600E, were under 60 years of age at diagnosis, and demonstrated no promoter region methylation for MLH1 in tumor DNA. A validation cohort of 44 colorectal cancers from mismatch repair germline mutation carriers from the Australasian Colorectal Cancer Family Registry (ACCFR) were sequenced for the most common truncating mutation hotspots (X117 and X659). RNF43 mutations were found in 9 of 24 (37.5%) Lynch syndrome colorectal cancers. The majority of mutations were frameshift deletions in the G659 G7 repeat tract (29%); 2 cancers (2/24, 8%) from the one patient harbored frameshift mutations at codon R117 (C6 repeat tract) within exon 3. In the ACCFR validation cohort, RNF43 hotspot mutations were identified in 19/44 (43.2%) of samples, which was not significantly different to the initial series. The proportion of mutant RNF43 in Lynch syndrome related colorectal cancers is significantly lower than the previously reported mutation rate found in sporadic MSI colorectal cancers. These findings identify further genetic differences between sporadic and hereditary colorectal cancers. This may be because Lynch Syndrome cancers

  20. Deriving a Mutation Index of Carcinogenicity Using Protein Structure and Protein Interfaces

    Science.gov (United States)

    Hakas, Jarle; Pearl, Frances; Zvelebil, Marketa

    2014-01-01

    With the advent of Next Generation Sequencing the identification of mutations in the genomes of healthy and diseased tissues has become commonplace. While much progress has been made to elucidate the aetiology of disease processes in cancer, the contributions to disease that many individual mutations make remain to be characterised and their downstream consequences on cancer phenotypes remain to be understood. Missense mutations commonly occur in cancers and their consequences remain challenging to predict. However, this knowledge is becoming more vital, for both assessing disease progression and for stratifying drug treatment regimes. Coupled with structural data, comprehensive genomic databases of mutations such as the 1000 Genomes project and COSMIC give an opportunity to investigate general principles of how cancer mutations disrupt proteins and their interactions at the molecular and network level. We describe a comprehensive comparison of cancer and neutral missense mutations; by combining features derived from structural and interface properties we have developed a carcinogenicity predictor, InCa (Index of Carcinogenicity). Upon comparison with other methods, we observe that InCa can predict mutations that might not be detected by other methods. We also discuss general limitations shared by all predictors that attempt to predict driver mutations and discuss how this could impact high-throughput predictions. A web interface to a server implementation is publicly available at http://inca.icr.ac.uk/. PMID:24454733

  1. Mutations in the LHX2 gene are not a frequent cause of micro/anophthalmia.

    Science.gov (United States)

    Desmaison, Annaïck; Vigouroux, Adeline; Rieubland, Claudine; Peres, Christine; Calvas, Patrick; Chassaing, Nicolas

    2010-12-18

    Microphthalmia and anophthalmia are at the severe end of the spectrum of abnormalities in ocular development. A few genes (orthodenticle homeobox 2 [OTX2], retina and anterior neural fold homeobox [RAX], SRY-box 2 [SOX2], CEH10 homeodomain-containing homolog [CHX10], and growth differentiation factor 6 [GDF6]) have been implicated mainly in isolated micro/anophthalmia but causative mutations of these genes explain less than a quarter of these developmental defects. The essential role of the LIM homeobox 2 (LHX2) transcription factor in early eye development has recently been documented. We postulated that mutations in this gene could lead to micro/anophthalmia, and thus performed molecular screening of its sequence in patients having micro/anophthalmia. Seventy patients having non-syndromic forms of colobomatous microphthalmia (n=25), isolated microphthalmia (n=18), or anophthalmia (n=17), and syndromic forms of micro/anophthalmia (n=10) were included in this study after negative molecular screening for OTX2, RAX, SOX2, and CHX10 mutations. Mutation screening of LHX2 was performed by direct sequencing of the coding sequences and intron/exon boundaries. Two heterozygous variants of unknown significance (c.128C>G [p.Pro43Arg]; c.776C>A [p.Pro259Gln]) were identified in LHX2 among the 70 patients. These variations were not identified in a panel of 100 control patients of mixed origins. The variation c.776C>A (p.Pro259Gln) was considered as non pathogenic by in silico analysis, while the variation c.128C>G (p.Pro43Arg) considered as deleterious by in silico analysis and was inherited from the asymptomatic father. Mutations in LHX2 do not represent a frequent cause of micro/anophthalmia.

  2. Missense mutation in CAPN1 is associated with spinocerebellar ataxia in the Parson Russell Terrier dog breed.

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    Oliver P Forman

    Full Text Available Spinocerebellar ataxia (SCA in the Parson Russell Terrier (PRT dog breed is a disease of progressive incoordination of gait and loss of balance. Clinical signs usually become notable between 6 and 12 months of age with affected dogs presenting with symmetric spinocerebellar ataxia particularly evident in the pelvic limbs. The degree of truncal ataxia, pelvic limb hypermetria and impaired balance is progressive, particularly during the initial months of disease. A certain degree of stabilisation as well as intermittent worsening may occur. At the later stages of the disease ambulation often becomes difficult, with owners often electing to euthanise affected dogs on welfare grounds. Using a GWAS approach and target-enriched massively-parallel sequencing, a strongly associated non-synonymous SNP in the CAPN1 gene, encoding the calcium dependent cysteine protease calpain1 (mu-calpain, was identified. The SNP is a missense mutation causing a cysteine to tyrosine substitution at residue 115 of the CAPN1 protein. Cysteine 115 is a highly conserved residue and forms a key part of a catalytic triad of amino acids that are crucial to the enzymatic activity of cysteine proteases. The CAPN1 gene shows high levels of expression in the brain and nervous system and roles for the protein in both neuronal necrosis and maintenance have been suggested. Given the functional implications and high level of conservation observed across species, the CAPN1 variant represents a provocative candidate for the cause of SCA in the PRT and a novel potential cause of ataxia in humans.

  3. TP53 mutations in serous tubal intraepithelial carcinoma and concurrent pelvic high-grade serous carcinoma—evidence supporting the clonal relationship of the two lesions

    Science.gov (United States)

    Kuhn, Elisabetta; Kurman, Robert J; Vang, Russell; Sehdev, Ann Smith; Han, Guangming; Soslow, Robert; Wang, Tian-Li; Shih, Ie-Ming

    2016-01-01

    Serous tubal intraepithelial carcinomas (STICs) have been proposed to be the most likely precursor of ovarian, tubal and ‘primary peritoneal’ (pelvic) high-grade serous carcinoma (HGSC). As somatic mutation of TP53 is the most common molecular genetic change of ovarian HGSC, occurring in more than 95% of cases, we undertook a mutational analysis of 29 pelvic HGSCs that had concurrent STICs to demonstrate the clonal relationship of STICs and HGSCs. In addition, we correlated the mutational data with p53 immunostaining to determine the role of p53 immunoreactivity as a surrogate for TP53 mutations in histological diagnosis. Somatic TP53 mutations were detected in all 29 HGSCs analysed and the identical mutations were detected in 27 of 29 pairs of STICs and concurrent HGSCs. Missense mutations were observed in 61% of STICs and frameshift/splicing junction/nonsense mutations in 39%. Interestingly, there were two HGSCs with two distinctly different TP53 mutations each, but only one of the mutations was detected in the concurrent STICs. Missense mutations were associated with intense and diffuse (≥ 60%) p53 nuclear immunoreactivity, while most of the null mutations were associated with complete loss of p53 staining (p STIC and pelvic HGSC and demonstrate the utility of p53 immunostaining as a surrogate for TP53 mutation in the histological diagnosis of STIC. In this regard, it is important to appreciate the significance of different staining patterns. Specifically, strong diffuse staining correlates with a missense mutation, whereas complete absence of staining correlates with null mutations. PMID:21990067

  4. A novel familial case of diffuse leukodystrophy related to NDUFV1 compound heterozygous mutations

    NARCIS (Netherlands)

    Ortega-Recalde, Oscar; Fonseca, Dora Janeth; Patiño, Liliana Catherine; Atuesta, Juan Jaime; Rivera-Nieto, Carolina; Restrepo, Carlos Martín; Mateus, Heidi Eliana; van der Knaap, Marjo S.; Laissue, Paul

    2013-01-01

    NDUFV1 mutations have been related to encephalopathic phenotypes due to mitochondrial energy metabolism disturbances. In this study, we report two siblings affected by a diffuse leukodystrophy, who carry the NDUFV1 c.1156C>T (p.Arg386Cys) missense mutation and a novel 42-bp deletion. Bioinformatic

  5. A novel NDUFV1 gene mutation in complex I deficiency in consanguineous siblings with brainstem lesions and Leigh syndrome.

    Science.gov (United States)

    Vilain, C; Rens, C; Aeby, A; Balériaux, D; Van Bogaert, P; Remiche, G; Smet, J; Van Coster, R; Abramowicz, M; Pirson, I

    2012-09-01

    Although deficiency of complex I of the mitochondrial respiratory chain is a frequent cause of encephalopathy in children, only a few mutations have been reported in each of its subunits. In the absence of families large enough for conclusive segregation analysis and of robust functional testing, it is difficult to unequivocally show the causality of the observed mutations and to delineate genotype-phenotype correlations, making additional observations necessary. We observed two consanguineous siblings with an early-onset encephalopathy, medulla, brainstem and mesencephalon lesions on brain magnetic resonance imaging and death before 8 months of age, caused by a complex I deficiency. We used a homozygosity mapping approach and identified a missense mutation in the NDUFV1 gene. The mutation, p.Arg386His, affects a highly conserved residue, contiguous to a cysteine residue known to coordinate an Fe ion. This observation adds to our understanding of complex I deficiency disease. It validates the important role of Arg386 and therefore supports the current molecular model of iron-sulfur clusters in NDUFV1. © 2011 John Wiley & Sons A/S.

  6. Norrie-Warburg syndrome: two novel mutations in patients with classical clinical phenotype.

    Science.gov (United States)

    Gal, A; Veske, A; Jojart, G; Grammatico, B; Huber, B; Gu, S; del Porto, G; Senyi, K

    1996-01-01

    Norrie-Warburg syndrome (NWS) is a rare X-linked disorder characterized by blindness, which is invariable, deafness and mental disturbances, which are present occasionally. We describe here two novel mutations, a missense mutation (C126S) and a 1-base pair insertion (insT466/T467), together with a recurrent mutation (M1V), found in patients presenting with the classical clinical phenotype of NWS. All three mutations are likely to result in prominent structural changes of the norrin protein.

  7. Screening for NDP mutations in 44 unrelated patients with familial exudative vitreoretinopathy or Norrie disease.

    Science.gov (United States)

    Yang, Huiqin; Li, Shiqiang; Xiao, Xueshan; Guo, Xiangming; Zhang, Qingjiong

    2012-08-01

    To screen mutations in the norrin (NDP) gene in 44 unrelated Chinese patients with familial exudative vitreoretinopathy (FEVR, 38 cases) or Norrie disease (6 cases) and to describe the associated phenotypes. Of the 44 patients, mutation in FZD4, LRP5, and TSPAN12 was excluded in 38 patients with FEVR in previous study. Sanger sequencing was used to analyze the 2 coding exons and their adjacent regions of NDP in the 44 patients. Clinical data were presented for patients with mutation. NDP variants in 5 of the 6 patients with Norrie disease were identified, including a novel missense mutation (c.164G>A, p.Cys55Phe) in one patient, two known missense mutations (c.122G>A, p.Arg41Lys; c.220C>T, p.Arg74Cys) in two patients, and a gross deletion encompassing the two coding exons in two patients. Of the 5 patients, 3 had a family history and 2 were singleton cases. No mutation in NDP was detected in the 38 patients with FEVR. NDP mutations are common cause of Norrie disease but might be rare cause for FEVR in Chinese.

  8. Defective nucleolar localization and dominant interfering properties of a parafibromin L95P missense mutant causing the hyperparathyroidism-jaw tumor syndrome

    Science.gov (United States)

    Panicker, Leelamma M.; Zhang, Jian-Hua; Dagur, Pradeep K.; Gastinger, Matthew J.; Simonds, William F.

    2011-01-01

    The hyperparathyroidism-jaw tumor syndrome (HPT-JT) is a familial cancer syndrome that can result from germline inactivation of HRPT2/CDC73, a putative tumor suppressor gene that encodes parafibromin, a component of the transcriptional regulatory PAF1 complex with homology to the yeast protein Cdc73p. The vast majority of HRPT2/CDC73 germline mutations identified have been truncation or frameshift mutations, and loss-of-function due to missense mutation is rare. We report here a kindred with HPT-JT due to a germline L95P missense mutation in parafibromin. The mutant parafibromin was studied in vitro to understand the basis of its presumed loss-of-function. When transfected in cultured cells the L95P mutant was expressed to a lower level than wild-type parafibromin, a difference that was not overcome by inhibition of the proteasome degradation pathway. The L95P mutant parafibromin retained the ability to assemble with endogenous PAF1 complex components as evidenced by co-immunoprecipitation. Analysis of subcellular localization showed that the L95P mutant was markedly deficient in nucleolar localization compared to the wild-type, an impairment likely resulting from disruption of a putative nucleolar localization signal immediately upstream of the L95P mutation. Transfection of the L95P parafibromin mutant, but not the wild type, enhanced cell-cycle progression and increased cell survival in NIH-3T3 and HEK 293 cells, resulting apparently from dominant interference with endogenous parafibromin action. The simultaneous loss of nucleolar localization and acquisition of a growth stimulatory phenotype with the L95P mutation raise the possibility that parafibromin must interact with targets in the nucleolus to fully execute its tumor suppressor functions. PMID:20304979

  9. Molecular analysis of the eighteen most frequent mutations in the BRCA1 gene in 63 Chilean breast cancer families

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    LILIAN JARA

    2004-01-01

    Full Text Available BRCA1 gene mutations account for nearly all families with multiple cases of both early onset breast and/or ovarian cancer and about 30% of hereditary breast cancer. Although to date more than 1,237 distinct mutations, polymorphisms, and variants have been described, several mutations have been found to be recurrent in this gene. We have analyzed 63 Chilean breast/ovarian cancer families for eighteen frequent BRCA1 mutations. The analysis of the five exons and two introns in which these mutations are located was made using mismatch PCR assay, ASO hybridization assay, restriction fragment analysis, allele specific PCR assay and direct sequentiation techniques. Two BRCA1 mutations (185delAG and C61G and one variant of unknown significance (E1250K were found in four of these families. Also, a new mutation (4185delCAAG and one previously described polymorphism (E1038G were found in two other families. The 185delAG was found in a 3.17 % of the families and the others were present only in one of the families of this cohort. Therefore these mutations are not prominent in the Chilean population. The variant of unknown significance and the polymorphism detected could represent a founder effect of Spanish origin

  10. Identification of a breast cancer family double heterozygote for RAD51C and BRCA2 gene mutations

    DEFF Research Database (Denmark)

    Ahlborn, Lise B; Steffensen, Ane Y; Jønson, Lars

    2015-01-01

    for mutations in the RAD51C and BRCA2 genes. The RAD51C missense mutation p.Arg258His has previously been identified in a homozygous state in a patient with Fanconi anemia. This mutation is known to affect the DNA repair function of the RAD51C protein. The BRCA2 p.Leu3216Leu synonymous mutation has not been...

  11. Splicing Analysis of Exonic OCRL Mutations Causing Lowe Syndrome or Dent-2 Disease

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    Lorena Suarez-Artiles

    2018-01-01

    Full Text Available Mutations in the OCRL gene are associated with both Lowe syndrome and Dent-2 disease. Patients with Lowe syndrome present congenital cataracts, mental disabilities and a renal proximal tubulopathy, whereas patients with Dent-2 disease exhibit similar proximal tubule dysfunction but only mild, or no additional clinical defects. It is not yet understood why some OCRL mutations cause the phenotype of Lowe syndrome, while others develop the milder phenotype of Dent-2 disease. Our goal was to gain new insights into the consequences of OCRL exonic mutations on pre-mRNA splicing. Using predictive bioinformatics tools, we selected thirteen missense mutations and one synonymous mutation based on their potential effects on splicing regulatory elements or splice sites. These mutations were analyzed in a minigene splicing assay. Results of the RNA analysis showed that three presumed missense mutations caused alterations in pre-mRNA splicing. Mutation c.741G>T; p.(Trp247Cys generated splicing silencer sequences and disrupted splicing enhancer motifs that resulted in skipping of exon 9, while mutations c.2581G>A; p.(Ala861Thr and c.2581G>C; p.(Ala861Pro abolished a 5′ splice site leading to skipping of exon 23. Mutation c.741G>T represents the first OCRL exonic variant outside the conserved splice site dinucleotides that results in alteration of pre-mRNA splicing. Our results highlight the importance of evaluating the effects of OCRL exonic mutations at the mRNA level.

  12. Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling?

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    Harry Liu

    2017-02-01

    Full Text Available Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A “gain of toxicity” model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s causes a “loss of function”, resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons of CMT2B are needed to precisely define the disease mechanisms.

  13. Charcot Marie Tooth 2B Peripheral Sensory Neuropathy: How Rab7 Mutations Impact NGF Signaling?

    Science.gov (United States)

    Liu, Harry; Wu, Chengbiao

    2017-02-04

    Charcot-Marie-Tooth 2B peripheral sensory neuropathy (CMT2B) is a debilitating autosomal dominant hereditary sensory neuropathy. Patients with this disease lose pain sensation and frequently need amputation. Axonal dysfunction and degeneration of peripheral sensory neurons is a major clinical manifestation of CMT2B. However, the cellular and molecular pathogenic mechanisms remain undefined. CMT2B is caused by missense point mutations (L129F, K157N, N161T/I, V162M) in Rab7 GTPase. Strong evidence suggests that the Rab7 mutation(s) enhances the cellular levels of activated Rab7 proteins, thus resulting in increased lysosomal activity and autophagy. As a consequence, trafficking and signaling of neurotrophic factors such as nerve growth factor (NGF) in the long axons of peripheral sensory neurons are particularly vulnerable to premature degradation. A "gain of toxicity" model has, thus, been proposed based on these observations. However, studies of fly photo-sensory neurons indicate that the Rab7 mutation(s) causes a "loss of function", resulting in haploinsufficiency. In the review, we summarize experimental evidence for both hypotheses. We argue that better models (rodent animals and human neurons) of CMT2B are needed to precisely define the disease mechanisms.

  14. Mutations in LRRC50 predispose zebrafish and humans to seminomas.

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    Sander G Basten

    2013-04-01

    Full Text Available Seminoma is a subclass of human testicular germ cell tumors (TGCT, the most frequently observed cancer in young men with a rising incidence. Here we describe the identification of a novel gene predisposing specifically to seminoma formation in a vertebrate model organism. Zebrafish carrying a heterozygous nonsense mutation in Leucine-Rich Repeat Containing protein 50 (lrrc50 also called dnaaf1, associated previously with ciliary function, are found to be highly susceptible to the formation of seminomas. Genotyping of these zebrafish tumors shows loss of heterozygosity (LOH of the wild-type lrrc50 allele in 44.4% of tumor samples, correlating with tumor progression. In humans we identified heterozygous germline LRRC50 mutations in two different pedigrees with a family history of seminomas, resulting in a nonsense Arg488* change and a missense Thr590Met change, which show reduced expression of the wild-type allele in seminomas. Zebrafish in vivo complementation studies indicate the Thr590Met to be a loss-of-function mutation. Moreover, we show that a pathogenic Gln307Glu change is significantly enriched in individuals with seminoma tumors (13% of our cohort. Together, our study introduces an animal model for seminoma and suggests LRRC50 to be a novel tumor suppressor implicated in human seminoma pathogenesis.

  15. Less frequently mutated genes in colorectal cancer: evidences from next-generation sequencing of 653 routine cases.

    Science.gov (United States)

    Malapelle, Umberto; Pisapia, Pasquale; Sgariglia, Roberta; Vigliar, Elena; Biglietto, Maria; Carlomagno, Chiara; Giuffrè, Giuseppe; Bellevicine, Claudio; Troncone, Giancarlo

    2016-09-01

    The incidence of RAS/RAF/PI3KA and TP53 gene mutations in colorectal cancer (CRC) is well established. Less information, however, is available on other components of the CRC genomic landscape, which are potential CRC prognostic/predictive markers. Following a previous validation study, ion-semiconductor next-generation sequencing (NGS) was employed to process 653 routine CRC samples by a multiplex PCR targeting 91 hotspot regions in 22 CRC significant genes. A total of 796 somatic mutations in 499 (76.4%) tumours were detected. Besides RAS/RAF/PI3KA and TP53, other 12 genes showed at least one mutation including FBXW7 (6%), PTEN (2.8%), SMAD4 (2.1%), EGFR (1.2%), CTNNB1 (1.1%), AKT1 (0.9%), STK11 (0.8%), ERBB2 (0.6%), ERBB4 (0.6%), ALK (0.2%), MAP2K1 (0.2%) and NOTCH1 (0.2%). In a routine diagnostic setting, NGS had the potential to generate robust and comprehensive genetic information also including less frequently mutated genes potentially relevant for prognostic assessments or for actionable treatments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  16. A missense mutation in Grm6 reduces but does not eliminate mGluR6 expression or rod depolarizing bipolar cell function.

    Science.gov (United States)

    Peachey, Neal S; Hasan, Nazarul; FitzMaurice, Bernard; Burrill, Samantha; Pangeni, Gobinda; Karst, Son Yong; Reinholdt, Laura; Berry, Melissa L; Strobel, Marge; Gregg, Ronald G; McCall, Maureen A; Chang, Bo

    2017-08-01

    GRM6 encodes the metabotropic glutamate receptor 6 (mGluR6) used by retinal depolarizing bipolar cells (DBCs). Mutations in GRM6 lead to DBC dysfunction and underlie the human condition autosomal recessive complete congenital stationary night blindness. Mouse mutants for Grm6 are important models for this condition. Here we report a new Grm6 mutant, identified in an electroretinogram (ERG) screen of mice maintained at The Jackson Laboratory. The Grm6 nob8 mouse has a reduced-amplitude b-wave component of the ERG, which reflects light-evoked DBC activity. Sequencing identified a missense mutation that converts a highly conserved methionine within the ligand binding domain to leucine (p.Met66Leu). Consistent with prior studies of Grm6 mutant mice, the laminar size and structure in the Grm6 nob8 retina were comparable to control. The Grm6 nob8 phenotype is distinguished from other Grm6 mutants that carry a null allele by a reduced but not absent ERG b-wave, decreased but present expression of mGluR6 at DBC dendritic tips, and mislocalization of mGluR6 to DBC somas. Consistent with a reduced but not absent b-wave, there were a subset of retinal ganglion cells whose responses to light onset have times to peak within the range of those in control retinas. These data indicate that the p.Met66Leu mutant mGluR6 is trafficked less than control. However, the mGluR6 that is localized to the DBC dendritic tips is able to initiate DBC signal transduction. The Grm6 nob8 mouse extends the Grm6 allelic series and will be useful for elucidating the role of mGluR6 in DBC signal transduction and in human disease. NEW & NOTEWORTHY This article describes a mouse model of the human disease complete congenital stationary night blindness in which the mutation reduces but does not eliminate GRM6 expression and bipolar cell function, a distinct phenotype from that seen in other Grm6 mouse models.

  17. Contribution of TARDBP mutations to sporadic amyotrophic lateral sclerosis.

    Science.gov (United States)

    Daoud, H; Valdmanis, P N; Kabashi, E; Dion, P; Dupré, N; Camu, W; Meininger, V; Rouleau, G A

    2009-02-01

    Mutations in the TARDBP gene, which encodes the TAR DNA binding protein (TDP-43), have been described in individuals with familial and sporadic amyotrophic lateral sclerosis (ALS). We screened the TARDBP gene in 285 French sporadic ALS patients to assess the frequency of TARDBP mutations in ALS. Six individuals had potentially deleterious mutations of which three were novel including a Y374X truncating mutation and P363A and A382P missense mutations. This suggests that TARDBP mutations may predispose to ALS in approximately 2% of the individuals followed in this study. Our findings, combined with those from other collections, brings the total number of mutations in unrelated ALS patients to 17, further suggesting that mutations in the TARDBP gene have an important role in the pathogenesis of ALS.

  18. Rapid screening for nuclear genes mutations in isolated respiratory chain complex I defects.

    Science.gov (United States)

    Pagniez-Mammeri, Hélène; Lombes, Anne; Brivet, Michèle; Ogier-de Baulny, Hélène; Landrieu, Pierre; Legrand, Alain; Slama, Abdelhamid

    2009-04-01

    Complex I or reduced nicotinamide adenine dinucleotide (NADH): ubiquinone oxydoreductase deficiency is the most common cause of respiratory chain defects. Molecular bases of complex I deficiencies are rarely identified because of the dual genetic origin of this multi-enzymatic complex (nuclear DNA and mitochondrial DNA) and the lack of phenotype-genotype correlation. We used a rapid method to screen patients with isolated complex I deficiencies for nuclear genes mutations by Surveyor nuclease digestion of cDNAs. Eight complex I nuclear genes, among the most frequently mutated (NDUFS1, NDUFS2, NDUFS3, NDUFS4, NDUFS7, NDUFS8, NDUFV1 and NDUFV2), were studied in 22 cDNA fragments spanning their coding sequences in 8 patients with a biochemically proved complex I deficiency. Single nucleotide polymorphisms and missense mutations were detected in 18.7% of the cDNA fragments by Surveyor nuclease treatment. Molecular defects were detected in 3 patients. Surveyor nuclease screening is a reliable method for genotyping nuclear complex I deficiencies, easy to interpret, and limits the number of sequence reactions. Its use will enhance the possibility of prenatal diagnosis and help us for a better understanding of complex I molecular defects.

  19. Missense and nonsense mutations in melanocortin 1 receptor (MC1R gene of different goat breeds: association with red and black coat colour phenotypes but with unexpected evidences

    Directory of Open Access Journals (Sweden)

    Davoli Roberta

    2009-08-01

    Full Text Available Abstract Background Agouti and Extension loci control the relative amount of eumelanin and pheomelanin production in melanocytes that, in turn, affects pigmentation of skin and hair. The Extension locus encodes the melanocortin 1 receptor (MC1R whose permanent activation, caused by functional mutations, results in black coat colour, whereas other inactivating mutations cause red coat colour in different mammals. Results The whole coding region of the MC1R gene was sequenced in goats of six different breeds showing different coat colours (Girgentana, white cream with usually small red spots in the face; Maltese, white with black cheeks and ears; Derivata di Siria, solid red; Murciano-Granadina, solid black or solid brown; Camosciata delle Alpi, brown with black stripes; Saanen, white; F1 goats and the parental animals. Five single nucleotide polymorphisms (SNPs were identified: one nonsense mutation (p.Q225X, three missense mutations (p.A81V, p.F250V, and p.C267W, and one silent mutation. The stop codon at position 225 should cause the production of a shorter MC1R protein whose functionality may be altered. These SNPs were investigated in a larger sample of animals belonging to the six breeds. The Girgentana breed was almost fixed for the p.225X allele. However, there was not complete association between the presence of red spots in the face and the presence of this allele in homozygous condition. The same allele was identified in the Derivata di Siria breed. However, its frequency was only 33%, despite the fact that these animals are completely red. The p.267W allele was present in all Murciano-Granadina black goats, whereas it was never identified in the brown ones. Moreover, the same substitution was present in almost all Maltese goats providing evidence of association between this mutation and black coat colour. Conclusion According to the results obtained in the investigated goat breeds, MC1R mutations may determine eumelanic and pheomelanic

  20. A COLQ missense mutation in Labrador Retrievers having congenital myasthenic syndrome.

    Directory of Open Access Journals (Sweden)

    Caitlin J Rinz

    Full Text Available Congenital myasthenic syndromes (CMSs are heterogeneous neuromuscular disorders characterized by skeletal muscle weakness caused by disruption of signal transmission across the neuromuscular junction (NMJ. CMSs are rarely encountered in veterinary medicine, and causative mutations have only been identified in Old Danish Pointing Dogs and Brahman cattle to date. Herein, we characterize a novel CMS in 2 Labrador Retriever littermates with an early onset of marked generalized muscle weakness. Because the sire and dam share 2 recent common ancestors, CMS is likely the result of recessive alleles inherited identical by descent (IBD. Genome-wide SNP profiles generated from the Illumina HD array for 9 nuclear family members were used to determine genomic inheritance patterns in chromosomal regions encompassing 18 functional candidate genes. SNP haplotypes spanning 3 genes were consistent with autosomal recessive transmission, and microsatellite data showed that only the segment encompassing COLQ was inherited IBD. COLQ encodes the collagenous tail of acetylcholinesterase, the enzyme responsible for termination of signal transduction in the NMJ. Sequences from COLQ revealed a variant in exon 14 (c.1010T>C that results in the substitution of a conserved amino acid (I337T within the C-terminal domain. Both affected puppies were homozygous for this variant, and 16 relatives were heterozygous, while 288 unrelated Labrador Retrievers and 112 dogs of other breeds were wild-type. A recent study in which 2 human CMS patients were found to be homozygous for an identical COLQ mutation (c.1010T>C; I337T provides further evidence that this mutation is pathogenic. This report describes the first COLQ mutation in canine CMS and demonstrates the utility of SNP profiles from nuclear family members for the identification of private mutations.

  1. Identification of SCN1A and PCDH19 mutations in Chinese children with Dravet syndrome.

    Directory of Open Access Journals (Sweden)

    Anna Ka-Yee Kwong

    Full Text Available BACKGROUND: Dravet syndrome is a severe form of epilepsy. Majority of patients have a mutation in SCN1A gene, which encodes a voltage-gated sodium channel. A recent study has demonstrated that 16% of SCN1A-negative patients have a mutation in PCDH19, the gene encoding protocadherin-19. Mutations in other genes account for only a very small proportion of families. TSPYL4 is a novel candidate gene within the locus 6q16.3-q22.31 identified by linkage study. OBJECTIVE: The present study examined the mutations in epileptic Chinese children with emphasis on Dravet syndrome. METHODS: A hundred children with severe epilepsy were divided into Dravet syndrome and non-Dravet syndrome groups and screened for SCN1A mutations by direct sequencing. SCN1A-negative Dravet syndrome patients and patients with phenotypes resembling Dravet syndrome were checked for PCDH19 and TSPYL4 mutations. RESULTS: Eighteen patients (9 males, 9 females were diagnosed to have Dravet syndrome. Among them, 83% (15/18 had SCN1A mutations including truncating (7, splice site (2 and missense mutations (6. The truncating/splice site mutations were associated with moderate to severe degree of intellectual disability (p<0.05. During the progression of disease, 73% (11/15 had features fitting into the diagnostic criteria of autism spectrum disorder and 53% (8/15 had history of vaccination-induced seizures. A novel PCDH19 p.D377N mutation was identified in one SCN1A-negative female patient with Dravet syndrome and a known PCDH19 p.N340S mutation in a female non-Dravet syndrome patient. The former also inherited a TSPYL4 p.G60R variant. CONCLUSION: A high percentage of SCN1A mutations was identified in our Chinese cohort of Dravet syndrome patients but none in the rest of patients. We demonstrated that truncating/splice site mutations were linked to moderate to severe intellectual disability in these patients. A de novo PCDH19 missense mutation together with an inherited TSPYL4 missense

  2. Identification of p.A684V missense mutation in the WFS1 gene as a frequent cause of autosomal dominant optic atrophy and hearing impairment

    DEFF Research Database (Denmark)

    Rendtorff, Nanna D; Lodahl, Marianne; Boulahbel, Houda

    2011-01-01

    DNA deletions were detected in muscle from one p.A684V patient analyzed. Finally, wolframin p.A684V mutant ectopically expressed in HEK cells showed reduced protein levels compared to wild-type wolframin, strongly indicating that the mutation is disease-causing. Our data support OA and SNHL...

  3. TP53 mutations in serous tubal intraepithelial carcinoma and concurrent pelvic high-grade serous carcinoma--evidence supporting the clonal relationship of the two lesions.

    Science.gov (United States)

    Kuhn, Elisabetta; Kurman, Robert J; Vang, Russell; Sehdev, Ann Smith; Han, Guangming; Soslow, Robert; Wang, Tian-Li; Shih, Ie-Ming

    2012-02-01

    Serous tubal intraepithelial carcinomas (STICs) have been proposed to be the most likely precursor of ovarian, tubal and 'primary peritoneal' (pelvic) high-grade serous carcinoma (HGSC). As somatic mutation of TP53 is the most common molecular genetic change of ovarian HGSC, occurring in more than 95% of cases, we undertook a mutational analysis of 29 pelvic HGSCs that had concurrent STICs to demonstrate the clonal relationship of STICs and HGSCs. In addition, we correlated the mutational data with p53 immunostaining to determine the role of p53 immunoreactivity as a surrogate for TP53 mutations in histological diagnosis. Somatic TP53 mutations were detected in all 29 HGSCs analysed and the identical mutations were detected in 27 of 29 pairs of STICs and concurrent HGSCs. Missense mutations were observed in 61% of STICs and frameshift/splicing junction/nonsense mutations in 39%. Interestingly, there were two HGSCs with two distinctly different TP53 mutations each, but only one of the mutations was detected in the concurrent STICs. Missense mutations were associated with intense and diffuse (≥ 60%) p53 nuclear immunoreactivity, while most of the null mutations were associated with complete loss of p53 staining (p STIC and pelvic HGSC and demonstrate the utility of p53 immunostaining as a surrogate for TP53 mutation in the histological diagnosis of STIC. In this regard, it is important to appreciate the significance of different staining patterns. Specifically, strong diffuse staining correlates with a missense mutation, whereas complete absence of staining correlates with null mutations. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  4. Mandibulofacial Dysostosis with Microcephaly: Mutation and Database Update

    DEFF Research Database (Denmark)

    Gregersen, Pernille Axel

    2016-01-01

    , we review the molecular basis of MFDM in the 69 individuals described to date, and report mutations in 38 new individuals, bringing the total number of reported individuals to 107 individuals from 94 kindreds. Pathogenic EFTUD2 variants comprise 76 distinct mutations and 7 microdeletions. Among point...... mutations, missense substitutions are infrequent (14/76; 18%) relative to stopgain (29/76; 38%), and splicing (33/76; 43%) mutations. Where known, mutation origin was de novo in 48/64 individuals (75%), dominantly-inherited in 12/64 (19%), and due to proven germline mosaicism in 4/64 (6%). Highly penetrant......-reported anomalies, include vestibular and ossicular malformations, reduced mouth opening, atrophy of cerebral white matter, structural brain malformations, and epibulbar dermoid. All reported EFTUD2 mutations can be found in the EFTUD2 mutation database (http://databases.lovd.nl/shared/genes/EFTUD2). This article...

  5. ADAM10 missense mutations potentiate β-amyloid accumulation by impairing prodomain chaperone function.

    Science.gov (United States)

    Suh, Jaehong; Choi, Se Hoon; Romano, Donna M; Gannon, Moira A; Lesinski, Andrea N; Kim, Doo Yeon; Tanzi, Rudolph E

    2013-10-16

    The generation of Aβ, the main component of senile plaques in Alzheimer's disease (AD), is precluded by α-secretase cleavage within the Aβ domain of the amyloid precursor protein (APP). We identified two rare mutations (Q170H and R181G) in the prodomain of the metalloprotease, ADAM10, that cosegregate with late-onset AD (LOAD). Here, we addressed the pathogenicity of these mutations in transgenic mice expressing human ADAM10 in brain. In Tg2576 AD mice, both mutations attenuated α-secretase activity of ADAM10 and shifted APP processing toward β-secretase-mediated cleavage, while enhancing Aβ plaque load and reactive gliosis. We also demonstrated ADAM10 expression potentiates adult hippocampal neurogenesis, which is reduced by the LOAD mutations. Mechanistically, both LOAD mutations impaired the molecular chaperone activity of ADAM10 prodomain. Collectively, these findings suggest that diminished α-secretase activity, owing to LOAD ADAM10 prodomain mutations, leads to AD-related pathology, strongly supporting ADAM10 as a promising therapeutic target for this devastating disease. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. A novel missense mutation of ADAR1 gene in a Chinese family ...

    Indian Academy of Sciences (India)

    This study was mainlyto explore the pathogenic mutation of ADAR1 gene and provide genetics counselling and prenatal diagnostic testing for childbearing individuals.Mutational analysis of ADAR1 gene was performed by polymerase chain reaction (PCR) and electrophoretic separation of PCR products by 1.5% agarose ...

  7. Early-onset severe hereditary sensory and autonomic neuropathy type 1 with S331F SPTLC1 mutation.

    Science.gov (United States)

    Suh, Bum Chun; Hong, Young Bin; Nakhro, Khriezhanuo; Nam, Soo Hyun; Chung, Ki Wha; Choi, Byung-Ok

    2014-02-01

    Hereditary sensory and autonomic neuropathy type I (HSAN I) is an autosomal dominant disease characterized by prominent sensory impairment, resulting in foot ulcers or amputations and has a juvenile to adult onset. The major underlying causes of HSAN I are mutations in SPTLC1, which encodes the first subunit of serine palmitoyltransferase (SPT). To date, there have been no reports with regard to an HSAN patient of Korean origin. In this report we discussed an HSAN I patient with a missense mutation in SPTLC1 (c.992C>T: p.S331F). The patient had noticed frequent falls, lower leg weakness and hand tremors at age five. The patient also presented with foot ulcers, muscle hypotrophy, cataracts, hoarseness, vocal cord palsy and respiratory difficulties and succumbed to the condition at the age of 28 years. In accordance with previous reports, a mutation in Ser331 in the present patient was associated with early-onset and a severe phenotype. Therefore, Ser331 in SPTLC1 is a crucial amino acid, which characterizes the HSAN I phenotype.

  8. Concomitant BCORL1 and BRAF Mutations in Vemurafenib-Resistant Melanoma Cells

    Directory of Open Access Journals (Sweden)

    Luca Mologni

    2018-05-01

    Full Text Available BRAF is the most frequently mutated gene in melanoma. Constitutive activation of mutant BRAFV600E leads to aberrant Ras-independent MAPK signaling and cell transformation. Inhibition of mutant BRAF is a current frontline therapy for such cases, with improved survival compared with chemotherapy. Unfortunately, reactivation of MAPK signaling by several mechanisms has been shown to cause drug resistance and disease recurrence. In this work, we describe the co-occurrence of an in-frame deletion within an amplified BRAFV600E locus and a missense point mutation of the transcriptional repressor BCORL1 in vemurafenib-resistant A375 melanoma cells. Functional data confirmed that truncated p47BRAFV600E and mutant BCORL1Q1076H both contribute to resistance. Interestingly, either endogenous BCORL1 silencing or ectopic BCORL1Q1076H expression mimicked the effects of a CRISPR/Cas9-edited BCORL1Q1076H locus, suggesting a complex mixture of loss- and gain-of-function effects caused by the mutation. Transcriptomic data confirmed this hypothesis. Finally, we show that the pan-RAF inhibitor sorafenib is not affected by expression of BRAF deletion variant and effectively synergizes with vemurafenib to block resistant cells, suggesting a possible intervention for this class of mutants.

  9. Dural ectasia and FBN1 mutation screening of 40 patients with Marfan syndrome and related disorders: role of dural ectasia for the diagnosis.

    Science.gov (United States)

    Attanasio, Monica; Pratelli, Elisa; Porciani, Maria Cristina; Evangelisti, Lucia; Torricelli, Elena; Pellicanò, Giannantonio; Abbate, Rosanna; Gensini, Gian Franco; Pepe, Guglielmina

    2013-07-01

    Marfan syndrome is an autosomal dominant disorder of connective tissue caused by mutations in the gene encoding fibrillin-1 (FBN1), a matrix component of microfibrils. Dural ectasia, i.e. enlargement of the neural canal mainly located in the lower lumbar and sacral region, frequently occurs in Marfan patients. The aim of our study was to investigate the role of dural ectasia in raising the diagnosis of Marfan syndrome and its association with FBN1 mutations. We studied 40 unrelated patients suspected for MFS, who underwent magnetic resonance imaging searching for dural ectasia. In all of them FBN1 gene analysis was also performed. Thirty-seven patients resulted affected by Marfan syndrome according to the '96 Ghent criteria; in 30 of them the diagnosis was confirmed when revaluated by the recently revised criteria (2010). Thirty-six patients resulted positive for dural ectasia. The degree of dural ectasia was grade 1 in 19 patients, grade 2 in 11 patients, and grade 3 in 6 patients. In 7 (24%) patients, the presence of dural ectasia allowed to reach a positive score for systemic feature criterion. Twenty-four patients carried an FBN1 mutation, that were represented by 13 missense (54%), and 11 (46%) mutations generating a premature termination codon (PTC, frameshifts and stop codons). No mutation was detected in the remaining 16 (6 patients with MFS and 10 with related disorders according to revised Ghent criteria). The prevalence of severe (grade 2 and grade 3) involvement of dura mater was higher in patients harbouring premature termination codon (PTC) mutations than those carrying missense-mutations (8/11 vs 2/13, P = 0.0111). Our data emphasizes the importance of dural ectasia screening to reach the diagnosis of Marfan syndrome especially when it is uncertain and indicates an association between PTC mutations and severe dural ectasia in Marfan patients. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  10. Two mutations in the same low-density lipoprotein receptor allele act in synergy to reduce receptor function in heterozygous familial hypercholesterolemia

    DEFF Research Database (Denmark)

    Jensen, H K; Jensen, T G; Faergeman, O

    1997-01-01

    Mutations in genes are not necessarily pathogenic. Expression of mutant genes in cells can therefore be required to demonstrate that mutations in fact disturb protein function. This applies especially to missense mutations, which cause an amino acid to be replaced by another amino acid. In the pr...

  11. A novel mutation in the connexin 26 gene (GJB2) in a child with clinical and histological features of keratitis-ichthyosis-deafness (KID) syndrome

    DEFF Research Database (Denmark)

    Koppelhus, Uffe; Tranebjaerg, L; Esberg, G

    2011-01-01

    Keratitis-ichthyosis-deafness (KID) syndrome is a rare congenital ectodermal disorder, caused by heterozygous missense mutation in GJB2, encoding the gap junction protein connexin 26. The commonest mutation is the p.Asp50Asn mutation, and only a few other mutations have been described to date....

  12. An experimental study of BIGH3 gene mutations in the patients with corneal dystrophies

    International Nuclear Information System (INIS)

    Jin Tao; Zou Liuhe; Yang Ling

    2004-01-01

    Objective: To evaluate BIGH3 gene mutations in Chinese patents with corneal dystrophies. Methods: 2ml peripheral venous blood was collected from 15 patients with granular corneal dystrophies and 5 normal subjects. Leucocytes DNA was extracted with standard method. With two pairs of oligonucleotide primers, exon 4 and exon 12 of the BIGH3 gene were amplified using the polymerase chain reaction. Amplified DNA fragments were purified and sequenced directly. Results: Mutations in BIGH3 gene were detected in all the patients with corneal dystrophies. BIGH3 gene mutations were not found in normal subjects. 12 patients with Avellino corneal dystrophy had the missense mutation R124H in the BIGH3 gene. 3 patients with granular corneal dystrophy had the missense mutation R555W in the BIGH3 gene. Conclusion: R124H and R555W mutations in BIGH3 gene were also found in the Chinese patients with Avellino and granular corneal dystrophies. In China, Avellino corneal dystrophy associated with the R124H mutation is the most common form in the corneal dystrophies resulted by BIGH3 gene mutions. Condon 124 and 555 are also the hot spots for the mutations in the BIGH3 gene in the Chinese patients with corneal dystrophies. Molecular genetic analysis may be repuired for proper diagnosis and subclassification of corneal dystrophies. (authors)

  13. Cortical synaptic transmission in CaV2.1 knockin mice with the S218L missense mutation which causes a severe familial hemiplegic migraine syndrome in humans.

    Directory of Open Access Journals (Sweden)

    Dania eVecchia

    2015-02-01

    Full Text Available Familial hemiplegic migraine type 1 (FHM1 is caused by gain-of-function mutations in CaV2.1 (P/Q-type Ca2+ channels. Knockin (KI mice carrying the FHM1 R192Q missense mutation show enhanced cortical excitatory synaptic transmission at pyramidal cell synapses but unaltered cortical inhibitory neurotransmission at fast-spiking interneuron synapses. Enhanced cortical glutamate release was shown to cause the facilitation of cortical spreading depression (CSD in R192Q KI mice. It, however, remains unknown how other FHM1 mutations affect cortical synaptic transmission. Here, we studied neurotransmission in cortical neurons in microculture from KI mice carrying the S218L mutation, which causes a severe FHM syndrome in humans and an allele-dosage dependent facilitation of experimental CSD in KI mice, which is larger than that caused by the R192Q mutation. We show gain-of-function of excitatory neurotransmission, due to increased action-potential evoked Ca2+ influx and increased probability of glutamate release at pyramidal cell synapses, but unaltered inhibitory neurotransmission at multipolar interneuron synapses in S218L KI mice. In contrast with the larger gain-of-function of neuronal CaV2.1 current in homozygous than heterozygous S218L KI mice, the gain-of-function of evoked glutamate release, the paired-pulse ratio and the Ca2+ dependence of the EPSC were all similar in homozygous and heterozygous S218L KI mice, suggesting compensatory changes in the homozygous mice. Furthermore, we reveal a unique feature of S218L KI cortical synapses which is the presence of a fraction of mutant CaV2.1 channels being open at resting potential. Our data suggest that, while the gain-of-function of evoked glutamate release may explain the facilitation of CSD in heterozygous S218L KI mice, the further facilitation of CSD in homozygous S218L KI mice is due to other CaV2.1-dependent mechanisms, that likely include Ca2+ influx at voltages sub-threshold for action

  14. Expanding the spectrum of HEXA mutations in Indian patients with Tay-Sachs disease.

    Science.gov (United States)

    Sheth, Jayesh; Mistri, Mehul; Datar, Chaitanya; Kalane, Umesh; Patil, Shekhar; Kamate, Mahesh; Shah, Harshuti; Nampoothiri, Sheela; Gupta, Sarita; Sheth, Frenny

    2014-01-01

    Tay-Sachs disease is an autosomal recessive neurodegenerative disorder occurring due to impaired activity of β-hexosaminidase-A (EC 3.2.1.52), resulting from the mutation in HEXA gene. Very little is known about the molecular pathology of TSD in Indian children except for a few mutations identified by us. The present study is aimed to determine additional mutations leading to Tay-Sachs disease in nine patients confirmed by the deficiency of β-hexosaminidase-A (C (D175A) and c.805G>C (p.G269R) in one case; and one small 1 bp deletion c.426delT (p.F142LfsX57) and one splice site mutation c.459+4A>C in the other two cases respectively. None of these mutations were detected in 100 chromosomes from healthy individuals of the same ethnic group. Three previously reported missense mutations, (i) c.532C>T (p.R178C), (ii) c.964G>T (p.D322Y), and (iii) c.1385A>T (p.E462V); two nonsense mutations (i) c.709C>T (p.Q237X) and (ii) c.1528C>T (p.R510X), one 4 bp insertion c.1277_1278insTATC (p.Y427IfsX5) and one splice site mutation c.459+5G>A were also identified in six cases. We observe from this study that novel mutations are more frequently observed in Indian patients with Tay-Sachs disease with clustering of ~ 73% of disease causing mutations in exons 5 to 12. This database can be used for a carrier rate screening in the larger population of the country.

  15. Unique mutation portraits and frequent COL2A1 gene alteration in chondrosarcoma

    Science.gov (United States)

    Totoki, Yasushi; Yoshida, Akihiko; Hosoda, Fumie; Nakamura, Hiromi; Hama, Natsuko; Ogura, Koichi; Yoshida, Aki; Fujiwara, Tomohiro; Arai, Yasuhito; Toguchida, Junya; Tsuda, Hitoshi; Miyano, Satoru; Kawai, Akira

    2014-01-01

    Chondrosarcoma is the second most frequent malignant bone tumor. However, the etiological background of chondrosarcomagenesis remains largely unknown, along with details on molecular alterations and potential therapeutic targets. Massively parallel paired-end sequencing of whole genomes of 10 primary chondrosarcomas revealed that the process of accumulation of somatic mutations is homogeneous irrespective of the pathological subtype or the presence of IDH1 mutations, is unique among a range of cancer types, and shares significant commonalities with that of prostate cancer. Clusters of structural alterations localized within a single chromosome were observed in four cases. Combined with targeted resequencing of additional cartilaginous tumor cohorts, we identified somatic alterations of the COL2A1 gene, which encodes an essential extracellular matrix protein in chondroskeletal development, in 19.3% of chondrosarcoma and 31.7% of enchondroma cases. Epigenetic regulators (IDH1 and YEATS2) and an activin/BMP signal component (ACVR2A) were recurrently altered. Furthermore, a novel FN1-ACVR2A fusion transcript was observed in both chondrosarcoma and osteochondromatosis cases. With the characteristic accumulative process of somatic changes as a background, molecular defects in chondrogenesis and aberrant epigenetic control are primarily causative of both benign and malignant cartilaginous tumors. PMID:25024164

  16. A missense mutation of HOXA13 underlies hand-foot-genital ...

    Indian Academy of Sciences (India)

    Lihua Cao

    2017-08-16

    Aug 16, 2017 ... These abnormalities in limb appears to be fully penetrant, bilateral, and ... gross deletions have also been reported (Frisén et al. 2003;. Utsch et al. 2007 .... known to be linked to human developmental disorders. Mutations in ...

  17. Antisense Oligonucleotide-based Splice Correction for USH2A-associated Retinal Degeneration Caused by a Frequent Deep-intronic Mutation

    NARCIS (Netherlands)

    Slijkerman, R.W.N.; Vache, C.; Dona, M.; Garcia-Garcia, G.; Claustres, M.; Hetterschijt, L.; Peters, T.A.; Hartel, B.P.; Pennings, R.J.E.; Millan, J.M.; Aller, E.; Garanto, A.; Collin, R.W.J.; Kremer, H.; Roux, A.F.; WIjk, E. van

    2016-01-01

    Usher syndrome (USH) is the most common cause of combined deaf-blindness in man. The hearing loss can be partly compensated by providing patients with hearing aids or cochlear implants, but the loss of vision is currently untreatable. In general, mutations in the USH2A gene are the most frequent

  18. Novel SOX2 mutations and genotype-phenotype correlation in anophthalmia and microphthalmia.

    Science.gov (United States)

    Schneider, Adele; Bardakjian, Tanya; Reis, Linda M; Tyler, Rebecca C; Semina, Elena V

    2009-12-01

    SOX2 represents a High Mobility Group domain containing transcription factor that is essential for normal development in vertebrates. Mutations in SOX2 are known to result in a spectrum of severe ocular phenotypes in humans, also typically associated with other systemic defects. Ocular phenotypes include anophthalmia/microphthalmia (A/M), optic nerve hypoplasia, ocular coloboma and other eye anomalies. We screened 51 unrelated individuals with A/M and identified SOX2 mutations in the coding region of the gene in 10 individuals. Seven of the identified mutations are novel alterations, while the remaining three individuals carry the previously reported recurrent 20-nucleotide deletion in SOX2, c.70del20. Among the SOX2-positive cases, seven patients had bilateral A/M and mutations resulting in premature termination of the normal protein sequence (7/38; 18% of all bilateral cases), one patient had bilateral A/M associated with a single amino acid insertion (1/38; 3% of bilateral cases), and the final two patients demonstrated unilateral A/M associated with missense mutations (2/13; 15% of all unilateral cases). These findings and review of previously reported cases suggest a potential genotype/phenotype correlation for SOX2 mutations with missense changes generally leading to less severe ocular defects. In addition, we report a new familial case of affected siblings with maternal mosaicism for the identified SOX2 mutation, which further underscores the importance of parental testing to provide accurate genetic counseling to families.

  19. Comprehensive Mutation Analysis of PMS2 in a Large Cohort of Probands Suspected of Lynch Syndrome or Constitutional Mismatch Repair Deficiency Syndrome.

    Science.gov (United States)

    van der Klift, Heleen M; Mensenkamp, Arjen R; Drost, Mark; Bik, Elsa C; Vos, Yvonne J; Gille, Hans J J P; Redeker, Bert E J W; Tiersma, Yvonne; Zonneveld, José B M; García, Encarna Gómez; Letteboer, Tom G W; Olderode-Berends, Maran J W; van Hest, Liselotte P; van Os, Theo A; Verhoef, Senno; Wagner, Anja; van Asperen, Christi J; Ten Broeke, Sanne W; Hes, Frederik J; de Wind, Niels; Nielsen, Maartje; Devilee, Peter; Ligtenberg, Marjolijn J L; Wijnen, Juul T; Tops, Carli M J

    2016-11-01

    Monoallelic PMS2 germline mutations cause 5%-15% of Lynch syndrome, a midlife cancer predisposition, whereas biallelic PMS2 mutations cause approximately 60% of constitutional mismatch repair deficiency (CMMRD), a rare childhood cancer syndrome. Recently improved DNA- and RNA-based strategies are applied to overcome problematic PMS2 mutation analysis due to the presence of pseudogenes and frequent gene conversion events. Here, we determined PMS2 mutation detection yield and mutation spectrum in a nationwide cohort of 396 probands. Furthermore, we studied concordance between tumor IHC/MSI (immunohistochemistry/microsatellite instability) profile and mutation carrier state. Overall, we found 52 different pathogenic PMS2 variants explaining 121 Lynch syndrome and nine CMMRD patients. In vitro mismatch repair assays suggested pathogenicity for three missense variants. Ninety-one PMS2 mutation carriers (70%) showed isolated loss of PMS2 in their tumors, for 31 (24%) no or inconclusive IHC was available, and eight carriers (6%) showed discordant IHC (presence of PMS2 or loss of both MLH1 and PMS2). Ten cases with isolated PMS2 loss (10%; 10/97) harbored MLH1 mutations. We confirmed that recently improved mutation analysis provides a high yield of PMS2 mutations in patients with isolated loss of PMS2 expression. Application of universal tumor prescreening methods will however miss some PMS2 germline mutation carriers. © 2016 WILEY PERIODICALS, INC.

  20. Kinase-dead ATM protein is highly oncogenic and can be preferentially targeted by Topo-isomerase I inhibitors.

    Science.gov (United States)

    Yamamoto, Kenta; Wang, Jiguang; Sprinzen, Lisa; Xu, Jun; Haddock, Christopher J; Li, Chen; Lee, Brian J; Loredan, Denis G; Jiang, Wenxia; Vindigni, Alessandro; Wang, Dong; Rabadan, Raul; Zha, Shan

    2016-06-15

    Missense mutations in ATM kinase, a master regulator of DNA damage responses, are found in many cancers, but their impact on ATM function and implications for cancer therapy are largely unknown. Here we report that 72% of cancer-associated ATM mutations are missense mutations that are enriched around the kinase domain. Expression of kinase-dead ATM (Atm(KD/-)) is more oncogenic than loss of ATM (Atm(-/-)) in mouse models, leading to earlier and more frequent lymphomas with Pten deletions. Kinase-dead ATM protein (Atm-KD), but not loss of ATM (Atm-null), prevents replication-dependent removal of Topo-isomerase I-DNA adducts at the step of strand cleavage, leading to severe genomic instability and hypersensitivity to Topo-isomerase I inhibitors. Correspondingly, Topo-isomerase I inhibitors effectively and preferentially eliminate Atm(KD/-), but not Atm-proficientor Atm(-/-) leukemia in animal models. These findings identify ATM kinase-domain missense mutations as a potent oncogenic event and a biomarker for Topo-isomerase I inhibitor based therapy.

  1. Case report: a novel KERA mutation associated with cornea plana and its predicted effect on protein function

    DEFF Research Database (Denmark)

    Roos, Laura; Bertelsen, Birgitte; Harris, Pernille

    2015-01-01

    of the keratocan gene (KERA) on chromosome 12q22. To date, only nine different disease-associated KERA mutations, including four missense mutations, have been described. Case presentation: In this report, we present clinical data from a Turkish family with autosomal recessive cornea plana. In some of the affected...

  2. Novel TBX22 mutations in Chinese nonsyndromic cleft lip/palate ...

    Indian Academy of Sciences (India)

    Jiewen Dai

    2018-06-06

    Jun 6, 2018 ... sense, frame-shift, splice-site, or missense mutation (Pauws et al. 2013). Except for ... 0.4.0, http:// · frodo.wi.mit.edu/) was used for primer design. The poly- ..... Sternberg M. J. 2015 The Phyre2 web portal for protein modeling ...

  3. A case report of novel mutation in PRF1 gene, which causes familial autosomal recessive hemophagocytic lymphohistiocytosis.

    Science.gov (United States)

    Bordbar, Mohammad Reza; Modarresi, Farzaneh; Farazi Fard, Mohammad Ali; Dastsooz, Hassan; Shakib Azad, Nader; Faghihi, Mohammad Ali

    2017-05-03

    Hemophagocytic Lymphohistiocytosis (HLH) is a life-threatening immunodeficiency and multi-organ disease that affects people of all ages and ethnic groups. Common symptoms and signs of this disease are high fever, hepatosplenomegaly, and cytopenias. Familial form of HLH disease, which is an autosomal recessive hematological disorder is due to disease-causing mutations in several genes essential for NK and T-cell granule-mediated cytotoxic function. For an effective cytotoxic response from cytotoxic T lymphocyte or NK cell encountering an infected cell or tumor cell, different processes are required, including trafficking, docking, priming, membrane fusion, and entry of cytotoxic granules into the target cell leading to apoptosis. Therefore, genes involved in these steps play important roles in the pathogenesis of HLH disease which include PRF1, UNC13D (MUNC13-4), STX11, and STXBP2 (MUNC18-2). Here, we report a novel missense mutation in an 8-year-old boy suffered from hepatosplenomegaly, hepatitis, epilepsy and pancytopenia. The patient was born to a first-cousin parents with no previous documented disease in his parents. To identify mutated gene in the proband, Whole Exome Sequencing (WES) utilizing next generation sequencing was used on an Illumina HiSeq 2000 platform on DNA sample from the patient. Results showed a novel deleterious homozygous missense mutation in PRF1 gene (NM_001083116: exon3: c. 1120 T > G, p.W374G) in the patient and then using Sanger sequencing it was confirmed in the proband and his parents. Since his parents were heterozygous for the identified mutation, autosomal recessive pattern of inheritance was confirmed in the family. Our study identified a rare new pathogenic missense mutation in PRF1 gene in patient with HLH disease and it is the first report of mutation in PRF1 in Iranian patients with this disease.

  4. A missense mutation of HOXA13 underlies hand-foot-genital ...

    Indian Academy of Sciences (India)

    Navya

    2017-01-27

    Jan 27, 2017 ... result in difficult pregnancy and fetal loss or neonatal death (Donnenfeld et al. 1992;. Fryns et al. 1993). Urinary abnormalities include ectopic ureteric orifices, vesicoureteric reflux, and pelviureteric junction obstruction (Donnenfeld et al. 1992). HFGS is caused by mutations in the homeobox transcription ...

  5. Abnormal cortical synaptic transmission in CaV2.1 knockin mice with the S218L missense mutation which causes a severe familial hemiplegic migraine syndrome in humans

    Science.gov (United States)

    Vecchia, Dania; Tottene, Angelita; van den Maagdenberg, Arn M.J.M.; Pietrobon, Daniela

    2015-01-01

    Familial hemiplegic migraine type 1 (FHM1) is caused by gain-of-function mutations in CaV2.1 (P/Q-type) Ca2+ channels. Knockin (KI) mice carrying the FHM1 R192Q missense mutation show enhanced cortical excitatory synaptic transmission at pyramidal cell synapses but unaltered cortical inhibitory neurotransmission at fast-spiking interneuron synapses. Enhanced cortical glutamate release was shown to cause the facilitation of cortical spreading depression (CSD) in R192Q KI mice. It, however, remains unknown how other FHM1 mutations affect cortical synaptic transmission. Here, we studied neurotransmission in cortical neurons in microculture from KI mice carrying the S218L mutation, which causes a severe FHM syndrome in humans and an allele-dosage dependent facilitation of experimental CSD in KI mice, which is larger than that caused by the R192Q mutation. We show gain-of-function of excitatory neurotransmission, due to increased action-potential evoked Ca2+ influx and increased probability of glutamate release at pyramidal cell synapses, but unaltered inhibitory neurotransmission at multipolar interneuron synapses in S218L KI mice. In contrast with the larger gain-of-function of neuronal CaV2.1 current in homozygous than heterozygous S218L KI mice, the gain-of-function of evoked glutamate release, the paired-pulse ratio and the Ca2+ dependence of the excitatory postsynaptic current were similar in homozygous and heterozygous S218L KI mice, suggesting compensatory changes in the homozygous mice. Furthermore, we reveal a unique feature of S218L KI cortical synapses which is the presence of a fraction of mutant CaV2.1 channels being open at resting potential. Our data suggest that, while the gain-of-function of evoked glutamate release may explain the facilitation of CSD in heterozygous S218L KI mice, the further facilitation of CSD in homozygous S218L KI mice is due to other CaV2.1-dependent mechanisms, that likely include Ca2+ influx at voltages sub-threshold for action

  6. Analysis of BRAF V600E mutation in 1,320 nervous system tumors reveals high mutation frequencies in pleomorphic xanthoastrocytoma, ganglioglioma and extra-cerebellar pilocytic astrocytoma

    NARCIS (Netherlands)

    Schindler, G.; Capper, D.; Meyer, J.; Janzarik, W.; Omran, H.; Herold-Mende, C.; Schmieder, K.; Wesseling, P.; Mawrin, C.; Hasselblatt, M.; Louis, D.N.; Korshunov, A.; Pfister, S.; Hartmann, C.; Paulus, W.; Reifenberger, G.; Deimling, A. Von

    2011-01-01

    Missense mutations of the V600E type constitute the vast majority of tumor-associated somatic alterations in the v-RAF murine sarcoma viral oncogene homolog B1 (BRAF) gene. Initially described in melanoma, colon and papillary thyroid carcinoma, these alterations have also been observed in primary

  7. Functional implications of the p.Cys680Arg mutation in the MLH1 mismatch repair protein

    DEFF Research Database (Denmark)

    Dominguez-Valentin, Mev; Drost, Mark; Therkildsen, Christina

    2014-01-01

    >C missense mutation in exon 18 of the human MLH1 gene and biochemically characterization of the p.Cys680Arg mutant MLH1 protein to implicate it in the pathogenicity of the Lynch syndrome (LS). We show that the mutation is deficient in DNA mismatch repair and, therefore, contributing to LS in the carriers....

  8. Steroidogenic factor-1 (SF-1 gene mutation as a frequent cause of primary amenorrhea in 46,XY female adolescents with low testosterone concentration

    Directory of Open Access Journals (Sweden)

    Servant Nadège

    2010-03-01

    Full Text Available Abstract Background Primary amenorrhea due to 46,XY disorders of sex differentiation (DSD is a frequent reason for consultation in endocrine and gynecology clinics. Among the genetic causes of low-testosterone primary amenorrhea due to 46,XY DSD, SRY gene is reported to be frequently involved, but other genes, such as SF1 and WT1, have never been studied for their prevalence. Methods We directly sequenced SRY, SF1 and WT1 genes in 15 adolescent girls with primary amenorrhea, low testosterone concentration, and XY karyotype, to determine the prevalence of mutations. We also analyzed the LH receptor gene in patients with high LH and normal FSH concentrations. Results Among the 15 adolescents with primary amenorrhea and low testosterone concentration, we identified two new SRY mutations, five new SF1 mutations and one new LH receptor gene mutation. Our study confirms the 10-15% prevalence of SRY mutations and shows the high prevalence (33% of SF1 abnormalities in primary amenorrhea due to 46,XY DSD with low plasma testosterone concentration. Conclusions The genetic analysis of low-testosterone primary amenorrhea is complex as several factors may be involved. This work underlines the need to systematically analyze the SF1 sequence in girls with primary amenorrhea due to 46,XY DSD and low testosterone, as well as in newborns with 46,XY DSD.

  9. Analysis of MYO7A in a Moroccan family with Usher syndrome type 1B: novel loss-of-function mutation and non-pathogenicity of p.Y1719C.

    Science.gov (United States)

    Boulouiz, Redouane; Li, Yun; Abidi, Omar; Bolz, Hanno; Chafik, Abdelaziz; Kubisch, Christian; Roub, Hassan; Wollnik, Bernd; Barakat, Abdelhamid

    2007-10-02

    Mutations in the MYO7A gene are responsible for Usher syndrome type 1B (USH1B), the most common USH1 subtype, which accounts for the largest proportion of USH1 cases in most populations. Molecular genetic diagnosis in Usher syndrome is well established and identification of the underlying mutations in Usher patients is important for confirmation of the clinical diagnosis and genetic counseling. We analyzed a large consanguineous USH1 family from Morocco and linked the disease in this family to the MYO7A/USH1B locus. We identified the frequently described missense change p.Y1719C. In addition, we found the homozygous c.1687G>A mutation in the last nucleotide of exon 14, which is predicted to result in aberrant splicing and may lead to loss of MYO7A transcript. We further showed that p.Y1719C is not disease-causing but does represent a frequent polymorphism in the Moroccan population, with an estimated carrier frequency of 0.07. This finding has an important impact for molecular diagnosis and genetic counseling in USH1B families.

  10. Mutation and Expression of the DCC Gene in Human Lung Cancer

    Directory of Open Access Journals (Sweden)

    Takashi Kohno

    2000-07-01

    Full Text Available Chromosome 18q is frequently deleted in lung cancers, a common region of 18q deletions was mapped to chromosome 18g21. Since the DCC candidate tumor suppressor gene has been mapped in this region, mutation and expression of the DCC gene were examined in 46 lung cancer cell lines, consisting of 14 small cell lung carcinomas (SCLCs and 32 non-small cell lung carcinomas (NSCLCs, to elucidate the pathogenetic significance of DCC alterations in human lung carcinogenesis. A heterozygous missense mutation was detected in a NSCLC cell line, Ma26, while homozygous deletion was not detected in any of the cell lines. The DCC gene was expressed in 11 (24% of the 46 cell lines, the incidence of DCC expression was significantly higher in SCLCs (7/14, 50% than in NSCLCs (4/32, 13% (P = .01, Fisher's exact test. Therefore, genetic alterations of DCC are infrequent; however, the levels of DCC expression vary among lung cancer cells, in particular, between SCLCs and NSCLCs. The present result does not implicate DCC as a specific mutational target of 18q deletions in human lung cancer; however, it suggests that DCC is a potential target of inactivation by genetic defects including intron or promoter mutations and/or epigenetic alterations. The present result also suggests that DCC expression is associated with some properties of SCLCs, such as a neuroendocrine (NE feature.

  11. High-incidence of PTEN mutations in Chinese patients with primary small cell carcinoma of the esophagus

    International Nuclear Information System (INIS)

    Zhang, Zhimin; Wang, Ge; Xiao, Hualiang; Xie, Fei; Zhang, Hui; Chen, Chuan; Xiao, He; Yang, Zhenzhou; Wang, Dong; Li, Zengpeng

    2014-01-01

    Primary small cell carcinoma of the esophagus (PSCCE) is a rare and aggressive tumor with poor prognosis. The aim of this study was to investigate the existence of EGFR, KRAS, PIK3CA and PTEN mutations in PSCCE. Clinical–pathological data and paraffin-embedded specimens were collected from 38 patients. Exons 18 to 21 of EGFR, KRAS and PIK3CA status were analyzed by real-time PCR based on ARMS and Scorpion technology in all patients, and the PTEN gene was also screened using real-time PCR and high-resolution melting curve analysis (HRMA). Only 1 (2.63%) out of 38 patients had EGFR mutations in L858R missense, and KRAS and PIK3CA were not found in the mutational spot in all patients. However, PTEN mutations presented in 14 (36.84%) out of 38 patients, including exon 5 coding for PTEN missense mutation (n =4, 10.53%), exon 6 (n =7, 18.42%), concurrent exon 5 and exon 6 (n =2, 5.26%), and exon 8 (n =1, 2.63%). Concurrent mutations of these genes were not detected in all samples. No statistically significant associations were found between the clinicopathological features and the mutation status of PTEN. The incidence of PTEN mutations in Chinese patients with PSCCE was higher than that of previous reports in other histological subtypes of esophageal cancer

  12. Identification of two novel mutations in the PHEX gene in Chinese patients with hypophosphatemic rickets/osteomalacia.

    Science.gov (United States)

    Yue, Hua; Yu, Jin-bo; He, Jin-wei; Zhang, Zeng; Fu, Wen-zhen; Zhang, Hao; Wang, Chun; Hu, Wei-wei; Gu, Jie-mei; Hu, Yun-qiu; Li, Miao; Liu, Yu-juan; Zhang, Zhen-Lin

    2014-01-01

    X-linked dominant hypophosphatemia (XLH) is the most prevalent form of inherited rickets/osteomalacia in humans. The aim of this study was to identify PHEX gene mutations and describe the clinical features observed in 6 unrelated Chinese families and 3 sporadic patients with hypophosphatemic rickets/osteomalacia. For this study, 45 individuals from 9 unrelated families of Chinese Han ethnicity (including 16 patients and 29 normal phenotype subjects), and 250 healthy donors were recruited. All 22 exons and exon-intron boundaries of the PHEX gene were amplified by polymerase chain reaction (PCR) and directly sequenced. The PHEX mutations were detected in 6 familial and 3 sporadic hypophosphatemic rickets/osteomalacia. Altogether, 2 novel mutations were detected: 1 missense mutation c.1183G>C in exon 11, resulting in p.Gly395Arg and 1 missense mutation c.1751A>C in exon 17, resulting in p.His584Pro. No mutations were found in the 250 healthy controls. Our study increases knowledge of the PHEX gene mutation types and clinical phenotypes found in Chinese patients with XLH, which is important for understanding the genetic basis of XLH. The molecular diagnosis of a PHEX genetic mutation is of great importance for confirming the clinical diagnosis of XLH, conducting genetic counseling, and facilitating prenatal intervention, especially in the case of sporadic patients.

  13. Mutation and Methylation Analysis of the Chromodomain-Helicase-DNA Binding 5 Gene in Ovarian Cancer

    Directory of Open Access Journals (Sweden)

    Kylie L. Gorringe

    2008-11-01

    Full Text Available Chromodomain, helicase, DNA binding 5 (CHD5 is a member of a subclass of the chromatin remodeling Swi/Snf proteins and has recently been proposed as a tumor suppressor in a diverse range of human cancers. We analyzed all 41 coding exons of CHD5 for somatic mutations in 123 primary ovarian cancers as well as 60 primary breast cancers using high-resolution melt analysis. We also examined methylation of the CHD5 promoter in 48 ovarian cancer samples by methylation-specific single-stranded conformation polymorphism and bisulfite sequencing. In contrast to previous studies, no mutations were identified in the breast cancers, but somatic heterozygous missense mutations were identified in 3 of 123 ovarian cancers. We identified promoter methylation in 3 of 45 samples with normal CHD5 and in 2 of 3 samples with CHD5 mutation, suggesting these tumors may have biallelic inactivation of CHD5. Hemizygous copy number loss at CHD5 occurred in 6 of 85 samples as assessed by single nucleotide polymorphism array. Tumors with CHD5 mutation or methylation were more likely to have mutation of KRAS or BRAF (P = .04. The aggregate frequency of CHD5 haploinsufficiency or inactivation is 16.2% in ovarian cancer. Thus, CHD5 may play a role as a tumor suppressor gene in ovarian cancer; however, it is likely that there is another target of the frequent copy number neutral loss of heterozygosity observed at 1p36.

  14. A glycogene mutation map for discovery of diseases of glycosylation

    DEFF Research Database (Denmark)

    Hansen, Lars; Lind-Thomsen, Allan; Joshi, Hiren J

    2015-01-01

    homologous families. However, Genome-Wide-Association Studies (GWAS) have identified such isoenzyme genes as candidates for different diseases, but validation is not straightforward without biomarkers. Large-scale whole exome sequencing (WES) provides access to mutations in e.g. glycosyltransferase genes...... in populations, which can be used to predict and/or analyze functional deleterious mutations. Here, we constructed a draft of a Functional Mutational Map of glycogenes, GlyMAP, from WES of a rather homogenous population of 2,000 Danes. We catalogued all missense mutations and used prediction algorithms, manual...... inspection, and in case of CAZy family GT27 experimental analysis of mutations to map deleterious mutations. GlyMAP provides a first global view of the genetic stability of the glycogenome and should serve as a tool for discovery of novel CDGs....

  15. HRAS mutations in Costello syndrome: detection of constitutional activating mutations in codon 12 and 13 and loss of wild-type allele in malignancy.

    Science.gov (United States)

    Estep, Anne L; Tidyman, William E; Teitell, Michael A; Cotter, Philip D; Rauen, Katherine A

    2006-01-01

    Costello syndrome (CS) is a complex developmental disorder involving characteristic craniofacial features, failure to thrive, developmental delay, cardiac and skeletal anomalies, and a predisposition to develop neoplasia. Based on similarities with other cancer syndromes, we previously hypothesized that CS is likely due to activation of signal transduction through the Ras/MAPK pathway [Tartaglia et al., 2003]. In this study, the HRAS coding region was sequenced for mutations in a large, well-characterized cohort of 36 CS patients. Heterogeneous missense point mutations predicting an amino acid substitution were identified in 33/36 (92%) patients. The majority (91%) had a 34G --> A transition in codon 12. Less frequent mutations included 35G --> C (codon 12) and 37G --> T (codon 13). Parental samples did not have an HRAS mutation supporting the hypothesis of de novo heterogeneous mutations. There is phenotypic variability among patients with a 34G --> A transition. The most consistent features included characteristic facies and skin, failure to thrive, developmental delay, musculoskeletal abnormalities, visual impairment, cardiac abnormalities, and generalized hyperpigmentation. The two patients with 35G --> C had cardiac arrhythmias whereas one patient with a 37G --> T transversion had an enlarged aortic root. Of the patients with a clinical diagnosis of CS, neoplasia was the most consistent phenotypic feature for predicating an HRAS mutation. To gain an understanding of the relationship between constitutional HRAS mutations and malignancy, HRAS was sequenced in an advanced biphasic rhabdomyosarcoma/fibrosarcoma from an individual with a 34G --> A mutation. Loss of the wild-type HRAS allele was observed, suggesting tumorigenesis in CS patients is accompanied by additional somatic changes affecting HRAS. Finally, due to phenotypic overlap between CS and cardio-facio-cutaneous (CFC) syndromes, the HRAS coding region was sequenced in a well-characterized CFC cohort

  16. Novel vitamin D 1α-hydroxylase gene mutations in a Chinese ...

    Indian Academy of Sciences (India)

    2011-08-19

    Aug 19, 2011 ... known as vitamin D 1α-hydroxylase deficiency or pseu- dovitamin D ... amplicons of the 378 bp were digested with restriction enzyme PvuI and ... have no enzymatic activity; a missense mutation c.473T>C. (p.L158P) in the ...

  17. DMD Mutations in 576 Dystrophinopathy Families: A Step Forward in Genotype-Phenotype Correlations.

    Directory of Open Access Journals (Sweden)

    Jonas Juan-Mateu

    Full Text Available Recent advances in molecular therapies for Duchenne muscular dystrophy (DMD require precise genetic diagnosis because most therapeutic strategies are mutation-specific. To understand more about the genotype-phenotype correlations of the DMD gene we performed a comprehensive analysis of the DMD mutational spectrum in a large series of families. Here we provide the clinical, pathological and genetic features of 576 dystrophinopathy patients. DMD gene analysis was performed using the MLPA technique and whole gene sequencing in blood DNA and muscle cDNA. The impact of the DNA variants on mRNA splicing and protein functionality was evaluated by in silico analysis using computational algorithms. DMD mutations were detected in 576 unrelated dystrophinopathy families by combining the analysis of exonic copies and the analysis of small mutations. We found that 471 of these mutations were large intragenic rearrangements. Of these, 406 (70.5% were exonic deletions, 64 (11.1% were exonic duplications, and one was a deletion/duplication complex rearrangement (0.2%. Small mutations were identified in 105 cases (18.2%, most being nonsense/frameshift types (75.2%. Mutations in splice sites, however, were relatively frequent (20%. In total, 276 mutations were identified, 85 of which have not been previously described. The diagnostic algorithm used proved to be accurate for the molecular diagnosis of dystrophinopathies. The reading frame rule was fulfilled in 90.4% of DMD patients and in 82.4% of Becker muscular dystrophy patients (BMD, with significant differences between the mutation types. We found that 58% of DMD patients would be included in single exon-exon skipping trials, 63% from strategies directed against multiexon-skipping exons 45 to 55, and 14% from PTC therapy. A detailed analysis of missense mutations provided valuable information about their impact on the protein structure.

  18. Expanding the spectrum of HEXA mutations in Indian patients with Tay–Sachs disease

    Directory of Open Access Journals (Sweden)

    Jayesh Sheth

    2014-01-01

    Full Text Available Tay–Sachs disease is an autosomal recessive neurodegenerative disorder occurring due to impaired activity of β-hexosaminidase-A (EC 3.2.1.52, resulting from the mutation in HEXA gene. Very little is known about the molecular pathology of TSD in Indian children except for a few mutations identified by us. The present study is aimed to determine additional mutations leading to Tay–Sachs disease in nine patients confirmed by the deficiency of β-hexosaminidase-A (C (D175A and c.805G>C (p.G269R in one case; and one small 1 bp deletion c.426delT (p.F142LfsX57 and one splice site mutation c.459+4A>C in the other two cases respectively. None of these mutations were detected in 100 chromosomes from healthy individuals of the same ethnic group. Three previously reported missense mutations, (i c.532C>T (p.R178C, (ii c.964G>T (p.D322Y, and (iii c.1385A>T (p.E462V; two nonsense mutations (i c.709C>T (p.Q237X and (ii c.1528C>T (p.R510X, one 4 bp insertion c.1277_1278insTATC (p.Y427IfsX5 and one splice site mutation c.459+5G>A were also identified in six cases. We observe from this study that novel mutations are more frequently observed in Indian patients with Tay–Sachs disease with clustering of ~73% of disease causing mutations in exons 5 to 12. This database can be used for a carrier rate screening in the larger population of the country.

  19. Acromelic frontonasal dysostosis and ZSWIM6 mutation

    DEFF Research Database (Denmark)

    Twigg, Stephen R F; Ousager, Lilian Bomme; Miller, Kerry A

    2016-01-01

    Acromelic frontonasal dysostosis (AFND) is a distinctive and rare frontonasal malformation that presents in combination with brain and limb abnormalities. A single recurrent heterozygous missense substitution in ZSWIM6, encoding a protein of unknown function, was previously shown to underlie this...... sequencing of DNA isolated from a variety of tissues, which each contain different levels of mutation. This has important implications for genetic counselling....

  20. MLL2 mutation detection in 86 patients with Kabuki syndrome: a genotype-phenotype study.

    Science.gov (United States)

    Makrythanasis, P; van Bon, B W; Steehouwer, M; Rodríguez-Santiago, B; Simpson, M; Dias, P; Anderlid, B M; Arts, P; Bhat, M; Augello, B; Biamino, E; Bongers, E M H F; Del Campo, M; Cordeiro, I; Cueto-González, A M; Cuscó, I; Deshpande, C; Frysira, E; Izatt, L; Flores, R; Galán, E; Gener, B; Gilissen, C; Granneman, S M; Hoyer, J; Yntema, H G; Kets, C M; Koolen, D A; Marcelis, C l; Medeira, A; Micale, L; Mohammed, S; de Munnik, S A; Nordgren, A; Psoni, S; Reardon, W; Revencu, N; Roscioli, T; Ruiterkamp-Versteeg, M; Santos, H G; Schoumans, J; Schuurs-Hoeijmakers, J H M; Silengo, M C; Toledo, L; Vendrell, T; van der Burgt, I; van Lier, B; Zweier, C; Reymond, A; Trembath, R C; Perez-Jurado, L; Dupont, J; de Vries, B B A; Brunner, H G; Veltman, J A; Merla, G; Antonarakis, S E; Hoischen, A

    2013-12-01

    Recently, pathogenic variants in the MLL2 gene were identified as the most common cause of Kabuki (Niikawa-Kuroki) syndrome (MIM#147920). To further elucidate the genotype-phenotype correlation, we studied a large cohort of 86 clinically defined patients with Kabuki syndrome (KS) for mutations in MLL2. All patients were assessed using a standardized phenotype list and all were scored using a newly developed clinical score list for KS (MLL2-Kabuki score 0-10). Sequencing of the full coding region and intron-exon boundaries of MLL2 identified a total of 45 likely pathogenic mutations (52%): 31 nonsense, 10 missense and four splice-site mutations, 34 of which were novel. In five additional patients, novel, i.e. non-dbSNP132 variants of clinically unknown relevance, were identified. Patients with likely pathogenic nonsense or missense MLL2 mutations were usually more severely affected (median 'MLL2-Kabuki score' of 6) as compared to the patients without MLL2 mutations (median 'MLL2-Kabuki score' of 5), a significant difference (p < 0.0014). Several typical facial features such as large dysplastic ears, arched eyebrows with sparse lateral third, blue sclerae, a flat nasal tip with a broad nasal root, and a thin upper and a full lower lip were observed more often in mutation positive patients. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Missense mutations in IHH impair Indian Hedgehog signaling in C3H10T1/2 cells: Implications for brachydactyly type A1, and new targets for Hedgehog signaling.

    Science.gov (United States)

    Guo, Shengzhen; Zhou, Jian; Gao, Bo; Hu, Jianxin; Wang, Hongsheng; Meng, Junwei; Zhao, Xinzhi; Ma, Gang; Lin, Chuwen; Xiao, Yue; Tang, Wei; Zhu, Xuming; Cheah, Kathryn S E; Feng, Guoying; Chan, Danny; He, Lin

    2010-01-01

    Heterozygous missense mutations in IHH result in Brachydactyly type A1 (BDA1; OMIM 112500), a condition characterized by the shortening of digits due to hypoplasia/aplasia of the middle phalanx. Indian Hedgehog signaling regulates the proliferation and differentiation of chondrocytes and is essential for endochondral bone formation. Analyses of activated IHH signaling in C3H10T1/2 cells showed that three BDA1-associated mutations (p.E95K, p.D100E and p.E131K) severely impaired the induction of targets such as Ptch1 and Gli1. However, this was not a complete loss of function, suggesting that these mutations may affect the interaction with the receptor PTCH1 or its partners, with an impact on the induction potency. From comparative microarray expression analyses and quantitative real-time PCR, we identified three additional targets, Sostdc1, Penk1 and Igfbp5, which were also severely affected. Penk1 and Igfbp5 were confirmed to be regulated by GLI1, while the induction of Sostdc1 by IHH is independent of GLI1. SOSTDC1 is a BMP antagonist, and altered BMP signaling is known to affect digit formation. The role of Penk1 and Igfbp5 in skeletogenesis is not known. However, we have shown that both Penk1 and Igfbp5 are expressed in the interzone region of the developing joint of mouse digits, providing another link for a role for IHH signaling in the formation of the distal digits.

  2. ENU-induced phenovariance in mice: inferences from 587 mutations

    Directory of Open Access Journals (Sweden)

    Arnold Carrie N

    2012-10-01

    Full Text Available Abstract Background We present a compendium of N-ethyl-N-nitrosourea (ENU-induced mouse mutations, identified in our laboratory over a period of 10 years either on the basis of phenotype or whole genome and/or whole exome sequencing, and archived in the Mutagenetix database. Our purpose is threefold: 1 to formally describe many point mutations, including those that were not previously disclosed in peer-reviewed publications; 2 to assess the characteristics of these mutations; and 3 to estimate the likelihood that a missense mutation induced by ENU will create a detectable phenotype. Findings In the context of an ENU mutagenesis program for C57BL/6J mice, a total of 185 phenotypes were tracked to mutations in 129 genes. In addition, 402 incidental mutations were identified and predicted to affect 390 genes. As previously reported, ENU shows strand asymmetry in its induction of mutations, particularly favoring T to A rather than A to T in the sense strand of coding regions and splice junctions. Some amino acid substitutions are far more likely to be damaging than others, and some are far more likely to be observed. Indeed, from among a total of 494 non-synonymous coding mutations, ENU was observed to create only 114 of the 182 possible amino acid substitutions that single base changes can achieve. Based on differences in overt null allele frequencies observed in phenotypic vs. non-phenotypic mutation sets, we infer that ENU-induced missense mutations create detectable phenotype only about 1 in 4.7 times. While the remaining mutations may not be functionally neutral, they are, on average, beneath the limits of detection of the phenotypic assays we applied. Conclusions Collectively, these mutations add to our understanding of the chemical specificity of ENU, the types of amino acid substitutions it creates, and its efficiency in causing phenovariance. Our data support the validity of computational algorithms for the prediction of damage caused by

  3. Analysis of patients with atypical hemolytic uremic syndrome treated at the Mie University Hospital: concentration of C3 p.I1157T mutation.

    Science.gov (United States)

    Matsumoto, Takeshi; Fan, Xinping; Ishikawa, Eiji; Ito, Masaaki; Amano, Keishirou; Toyoda, Hidemi; Komada, Yoshihiro; Ohishi, Kohshi; Katayama, Naoyuki; Yoshida, Yoko; Matsumoto, Masanori; Fujimura, Yoshihiro; Ikejiri, Makoto; Wada, Hideo; Miyata, Toshiyuki

    2014-11-01

    Atypical hemolytic uremic syndrome (aHUS) is caused by abnormalities of the complement system and has a significantly poor prognosis. The clinical phenotypes of 12 patients in nine families with aHUS with familial or recurrent onset and ADAMTS13 activity of ≥20 % treated at the Mie University Hospital were examined. In seven of the patients, the first episode of aHUS occurred during childhood and ten patients experienced a relapse. All patients had renal dysfunction and three had been treated with hemodialysis. Seven patients experienced probable triggering events including common cold, influenza, bacterial infection and/or vaccination for influenza. All patients had entered remission, and renal function was improved in 11 patients. DNA sequencing of six candidate genes, identified a C3 p.I1157T missense mutation in all eight patients in six families examined and this mutation was causative for aHUS. A causative mutation THBD p.D486Y was also identified in an aHUS patient. Four missense mutations, CFH p.V837I, p.Y1058H, p.V1060L and THBD p.R403K may predispose to aHUS manifestation; the remaining seven missense mutations were likely neutral. In conclusion, the clinical phenotypes of aHUS are various, and there are often trigger factors. The C3 p.I1157T mutation was identified as the causative mutation for aHUS in all patients examined, and may be geographically concentrated in or around the Mie prefecture in central Japan.

  4. Diffuse reticuloendothelial system involvement in type IV glycogen storage disease with a novel GBE1 mutation: a case report and review.

    Science.gov (United States)

    Magoulas, Pilar L; El-Hattab, Ayman W; Roy, Angshumoy; Bali, Deeksha S; Finegold, Milton J; Craigen, William J

    2012-06-01

    Glycogen storage disease type IV is a rare autosomal recessive disorder of glycogen metabolism caused by mutations in the GBE1 gene that encodes the 1,4-alpha-glucan-branching enzyme 1. Its clinical presentation is variable, with the most common form presenting in early childhood with primary hepatic involvement. Histologic manifestations in glycogen storage disease type IV typically consist of intracytoplasmic non-membrane-bound inclusions containing abnormally branched glycogen (polyglucosan bodies) within hepatocytes and myocytes. We report a female infant with classic hepatic form of glycogen storage disease type IV who demonstrated diffuse reticuloendothelial system involvement with the spleen, bone marrow, and lymph nodes infiltrated by foamy histiocytes with intracytoplasmic polyglucosan deposits. Sequence analysis of the GBE1 gene revealed compound heterozygosity for a previously described frameshift mutation (c.1239delT) and a novel missense mutation (c.1279G>A) that is predicted to alter a conserved glycine residue. GBE enzyme analysis revealed no detectable activity. A review of the literature for glycogen storage disease type IV patients with characterized molecular defects and deficient enzyme activity reveals most GBE1 mutations to be missense mutations clustering in the catalytic enzyme domain. Individuals with the classic hepatic form of glycogen storage disease type IV tend to be compound heterozygotes for null and missense mutations. Although the extensive reticuloendothelial system involvement that was observed in our patient is not typical of glycogen storage disease type IV, it may be associated with severe enzymatic deficiency and a poor outcome. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Mutation analysis of the ERCC4/FANCQ gene in hereditary breast cancer.

    Directory of Open Access Journals (Sweden)

    Sandra Kohlhase

    Full Text Available The ERCC4 protein forms a structure-specific endonuclease involved in the DNA damage response. Different cancer syndromes such as a subtype of Xeroderma pigmentosum, XPF, and recently a subtype of Fanconi Anemia, FA-Q, have been attributed to biallelic ERCC4 gene mutations. To investigate whether monoallelic ERCC4 gene defects play some role in the inherited component of breast cancer susceptibility, we sequenced the whole ERCC4 coding region and flanking untranslated portions in a series of 101 Byelorussian and German breast cancer patients selected for familial disease (set 1, n = 63 or for the presence of the rs1800067 risk haplotype (set 2, n = 38. This study confirmed six known and one novel exonic variants, including four missense substitutions but no truncating mutation. Missense substitution p.R415Q (rs1800067, a previously postulated breast cancer susceptibility allele, was subsequently screened for in a total of 3,698 breast cancer cases and 2,868 controls from Germany, Belarus or Russia. The Gln415 allele appeared protective against breast cancer in the German series, with the strongest effect for ductal histology (OR 0.67; 95%CI 0.49; 0.92; p = 0.003, but this association was not confirmed in the other two series, with the combined analysis yielding an overall Mantel-Haenszel OR of 0.94 (95% CI 0.81; 1.08. There was no significant effect of p.R415Q on breast cancer survival in the German patient series. The other three detected ERCC4 missense mutations included two known rare variants as well as a novel substitution, p.E17V, that we identified on a p.R415Q haplotype background. The p.E17V mutation is predicted to be probably damaging but was present in just one heterozygous patient. We conclude that the contribution of ERCC4/FANCQ coding mutations to hereditary breast cancer in Central and Eastern Europe is likely to be small.

  6. Concomitant BCORL1 and BRAF Mutations in Vemurafenib-Resistant Melanoma Cells.

    Science.gov (United States)

    Mologni, Luca; Costanza, Mariantonia; Sharma, Geeta Geeta; Viltadi, Michela; Massimino, Luca; Citterio, Stefania; Purgante, Stefania; Raman, Hima; Pirola, Alessandra; Zucchetti, Massimo; Piazza, Rocco; Gambacorti-Passerini, Carlo

    2018-05-01

    BRAF is the most frequently mutated gene in melanoma. Constitutive activation of mutant BRAF V600E leads to aberrant Ras-independent MAPK signaling and cell transformation. Inhibition of mutant BRAF is a current frontline therapy for such cases, with improved survival compared with chemotherapy. Unfortunately, reactivation of MAPK signaling by several mechanisms has been shown to cause drug resistance and disease recurrence. In this work, we describe the co-occurrence of an in-frame deletion within an amplified BRAF V600E locus and a missense point mutation of the transcriptional repressor BCORL1 in vemurafenib-resistant A375 melanoma cells. Functional data confirmed that truncated p47BRAF V600E and mutant BCORL1 Q1076H both contribute to resistance. Interestingly, either endogenous BCORL1 silencing or ectopic BCORL1 Q1076H expression mimicked the effects of a CRISPR/Cas9-edited BCORL1 Q1076H locus, suggesting a complex mixture of loss- and gain-of-function effects caused by the mutation. Transcriptomic data confirmed this hypothesis. Finally, we show that the pan-RAF inhibitor sorafenib is not affected by expression of BRAF deletion variant and effectively synergizes with vemurafenib to block resistant cells, suggesting a possible intervention for this class of mutants. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  7. A novel lipoprotein lipase gene missense mutation in Chinese patients with severe hypertriglyceridemia and pancreatitis

    Science.gov (United States)

    2014-01-01

    Background Alterations or mutations in the lipoprotein lipase (LPL) gene contribute to severe hypertriglyceridemia (HTG). This study reported on two patients in a Chinese family with LPL gene mutations and severe HTG and acute pancreatitis. Methods Two patients with other five family members were included in this study for DNA-sequences of hyperlipidemia-related genes (such as LPL, APOC2, APOA5, LMF1, and GPIHBP1) and 43 healthy individuals and 70 HTG subjects were included for the screening of LPL gene mutations. Results Both patients were found to have a compound heterozygote for a novel LPL gene mutation (L279V) and a known mutation (A98T). Furthermore, one HTG subject out of 70 was found to carry this novel LPL L279V mutation. Conclusions The data from this study showed that compound heterozygote mutations of A98T and L279V inactivate lipoprotein lipase enzymatic activity and contribute to severe HTG and acute pancreatitis in two Chinese patients. Further study will investigate how these LPL gene mutations genetically inactivate the LPL enzyme. PMID:24646025

  8. Neonatal epileptic encephalopathy caused by mutations in the PNPO gene encoding pyridox(am)ine 5'-phosphate oxidase.

    Science.gov (United States)

    Mills, Philippa B; Surtees, Robert A H; Champion, Michael P; Beesley, Clare E; Dalton, Neil; Scambler, Peter J; Heales, Simon J R; Briddon, Anthony; Scheimberg, Irene; Hoffmann, Georg F; Zschocke, Johannes; Clayton, Peter T

    2005-04-15

    In the mouse, neurotransmitter metabolism can be regulated by modulation of the synthesis of pyridoxal 5'-phosphate and failure to maintain pyridoxal phosphate (PLP) levels results in epilepsy. This study of five patients with neonatal epileptic encephalopathy suggests that the same is true in man. Cerebrospinal fluid and urine analyses indicated reduced activity of aromatic L-amino acid decarboxylase and other PLP-dependent enzymes. Seizures ceased with the administration of PLP, having been resistant to treatment with pyridoxine, suggesting a defect of pyridox(am)ine 5'-phosphate oxidase (PNPO). Sequencing of the PNPO gene identified homozygous missense, splice site and stop codon mutations. Expression studies in Chinese hamster ovary cells showed that the splice site (IVS3-1g>a) and stop codon (X262Q) mutations were null activity mutations and that the missense mutation (R229W) markedly reduced pyridox(am)ine phosphate oxidase activity. Maintenance of optimal PLP levels in the brain may be important in many neurological disorders in which neurotransmitter metabolism is disturbed (either as a primary or as a secondary phenomenon).

  9. [Mutation analysis of the PAH gene in children with phenylketonuria from the Qinghai area of China].

    Science.gov (United States)

    He, Jiang; Wang, Hui-Zhen; Xu, Fa-Liang; Yang, Xi; Wang, Rui; Zou, Hong-Yun; Yu, Wu-Zhong

    2015-11-01

    To study the mutation characteristics of the phenylalanine hydroxylase (PAH) gene in children with phenylketonuria (PKU) from the Qinghai area of China, in order to provide basic information for genetic counseling and prenatal diagnosis. Mutations of the PAH gene were detected in the promoter and exons 1-13 and their flanking intronic sequences of PAH gene by PCR and DNA sequencing in 49 children with PKU and their parents from the Qinghai area of China. A total of 30 different mutations were detected in 80 out of 98 mutant alleles (82%), including 19 missense (63%), 5 nonsense (17%), 3 splice-site (10%) and 3 deletions (10%). Most mutations were detected in exons 3, 6, 7, 11 and intron 4 of PAH gene. The most frequent mutations were p.R243Q (19%), IVS4-1G>A (9%), p.Y356X (7%) and p.EX6-96A>G(5%). Two novel mutations p.N93fsX5 (c.279-282delCATC) and p.G171E (c.512G>A) were found. p.H64fsX9(c.190delC) was documented for the second time in Chinese PAH gene. The mutation spectrum of the gene PAH in the Qinghai population was similar to that in other populations in North China while significantly different from that in the populations from some provinces in southern China, Japan and Europe. The mutations of PAH gene in the Qinghai area of China demonstrate a unique diversity, complexity and specificity.

  10. Seemingly neutral polymorphic variants may confer immunity to splicing-inactivating mutations

    DEFF Research Database (Denmark)

    Nielsen, Karsten Bork; Sørensen, Suzette; Cartegni, Luca

    2007-01-01

    assays to show that a missense mutation in exon 5 of the medium-chain acyl-CoA dehydrogenase (MCAD) gene primarily causes exon skipping by inactivating a crucial exonic splicing enhancer (ESE), thus leading to loss of a functional protein and to MCAD deficiency. This ESE functions by antagonizing...

  11. The BAG3 gene variants in Polish patients with dilated cardiomyopathy: four novel mutations and a genotype-phenotype correlation.

    Science.gov (United States)

    Franaszczyk, Maria; Bilinska, Zofia T; Sobieszczańska-Małek, Małgorzata; Michalak, Ewa; Sleszycka, Justyna; Sioma, Agnieszka; Małek, Łukasz A; Kaczmarska, Dorota; Walczak, Ewa; Włodarski, Paweł; Hutnik, Łukasz; Milanowska, Blanka; Dzielinska, Zofia; Religa, Grzegorz; Grzybowski, Jacek; Zieliński, Tomasz; Ploski, Rafal

    2014-07-09

    BAG3 gene mutations have been recently implicated as a novel cause of dilated cardiomyopathy (DCM). Our aim was to evaluate the prevalence of BAG3 mutations in Polish patients with DCM and to search for genotype-phenotype correlations. We studied 90 unrelated probands by direct sequencing of BAG3 exons and splice sites. Large deletions/insertions were screened for by quantitative real time polymerase chain reaction (qPCR). We found 5 different mutations in 6 probands and a total of 21 mutations among their relatives: the known p.Glu455Lys mutation (2 families), 4 novel mutations: p.Gln353ArgfsX10 (c.1055delC), p.Gly379AlafsX45 (c.1135delG), p.Tyr451X (c.1353C>A) and a large deletion of 17,990 bp removing BAG3 exons 3-4. Analysis of mutation positive relatives of the probands from this study pooled with those previously reported showed higher DCM prevalence among those with missense vs. truncating mutations (OR = 8.33, P = 0.0058) as well as a difference in age at disease onset between the former and the latter in Kaplan-Meier survival analysis (P = 0.006). Clinical data from our study suggested that in BAG3 mutation carriers acute onset DCM with hemodynamic compromise may be triggered by infection. BAG3 point mutations and large deletions are relatively frequent cause of DCM. Delayed DCM onset associated with truncating vs. non-truncating mutations may be important for genetic counseling.

  12. CBS mutations and MTFHR SNPs causative of hyperhomocysteinemia in Pakistani children.

    Science.gov (United States)

    Ibrahim, Shahnaz; Maqbool, Saadia; Azam, Maleeha; Iqbal, Mohammad Perwaiz; Qamar, Raheel

    2018-03-29

    Three index patients with hyperhomocysteinemia and ocular anomalies were screened for cystathionine beta synthase (CBS) and methylenetetrahydrofolate reductase (MTHFR) polymorphisms. Genotyping of hyperhomocysteinemia associated MTHFR polymorphisms C677T (rs1801133) and A1298C (rs1801131) was done by PCR-restriction fragment length polymorphism. Sanger sequencing was performed for CBS exonic sequences along with consensus splice sites. In the case of MTHFR polymorphisms, all the patients were heterozygous CT for the single nucleotide polymorphism (SNP) C677T and were therefore carriers of the risk allele (T), while the patients were homozygous CC for the risk genotype of the SNP A1298C. CBS sequencing resulted in the identification of two novel mutations, a missense change (c.467T>C; p.Leu156Pro) in exon 7 and an in-frame deletion (c.808_810del; p.Glu270del) in exon 10. In addition, a recurrent missense mutation (c.770C>T; p.Thr257Met) in exon 10 of the gene was also identified. The mutations were present homozygously in the patients and were inherited from the carrier parents. This is the first report from Pakistan where novel as well as recurrent CBS mutations causing hyperhomocysteinemia and lens dislocation in three patients from different families are being reported with the predicted effect of the risk allele of the MTHFR SNP in causing hyperhomocysteinemia.

  13. ALDH1A3 mutations cause recessive anophthalmia and microphthalmia.

    Science.gov (United States)

    Fares-Taie, Lucas; Gerber, Sylvie; Chassaing, Nicolas; Clayton-Smith, Jill; Hanein, Sylvain; Silva, Eduardo; Serey, Margaux; Serre, Valérie; Gérard, Xavier; Baumann, Clarisse; Plessis, Ghislaine; Demeer, Bénédicte; Brétillon, Lionel; Bole, Christine; Nitschke, Patrick; Munnich, Arnold; Lyonnet, Stanislas; Calvas, Patrick; Kaplan, Josseline; Ragge, Nicola; Rozet, Jean-Michel

    2013-02-07

    Anophthalmia and microphthalmia (A/M) are early-eye-development anomalies resulting in absent or small ocular globes, respectively. A/M anomalies occur in syndromic or nonsyndromic forms. They are genetically heterogeneous, some mutations in some genes being responsible for both anophthalmia and microphthalmia. Using a combination of homozygosity mapping, exome sequencing, and Sanger sequencing, we identified homozygosity for one splice-site and two missense mutations in the gene encoding the A3 isoform of the aldehyde dehydrogenase 1 (ALDH1A3) in three consanguineous families segregating A/M with occasional orbital cystic, neurological, and cardiac anomalies. ALDH1A3 is a key enzyme in the formation of a retinoic acid gradient along the dorso-ventral axis during early eye development. Transitory expression of mutant ALDH1A3 open reading frames showed that both missense mutations reduce the accumulation of the enzyme, potentially leading to altered retinoic acid synthesis. Although the role of retinoic acid signaling in eye development is well established, our findings provide genetic evidence of a direct link between retinoic-acid-synthesis dysfunction and early-eye-development anomalies in humans. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  14. CDKL5 Mutations in Boys With Encephalopathy and Early-Onset Intractable Epilepsy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-10-01

    Full Text Available Clinical and EEG data of 3 Italian boys (ages 3, 9, and 13 years with severe early-onset encephalopathy, mental retardation, facial dysmorphisms, and intractable epilepsy were found to carry missense mutations in the CDKL5 gene, in a report from Troina, Italy.

  15. Mitchell-Riley Syndrome: A Novel Mutation in RFX6 Gene

    Directory of Open Access Journals (Sweden)

    Marta Zegre Amorim

    2015-01-01

    Full Text Available A novel RFX6 homozygous missense mutation was identified in an infant with Mitchell-Riley syndrome. The most common features of Mitchell-Riley syndrome were present, including severe neonatal diabetes associated with annular pancreas, intestinal malrotation, gallbladder agenesis, cholestatic disease, chronic diarrhea, and severe intrauterine growth restriction. Perijejunal tissue similar to pancreatic tissue was found in the submucosa, a finding that has not been previously reported in this syndrome. This case associating RFX6 mutation with structural and functional pancreatic abnormalities reinforces the RFX6 gene role in pancreas development and β-cell function, adding information to the existent mutation databases.

  16. A Novel KCNJ2 Mutation Identified in an Autistic Proband Affects the Single Channel Properties of Kir2.1

    Directory of Open Access Journals (Sweden)

    Anna Binda

    2018-03-01

    Full Text Available Inwardly rectifying potassium channels (Kir have been historically associated to several cardiovascular disorders. In particular, loss-of-function mutations in the Kir2.1 channel have been reported in cases affected by Andersen-Tawil syndrome while gain-of-function mutations in the same channel cause the short QT3 syndrome. Recently, a missense mutation in Kir2.1, as well as mutations in the Kir4.1, were reported to be involved in autism spectrum disorders (ASDs suggesting a role of potassium channels in these diseases and introducing the idea of the existence of K+ channel ASDs. Here, we report the identification in an Italian affected family of a novel missense mutation (p.Phe58Ser in the KCNJ2 gene detected in heterozygosity in a proband affected by autism and borderline for short QT syndrome type 3. The mutation is located in the N-terminal region of the gene coding for the Kir2.1 channel and in particular in a very conserved domain. In vitro assays demonstrated that this mutation results in an increase of the channel conductance and in its open probability. This gain-of-function of the protein is consistent with the autistic phenotype, which is normally associated to an altered neuronal excitability.

  17. Mutations of the cystic fibrosis gene, but not cationic trypsinogen gene, are associated with recurrent or chronic idiopathic pancreatitis.

    Science.gov (United States)

    Ockenga, J; Stuhrmann, M; Ballmann, M; Teich, N; Keim, V; Dörk, T; Manns, M P

    2000-08-01

    We investigated whether mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and cationic trypsinogen gene are associated with recurrent acute, or chronic idiopathic pancreatitis. Twenty patients with idiopathic pancreatitis (11 women, nine men; mean age, 30 yr) were studied for the presence of a CFTR mutation by screening the genomic DNA for more than 30 mutations and variants in the CFTR gene. Selected mutations of the cationic trypsinogen gene were screened by Afl III restriction digestion or by a mutation-specific polymerase chain reaction (PCR). In each patient exons 1, 2, and 3 of the cationic trypsinogen gene were sequenced. Patients with a CFTR mutation underwent evaluation of further functional electrophysiological test (intestinal current measurement). No mutation of the cationic trypsinogen gene was detected. A CFTR mutation was detected in 6/20 (30.0%) patients. Three patients (15.0%) had a cystic fibrosis (CF) mutation on one chromosome (deltaF508, I336K, Y1092X), which is known to cause phenotypical severe cystic fibrosis. One patient was heterozygous for the 5T allele. In addition, two possibly predisposing CFTR variants (R75Q, 1716G-->A) were detected on four patients, one of these being a compound heterozygous for the missense mutation I336K and R75Q. No other family member (maternal I336K; paternal R75Q; sister I1336K) developed pancreatitis. An intestinal current measurement in rectum samples of patients with a CFTR mutation revealed no CF-typical constellations. CFTR mutations are associated with recurrent acute, or chronic idiopathic pancreatitis, whereas mutations of the cationic trypsinogen mutation do not appear to be a frequent pathogenetic factor.

  18. A survey of new temperature-sensitive, embryonic-lethal mutations in C. elegans: 24 alleles of thirteen genes.

    Directory of Open Access Journals (Sweden)

    Sean M O'Rourke

    2011-03-01

    Full Text Available To study essential maternal gene requirements in the early C. elegans embryo, we have screened for temperature-sensitive, embryonic lethal mutations in an effort to bypass essential zygotic requirements for such genes during larval and adult germline development. With conditional alleles, multiple essential requirements can be examined by shifting at different times from the permissive temperature of 15°C to the restrictive temperature of 26°C. Here we describe 24 conditional mutations that affect 13 different loci and report the identity of the gene mutations responsible for the conditional lethality in 22 of the mutants. All but four are mis-sense mutations, with two mutations affecting splice sites, another creating an in-frame deletion, and one creating a premature stop codon. Almost all of the mis-sense mutations affect residues conserved in orthologs, and thus may be useful for engineering conditional mutations in other organisms. We find that 62% of the mutants display additional phenotypes when shifted to the restrictive temperature as L1 larvae, in addition to causing embryonic lethality after L4 upshifts. Remarkably, we also found that 13 out of the 24 mutations appear to be fast-acting, making them particularly useful for careful dissection of multiple essential requirements. Our findings highlight the value of C. elegans for identifying useful temperature-sensitive mutations in essential genes, and provide new insights into the requirements for some of the affected loci.

  19. SNP2Structure: A Public and Versatile Resource for Mapping and Three-Dimensional Modeling of Missense SNPs on Human Protein Structures

    Directory of Open Access Journals (Sweden)

    Difei Wang

    2015-01-01

    Full Text Available One of the long-standing challenges in biology is to understand how non-synonymous single nucleotide polymorphisms (nsSNPs change protein structure and further affect their function. While it is impractical to solve all the mutated protein structures experimentally, it is quite feasible to model the mutated structures in silico. Toward this goal, we built a publicly available structure database resource (SNP2Structure, https://apps.icbi.georgetown.edu/snp2structure focusing on missense mutations, msSNP. Compared with web portals with similar aims, SNP2Structure has the following major advantages. First, our portal offers direct comparison of two related 3D structures. Second, the protein models include all interacting molecules in the original PDB structures, so users are able to determine regions of potential interaction changes when a protein mutation occurs. Third, the mutated structures are available to download locally for further structural and functional analysis. Fourth, we used Jsmol package to display the protein structure that has no system compatibility issue. SNP2Structure provides reliable, high quality mapping of nsSNPs to 3D protein structures enabling researchers to explore the likely functional impact of human disease-causing mutations.

  20. Further evidence for P59L mutation in GJA3 associated with autosomal dominant congenital cataract

    Directory of Open Access Journals (Sweden)

    Li Wang

    2016-01-01

    Full Text Available Context: Congenital cataracts are one of the common eye disorders leading to visual impairment or blindness in children worldwide. We found a Chinese family with autosomal dominant pulverulent cataract. Aims: To identify the pathogenic gene mutation in a Chinese family with autosomal dominant inherited pulverulent cataract. Subjects and Methods: After obtained informed consent, detailed ophthalmic examinations were carried out; genomic DNAs were obtained from seven family members in a three-generation Chinese family with three affected. All exons of candidate genes were amplified by polymerase chain reaction and were sequenced performed by bidirectional sequencing. Results: By sequencing the encoding regions of the candidate genes, a missense mutation (c. 176C>T was detected in gap junction protein alpha 3 genes (GJA3, which resulted in the substitution of highly conserved proline by leucine at codon 59 (p.P59L. The mutation co-segregated with all patients and was absent in 100 normal Chinese controls. Conclusions: The study identified a missense mutation (c. 176C>T in GJA3 gene associated with autosomal dominant congenital pulverulent cataract in a Chinese family. It gave further evidence of phenotype heterogeneity for P59L mutation in GJA3 associated with congenital cataract.

  1. De novo mutations in the motor domain of KIF1A cause cognitive impairment, spastic paraparesis, axonal neuropathy, and cerebellar atrophy

    NARCIS (Netherlands)

    Lee, Jae Ran; Srour, Myriam; Kim, Doyoun; Hamdan, Fadi F.; Lim, So Hee; Brunel-Guitton, Catherine; Décarie, Jean Claude; Rossignol, Elsa; Mitchell, Grant A.; Schreiber, Allison; Moran, Rocio; Van Haren, Keith; Richardson, Randal; Nicolai, Joost; Oberndorff, Karin M E J; Wagner, Justin D.; Boycott, Kym M.; Rahikkala, Elisa; Junna, Nella; Tyynismaa, Henna; Cuppen, Inge; Verbeek, Nienke E.; Stumpel, Connie T R M; Willemsen, Michel A.; de Munnik, Sonja A.; Rouleau, Guy A.; Kim, Eunjoon; Kamsteeg, Erik Jan; Kleefstra, Tjitske; Michaud, Jacques L.

    2015-01-01

    KIF1A is a neuron-specific motor protein that plays important roles in cargo transport along neurites. Recessive mutations in KIF1A were previously described in families with spastic paraparesis or sensory and autonomic neuropathy type-2. Here, we report 11 heterozygous de novo missense mutations

  2. ANXA11 mutations prevail in Chinese ALS patients with and without cognitive dementia.

    Science.gov (United States)

    Zhang, Kang; Liu, Qing; Liu, Keqiang; Shen, Dongchao; Tai, Hongfei; Shu, Shi; Ding, Qingyun; Fu, Hanhui; Liu, Shuangwu; Wang, Zhili; Li, Xiaoguang; Liu, Mingsheng; Zhang, Xue; Cui, Liying

    2018-06-01

    To investigate the genetic contribution of ANXA11 , a gene associated with amyotrophic lateral sclerosis (ALS), in Chinese ALS patients with and without cognitive dementia. Sequencing all the coding exons of ANXA11 and intron-exon boundaries in 18 familial amyotrophic lateral sclerosis (FALS), 353 unrelated sporadic amyotrophic lateral sclerosis (SALS), and 12 Chinese patients with ALS-frontotemporal lobar dementia (ALS-FTD). The transcripts in peripheral blood generated from a splicing mutation were examined by reverse transcriptase PCR. We identified 6 nonsynonymous heterozygous mutations (5 novel and 1 recurrent), 1 splice site mutation, and 1 deletion of 10 amino acids (not accounted in the mutant frequency) in 11 unrelated patients, accounting for a mutant frequency of 5.6% (1/18) in FALS, 2.3% (8/353) in SALS, and 8.3% (1/12) in ALS-FTD. The deletion of 10 amino acids was detected in 1 clinically undetermined male with an ALS family history who had atrophy in hand muscles and myotonic discharges revealed by EMG. The novel p. P36R mutation was identified in 1 FALS index, 1 patient with SALS, and 1 ALS-FTD. The splicing mutation (c.174-2A>G) caused in-frame skipping of the entire exon 6. The rest missense mutations including p.D40G, p.V128M, p.S229R, p.R302C and p.G491R were found in 6 unrelated patients with SALS. The ANXA11 gene is one of the most frequently mutated genes in Chinese patients with SALS. A canonical splice site mutation leading to skipping of the entire exon 6 further supports the loss-of-function mechanism. In addition, the study findings further expand the ANXA11 phenotype, first highlighting its pathogenic role in ALS-FTD.

  3. Primary Type3 (Non-ABC, Non-GCB Subtype of Extranodal Diffuse Large B-Cell Lymphoma of the Thyroid Bearing No MYD88 Mutation by Padlock Probe Hybridization

    Directory of Open Access Journals (Sweden)

    Yukiko Nishi

    2017-06-01

    Full Text Available Primary extranodal malignant lymphoma of the thyroid is a rare entity composed of mostly neoplastic transformation of germinal center-like B cells (GCB or memory B cells. Other B-cell-type malignancies arising primarily in the thyroid have rarely been described. Immunohistochemical examination of autopsied primary malignant lymphoma of the thyroid in an 83-year-old Japanese female revealed the presence of a non-GCB subtype of diffuse large B-cell lymphoma (DLBCL without the typical codon 206 or 265 missense mutation of MYD88. The lack of the highly oncogenic MYD88 gene mutation, frequently observed in DLBCL of the activated B-cell (ABC subtype, and the detection of an extremely aggressive yet local clinical phenotype demonstrated that the present case was an exceptional entity of the type3 (non-GCB and non-ABC subtype.

  4. (TSC) in Bulgaria: six novel mutations in the TSC1 and TSC2 genes

    Indian Academy of Sciences (India)

    G2-Trombo

    Zdrave” str., ... Our data is similar to previous studies with .... The TSC1 and TSC2 protein products, hamartin (TSC1) with 1164 amino acids and tuberin ... cohort are missense, frameshift and nonsense mutations, while in the TSC1 gene most of ...

  5. Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta

    Directory of Open Access Journals (Sweden)

    Barbara Gasse

    2017-06-01

    Full Text Available Amelogenesis imperfecta (AI designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene (MMP20 produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues, pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI.

  6. Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta.

    Science.gov (United States)

    Gasse, Barbara; Prasad, Megana; Delgado, Sidney; Huckert, Mathilde; Kawczynski, Marzena; Garret-Bernardin, Annelyse; Lopez-Cazaux, Serena; Bailleul-Forestier, Isabelle; Manière, Marie-Cécile; Stoetzel, Corinne; Bloch-Zupan, Agnès; Sire, Jean-Yves

    2017-01-01

    Amelogenesis imperfecta (AI) designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene ( MMP20 ) produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues), pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI.

  7. Distinct effects of the recurrent Mlh1G67R mutation on MMR functions, cancer, and meiosis

    OpenAIRE

    Avdievich, Elena; Reiss, Cora; Scherer, Stefan J.; Zhang, Yongwei; Maier, Sandra M.; Jin, Bo; Hou, Harry; Rosenwald, Andreas; Riedmiller, Hubertus; Kucherlapati, Raju; Cohen, Paula E.; Edelmann, Winfried; Kneitz, Burkhard

    2008-01-01

    Mutations in the human DNA mismatch repair (MMR) gene MLH1 are associated with hereditary nonpolyposis colorectal cancer (Lynch syndrome, HNPCC) and a significant proportion of sporadic colorectal cancer. The inactivation of MLH1 results in the accumulation of somatic mutations in the genome of tumor cells and resistance to the genotoxic effects of a variety of DNA damaging agents. To study the effect of MLH1 missense mutations on cancer susceptibility, we generated a mouse line carrying the ...

  8. Identification of Missense Mutation (I12T in the BSND Gene and Bioinformatics Analysis

    Directory of Open Access Journals (Sweden)

    Hina Iqbal

    2011-01-01

    Full Text Available Nonsyndromic hearing loss is a paradigm of genetic heterogeneity with 85 loci and 39 nuclear disease genes reported so far. Mutations of BSND have been shown to cause Bartter syndrome type IV, characterized by significant renal abnormalities and deafness and nonsyndromic nearing loss. We studied a Pakistani consanguineous family. Clinical examinations of affected individuals did not reveal the presence of any associated signs, which are hallmarks of the Bartter syndrome type IV. Linkage analysis identified an area of 18.36 Mb shared by all affected individuals between markers D1S2706 and D1S1596. A maximum two-point LOD score of 2.55 with markers D1S2700 and multipoint LOD score of 3.42 with marker D1S1661 were obtained. BSND mutation, that is, p.I12T, cosegregated in all extant members of our pedigree. BSND mutations can cause nonsyndromic hearing loss, and it is a second report for this mutation. The respected protein, that is, BSND, was first modeled, and then, the identified mutation was further analyzed by using different bioinformatics tools; finally, this protein and its mutant was docked with CLCNKB and REN, interactions of BSND, respectively.

  9. Molecular genetic mutation analysis in Menkes-disease with prenatal diagnosis

    DEFF Research Database (Denmark)

    László, Aranka; Endreffy, Emoke; Tümer, Zeynep

    2010-01-01

    Menkes disease (MD) is an X-linked recessive multisystemic lethal, heredodegenerative disorder. Progressive neurodegeneration and connective tissue disturbances with microscopically kinky hair are the main symptoms. Molecular genetic mutation analysis was made at a Hungarian male infant suffering...... from MD and prenatal diagnosis was done in this MD loaded family. METHOD: The 12th exon of ATP7A gene has been analyzed by dideoxy-finger printing (DDF), polymerase chain reaction (PCR), direct sequencing of exon 12. The specific mutation was screened from chorionic villi of the maternal aunt at the 14......th gestational week. RESULTS: In the exon 12th a basic pair substitution with Arg 844 His change was detected leading to very severe fatal missense mutation....

  10. De novo mutations in the genome organizer CTCF cause intellectual disability

    DEFF Research Database (Denmark)

    Gregor, Anne; Oti, Martin; Kouwenhoven, Evelyn N

    2013-01-01

    An increasing number of genes involved in chromatin structure and epigenetic regulation has been implicated in a variety of developmental disorders, often including intellectual disability. By trio exome sequencing and subsequent mutational screening we now identified two de novo frameshift...... mutations and one de novo missense mutation in CTCF in individuals with intellectual disability, microcephaly, and growth retardation. Furthermore, an individual with a larger deletion including CTCF was identified. CTCF (CCCTC-binding factor) is one of the most important chromatin organizers in vertebrates...... and is involved in various chromatin regulation processes such as higher order of chromatin organization, enhancer function, and maintenance of three-dimensional chromatin structure. Transcriptome analyses in all three individuals with point mutations revealed deregulation of genes involved in signal transduction...

  11. BRCA2 Hypomorphic Missense Variants Confer Moderate Risks of Breast Cancer

    NARCIS (Netherlands)

    Shimelis, Hermela; Mesman, Romy L. S.; Von Nicolai, Catharina; Ehlen, Asa; Guidugli, Lucia; Martin, Charlotte; Calléja, Fabienne M. G. R.; Meeks, Huong; Hallberg, Emily; Hinton, Jamie; Lilyquist, Jenna; Hu, Chunling; Aalfs, Cora M.; Aittomäki, Kristiina; Andrulis, Irene; Anton-Culver, Hoda; Arndt, Volker; Beckmann, Matthias W.; Benitez, Javier; Bogdanova, Natalia V.; Bojesen, Stig E.; Bolla, Manjeet K.; Borresen-Dale, Anne-Lise; Brauch, Hiltrud; Brennan, Paul; Brenner, Hermann; Broeks, Annegien; Brouwers, Barbara; Brüning, Thomas; Burwinkel, Barbara; Chang-Claude, Jenny; Chenevix-Trench, Georgia; Cheng, Ching-Yu; Choi, Ji-Yeob; Collée, J. Margriet; Cox, Angela; Cross, Simon S.; Czene, Kamila; Darabi, Hatef; Dennis, Joe; Dörk, Thilo; Dos-Santos-Silva, Isabel; Dunning, Alison M.; Fasching, Peter A.; Figueroa, Jonine; Flyger, Henrik; García-Closas, Montserrat; Giles, Graham G.; Glendon, Gord; Guénel, Pascal; Haiman, Christopher A.; Hall, Per; Hamann, Ute; Hartman, Mikael; Hogervorst, Frans B.; Hollestelle, Antoinette; Hopper, John L.; Ito, Hidemi; Jakubowska, Anna; Kang, Daehee; Kosma, Veli-Matti; Kristensen, Vessela; Lai, Kah-Nyin; Lambrechts, Diether; Marchand, Loic Le; Li, Jingmei; Lindblom, Annika; Lophatananon, Artitaya; Lubinski, Jan; Machackova, Eva; Mannermaa, Arto; Margolin, Sara; Marme, Frederik; Matsuo, Keitaro; Miao, Hui; Michailidou, Kyriaki; Milne, Roger L.; Muir, Kenneth; Neuhausen, Susan L.; Nevanlinna, Heli; Olson, Janet E.; Olswold, Curtis; Oosterwijk, Jan J. C.; Osorio, Ana; Peterlongo, Paolo; Peto, Julian; Pharoah, Paul D. P.; Pylkäs, Katri; Radice, Paolo; Rashid, Muhammad Usman; Rhenius, Valerie; Rudolph, Anja; Sangrajrang, Suleeporn; Sawyer, Elinor J.; Schmidt, Marjanka K.; Schoemaker, Minouk J.; Seynaeve, Caroline; Shah, Mitul; Shen, Chen-Yang; Shrubsole, Martha; Shu, Xiao-Ou; Slager, Susan; Southey, Melissa C.; Stram, Daniel O.; Swerdlow, Anthony; teo, Soo H.; Tomlinson, Ian; Torres, Diana; Truong, Thérèse; van Asperen, Christi J.; van der Kolk, Lizet E.; Wang, Qin; Winqvist, Robert; Wu, Anna H.; Yu, Jyh-Cherng; Zheng, Wei; Zheng, Ying; Leary, Jennifer; Walker, Logan; Foretova, Lenka; Fostira, Florentia; Claes, Kathleen B. M.; Varesco, Liliana; Moghadasi, Setareh; Easton, Douglas F.; Spurdle, Amanda; Devilee, Peter; Vrieling, Harry; Monteiro, Alvaro N. A.; Goldgar, David E.; Carreira, Aura; Vreeswijk, Maaike P. G.; Couch, Fergus J.

    2017-01-01

    Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk

  12. Confirmation of the pathogenicity of a mutation p.G337C in the COL1A2 gene associated with osteogenesis imperfecta

    Science.gov (United States)

    Jia, Mingrui; Shi, Ranran; Zhao, Xuli; Fu, Zhijian; Bai, Zhijing; Sun, Tao; Zhao, Xuejun; Wang, Wenbo; Xu, Chao; Yan, Fang

    2017-01-01

    Abstract Mutation analysis as the gold standard is particularly important in diagnosis of osteogenesis imperfecta (OI) and it may be preventable upon early diagnosis. In this study, we aimed to analyze the clinical and genetic materials of an OI pedigree as well as to confirm the deleterious property of the mutation. A pedigree with OI was identified. All family members received careful clinical examinations and blood was drawn for genetic analyses. Genes implicated in OI were screened for mutation. The function and structure of the mutant protein were predicted using bioinformatics analysis. The proband, a 9-month fetus, showed abnormal sonographic images. Disproportionately short and triangular face with blue sclera was noticed at birth. She can barely walk and suffered multiple fractures till 2-year old. Her mother appeared small stature, frequent fractures, blue sclera, and deformity of extremities. A heterozygous missense mutation c.1009G>T (p.G337C) in the COL1A2 gene was identified in her mother and her. Bioinformatics analysis showed p.G337 was well-conserved among multiple species and the mutation probably changed the structure and damaged the function of collagen. We suggest that the mutation p.G337C in the COL1A2 gene is pathogenic for OI by affecting the protein structure and the function of collagen. PMID:28953610

  13. Mutation and polymorphism analysis of the human homogentisate 1, 2-dioxygenase gene in alkaptonuria patients.

    Science.gov (United States)

    Beltrán-Valero de Bernabé, D; Granadino, B; Chiarelli, I; Porfirio, B; Mayatepek, E; Aquaron, R; Moore, M M; Festen, J J; Sanmartí, R; Peñalva, M A; de Córdoba, S R

    1998-01-01

    Alkaptonuria (AKU), a rare hereditary disorder of phenylalanine and tyrosine catabolism, was the first disease to be interpreted as an inborn error of metabolism. AKU patients are deficient for homogentisate 1,2 dioxygenase (HGO); this deficiency causes homogentisic aciduria, ochronosis, and arthritis. We cloned the human HGO gene and characterized two loss-of-function mutations, P230S and V300G, in the HGO gene in AKU patients. Here we report haplotype and mutational analysis of the HGO gene in 29 novel AKU chromosomes. We identified 12 novel mutations: 8 (E42A, W97G, D153G, S189I, I216T, R225H, F227S, and M368V) missense mutations that result in amino acid substitutions at positions conserved in HGO in different species, 1 (F10fs) frameshift mutation, 2 intronic mutations (IVS9-56G-->A, IVS9-17G-->A), and 1 splice-site mutation (IVS5+1G-->T). We also report characterization of five polymorphic sites in HGO and describe the haplotypic associations of alleles at these sites in normal and AKU chromosomes. One of these sites, HGO-3, is a variable dinucleotide repeat; IVS2+35T/A, IVS5+25T/C, and IVS6+46C/A are intronic sites at which single nucleotide substitutions (dimorphisms) have been detected; and c407T/A is a relatively frequent nucleotide substitution in the coding sequence, exon 4, resulting in an amino acid change (H80Q). These data provide insight into the origin and evolution of the various AKU alleles. PMID:9529363

  14. Recurrent PTPRB and PLCG1 mutations in angiosarcoma.

    Science.gov (United States)

    Behjati, Sam; Tarpey, Patrick S; Sheldon, Helen; Martincorena, Inigo; Van Loo, Peter; Gundem, Gunes; Wedge, David C; Ramakrishna, Manasa; Cooke, Susanna L; Pillay, Nischalan; Vollan, Hans Kristian M; Papaemmanuil, Elli; Koss, Hans; Bunney, Tom D; Hardy, Claire; Joseph, Olivia R; Martin, Sancha; Mudie, Laura; Butler, Adam; Teague, Jon W; Patil, Meena; Steers, Graham; Cao, Yu; Gumbs, Curtis; Ingram, Davis; Lazar, Alexander J; Little, Latasha; Mahadeshwar, Harshad; Protopopov, Alexei; Al Sannaa, Ghadah A; Seth, Sahil; Song, Xingzhi; Tang, Jiabin; Zhang, Jianhua; Ravi, Vinod; Torres, Keila E; Khatri, Bhavisha; Halai, Dina; Roxanis, Ioannis; Baumhoer, Daniel; Tirabosco, Roberto; Amary, M Fernanda; Boshoff, Chris; McDermott, Ultan; Katan, Matilda; Stratton, Michael R; Futreal, P Andrew; Flanagan, Adrienne M; Harris, Adrian; Campbell, Peter J

    2014-04-01

    Angiosarcoma is an aggressive malignancy that arises spontaneously or secondarily to ionizing radiation or chronic lymphoedema. Previous work has identified aberrant angiogenesis, including occasional somatic mutations in angiogenesis signaling genes, as a key driver of angiosarcoma. Here we employed whole-genome, whole-exome and targeted sequencing to study the somatic changes underpinning primary and secondary angiosarcoma. We identified recurrent mutations in two genes, PTPRB and PLCG1, which are intimately linked to angiogenesis. The endothelial phosphatase PTPRB, a negative regulator of vascular growth factor tyrosine kinases, harbored predominantly truncating mutations in 10 of 39 tumors (26%). PLCG1, a signal transducer of tyrosine kinases, encoded a recurrent, likely activating p.Arg707Gln missense variant in 3 of 34 cases (9%). Overall, 15 of 39 tumors (38%) harbored at least one driver mutation in angiogenesis signaling genes. Our findings inform and reinforce current therapeutic efforts to target angiogenesis signaling in angiosarcoma.

  15. FANCA Gene Mutations with 8 Novel Molecular Changes in Indian Fanconi Anemia Patients

    OpenAIRE

    Solanki, Avani; Mohanty, Purvi; Shukla, Pallavi; Rao, Anita; Ghosh, Kanjaksha; Vundinti, Babu Rao

    2016-01-01

    Fanconi anemia (FA), a rare heterogeneous genetic disorder, is known to be associated with 19 genes and a spectrum of clinical features. We studied FANCA molecular changes in 34 unrelated and 2 siblings of Indian patients with FA and have identified 26 different molecular changes of FANCA gene, of which 8 were novel mutations (a small deletion c.2500delC, 4 non-sense mutations c.2182C>T, c.2630C>G, c.3677C>G, c.3189G>A; and 3 missense mutations; c.1273G>C, c.3679 G>C, and c.3992 T>C). Among t...

  16. Induction of spontaneous and UV-induced mutations during commitment to meiosis in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Machida, I.; Nakai, S.

    1980-01-01

    Inductions of reversions of nonsense, missense and frameshift-type mutations were investigated in a diploid cell population of Saccharomyces cerevisiae during commitment to meiosis, by using the medium-transfer technique from sporulation medium to vegetative medium. The yields of spontaneous reverse mutations obtained from the cells that were committed to different stages during meiosis were rather constant irrespective of the alleles tested, although the yields of both intergenic and intragenic recombinations markedly increased. The susceptibilities to UV-induced reverse mutations examined during commitment to meiosis were not changed appreciably. It is concluded that induction of base-change-type mutations in meiosis is not essentially different from that in mitosis. (orig.)

  17. MUTATIONS IN THE ARX GENE: CLINICAL, ELECTROENCEPHALOGRAPHIC AND NEUROIMAGING FEATURES IN 3 PATIENTS

    Directory of Open Access Journals (Sweden)

    I. V. Ivanova

    2017-01-01

    Full Text Available The Aristaless-related homeobox (ARX gene is a member of the paired-type homeodomain transcription factor family with critical roles in embryonic development, particularly in the developing brain. Mutations in ARX gene demonstrate striking intra- and interfamilial pleiotropy together with genetic heterogeneity and lead to a broad spectrum of diseases. They give rise to 4 key phenotypic features: a different types of brain malformation, abnormal genitalia, epilepsy and intellectual disability. Authors present 3 clinical cases: a girl with duplication on the short arm of X-chromosome (Xp11.22-p22.33, which include genes ARX and CDKL5; a girl and a boy with a missense mutation in ARX gene that have not been previously described (chrX:25031522C>A, causes the substitution of an amino acid in the 197 protein position (p.Gly197Val, NM_139058.2. All patients suffer from severe epilepsy, that is refractory to antiepileptic drugs, and all of them have different degrees of psychomotor delay. The patients with missense mutation also have movement disorders: stereotypic movements in the girl and choreo athetosis and dystonia in the boy. Electroencephalographic abnormalities have been identified in all patients, and there were not significant abnormalities on magnetic resonance imaging in all cases. The described cases broaden the clinical spectrum of mutations in ARX gene.

  18. Waardenburg Syndrome: description of two novel mutations in the PAX3 gene, one of which incompletely penetrant

    Directory of Open Access Journals (Sweden)

    Eliete Pardono

    2006-01-01

    Full Text Available We describe two different novel mutations in the PAX3 gene, detected in two families with cases of Waardenburg syndrome type I (WSI. The missense mutation detected in one family involved a single substitution in exon 2 (c.142 G > T and was present both in the affected individual and in his clinically normal father. The mutation found in the second family consisted of a deletion of 13 bases, c.764-776del(TTACCCTGACATT, in exon 5.

  19. Antisense Oligonucleotide (AON-based Therapy for Leber Congenital Amaurosis Caused by a Frequent Mutation in CEP290

    Directory of Open Access Journals (Sweden)

    Rob WJ Collin

    2012-01-01

    Full Text Available Leber congenital amaurosis (LCA is the most severe form of inherited retinal degeneration, with an onset in the first year of life. The most frequent mutation that causes LCA, present in at least 10% of individuals with LCA from North-American and Northern-European descent, is an intronic mutation in CEP290 that results in the inclusion of an aberrant exon in the CEP290 mRNA. Here, we describe a genetic therapy approach that is based on antisense oligonucleotides (AONs, small RNA molecules that are able to redirect normal splicing of aberrantly processed pre-mRNA. Immortalized lymphoblastoid cells of individuals with LCA homozygously carrying the intronic CEP290 mutation were transfected with several AONs that target the aberrant exon that is incorporated in the mutant CEP290 mRNA. Subsequent RNA isolation and reverse transcription-PCR analysis revealed that a number of AONs were capable of almost fully redirecting normal CEP290 splicing, in a dose-dependent manner. Other AONs however, displayed no effect on CEP290 splicing at all, indicating that the rescue of aberrant CEP290 splicing shows a high degree of sequence specificity. Together, our data show that AON-based therapy is a promising therapeutic approach for CEP290-associated LCA that warrants future research in animal models to develop a cure for this blinding disease.

  20. Identification and functional characterisation of novel glucokinase mutations causing maturity-onset diabetes of the young in Slovakia.

    Directory of Open Access Journals (Sweden)

    Lucia Valentínová

    Full Text Available Heterozygous glucokinase (GCK mutations cause a subtype of maturity-onset diabetes of the young (GCK-MODY. Over 600 GCK mutations have been reported of which ∼65% are missense. In many cases co-segregation has not been established and despite the importance of functional studies in ascribing pathogenicity for missense variants these have only been performed for C, c.1113-1114delGC were novel. Parental DNA was available for 22 probands (covering 14/22 mutations and co-segregation established in all cases. Bioinformatic analysis predicted all missense mutations to be damaging. Nine (I110N, V200A, N204D, G223S, G258R, F419S, V244G, L315H, I436N mutations were functionally evaluated. Basic kinetic analysis explained pathogenicity for 7 mutants which showed reduced glucokinase activity with relative activity indices (RAI between 0.6 to <0.001 compared to wild-type GCK (1.0. For the remaining 2 mutants additional molecular mechanisms were investigated. Differences in glucokinase regulatory protein (GKRP -mediated-inhibition of GCK were observed for both L315H & I436N when compared to wild type (IC(50 14.6±0.1 mM & 20.3±1.6 mM vs.13.3±0.1 mM respectively [p<0.03]. Protein instability as assessed by thermal lability studies demonstrated that both L315H and I436N show marked thermal instability compared to wild-type GCK (RAI at 55°C 8.8±0.8% & 3.1±0.4% vs. 42.5±3.9% respectively [p<0.001]. The minimum prevalence of GCK-MODY amongst Slovakian patients with diabetes was 0.03%. In conclusion, we have identified 22 GCK mutations in 36 Slovakian probands and demonstrate that combining family, bioinformatic and functional studies can aid the interpretation of variants identified by molecular diagnostic screening.

  1. A novel de novo activating mutation in STAT3 identified in a patient with common variable immunodeficiency (CVID).

    Science.gov (United States)

    Russell, Mark A; Pigors, Manuela; Houssen, Maha E; Manson, Ania; Kelsell, David; Longhurst, Hilary; Morgan, Noel G

    2018-02-01

    Common variable immunodeficiency (CVID) is characterised by repeated infection associated with primary acquired hypogammaglobulinemia. CVID frequently has a complex aetiology but, in certain cases, it has a monogenic cause. Recently, variants within the gene encoding the transcription factor STAT3 were implicated in monogenic CVID. Here, we describe a patient presenting with symptoms synonymous with CVID, who displayed reduced levels of IgG and IgA, repeated viral infections and multiple additional co-morbidities. Whole-exome sequencing revealed a de novo novel missense mutation in the coiled-coil domain of STAT3 (c.870A>T; p.K290N). Accordingly, the K290N variant of STAT3 was generated, and a STAT3 responsive dual-luciferase reporter assay revealed that the variant strongly enhances STAT3 transcriptional activity both under basal and stimulated (with IL-6) conditions. Overall, these data complement earlier studies in which CVID-associated STAT3 mutations are predicted to enhance transcriptional activity, suggesting that such patients may respond favourably to IL-6 receptor antagonists (e.g. tocilizumab). Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Identification of five novel FBN1 mutations by non-radioactive single-strand conformation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.; Qian, C.; Comeau, K.; Francke, U. [Stanford Univ. Medical Center, Stanford, CA (United States)

    1994-09-01

    Marfan syndrome (MFS), one of the most common genetic disorders of connective tissue, is characterized by variable manifestations in skeletal, cardiovascular and ocular systems. Mutations in the fibrillin gene on chromosome 15 (FBN1) have been shown to cause MFS. To examine the relationship between FBN1 gene mutations, fibrillin protein function and MFS phenotypes, we screened for alternations in the fibrillin coding sequence in fibroblast derived cDNA from MFS patients. To date, abnormally migrating bands in more than 20 unrelated MFS patients have been identified by using non-radioactive single-strand conformation analysis and silver staining. Five altered bands have been directly sequenced. Two missense mutations and three splice site mutations have been identified. Both missense mutations substitute another amino acid for a cysteine residue (C1402W and C1672R) in EGF-like motifs of the fibrillin polypeptide chain. The two splice site mutations are at nucleotide positions 6994+1 (G{yields}A), and 7205-2 (A{yields}G) and result in in-frame skipping of exon 56 and 58, respectively. Skipping of exon 56 occurs in 50% of mutant transcripts. Use of a cryptic splice site 51 bp upstream of the normal donor site results in half of the mutant transcripts containing part of exon 56. Both products contain in-frame deletions. Another splice site mutation, identified by exon screening from patient genomic DNA using intron primers, is at nucleotide position 2293+2 (T{yields}A), but the predicted exon skipping has not been detected at the RT-PCR level. This may be due to instability of the mutant transcript. Including the mutations reported here, a total of 8 out of 36 published FBN1 gene mutations involve exon skipping. It may be inferred that FBN1 exon skipping plays an important pathogenic role in MFS.

  3. Molecular pathogenesis of megalencephalic leukoencephalopathy with subcortical cysts: mutations in MLC1 cause folding defects

    NARCIS (Netherlands)

    Duarri, A.; Teijido, O.; Lopez-Hernandez, T.; Scheper, G.C.; Barriere, H.; Boor, P.K.I.; Aguado, F.; Zorzano, A.; Palacin, M.; Martinez, A; Lukacs, G.L.; van der Knaap, M.S.; Nunes, V.; Estevez, R.

    2008-01-01

    Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare type of leukodystrophy, most often caused by mutations in the MLC1 gene. MLC1 is an oligomeric plasma membrane (PM) protein of unknown function expressed mainly in glial cells and neurons. Most disease-causing missense

  4. Epidermal growth factor receptor mutation in gastric cancer.

    Science.gov (United States)

    Liu, Zhimin; Liu, Lina; Li, Mei; Wang, Zhaohui; Feng, Lu; Zhang, Qiuping; Cheng, Shihua; Lu, Shen

    2011-04-01

    Epidermal growth factor receptor (EGFR) and Kirsten-RAS (KRAS) mutations have been identified as predictors of response to EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer. We aimed to screen the mutations of both genes in gastric carcinoma to detect the suitability of EGFR TKIs for patients with gastric carcinoma. We screened EGFR mutation in exons 19-21 and KRAS mutation in exon 2 in 58 gastric adenocarcinomas from China using high resolution melting analysis (HRMA). Positive samples were confirmed by DNA sequencing. Three EGFR missense mutations (5.2%) and 22 single nucleotide polymorphisms (SNP, Q787Q, 37.9%) were identified. To our knowledge, we report for the first time three mutation patterns of EGFR, Y801C, L858R and G863D, in gastric carcinoma. Two samples with EGFR mutation were mucinous adenocarcinoma. These three samples were collected from male patients aged over 75 years old. The frequency of KRAS mutation was 10.3% (6/58). The exclusiveness of EGFR and KRAS mutations was proven for the first time in gastric cancer. Gastric carcinoma of the mucinous adenocarcinoma type collected from older male patients may harbour EGFR mutations. The small subset of gastric adenocarcinoma patients may respond to EGFR TKIs.

  5. Hot-spot KIF5A mutations cause familial ALS

    Science.gov (United States)

    Yilmaz, Rüstem; Müller, Kathrin; Grehl, Torsten; Petri, Susanne; Meyer, Thomas; Grosskreutz, Julian; Weydt, Patrick; Ruf, Wolfgang; Neuwirth, Christoph; Weber, Markus; Pinto, Susana; Claeys, Kristl G; Schrank, Berthold; Jordan, Berit; Knehr, Antje; Günther, Kornelia; Hübers, Annemarie; Zeller, Daniel; Kubisch, Christian; Jablonka, Sibylle; Klopstock, Thomas; de Carvalho, Mamede; Sperfeld, Anne; Borck, Guntram; Volk, Alexander E; Dorst, Johannes; Weis, Joachim; Otto, Markus; Schuster, Joachim; Del Tredici, Kelly; Braak, Heiko; Danzer, Karin M; Freischmidt, Axel; Meitinger, Thomas; Strom, Tim M; Ludolph, Albert C; Andersen, Peter M; Weishaupt, Jochen H; Weyen, Ute; Hermann, Andreas; Hagenacker, Tim; Koch, Jan Christoph; Lingor, Paul; Göricke, Bettina; Zierz, Stephan; Baum, Petra; Wolf, Joachim; Winkler, Andrea; Young, Peter; Bogdahn, Ulrich; Prudlo, Johannes; Kassubek., Jan

    2018-01-01

    Abstract Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 × 10−3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p.Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor

  6. Accumulation of multiple mutations in linezolid-resistant Staphylococcus epidermidis causing bloodstream infections; in silico analysis of L3 amino acid substitutions that might confer high-level linezolid resistance.

    Science.gov (United States)

    Ikonomidis, Alexandros; Grapsa, Anastasia; Pavlioglou, Charikleia; Demiri, Antonia; Batarli, Alexandra; Panopoulou, Maria

    2016-12-01

    Fifty-six Staphylococcus epidermidis clinical isolates, showing high-level linezolid resistance and causing bacteremia in critically ill patients, were studied. All isolates belonged to ST22 clone and carried the T2504A and C2534T mutations in gene coding for 23SrRNA as well as the C189A, G208A, C209T and G384C missense mutations in L3 protein which resulted in Asp159Tyr, Gly152Asp and Leu94Val substitutions. Other silent mutations were also detected in genes coding for ribosomal proteins L3 and L22. In silico analysis of missense mutations showed that although L3 protein retained the sequence of secondary motifs, the tertiary structure was influenced. The observed alteration in L3 protein folding provides an indication on the putative role of L3-coding gene mutations in high-level linezolid resistance. Furthermore, linezolid pressure in health care settings where linezolid consumption is of high rates might lead to the selection of resistant mutants possessing L3 mutations that might confer high-level linezolid resistance.

  7. Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity

    NARCIS (Netherlands)

    Saksens, N.T.; Krebs, M.P.; Schoenmaker, F.E.; Hicks, W.; Yu, M.; Shi, L.; Rowe, L.; Collin, G.B.; Charette, J.R.; Letteboer, S.J.; Neveling, K.; Moorsel, T.W. van; Abu-Ltaif, S.; Baere, E. De; Walraedt, S.; Banfi, S.; Simonelli, F.; Cremers, F.P.; Boon, C.J.; Roepman, R.; Leroy, B.P.; Peachey, N.S.; Hoyng, C.B.; Nishina, P.M.; Hollander, A.I. den

    2016-01-01

    Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here we report the identification of heterozygous missense mutations in the CTNNA1 gene (encoding alpha-catenin 1) in three families with butterfly-shaped pigment

  8. A novel missense mutation in collagenous domain of EDA gene in a ...

    Indian Academy of Sciences (India)

    2Department of Genetics and Molecular Biology, Xi'an Jiaotong University College of Medicine, Xi'an,. Shaanxi 710061 .... The mutation p.P220L of EDA responsible for XLHED affects the evolu- tionarily highly .... for University Students (no.

  9. First report of HGD mutations in a Chinese with alkaptonuria.

    Science.gov (United States)

    Yang, Yong-jia; Guo, Ji-hong; Chen, Wei-jian; Zhao, Rui; Tang, Jin-song; Meng, Xiao-hua; Zhao, Liu; Tu, Ming; He, Xin-yu; Wu, Ling-qian; Zhu, Yi-min

    2013-04-15

    Alkaptonuria (AKU) is one of the first prototypic inborn errors in metabolism and the first human disease found to be transmitted via Mendelian autosomal recessive inheritance. It is caused by HGD mutations, which leads to a deficiency in homogentisate 1,2-dioxygenase (HGD) activity. To date, several HGD mutations have been identified as the cause of the prototypic disease across different ethnic populations worldwide. However, in Asia, the HGD mutation is very rarely reported. For the Chinese population, no literature on HGD mutation screening is available to date. In this paper, we describe two novel HGD mutations in a Chinese AKU family, the splicing mutation of IVS7+1G>C, a donor splice site of exon 7, and a missense mutation of F329C in exon 12. The predicted new splicing site of the mutated exon 7 sequence demonstrated a 303bp extension after the mutation site. The F329C mutation most probably disturbed the stability of the conformation of the two loops critical to the Fe(2+) active site of the HGD enzyme. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Cross-comparison of the genome sequences from human, chimpanzee, Neanderthal and a Denisovan hominin identifies novel potentially compensated mutations

    Directory of Open Access Journals (Sweden)

    Zhang Guojie

    2011-07-01

    Full Text Available Abstract The recent publication of the draft genome sequences of the Neanderthal and a ~50,000-year-old archaic hominin from Denisova Cave in southern Siberia has ushered in a new age in molecular archaeology. We previously cross-compared the human, chimpanzee and Neanderthal genome sequences with respect to a set of disease-causing/disease-associated missense and regulatory mutations (Human Gene Mutation Database and succeeded in identifying genetic variants which, although apparently pathogenic in humans, may represent a 'compensated' wild-type state in at least one of the other two species. Here, in an attempt to identify further 'potentially compensated mutations' (PCMs of interest, we have compared our dataset of disease-causing/disease-associated mutations with their corresponding nucleotide positions in the Denisovan hominin, Neanderthal and chimpanzee genomes. Of the 15 human putatively disease-causing mutations that were found to be compensated in chimpanzee, Denisovan or Neanderthal, only a solitary F5 variant (Val1736Met was specific to the Denisovan. In humans, this missense mutation is associated with activated protein C resistance and an increased risk of thromboembolism and recurrent miscarriage. It is unclear at this juncture whether this variant was indeed a PCM in the Denisovan or whether it could instead have been associated with disease in this ancient hominin.

  11. Common mutations in the fibroblast growth factor receptor 3 (FGFR 3) gene account for achondroplasia, hypochondroplasia, and thanatophoric dwarfism

    Energy Technology Data Exchange (ETDEWEB)

    Bonaventure, J.; Rousseau, F.; Legeai-Mallet, L.; LeMerrer, M.; Munnich, A.; Maroteaux, P. [INSERM, Paris (France)

    1996-05-03

    The mapping of the achondroplasia locus to the short arm of chromosome 4 and the subsequent identification of a recurrent missense mutation (G380R) in the fibroblast growth factor receptor 3 (FGFR-3) gene has been followed by the detection of common FGFR-3 mutations in two clinically related disorders: thanatophoric dwarfism (types I and II) and hypochondroplasia. The relative clinical homogeneity of achondroplasia was substantiated by demonstration of its genetic homogeneity as more than 98% of all patients hitherto reported exhibit mutations in the transmembrane receptor domain. Although most hypochondroplasia cases were accounted for by a recurrent missense substitution (N540K) in the first tyrosine kinase (TK 1) domain of the receptor, a significant proportion (40%) of our patients did not harbor the N540K mutation and three hypochondroplasia families were not linked to the FGFR-3 locus, thus supporting clinical heterogeneity of this condition. In thanatophoric dwarfism (TD), a recurrent FGFR-3 mutation located in the second tyrosine kinase (TK 2) domain of the receptor was originally detected in 100% of TD II cases; in our series, seven distinct mutations in three different protein domains were identified in 25 of 26 TD I patients, suggesting that TD, like achondroplasia, is a genetically homogenous skeletal disorder. 31 refs., 4 figs., 2 tabs.

  12. A dominant mutation in the gene encoding the erythroid transcription factor KLF1 causes a congenital dyserythropoietic anemia

    DEFF Research Database (Denmark)

    Arnaud, Lionel; Saison, Carole; Helias, Virginie

    2010-01-01

    The congenital dyserythropoietic anemias (CDAs) are inherited red blood cell disorders whose hallmarks are ineffective erythropoiesis, hemolysis, and morphological abnormalities of erythroblasts in bone marrow. We have identified a missense mutation in KLF1 of patients with a hitherto unclassified...

  13. Biochemical Characterization of P4-ATPase Mutations Associated with Intrahepatic Cholestatic Disease

    DEFF Research Database (Denmark)

    Gantzel, Rasmus; Vestergaard, Anna Lindeløv; Mikkelsen, Stine

    The cholestatic disorders progressive familial intrahepatic cholestasis type 1 (PFIC1, also referred to as Byler’s disease) and benign recurrent intrahepatic cholestasis type 1 (BRIC1) are caused by mutation of the P4-ATPase ATP8B1. The substrate of ATP8B1 is very likely to be phosphatidylserine...... families have been investigated, and more than 50 distinct disease mutations have been identified, with roughly half being missense mutations. In this project we try to answer the question whether PFIC1 mutations are generally more disturbing than BRIC1 mutations with respect to expression, structural...... stability and function. We investigate the mutations in our well functioning system of ATP8A2, being expressed in mammalian HEK293T cells, affinity-purified, and reconstituted in lipid vesicles. Well-known mutations from both groups of patients have been selected for study. I91P in ATP8A2 (L127P in ATP8B1...

  14. De novo mutation in the dopamine transporter gene associates dopamine dysfunction with autism spectrum disorder

    DEFF Research Database (Denmark)

    Hamilton, P J; Campbell, N G; Sharma, S

    2013-01-01

    De novo genetic variation is an important class of risk factors for autism spectrum disorder (ASD). Recently, whole-exome sequencing of ASD families has identified a novel de novo missense mutation in the human dopamine (DA) transporter (hDAT) gene, which results in a Thr to Met substitution...

  15. SCN5A mutations and polymorphisms in patients with ventricular fibrillation during acute myocardial infarction.

    Science.gov (United States)

    Boehringer, Tim; Bugert, Peter; Borggrefe, Martin; Elmas, Elif

    2014-10-01

    Mutations in the SCN5A gene encoding the Nav1.5 channel α-subunit are known to be risk factors of arrhythmia, including Brugada Syndrome and Long QT syndrome subtype 3. The present study focused on the role of SCN5A variants in the development of ventricular fibrillation (VF) during acute myocardial infarction (AMI). Since VF during AMI is the major cause of sudden death in the Western world, SCN5A mutations represent genetic risk factors for sudden death. By exon re-sequencing, the entire coding region and flanking intron regions were sequenced in 46 AMI/VF+ patients. In total, nine single nucleotide variants were identified of which four represented common single nucleotide polymorphisms (SNPs; 87G>A, 1673A>G, IVS16‑6C>T and 5457T>A). Only five rare variants were identified, each in only one patient. Only two of the rare variants represented missense mutations (3578G>A and 4786T>A). The common SNPs and the missense mutations were also genotyped using polymerase chain reaction methods in 79 AMI/VF‑ patients and 480 healthy controls. The SNPs did not demonstrate significant differences in allele and genotype frequencies between the study groups. The 3578G>A mutation was identified in one out of the 480 controls, whereas the 4786T>A mutation was not present in AMI/VF- patients and controls. In conclusion, the majority of AMI/VF+ patients demonstrated a wild type sequence or common SNPs in SCN5A. Only two out of 46 (4.3%) AMI/VF+ patients revealed mutations that may be involved in Nav1.5 dysfunction and VF. However, this requires further functional validation.

  16. Mutational analysis of COL1A1 and COL1A2 genes among Estonian osteogenesis imperfecta patients.

    Science.gov (United States)

    Zhytnik, Lidiia; Maasalu, Katre; Reimann, Ene; Prans, Ele; Kõks, Sulev; Märtson, Aare

    2017-08-15

    Osteogenesis imperfecta (OI) is a rare bone disorder. In 90% of cases, OI is caused by mutations in the COL1A1/2 genes, which code procollagen α1 and α2 chains. The main aim of the current research was to identify the mutational spectrum of COL1A1/2 genes in Estonian patients. The small population size of Estonia provides a unique chance to explore the collagen I mutational profile of 100% of OI families in the country. We performed mutational analysis of peripheral blood gDNA of 30 unrelated Estonian OI patients using Sanger sequencing of COL1A1 and COL1A2 genes, including all intron-exon junctions and 5'UTR and 3'UTR regions, to identify causative OI mutations. We identified COL1A1/2 mutations in 86.67% of patients (26/30). 76.92% of discovered mutations were located in the COL1A1 (n = 20) and 23.08% in the COL1A2 (n = 6) gene. Half of the COL1A1/2 mutations appeared to be novel. The percentage of quantitative COL1A1/2 mutations was 69.23%. Glycine substitution with serine was the most prevalent among missense mutations. All qualitative mutations were situated in the chain domain of pro-α1/2 chains. Our study shows that among the Estonian OI population, the range of collagen I mutations is quite high, which agrees with other described OI cohorts of Northern Europe. The Estonian OI cohort differs due to the high number of quantitative variants and simple missense variants, which are mostly Gly to Ser substitutions and do not extend the chain domain of COL1A1/2 products.

  17. Whole-genome sequencing reveals a potential causal mutation for dwarfism in the Miniature Shetland pony.

    Science.gov (United States)

    Metzger, Julia; Gast, Alana Christina; Schrimpf, Rahel; Rau, Janina; Eikelberg, Deborah; Beineke, Andreas; Hellige, Maren; Distl, Ottmar

    2017-04-01

    The Miniature Shetland pony represents a horse breed with an extremely small body size. Clinical examination of a dwarf Miniature Shetland pony revealed a lowered size at the withers, malformed skull and brachygnathia superior. Computed tomography (CT) showed a shortened maxilla and a cleft of the hard and soft palate which protruded into the nasal passage leading to breathing difficulties. Pathological examination confirmed these findings but did not reveal histopathological signs of premature ossification in limbs or cranial sutures. Whole-genome sequencing of this dwarf Miniature Shetland pony and comparative sequence analysis using 26 reference equids from NCBI Sequence Read Archive revealed three probably damaging missense variants which could be exclusively found in the affected foal. Validation of these three missense mutations in 159 control horses from different horse breeds and five donkeys revealed only the aggrecan (ACAN)-associated g.94370258G>C variant as homozygous wild-type in all control samples. The dwarf Miniature Shetland pony had the homozygous mutant genotype C/C of the ACAN:g.94370258G>C variant and the normal parents were heterozygous G/C. An unaffected full sib and 3/5 unaffected half-sibs were heterozygous G/C for the ACAN:g.94370258G>C variant. In summary, we could demonstrate a dwarf phenotype in a miniature pony breed perfectly associated with a missense mutation within the ACAN gene.

  18. NIPA1 mutation in complex hereditary spastic paraplegia with epilepsy

    DEFF Research Database (Denmark)

    Svenstrup, K; Møller, R S; Christensen, J

    2011-01-01

    or signs are found. Mutations in the NIPA1 gene have been reported to cause spastic paraplegia type 6 (SPG6) in 10 families. SPG6 is a rare form of autosomal dominantly inherited HSP associated with a pure phenotype; however, in one complex SPG6 family, idiopathic generalized epilepsy (IGE) has been...... described and in addition, recurrent microdeletions at 15q11.2 including NIPA1 have been identified in patients with IGE. The purpose was to identify NIPA1 mutations in patients with pure and complex HSP. Methods: Fifty-two patients with HSP were screened for mutations in NIPA1. Results: One previously...... reported missense mutation c.316G>A, p.Gly106Arg, was identified in a complex HSP patient with spastic dysarthria, facial dystonia, atrophy of the small hand muscles, upper limb spasticity, and presumably IGE. The epilepsy co-segregated with HSP in the family. Conclusion: NIPA1 mutations were rare in our...

  19. Antisense Oligonucleotide-based Splice Correction for USH2A-associated Retinal Degeneration Caused by a Frequent Deep-intronic Mutation

    Directory of Open Access Journals (Sweden)

    Radulfus WN Slijkerman

    2016-01-01

    Full Text Available Usher syndrome (USH is the most common cause of combined deaf-blindness in man. The hearing loss can be partly compensated by providing patients with hearing aids or cochlear implants, but the loss of vision is currently untreatable. In general, mutations in the USH2A gene are the most frequent cause of USH explaining up to 50% of all patients worldwide. The first deep-intronic mutation in the USH2A gene (c.7595-2144A>G was reported in 2012, leading to the insertion of a pseudoexon (PE40 into the mature USH2A transcript. When translated, this PE40-containing transcript is predicted to result in a truncated non-functional USH2A protein. In this study, we explored the potential of antisense oligonucleotides (AONs to prevent aberrant splicing of USH2A pre-mRNA as a consequence of the c.7595-2144A>G mutation. Engineered 2'-O-methylphosphorothioate AONs targeting the PE40 splice acceptor site and/or exonic splice enhancer regions displayed significant splice correction potential in both patient derived fibroblasts and a minigene splice assay for USH2A c.7595-2144A>G, whereas a non-binding sense oligonucleotide had no effect on splicing. Altogether, AON-based splice correction could be a promising approach for the development of a future treatment for USH2A-associated retinitis pigmentosa caused by the deep-intronic c.7595-2144A>G mutation.

  20. Microarray-based mutation detection and phenotypic characterization in Korean patients with retinitis pigmentosa

    Science.gov (United States)

    Kim, Cinoo; Kim, Kwang Joong; Bok, Jeong; Lee, Eun-Ju; Kim, Dong-Joon; Oh, Ji Hee; Park, Sung Pyo; Shin, Joo Young; Lee, Jong-Young

    2012-01-01

    Purpose To evaluate microarray-based genotyping technology for the detection of mutations responsible for retinitis pigmentosa (RP) and to perform phenotypic characterization of patients with pathogenic mutations. Methods DNA from 336 patients with RP and 360 controls was analyzed using the GoldenGate assay with microbeads containing 95 previously reported disease-associated mutations from 28 RP genes. Mutations identified by microarray-based genotyping were confirmed by direct sequencing. Segregation analysis and phenotypic characterization were performed in patients with mutations. The disease severity was assessed by visual acuity, electroretinography, optical coherence tomography, and kinetic perimetry. Results Ten RP-related mutations of five RP genes (PRP3 pre-mRNA processing factor 3 homolog [PRPF3], rhodopsin [RHO], phosphodiesterase 6B [PDE6B], peripherin 2 [PRPH2], and retinitis pigmentosa 1 [RP1]) were identified in 26 of the 336 patients (7.7%) and in six of the 360 controls (1.7%). The p.H557Y mutation in PDE6B, which was homozygous in four patients and heterozygous in nine patients, was the most frequent mutation (2.5%). Mutation segregation was assessed in four families. Among the patients with missense mutations, the most severe phenotype occurred in patients with p.D984G in RP1; less severe phenotypes occurred in patients with p.R135W in RHO; a relatively moderate phenotype occurred in patients with p.T494M in PRPF3, p.H557Y in PDE6B, or p.W316G in PRPH2; and a mild phenotype was seen in a patient with p.D190N in RHO. Conclusions The results reveal that the GoldenGate assay may not be an efficient method for molecular diagnosis in RP patients with rare mutations, although it has proven to be reliable and efficient for high-throughput genotyping of single-nucleotide polymorphisms. The clinical features varied according to the mutations. Continuous effort to identify novel RP genes and mutations in a population is needed to improve the efficiency and

  1. Novel and recurrent NDP gene mutations in familial cases of Norrie disease and X-linked exudative vitreoretinopathy.

    Science.gov (United States)

    Pelcastre, Erika L; Villanueva-Mendoza, Cristina; Zenteno, Juan C

    2010-05-01

    To present the results of molecular analysis of the NDP gene in Mexican families with Norrie disease (ND) and X-linked familial exudative vitreoretinopathy (XL-FEVR). Two unrelated families with ND and two with XL-FEVR were studied. Clinical diagnosis was suspected on the basis of a complete ophthalmologic examination. Molecular methods included DNA isolation from peripheral blood leucocytes, polymerase chain reaction amplification and direct nucleotide sequencing analysis of the complete coding region and exon-intron junctions of NDP. Haplotype analysis using NDP-linked microsatellites markers was performed in both ND families. A novel Norrin missense mutation, p.Arg41Thr, was identified in two apparently unrelated families with ND. Haplotype analysis demonstrated that affected males in these two families shared the same ND-linked haplotype, suggesting a common origin for this novel mutation. The previously reported p.Arg121Trp and p.Arg121Gln Norrin mutations were identified in the two families with XL-FEVR. Our results expand the mutational spectrum in ND. This is the first report of ND resulting from mutation at arginine position 41 of Norrin. Interestingly, mutations at the same residue but resulting in a different missense change were previously described in subjects with XL-FEVR (p.Arg41Lys) or persistent fetal vasculature syndrome (p.Arg41Ser), indicating that the novel p.Arg41Thr change causes a more severe retinal phenotype. Preliminary data suggest a founder effect for the ND p.Arg41Thr mutation in these two Mexican families.

  2. Hereditary spastic paraplegia type 43 (SPG43) is caused by mutation in C19orf12

    Science.gov (United States)

    Landouré, Guida; Zhu, Peng-Peng; Lourenço, Charles M.; Johnson, Janel O.; Toro, Camilo; Bricceno, Katherine V.; Rinaldi, Carlo; Meilleur, Katherine G.; Sangaré, Modibo; Diallo, Oumarou; Pierson, Tyler M.; Ishiura, Hiroyuki; Tsuji, Shoji; Hein, Nichole; Fink, John K.; Stoll, Marion; Nicholson, Garth; Gonzalez, Michael; Speziani, Fiorella; Dürr, Alexandra; Stevanin, Giovanni; Biesecker, Leslie G.; Accardi, John; Landis, Dennis M. D.; Gahl, William A.; Traynor, Bryan J.; Marques, Wilson; Züchner, Stephan; Blackstone, Craig; Fischbeck, Kenneth H.; Burnett, Barrington G.

    2013-01-01

    We report here the genetic basis for a form of progressive hereditary spastic paraplegia (SPG43) previously described in two Malian sisters. Exome sequencing revealed a homozygous missense variant (c.187G>C; p.Ala63Pro) in C19orf12, a gene recently implicated in neurodegeneration with brain iron accumulation (NBIA). The same mutation was subsequently also found in a Brazilian family with features of NBIA, and we identified another NBIA patient with a three-nucleotide deletion (c.197_199del; p.Gly66del). Haplotype analysis revealed that the p.Ala63Pro mutations have a common origin, but MRI scans showed no brain iron deposition in the Malian SPG43 subjects. Heterologous expression of these SPG43 and NBIA variants resulted in similar alterations in the subcellular distribution of C19orf12. The SPG43 and NBIA variants reported here as well as the most common C19orf12 missense mutation reported in NBIA patients are found within a highly-conserved, extended hydrophobic domain in C19orf12, underscoring the functional importance of this domain. PMID:23857908

  3. Diseases associated with growth hormone-releasing hormone receptor (GHRHR) mutations.

    Science.gov (United States)

    Martari, Marco; Salvatori, Roberto

    2009-01-01

    The growth hormone (GH)-releasing hormone (GHRH) receptor (GHRHR) belongs to the G protein-coupled receptors family. It is expressed almost exclusively in the anterior pituitary, where it is necessary for somatotroph cells proliferation and for GH synthesis and secretion. Mutations in the human GHRHR gene (GHRHR) can impair ligand binding and signal transduction, and have been estimated to cause about 10% of autosomal recessive familial isolated growth hormone deficiency (IGHD). Mutations reported to date include five splice donor site mutations, two microdeletions, two nonsense mutations, seven missense mutations, and one mutation in the promoter. These mutations have an autosomal recessive mode of inheritance, and heterozygous individuals do not show signs of IGHD, although the presence of an intermediate phenotype has been hypothesized. Conversely, patients with biallelic mutations have low serum insulin-like growth factor-1 and GH levels (with absent or reduced GH response to exogenous stimuli), resulting--if not treated--in proportionate dwarfism. This chapter reviews the biology of the GHRHR, the mutations that affect its gene and their effects in homozygous and heterozygous individuals. Copyright © 2009 Elsevier Inc. All rights reserved.

  4. Identification of HIV Mutation as Diagnostic Biomarker through Next Generation Sequencing.

    Science.gov (United States)

    Shaw, Wen Hui; Lin, Qianqian; Muhammad, Zikry Zhiwei Bin Roslee; Lee, Jia Jun; Khong, Wei Xin; Ng, Oon Tek; Tan, Eng Lee; Li, Peng

    2016-07-01

    Current clinical detection of Human immunodeficiency virus 1 (HIV-1) is used to target viral genes and proteins. However, the immunoassay, such as viral culture or Polymerase Chain Reaction (PCR), lacks accuracy in the diagnosis, as these conventional assays rely on the stable genome and HIV-1 is a highly-mutated virus. Next generation sequencing (NGS) promises to be transformative for the practice of infectious disease, and the rapidly reducing cost and processing time mean that this will become a feasible technology in diagnostic and research laboratories in the near future. The technology offers the superior sensitivity to detect the pathogenic viruses, including unknown and unexpected strains. To leverage the NGS technology in order to improve current HIV-1 diagnosis and genotyping methods. Ten blood samples were collected from HIV-1 infected patients which were diagnosed by RT PCR at Singapore Communicable Disease Centre, Tan Tock Seng Hospital from October 2014 to March 2015. Viral RNAs were extracted from blood plasma and reversed into cDNA. The HIV-1 cDNA samples were cleaned up using a PCR purification kit and the sequencing library was prepared and identified through MiSeq. Two common mutations were observed in all ten samples. The common mutations were identified at genome locations 1908 and 2104 as missense and silent mutations respectively, conferring S37N and S3S found on aspartic protease and reverse transcriptase subunits. The common mutations identified in this study were not previously reported, therefore suggesting the potential for them to be used for identification of viral infection, disease transmission and drug resistance. This was especially the case for, missense mutation S37N which could cause an amino acid change in viral proteases thus reducing the binding affinity of some protease inhibitors. Thus, the unique common mutations identified in this study could be used as diagnostic biomarkers to indicate the origin of infection as being

  5. Mutation in LIM2 Is Responsible for Autosomal Recessive Congenital Cataracts.

    Directory of Open Access Journals (Sweden)

    Bushra Irum

    Full Text Available To identify the molecular basis of non-syndromic autosomal recessive congenital cataracts (arCC in a consanguineous family.All family members participating in the study received a comprehensive ophthalmic examination to determine their ocular phenotype and contributed a blood sample, from which genomic DNA was extracted. Available medical records and interviews with the family were used to compile the medical history of the family. The symptomatic history of the individuals exhibiting cataracts was confirmed by slit-lamp biomicroscopy. A genome-wide linkage analysis was performed to localize the disease interval. The candidate gene, LIM2 (lens intrinsic membrane protein 2, was sequenced bi-directionally to identify the disease-causing mutation. The physical changes caused by the mutation were analyzed in silico through homology modeling, mutation and bioinformatic algorithms, and evolutionary conservation databases. The physiological importance of LIM2 to ocular development was assessed in vivo by real-time expression analysis of Lim2 in a mouse model.Ophthalmic examination confirmed the diagnosis of nuclear cataracts in the affected members of the family; the inheritance pattern and cataract development in early infancy indicated arCC. Genome-wide linkage analysis localized the critical interval to chromosome 19q with a two-point logarithm of odds (LOD score of 3.25. Bidirectional sequencing identified a novel missense mutation, c.233G>A (p.G78D in LIM2. This mutation segregated with the disease phenotype and was absent in 192 ethnically matched control chromosomes. In silico analysis predicted lower hydropathicity and hydrophobicity but higher polarity of the mutant LIM2-encoded protein (MP19 compared to the wild-type. Moreover, these analyses predicted that the mutation would disrupt the secondary structure of a transmembrane domain of MP19. The expression of Lim2, which was detected in the mouse lens as early as embryonic day 15 (E15

  6. Mutations in EXTL3 Cause Neuro-immuno-skeletal Dysplasia Syndrome.

    Science.gov (United States)

    Oud, Machteld M; Tuijnenburg, Paul; Hempel, Maja; van Vlies, Naomi; Ren, Zemin; Ferdinandusse, Sacha; Jansen, Machiel H; Santer, René; Johannsen, Jessika; Bacchelli, Chiara; Alders, Marielle; Li, Rui; Davies, Rosalind; Dupuis, Lucie; Cale, Catherine M; Wanders, Ronald J A; Pals, Steven T; Ocaka, Louise; James, Chela; Müller, Ingo; Lehmberg, Kai; Strom, Tim; Engels, Hartmut; Williams, Hywel J; Beales, Phil; Roepman, Ronald; Dias, Patricia; Brunner, Han G; Cobben, Jan-Maarten; Hall, Christine; Hartley, Taila; Le Quesne Stabej, Polona; Mendoza-Londono, Roberto; Davies, E Graham; de Sousa, Sérgio B; Lessel, Davor; Arts, Heleen H; Kuijpers, Taco W

    2017-02-02

    EXTL3 regulates the biosynthesis of heparan sulfate (HS), important for both skeletal development and hematopoiesis, through the formation of HS proteoglycans (HSPGs). By whole-exome sequencing, we identified homozygous missense mutations c.1382C>T, c.1537C>T, c.1970A>G, and c.2008T>G in EXTL3 in nine affected individuals from five unrelated families. Notably, we found the identical homozygous missense mutation c.1382C>T (p.Pro461Leu) in four affected individuals from two unrelated families. Affected individuals presented with variable skeletal abnormalities and neurodevelopmental defects. Severe combined immunodeficiency (SCID) with a complete absence of T cells was observed in three families. EXTL3 was most abundant in hematopoietic stem cells and early progenitor T cells, which is in line with a SCID phenotype at the level of early T cell development in the thymus. To provide further support for the hypothesis that mutations in EXTL3 cause a neuro-immuno-skeletal dysplasia syndrome, and to gain insight into the pathogenesis of the disorder, we analyzed the localization of EXTL3 in fibroblasts derived from affected individuals and determined glycosaminoglycan concentrations in these cells as well as in urine and blood. We observed abnormal glycosaminoglycan concentrations and increased concentrations of the non-sulfated chondroitin disaccharide D0a0 and the disaccharide D0a4 in serum and urine of all analyzed affected individuals. In summary, we show that biallelic mutations in EXTL3 disturb glycosaminoglycan synthesis and thus lead to a recognizable syndrome characterized by variable expression of skeletal, neurological, and immunological abnormalities. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  7. Noonan syndrome: Severe phenotype and PTPN11 mutations.

    Science.gov (United States)

    Carrasco Salas, Pilar; Gómez-Molina, Gertrudis; Carreto-Alba, Páxedes; Granell-Escobar, Reyes; Vázquez-Rico, Ignacio; León-Justel, Antonio

    2018-04-24

    Noonan syndrome (NS) is a genetic disorder characterized by a wide range of distinctive features and health problems. It caused in 50% of cases by missense mutations in PTPN11 gene. It has been postulated that it is possible to predict the disease course based into the impact of mutations on the protein. We report two cases of severe NS phenotype including hydrops fetalis. PTPN11 gene was studied in germinal cells of both patients by sequencing. Two different mutations (p.Gly503Arg and p.Met504Val) was detected in PTPN11 gene. These mutations have been reported previously, and when they were germinal variants, patients presented classic NS, NS with other malignancies and recently, p.Gly503Arg has been also observed in a patient with severe NS and hydrops fetalis, as our cases. Therefore, these observations shade light on that it is not always possibly to determine the genotype-phenotype relation based into the impact of mutations on the protein in NS patients with PTPN11 mutations. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

  8. Founder effect in the Horn of Africa for an insulin receptor mutation that may impair receptor recycling

    DEFF Research Database (Denmark)

    Raffan, E; Soos, M A; Rocha, N

    2011-01-01

    Genetic insulin receptoropathies are a rare cause of severe insulin resistance. We identified the Ile119Met missense mutation in the insulin receptor INSR gene, previously reported in a Yemeni kindred, in four unrelated patients with Somali ancestry. We aimed to investigate a possible genetic...

  9. Establishment of mouse model of MYH9 disorders: heterozygous R702C mutation provokes macrothrombocytopenia with leukocyte inclusion bodies, renal glomerulosclerosis and hearing disability.

    Science.gov (United States)

    Suzuki, Nobuaki; Kunishima, Shinji; Ikejiri, Makoto; Maruyama, Shoichi; Sone, Michihiko; Takagi, Akira; Ikawa, Masahito; Okabe, Masaru; Kojima, Tetsuhito; Saito, Hidehiko; Naoe, Tomoki; Matsushita, Tadashi

    2013-01-01

    Nonmuscle myosin heavy chain IIA (NMMHCIIA) encoded by MYH9 is associated with autosomal dominantly inherited diseases called MYH9 disorders. MYH9 disorders are characterized by macrothrombocytopenia and very characteristic inclusion bodies in granulocytes. MYH9 disorders frequently cause nephritis, sensorineural hearing disability and cataracts. One of the most common and deleterious mutations causing these disorders is the R702C missense mutation. We generated knock-in mice expressing the Myh9 R702C mutation. R702C knock-in hetero mice (R702C+/- mice) showed macrothrombocytopenia. We studied megakaryopoiesis of cultured fetal liver cells of R702C+/- mice and found that proplatelet formation was impaired: the number of proplatelet tips was decreased, proplatelet size was increased, and proplatelet shafts were short and enlarged. Although granulocyte inclusion bodies were not visible by May-Grünwald Giemsa staining, immunofluorescence analysis indicated that NMMHCIIA proteins aggregated and accumulated in the granulocyte cytoplasm. In other organs, R702C+/- mice displayed albuminuria which increased with age. Renal pathology examination revealed glomerulosclerosis. Sensory hearing loss was indicated by lowered auditory brainstem response. These findings indicate that Myh9 R702C knock-in mice mirror features of human MYH9 disorders arising from the R702C mutation.

  10. Novel POC1A mutation in primordial dwarfism reveals new insights for centriole biogenesis.

    Science.gov (United States)

    Koparir, Asuman; Karatas, Omer F; Yuceturk, Betul; Yuksel, Bayram; Bayrak, Ali O; Gerdan, Omer F; Sagiroglu, Mahmut S; Gezdirici, Alper; Kirimtay, Koray; Selcuk, Ece; Karabay, Arzu; Creighton, Chad J; Yuksel, Adnan; Ozen, Mustafa

    2015-10-01

    POC1A encodes a WD repeat protein localizing to centrioles and spindle poles and is associated with short stature, onychodysplasia, facial dysmorphism and hypotrichosis (SOFT) syndrome. These main features are related to the defect in cell proliferation of chondrocytes in growth plate. In the current study, we aimed at identifying the molecular basis of two patients with primordial dwarfism (PD) in a single family through utilization of whole-exome sequencing. A novel homozygous p.T120A missense mutation was detected in POC1A in both patients, a known causative gene of SOFT syndrome, and confirmed using Sanger sequencing. To test the pathogenicity of the detected mutation, primary fibroblast cultures obtained from the patients and a control individual were used. For evaluating the global gene expression profile of cells carrying p.T120A mutation in POC1A, we performed the gene expression array and compared their expression profiles to those of control fibroblast cells. The gene expression array analysis showed that 4800 transcript probes were significantly deregulated in cells with p.T120A mutation in comparison to the control. GO term association results showed that deregulated genes are mostly involved in the extracellular matrix and cytoskeleton. Furthermore, the p.T120A missense mutation in POC1A caused the formation of abnormal mitotic spindle structure, including supernumerary centrosomes, and changes in POC1A were accompanied by alterations in another centrosome-associated WD repeat protein p80-katanin. As a result, we identified a novel mutation in POC1A of patients with PD and showed that this mutation causes the formation of multiple numbers of centrioles and multipolar spindles with abnormal chromosome arrangement. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. A novel germ-line point mutation in RET exon 8 (Gly(533)Cys) in a large kindred with familial medullary thyroid carcinoma

    OpenAIRE

    Silva, Adriana Madeira Alvares da [UNIFESP; Maciel, Rui Monteiro de Barros [UNIFESP; Dias-da-Silva, Magnus Régios [UNIFESP; Toledo, Silvia Regina Caminada de [UNIFESP; De Carvalho, Marcos B.; Cerutti, Janete Maria [UNIFESP

    2003-01-01

    Familial medullary thyroid carcinoma is related to germ-line mutations in the RET oncogene, mainly in cysteine codon 10 or 11, whereas noncysteine mutations in codons 13 - 15 are rare. We now report a new missense point mutation in exon 8 of the RET gene (1597G-->T) corresponding to a Gly(533)Cys substitution in the cystein-rich domain of RET protein in 76 patients from a 6-generation Brazilian family with 229 subjects, with ascendants from Spain. It is likely that the mutation causes familia...

  12. TBC1D24 Mutations in a Sibship with Multifocal Polymyoclonus

    Directory of Open Access Journals (Sweden)

    Adeline Ngoh

    2017-04-01

    Full Text Available Background: Advances in molecular genetic technologies have improved our understanding of genetic causes of rare neurological disorders with features of myoclonus.Case Report: A family with two affected siblings, presenting with multifocal polymyoclonus and neurodevelopmental delay, was recruited for whole-exome sequencing following unyielding diagnostic neurometabolic investigations. Compound heterozygous mutations in TBC1D24, a gene previously associated with various epilepsy phenotypes and hearing loss, were identified in both siblings. The mutations included a missense change c.457G>A (p.Glu157Lys, and a novel frameshift mutation c.545del (p.Thr182Serfs*6.Discussion: We propose that TBC1D24-related diseases should be in the differential diagnosis for children with polymyoclonus. 

  13. Germline mutations in lysine specific demethylase 1 (LSD1/KDM1A) confer susceptibility to multiple myeloma.

    Science.gov (United States)

    Wei, Xiaomu; Calvo-Vidal, M Nieves; Chen, Siwei; Wu, Gang; Revuelta, Maria V; Sun, Jian; Zhang, Jinghui; Walsh, Michael F; Nichols, Kim E; Joseph, Vijai; Snyder, Carrie; Vachon, Celine M; McKay, James D; Wang, Shu-Ping; Jayabalan, David S; Jacobs, Lauren M; Becirovic, Dina; Waller, Rosalie G; Artomov, Mykyta; Viale, Agnes; Patel, Jayeshkumar; Phillip, Jude M; Chen-Kiang, Selina; Curtin, Karen; Salama, Mohamed; Atanackovic, Djordje; Niesvizky, Ruben; Landgren, Ola; Slager, Susan L; Godley, Lucy A; Churpek, Jane; Garber, Judy E; Anderson, Kenneth C; Daly, Mark J; Roeder, Robert G; Dumontet, Charles; Lynch, Henry T; Mullighan, Charles G; Camp, Nicola J; Offit, Kenneth; Klein, Robert J; Yu, Haiyuan; Cerchietti, Leandro; Lipkin, Steven M

    2018-03-20

    Given the frequent and largely incurable occurrence of multiple myeloma (MM), identification of germline genetic mutations that predispose cells to MM may provide insight into disease etiology and the developmental mechanisms of its cell of origin, the plasma cell. Here we identified familial and early-onset MM kindreds with truncating mutations in lysine-specific demethylase 1 (LSD1/KDM1A), an epigenetic transcriptional repressor that primarily demethylates histone H3 on lysine 4 and regulates hematopoietic stem cell self-renewal. Additionally, we found higher rates of germline truncating and predicted deleterious missense KDM1A mutations in MM patients unselected for family history compared to controls. Both monoclonal gammopathy of unknown significance (MGUS) and MM cells have significantly lower KDM1A transcript levels compared with normal plasma cells. Transcriptome analysis of MM cells from KDM1A mutation carriers shows enrichment of pathways and MYC target genes previously associated with myeloma pathogenesis. In mice, antigen challenge followed by pharmacological inhibition of KDM1A promoted plasma cell expansion, enhanced secondary immune response, elicited appearance of serum paraprotein, and mediated upregulation of MYC transcriptional targets. These changes are consistent with the development of MGUS. Collectively, our findings show KDM1A is the first autosomal dominant MM germline predisposition gene, providing new insights into its mechanistic roles as a tumor suppressor during post-germinal center B cell differentiation. Copyright ©2018, American Association for Cancer Research.

  14. Diversity of ARSACS mutations in French-Canadians.

    Science.gov (United States)

    Thiffault, I; Dicaire, M J; Tetreault, M; Huang, K N; Demers-Lamarche, J; Bernard, G; Duquette, A; Larivière, R; Gehring, K; Montpetit, A; McPherson, P S; Richter, A; Montermini, L; Mercier, J; Mitchell, G A; Dupré, N; Prévost, C; Bouchard, J P; Mathieu, J; Brais, B

    2013-01-01

    The growing number of spastic ataxia of Charlevoix-Saguenay (SACS) gene mutations reported worldwide has broadened the clinical phenotype of autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS). The identification of Quebec ARSACS cases without two known SACS mutation led to the development of a multi-modal genomic strategy to uncover mutations in this large gene and explore phenotype variability. Search for SACS mutations by combining various methods on 20 cases with a classical French-Canadian ARSACS phenotype without two mutations and a group of 104 sporadic or recessive spastic ataxia cases of unknown cause. Western blot on lymphoblast protein from cases with different genotypes was probed to establish if they still expressed sacsin. A total of 12 mutations, including 7 novels, were uncovered in Quebec ARSACS cases. The screening of 104 spastic ataxia cases of unknown cause for 98 SACS mutations did not uncover carriers of two mutations. Compounds heterozygotes for one missense SACS mutation were found to minimally express sacsin. The large number of SACS mutations present even in Quebec suggests that the size of the gene alone may explain the great genotypic diversity. This study does not support an expanding ARSACS phenotype in the French-Canadian population. Most mutations lead to loss of function, though phenotypic variability in other populations may reflect partial loss of function with preservation of some sacsin expression. Our results also highlight the challenge of SACS mutation screening and the necessity to develop new generation sequencing methods to ensure low cost complete gene sequencing.

  15. Functional analysis of Peutz-Jeghers mutations reveals that the LKB1 C-terminal region exerts a crucial role in regulating both the AMPK pathway and the cell polarity.

    NARCIS (Netherlands)

    Forcet, C.; Etienne-Manneville, S.; Gaude, H.; Fournier, L.; Debilly, S.; Salmi, M.; Baas, A.; Olschwang, S.; Clevers, J.C.; Billaud, M.

    2005-01-01

    Germline mutations of the LKB1 gene are responsible for the cancer-prone Peutz-Jeghers syndrome (PJS). LKB1 encodes a serine-threonine kinase that acts as a regulator of cell cycle, metabolism and cell polarity. The majority of PJS missense mutations abolish LKB1 enzymatic activity and thereby

  16. Alagille syndrome in a Vietnamese cohort: mutation analysis and assessment of facial features.

    Science.gov (United States)

    Lin, Henry C; Le Hoang, Phuc; Hutchinson, Anne; Chao, Grace; Gerfen, Jennifer; Loomes, Kathleen M; Krantz, Ian; Kamath, Binita M; Spinner, Nancy B

    2012-05-01

    Alagille syndrome (ALGS, OMIM #118450) is an autosomal dominant disorder that affects multiple organ systems including the liver, heart, eyes, vertebrae, and face. ALGS is caused by mutations in one of two genes in the Notch Signaling Pathway, Jagged1 (JAG1) or NOTCH2. In this study, analysis of 21 Vietnamese ALGS individuals led to the identification of 19 different mutations (18 JAG1 and 1 NOTCH2), 17 of which are novel, including the third reported NOTCH2 mutation in Alagille Syndrome. The spectrum of JAG1 mutations in the Vietnamese patients is similar to that previously reported, including nine frameshift, three missense, two splice site, one nonsense, two whole gene, and one partial gene deletion. The missense mutations are all likely to be disease causing, as two are loss of cysteines (C22R and C78G) and the third creates a cryptic splice site in exon 9 (G386R). No correlation between genotype and phenotype was observed. Assessment of clinical phenotype revealed that skeletal manifestations occur with a higher frequency than in previously reported Alagille cohorts. Facial features were difficult to assess and a Vietnamese pediatric gastroenterologist was only able to identify the facial phenotype in 61% of the cohort. To assess the agreement among North American dysmorphologists at detecting the presence of ALGS facial features in the Vietnamese patients, 37 clinical dysmorphologists evaluated a photographic panel of 20 Vietnamese children with and without ALGS. The dysmorphologists were unable to identify the individuals with ALGS in the majority of cases, suggesting that evaluation of facial features should not be used in the diagnosis of ALGS in this population. This is the first report of mutations and phenotypic spectrum of ALGS in a Vietnamese population. Copyright © 2012 Wiley Periodicals, Inc.

  17. Norrie disease: first mutation report and prenatal diagnosis in an Indian family.

    Science.gov (United States)

    Ghosh, Manju; Sharma, Shipra; Shastri, Shivaram; Arora, Sadhna; Shukla, Rashmi; Gupta, Neerja; Deka, Deepika; Kabra, Madhulika

    2012-11-01

    Norrie Disease (ND) is a rare X-linked recessive disorder characterised by congenital blindness due to severe retinal dysgenesis. Hearing loss and intellectual disability is present in 30-50 % cases. ND is caused by mutations in the NDP gene, located at Xp11.3. The authors describe mutation analysis of a proband with ND and subsequently prenatal diagnosis. Sequence analysis of the NDP gene revealed a hemizygous missense mutation arginine to serine in codon 41 (p.Arg41Ser) in the affected child. Mother was carrier for the mutation. In a subsequent di-chorionic di-amniotic pregnancy, the authors performed prenatal diagnosis by mutation analysis on chorionic villi sample at 11 wk of gestation. The fetuses were unaffected. This is a first mutation report and prenatal diagnosis of a familial case of Norrie disease from India. The importance of genetic testing of Norrie disease for confirmation, carrier testing, prenatal diagnosis and genetic counseling is emphasized.

  18. Mutations in FUS cause FALS and SALS in French and French Canadian populations.

    Science.gov (United States)

    Belzil, V V; Valdmanis, P N; Dion, P A; Daoud, H; Kabashi, E; Noreau, A; Gauthier, J; Hince, P; Desjarlais, A; Bouchard, J-P; Lacomblez, L; Salachas, F; Pradat, P-F; Camu, W; Meininger, V; Dupré, N; Rouleau, G A

    2009-10-13

    The identification of mutations in the TARDBP and more recently the identification of mutations in the FUS gene as the cause of amyotrophic lateral sclerosis (ALS) is providing the field with new insight about the mechanisms involved in this severe neurodegenerative disease. To extend these recent genetic reports, we screened the entire gene in a cohort of 200 patients with ALS. An additional 285 patients with sporadic ALS were screened for variants in exon 15 for which mutations were previously reported. In total, 3 different mutations were identified in 4 different patients, including 1 3-bp deletion in exon 3 of a patient with sporadic ALS and 2 missense mutations in exon 15 of 1 patient with familial ALS and 2 patients with sporadic ALS. Our study identified sporadic patients with mutations in the FUS gene. The accumulation and description of different genes and mutations helps to develop a more comprehensive picture of the genetic events underlying amyotrophic lateral sclerosis.

  19. Novel GABRG2 mutations cause familial febrile seizures

    Science.gov (United States)

    Boillot, Morgane; Morin-Brureau, Mélanie; Picard, Fabienne; Weckhuysen, Sarah; Lambrecq, Virginie; Minetti, Carlo; Striano, Pasquale; Zara, Federico; Iacomino, Michele; Ishida, Saeko; An-Gourfinkel, Isabelle; Daniau, Mailys; Hardies, Katia; Baulac, Michel; Dulac, Olivier; Leguern, Eric; Nabbout, Rima

    2015-01-01

    Objective: To identify the genetic cause in a large family with febrile seizures (FS) and temporal lobe epilepsy (TLE) and subsequently search for additional mutations in a cohort of 107 families with FS, with or without epilepsy. Methods: The cohort consisted of 1 large family with FS and TLE, 64 smaller French families recruited through a national French campaign, and 43 Italian families. Molecular analyses consisted of whole-exome sequencing and mutational screening. Results: Exome sequencing revealed a p.Glu402fs*3 mutation in the γ2 subunit of the GABAA receptor gene (GABRG2) in the large family with FS and TLE. Three additional nonsense and frameshift GABRG2 mutations (p.Arg136*, p.Val462fs*33, and p.Pro59fs*12), 1 missense mutation (p.Met199Val), and 1 exonic deletion were subsequently identified in 5 families of the follow-up cohort. Conclusions: We report GABRG2 mutations in 5.6% (6/108) of families with FS, with or without associated epilepsy. This study provides evidence that GABRG2 mutations are linked to the FS phenotype, rather than epilepsy, and that loss-of-function of GABAA receptor γ2 subunit is the probable underlying pathogenic mechanism. PMID:27066572

  20. Splicing analysis of 14 BRCA1 missense variants classifies nine variants as pathogenic

    DEFF Research Database (Denmark)

    Ahlborn, Lise B; Dandanell, Mette; Steffensen, Ane Y

    2015-01-01

    by functional analysis at the protein level. Results from a validated mini-gene splicing assay indicated that nine BRCA1 variants resulted in splicing aberrations leading to truncated transcripts and thus can be considered pathogenic (c.4987A>T/p.Met1663Leu, c.4988T>A/p.Met1663Lys, c.5072C>T/p.Thr1691Ile, c......Pathogenic germline mutations in the BRCA1 gene predispose carriers to early onset breast and ovarian cancer. Clinical genetic screening of BRCA1 often reveals variants with uncertain clinical significance, complicating patient and family management. Therefore, functional examinations are urgently...... needed to classify whether these uncertain variants are pathogenic or benign. In this study, we investigated 14 BRCA1 variants by in silico splicing analysis and mini-gene splicing assay. All 14 alterations were missense variants located within the BRCT domain of BRCA1 and had previously been examined...

  1. A novel syndrome of autosomal-dominant hyperinsulinemic hypoglycemia linked to a mutation in the human insulin receptor gene

    DEFF Research Database (Denmark)

    Højlund, Kurt; Hansen, Torben; Lajer, Maria

    2004-01-01

    a missense mutation (Arg1174Gln) in the tyrosine kinase domain of the insulin receptor gene that cosegregated with the disease phenotype (logarithm of odds [LOD] score 3.21). In conclusion, we report a novel syndrome of autosomal-dominant hyperinsulinemic hypoglycemia. The findings demonstrate...

  2. Resistance to cyclosporin A derives from mutations in hepatitis C virus nonstructural proteins.

    Science.gov (United States)

    Arai, Masaaki; Tsukiyama-Kohara, Kyoko; Takagi, Asako; Tobita, Yoshimi; Inoue, Kazuaki; Kohara, Michinori

    2014-05-23

    Cyclosporine A (CsA) is an immunosuppressive drug that targets cyclophilins, cellular cofactors that regulate the immune system. Replication of hepatitis C virus (HCV) is suppressed by CsA, but the molecular basis of this suppression is still not fully understood. To investigate this suppression, we cultured HCV replicon cells (Con1, HCV genotype 1b, FLR-N cell) in the presence of CsA and obtained nine CsA-resistant FLR-N cell lines. We determined full-length HCV sequences for all nine clones, and chose two (clones #6 and #7) of the nine clones that have high replication activity in the presence of CsA for further analysis. Both clones showed two consensus mutations, one in NS3 (T1280V) and the other in NS5A (D2292E). Characterization of various mutants indicated that the D2292E mutation conferred resistance to high concentrations of CsA (up to 2 μM). In addition, the missense mutation T1280V contributed to the recovery of colony formation activity. The effects of these mutations are also evident in two established HCV replicon cell lines-HCV-RMT ([1], genotype 1a) and JFH1 (genotype 2a). Moreover, three other missense mutations in NS5A-D2303H, S2362G, and E2414K-enhanced the resistance to CsA conferred by D2292E; these double or all quadruple mutants could resist approximately 8- to 25-fold higher concentrations of CsA than could wild-type Con1. These four mutations, either as single or combinations, also made Con1 strain resistant to two other cyclophilin inhibitors, N-methyl-4-isoleucine-cyclosporin (NIM811) or Debio-025. Interestingly, the changes in IC50 values that resulted from each of these mutations were the lowest in the Debio-025-treated cells, indicating its highest resistant activity against the adaptive mutation. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  3. De novo mutations in HCN1 cause early infantile epileptic encephalopathy.

    Science.gov (United States)

    Nava, Caroline; Dalle, Carine; Rastetter, Agnès; Striano, Pasquale; de Kovel, Carolien G F; Nabbout, Rima; Cancès, Claude; Ville, Dorothée; Brilstra, Eva H; Gobbi, Giuseppe; Raffo, Emmanuel; Bouteiller, Delphine; Marie, Yannick; Trouillard, Oriane; Robbiano, Angela; Keren, Boris; Agher, Dahbia; Roze, Emmanuel; Lesage, Suzanne; Nicolas, Aude; Brice, Alexis; Baulac, Michel; Vogt, Cornelia; El Hajj, Nady; Schneider, Eberhard; Suls, Arvid; Weckhuysen, Sarah; Gormley, Padhraig; Lehesjoki, Anna-Elina; De Jonghe, Peter; Helbig, Ingo; Baulac, Stéphanie; Zara, Federico; Koeleman, Bobby P C; Haaf, Thomas; LeGuern, Eric; Depienne, Christel

    2014-06-01

    Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels contribute to cationic Ih current in neurons and regulate the excitability of neuronal networks. Studies in rat models have shown that the Hcn1 gene has a key role in epilepsy, but clinical evidence implicating HCN1 mutations in human epilepsy is lacking. We carried out exome sequencing for parent-offspring trios with fever-sensitive, intractable epileptic encephalopathy, leading to the discovery of two de novo missense HCN1 mutations. Screening of follow-up cohorts comprising 157 cases in total identified 4 additional amino acid substitutions. Patch-clamp recordings of Ih currents in cells expressing wild-type or mutant human HCN1 channels showed that the mutations had striking but divergent effects on homomeric channels. Individuals with mutations had clinical features resembling those of Dravet syndrome with progression toward atypical absences, intellectual disability and autistic traits. These findings provide clear evidence that de novo HCN1 point mutations cause a recognizable early-onset epileptic encephalopathy in humans.

  4. Multiple self-healing squamous epithelioma is caused by a disease-specific spectrum of mutations in TGFBR1

    DEFF Research Database (Denmark)

    Goudie, David R; D'Alessandro, Mariella; Merriman, Barry

    2011-01-01

    Multiple self-healing squamous epithelioma (MSSE), also known as Ferguson-Smith disease (FSD), is an autosomal-dominant skin cancer condition characterized by multiple squamous-carcinoma-like locally invasive skin tumors that grow rapidly for a few weeks before spontaneously regressing, leaving s......-of-function TGFBR1 mutations and MSSE. This distinguishes MSSE from the Marfan syndrome-related disorders in which missense mutations in TGFBR1 lead to developmental defects with vascular involvement but no reported predisposition to cancer....

  5. Multiple self-healing squamous epithelioma is caused by a disease-specific spectrum of mutations in TGFBR1

    DEFF Research Database (Denmark)

    Goudie, David R; D'Alessandro, Mariella; Merriman, Barry

    2011-01-01

    Multiple self-healing squamous epithelioma (MSSE), also known as Ferguson-Smith disease (FSD), is an autosomal-dominant skin cancer condition characterized by multiple squamous-carcinoma-like locally invasive skin tumors that grow rapidly for a few weeks before spontaneously regressing, leaving......-of-function TGFBR1 mutations and MSSE. This distinguishes MSSE from the Marfan syndrome-related disorders in which missense mutations in TGFBR1 lead to developmental defects with vascular involvement but no reported predisposition to cancer....

  6. Homocystinuria due to cystathionine beta-synthase (CBS deficiency in Russia: Molecular and clinical characterization

    Directory of Open Access Journals (Sweden)

    Elena Voskoboeva

    2018-03-01

    Full Text Available We present the results of the 45-year clinical observation of 27 Russian homocystinuria patients. We made a mutation analysis of the CBS gene for thirteen patients from eleven unrelated genealogies. All patients except for the two were compound heterozygotes for the mutations detected. The most frequent mutation in the cohort investigated was splice mutation IVS11-2a->c. We detected one new nonsense mutation, one new missense-mutation and three novel small deletions. We also report the clinical case of the B6-responsive patient genotyped as Ile278Thr/Cys109Arg.

  7. Novel FGFR1 and KISS1R Mutations in Chinese Kallmann Syndrome Males with Cleft Lip/Palate

    Directory of Open Access Journals (Sweden)

    Hao Xu

    2015-01-01

    Full Text Available Kallmann syndrome (KS is characterized by isolated hypogonadotropic hypogonadism (IHH with anosmia and is sometimes associated with cleft lip/palate (CLP. In order to describe the clinical features, genetic etiology, and treatment outcome of KS males with CLP, we performed genetic screening for 15 known causal IHH genes (KAL1, FGFR1, NELF, FGF8, CHD7, WDR11, SEMA3A, KISS1R, KISS1, PROKR2, PROK2, TAC3, TACR3, GNRH1, and GNRHR in four KS with CLP patients and six IHH patients without CLP. Two novel heterozygous missense mutations in FGFR1, (NM_001174066: c.776G>A (p.G259E and (NM_001174066: c.358C>T (p.R120C, were identified in a 23-year-old KS male with cleft lip and an 18-year-old KS patient with cleft lip and palate, dental agenesis, and high arched palate, respectively. These two mutations were not presented in their healthy parents and 200 normal controls. One novel heterozygous missense mutation in KISS1R, (NM_032551: c.587C>A (p.P196H, was identified in an 18-year-old KS male with cleft lip and dental agenesis who developed sperm after being treated with gonadotropin. This mutation was also presented in his healthy father and grandfather. These results have implications for the diagnosis, genetic counseling, and treatment of KS and CLP males with mutations in FGFR1 gene.

  8. Identification of seven novel mutations including the first two genomic rearrangements in SLC26A3 mutated in congenital chloride diarrhea.

    Science.gov (United States)

    Höglund, P; Sormaala, M; Haila, S; Socha, J; Rajaram, U; Scheurlen, W; Sinaasappel, M; de Jonge, H; Holmberg, C; Yoshikawa, H; Kere, J

    2001-09-01

    Congenital chloride diarrhea (CLD) is an autosomal recessive disorder characterized by defective intestinal electrolyte absorption, resulting in voluminous osmotic diarrhea with high chloride content. A variety of mutations in the solute carrier family 26, member 3 gene (SLC26A3, previously known as CLD or DRA) are responsible for the disease. Since the identification of the SLC26A3 gene and the determination of its genomic structure, altogether three founder and 17 private mutations have been characterized within miscellaneous ethnic groups. We screened for mutations in seven unrelated families with CLD. The diagnoses were confirmed by fecal chloride measurements. The combined PCR-SSCP and sequencing analyses revealed altogether seven novel mutations including two missense mutations (S206P, D468V), two splicing defects (IVS12-1G>C, IVS13-2delA), one nonsense mutation (Q436X), one insertion/deletion mutation (2104-2105delGGins29-bp), and an intragenic deletion of SLC26A3 exons 7 and 8. Two previously identified mutations were also found. This is the first report of rearrangement mutations in SLC26A3. Molecular features predisposing SLC26A3 for the two rearrangements may include repetitive elements and palindromic-like sequences. The increasingly wide diversity of SLC26A3 mutations suggests that mutations in the SLC26A3 gene may not be rare events. Copyright 2001 Wiley-Liss, Inc.

  9. Hot-spot KIF5A mutations cause familial ALS.

    Science.gov (United States)

    Brenner, David; Yilmaz, Rüstem; Müller, Kathrin; Grehl, Torsten; Petri, Susanne; Meyer, Thomas; Grosskreutz, Julian; Weydt, Patrick; Ruf, Wolfgang; Neuwirth, Christoph; Weber, Markus; Pinto, Susana; Claeys, Kristl G; Schrank, Berthold; Jordan, Berit; Knehr, Antje; Günther, Kornelia; Hübers, Annemarie; Zeller, Daniel; Kubisch, Christian; Jablonka, Sibylle; Sendtner, Michael; Klopstock, Thomas; de Carvalho, Mamede; Sperfeld, Anne; Borck, Guntram; Volk, Alexander E; Dorst, Johannes; Weis, Joachim; Otto, Markus; Schuster, Joachim; Del Tredici, Kelly; Braak, Heiko; Danzer, Karin M; Freischmidt, Axel; Meitinger, Thomas; Strom, Tim M; Ludolph, Albert C; Andersen, Peter M; Weishaupt, Jochen H

    2018-01-12

    Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 × 10-3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p.Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor allele

  10. Thyroglobulin Gene Mutation with Cold Nodule on Thyroid Scintigraphy

    Directory of Open Access Journals (Sweden)

    Toshio Kahara

    2012-01-01

    Full Text Available Thyroglobulin gene mutation is a rare cause of congenital hypothyroidism, but thyroglobulin gene mutations are thought to be associated with thyroid cancer development. A 21-year-old Japanese man treated with levothyroxine for congenital hypothyroidism had an enlarged thyroid gland with undetectable serum thyroglobulin despite elevated serum TSH level. The patient was diagnosed with thyroglobulin gene mutation, with compound heterozygosity for Gly304Cys missense mutation and Arg432X nonsense mutation. Ultrasonography showed a hypovascular large tumor in the left lobe that appeared as a cold nodule on thyroid scintigraphy. He underwent total thyroidectomy, but pathological study did not reveal findings of thyroid carcinoma, but rather a hyperplastic nodule with hemorrhage. Strong cytoplasmic thyroglobulin immunostaining was observed, but sodium iodide symporter immunostaining was hardly detected in the hyperplastic nodule. The clinical characteristics of patients with thyroglobulin gene mutations are diverse, and some patients are diagnosed by chance on examination of goiter in adults. The presence of thyroid tumors that appear as cold nodules on thyroid scintigraphy should consider the potential for thyroid carcinoma, if the patient has relatively low serum thyroglobulin concentration in relation to the degree of TSH without thyroglobulin autoantibody.

  11. Systematic Analysis of Splice-Site-Creating Mutations in Cancer.

    Science.gov (United States)

    Jayasinghe, Reyka G; Cao, Song; Gao, Qingsong; Wendl, Michael C; Vo, Nam Sy; Reynolds, Sheila M; Zhao, Yanyan; Climente-González, Héctor; Chai, Shengjie; Wang, Fang; Varghese, Rajees; Huang, Mo; Liang, Wen-Wei; Wyczalkowski, Matthew A; Sengupta, Sohini; Li, Zhi; Payne, Samuel H; Fenyö, David; Miner, Jeffrey H; Walter, Matthew J; Vincent, Benjamin; Eyras, Eduardo; Chen, Ken; Shmulevich, Ilya; Chen, Feng; Ding, Li

    2018-04-03

    For the past decade, cancer genomic studies have focused on mutations leading to splice-site disruption, overlooking those having splice-creating potential. Here, we applied a bioinformatic tool, MiSplice, for the large-scale discovery of splice-site-creating mutations (SCMs) across 8,656 TCGA tumors. We report 1,964 originally mis-annotated mutations having clear evidence of creating alternative splice junctions. TP53 and GATA3 have 26 and 18 SCMs, respectively, and ATRX has 5 from lower-grade gliomas. Mutations in 11 genes, including PARP1, BRCA1, and BAP1, were experimentally validated for splice-site-creating function. Notably, we found that neoantigens induced by SCMs are likely several folds more immunogenic compared to missense mutations, exemplified by the recurrent GATA3 SCM. Further, high expression of PD-1 and PD-L1 was observed in tumors with SCMs, suggesting candidates for immune blockade therapy. Our work highlights the importance of integrating DNA and RNA data for understanding the functional and the clinical implications of mutations in human diseases. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Exome sequencing identifies mutations in ABCD1 and DACH2 in two brothers with a distinct phenotype.

    Science.gov (United States)

    Zhang, Yanliang; Liu, Yanhui; Li, Ya; Duan, Yong; Zhang, Keyun; Wang, Junwang; Dai, Yong

    2014-09-19

    We report on two brothers with a distinct syndromic phenotype and explore the potential pathogenic cause. Cytogenetic tests and exome sequencing were performed on the two brothers and their parents. Variants detected by exome sequencing were validated by Sanger sequencing. The main phenotype of the two brothers included congenital language disorder, growth retardation, intellectual disability, difficulty in standing and walking, and urinary and fecal incontinence. To the best of our knowledge, no similar phenotype has been reported previously. No abnormalities were detected by G-banding chromosome analysis or array comparative genomic hybridization. However, exome sequencing revealed novel mutations in the ATP-binding cassette, sub-family D member 1 (ABCD1) and Dachshund homolog 2 (DACH2) genes in both brothers. The ABCD1 mutation was a missense mutation c.1126G > C in exon 3 leading to a p.E376Q substitution. The DACH2 mutation was also a missense mutation c.1069A > T in exon 6, leading to a p.S357C substitution. The mother was an asymptomatic heterozygous carrier. Plasma levels of very-long-chain fatty acids were increased in both brothers, suggesting a diagnosis of adrenoleukodystrophy (ALD); however, their phenotype was not compatible with any reported forms of ALD. DACH2 plays an important role in the regulation of brain and limb development, suggesting that this mutation may be involved in the phenotype of the two brothers. The distinct phenotype demonstrated by these two brothers might represent a new form of ALD or a new syndrome. The combination of mutations in ABCD1 and DACH2 provides a plausible mechanism for this phenotype.

  13. Sector Retinitis Pigmentosa Associated With Novel Compound Heterozygous Mutations of CDH23.

    Science.gov (United States)

    Branson, Sara V; McClintic, Jedediah I; Stamper, Tara H; Haldeman-Englert, Chad R; John, Vishak J

    2016-02-01

    Usher syndrome is an autosomal recessive condition characterized by retinitis pigmentosa (RP) and congenital hearing loss, with or without vestibular dysfunction. Allelic variants of CDH23 cause both Usher syndrome type 1D (USH1D) and a form of nonsyndromic hearing loss (DFNB12). The authors describe here a 34-year-old patient with congenital hearing loss and a new diagnosis of sector RP who was found to have two novel compound heterozygous mutations in CDH23, including one missense (c.8530C > A; p.Pro2844Thr) and one splice-site (c.5820 + 5G > A) mutation. This is the first report of sector RP associated with these types of mutations in CDH23. Copyright 2016, SLACK Incorporated.

  14. Novel growth hormone receptor gene mutation in a patient with Laron syndrome.

    Science.gov (United States)

    Arman, Ahmet; Yüksel, Bilgin; Coker, Ajda; Sarioz, Ozlem; Temiz, Fatih; Topaloglu, Ali Kemal

    2010-04-01

    Growth Hormone (GH) is a 22 kDa protein that has effects on growth and glucose and fat metabolisms. These effects are initiated by binding of growth hormone (GH) to growth hormone receptors (GHR) expressed in target cells. Mutations or deletions in the growth hormone receptor cause an autosomal disorder called Laron-type dwarfism (LS) characterized by high circulating levels of serum GH and low levels of insulin like growth factor-1 (IGF-1). We analyzed the GHR gene for genetic defect in seven patients identified as Laron type dwarfism. We identified two missense mutations (S40L and W104R), and four polymorphisms (S473S, L526I, G168G and exon 3 deletion). We are reporting a mutation (W104R) at exon 5 of GHR gene that is not previously reported, and it is a novel mutation.

  15. Mutations Affecting G-Protein Subunit α11 in Hypercalcemia and Hypocalcemia

    Science.gov (United States)

    Babinsky, Valerie N.; Head, Rosie A.; Cranston, Treena; Rust, Nigel; Hobbs, Maurine R.; Heath, Hunter; Thakker, Rajesh V.

    2013-01-01

    BACKGROUND Familial hypocalciuric hypercalcemia is a genetically heterogeneous disorder with three variants: types 1, 2, and 3. Type 1 is due to loss-of-function mutations of the calcium-sensing receptor, a guanine nucleotide–binding protein (G-protein)–coupled receptor that signals through the G-protein subunit α11 (Gα11). Type 3 is associated with adaptor-related protein complex 2, sigma 1 subunit (AP2S1) mutations, which result in altered calcium-sensing receptor endocytosis. We hypothesized that type 2 is due to mutations effecting Gα11 loss of function, since Gα11 is involved in calcium-sensing receptor signaling, and its gene (GNA11) and the type 2 locus are colocalized on chromosome 19p13.3. We also postulated that mutations effecting Gα11 gain of function, like the mutations effecting calcium-sensing receptor gain of function that cause autosomal dominant hypocalcemia type 1, may lead to hypocalcemia. METHODS We performed GNA11 mutational analysis in a kindred with familial hypocalciuric hypercalcemia type 2 and in nine unrelated patients with familial hypocalciuric hypercalcemia who did not have mutations in the gene encoding the calcium-sensing receptor (CASR) or AP2S1. We also performed this analysis in eight unrelated patients with hypocalcemia who did not have CASR mutations. In addition, we studied the effects of GNA11 mutations on Gα11 protein structure and calcium-sensing receptor signaling in human embryonic kidney 293 (HEK293) cells. RESULTS The kindred with familial hypocalciuric hypercalcemia type 2 had an in-frame deletion of a conserved Gα11 isoleucine (Ile200del), and one of the nine unrelated patients with familial hypocalciuric hypercalcemia had a missense GNA11 mutation (Leu135Gln). Missense GNA11 mutations (Arg181Gln and Phe341Leu) were detected in two unrelated patients with hypocalcemia; they were therefore identified as having autosomal dominant hypocalcemia type 2. All four GNA11 mutations predicted disrupted protein

  16. Targeted next generation sequencing identifies functionally deleterious germline mutations in novel genes in early-onset/familial prostate cancer.

    Directory of Open Access Journals (Sweden)

    Paula Paulo

    2018-04-01

    Full Text Available Considering that mutations in known prostate cancer (PrCa predisposition genes, including those responsible for hereditary breast/ovarian cancer and Lynch syndromes, explain less than 5% of early-onset/familial PrCa, we have sequenced 94 genes associated with cancer predisposition using next generation sequencing (NGS in a series of 121 PrCa patients. We found monoallelic truncating/functionally deleterious mutations in seven genes, including ATM and CHEK2, which have previously been associated with PrCa predisposition, and five new candidate PrCa associated genes involved in cancer predisposing recessive disorders, namely RAD51C, FANCD2, FANCI, CEP57 and RECQL4. Furthermore, using in silico pathogenicity prediction of missense variants among 18 genes associated with breast/ovarian cancer and/or Lynch syndrome, followed by KASP genotyping in 710 healthy controls, we identified "likely pathogenic" missense variants in ATM, BRIP1, CHEK2 and TP53. In conclusion, this study has identified putative PrCa predisposing germline mutations in 14.9% of early-onset/familial PrCa patients. Further data will be necessary to confirm the genetic heterogeneity of inherited PrCa predisposition hinted in this study.

  17. BRCA2 Hypomorphic Missense Variants Confer Moderate Risks of Breast Cancer.

    OpenAIRE

    Shimelis, Hermela; Mesman, Romy LS; Von, Nicolai Catharina; Ehlen, Asa; Guidugli, Lucia; Martin, Charlotte; Calléja, Fabienne MGR; Meeks, Huong; Hallberg, Emily; Hinton, Jamie; Lilyquist, Jenna; Hu, Chunling; Aalfs, Cora M; Aittomäki, Kristiina; Andrulis, Irene

    2017-01-01

    Breast cancer risks conferred by many germline missense variants in the $\\textit{BRCA1}$ and $\\textit{BRCA2}$ genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case-control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine ...

  18. Genetic Analysis of PARK2 and PINK1 Genes in Brazilian Patients with Early-Onset Parkinson's Disease

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    Karla Cristina Vasconcelos Moura

    2013-01-01

    Full Text Available Parkinson's disease is the second most frequent neurodegenerative disorder in the world, affecting 1-2% of individuals over the age of 65. The etiology of Parkinson's disease is complex, with the involvement of gene-environment interactions. Although it is considered a disease of late manifestation, early-onset forms of parkinsonism contribute to 5–10% of all cases. In the present study, we screened mutations in coding regions of PARK2 and PINK1 genes in 136 unrelated Brazilian patients with early-onset Parkinson's disease through automatic sequencing. We identified six missense variants in PARK2 gene: one known pathogenic mutation, two variants of uncertain role, and three nonpathogenic changes. No pathogenic mutation was identified in PINK1 gene, only benign polymorphisms. All putative pathogenic variants found in this study were in heterozygous state. Our data show that PARK2 point mutations are more common in Brazilian early-onset Parkinson's disease patients (2.9% than PINK1 missense variants (0%, corroborating other studies worldwide.

  19. Genetic Testing for TMEM154 Mutations Associated with Lentivirus Susceptibility in Sheep

    Science.gov (United States)

    Petrik, Dustin T.; Simpson, Barry; Kijas, James W.; Clawson, Michael L.; Chitko-McKown, Carol G.; Harhay, Gregory P.; Leymaster, Kreg A.

    2013-01-01

    In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV) in the U.S., and Visna/Maedi virus (VMV) elsewhere, these viruses reduce an animal’s health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154) has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E) at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V) and the extracellular domains (E31Q, I74F, and I102T) of TMEM154. A matrix-assisted laser desorption/ionization–time-of flight mass spectrometry (MALDI-TOF MS) assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes). The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks. PMID:23408992

  20. Genetic testing for TMEM154 mutations associated with lentivirus susceptibility in sheep.

    Directory of Open Access Journals (Sweden)

    Michael P Heaton

    Full Text Available In sheep, small ruminant lentiviruses cause an incurable, progressive, lymphoproliferative disease that affects millions of animals worldwide. Known as ovine progressive pneumonia virus (OPPV in the U.S., and Visna/Maedi virus (VMV elsewhere, these viruses reduce an animal's health, productivity, and lifespan. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154 has been previously associated with OPPV infection in U.S. sheep. Sheep with the ancestral TMEM154 haplotype encoding glutamate (E at position 35, and either form of an N70I variant, were highly-susceptible compared to sheep homozygous for the K35 missense mutation. Our current overall aim was to characterize TMEM154 in sheep from around the world to develop an efficient genetic test for reduced susceptibility. The average frequency of TMEM154 E35 among 74 breeds was 0.51 and indicated that highly-susceptible alleles were present in most breeds around the world. Analysis of whole genome sequences from an international panel of 75 sheep revealed more than 1,300 previously unreported polymorphisms in a 62 kb region containing TMEM154 and confirmed that the most susceptible haplotypes were distributed worldwide. Novel missense mutations were discovered in the signal peptide (A13V and the extracellular domains (E31Q, I74F, and I102T of TMEM154. A matrix-assisted laser desorption/ionization-time-of flight mass spectrometry (MALDI-TOF MS assay was developed to detect these and six previously reported missense and two deletion mutations in TMEM154. In blinded trials, the call rate for the eight most common coding polymorphisms was 99.4% for 499 sheep tested and 96.0% of the animals were assigned paired TMEM154 haplotypes (i.e., diplotypes. The widespread distribution of highly-susceptible TMEM154 alleles suggests that genetic testing and selection may improve the health and productivity of infected flocks.

  1. Recessive NRL mutations in patients with clumped pigmentary retinal degeneration and relative preservation of blue cone function.

    Science.gov (United States)

    Nishiguchi, Koji M; Friedman, James S; Sandberg, Michael A; Swaroop, Anand; Berson, Eliot L; Dryja, Thaddeus P

    2004-12-21

    Mice lacking the transcription factor Nrl have no rod photoreceptors and an increased number of short-wavelength-sensitive cones. Missense mutations in NRL are associated with autosomal dominant retinitis pigmentosa; however, the phenotype associated with the loss of NRL function in humans has not been reported. We identified two siblings who carried two allelic mutations: a predicted null allele (L75fs) and a missense mutation (L160P) altering a highly conserved residue in the domain involved in DNA-binding-site recognition. In vitro luciferase reporter assays demonstrated that the NRL-L160P mutant had severely reduced transcriptional activity compared with the WT NRL protein, consistent with a severe loss of function. The affected patients had night blindness since early childhood, consistent with a severe reduction in rod function. Color vision was normal, suggesting the presence of all cone color types; nevertheless, a comparison of central visual fields evaluated with white-on-white and blue-on-yellow light stimuli was consistent with a relatively enhanced function of short-wavelength-sensitive cones in the macula. The fundi had signs of retinal degeneration (such as vascular attenuation) and clusters of large, clumped, pigment deposits in the peripheral fundus at the level of the retinal pigment epithelium (clumped pigmentary retinal degeneration). Our report presents an unusual clinical phenotype in humans with loss-of-function mutations in NRL.

  2. The HCM-linked W792R mutation in cardiac myosin-binding protein C reduces C6 FnIII domain stability.

    Science.gov (United States)

    Smelter, Dan F; de Lange, Willem J; Cai, Wenxuan; Ge, Ying; Ralphe, J Carter

    2018-06-01

    Cardiac myosin-binding protein C (cMyBP-C) is a functional sarcomeric protein that regulates contractility in response to contractile demand, and many mutations in cMyBP-C lead to hypertrophic cardiomyopathy (HCM). To gain insight into the effects of disease-causing cMyBP-C missense mutations on contractile function, we expressed the pathogenic W792R mutation (substitution of a highly conserved tryptophan residue by an arginine residue at position 792) in mouse cardiomyocytes lacking endogenous cMyBP-C and studied the functional effects using three-dimensional engineered cardiac tissue constructs (mECTs). Based on complete conservation of tryptophan at this location in fibronectin type II (FnIII) domains, we hypothesized that the W792R mutation affects folding of the C6 FnIII domain, destabilizing the mutant protein. Adenoviral transduction of wild-type (WT) and W792R cDNA achieved equivalent mRNA transcript abundance, but not equivalent protein levels, with W792R compared with WT controls. mECTs expressing W792R demonstrated abnormal contractile kinetics compared with WT mECTs that were nearly identical to cMyBP-C-deficient mECTs. We studied whether common pathways of protein degradation were responsible for the rapid degradation of W792R cMyBP-C. Inhibition of both ubiquitin-proteasome and lysosomal degradation pathways failed to increase full-length mutant protein abundance to WT equivalence, suggesting rapid cytosolic degradation. Bacterial expression of WT and W792R protein fragments demonstrated decreased mutant stability with altered thermal denaturation and increased susceptibility to trypsin digestion. These data suggest that the W792R mutation destabilizes the C6 FnIII domain of cMyBP-C, resulting in decreased full-length protein expression. This study highlights the vulnerability of FnIII-like domains to mutations that alter domain stability and further indicates that missense mutations in cMyBP-C can cause disease through a mechanism of

  3. Analysis of mutations in the entire coding sequence of the factor VIII gene

    Energy Technology Data Exchange (ETDEWEB)

    Bidichadani, S.I.; Lanyon, W.G.; Connor, J.M. [Glascow Univ. (United Kingdom)] [and others

    1994-09-01

    Hemophilia A is a common X-linked recessive disorder of bleeding caused by deleterious mutations in the gene for clotting factor VIII. The large size of the factor VIII gene, the high frequency of de novo mutations and its tissue-specific expression complicate the detection of mutations. We have used a combination of RT-PCR of ectopic factor VIII transcripts and genomic DNA-PCRs to amplify the entire essential sequence of the factor VIII gene. This is followed by chemical mismatch cleavage analysis and direct sequencing in order to facilitate a comprehensive search for mutations. We describe the characterization of nine potentially pathogenic mutations, six of which are novel. In each case, a correlation of the genotype with the observed phenotype is presented. In order to evaluate the pathogenicity of the five missense mutations detected, we have analyzed them for evolutionary sequence conservation and for their involvement of sequence motifs catalogued in the PROSITE database of protein sites and patterns.

  4. Identification of a novel p.R1443W mutation in RP1 gene associated with retinitis pigmentosa sine pigmento

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    Li Ma

    2013-08-01

    Full Text Available AIM: To screen mutations in the retinitis pigmentosa 1 (RP1 gene and the rhodopsin (RHO gene in Chinese patients with retinitis pigmentosa sine pigmento (RPSP and describe the genotype-phenotype relationship of the mutations.METHODS:Twenty affected, unrelated Chinese individuals with RPSP (4 autosomal dominant RPSP, 12 autosomal recessive RPSP and 4 unknown inheritance pattern were recruited between 2009 and 2012. The clinical features were determined by complete ophthalmologic examinations. Polymerase chain reaction (PCR and direct DNA sequencing were used to screen the entire coding region and splice junctions of the RP1 gene and the RHO gene. The cosegregation analysis and population frequency studies were performed for patients with identified mutations.RESULTS: Five variants in the RP1 gene and one in the RHO gene were detected in 20 probands. Four missense changes (rs444772, rs446227, rs414352, rs441800 and one non-coding variant (rs56340615 were common SNPs and none of them showed a significant relationship with RPSP. A missense mutation p.R1443W was identified in the RP1 gene in three affected individuals from a family with autosomal dominant RPSP and was found to cosegregate with the phenotype in this family, suggestive of pathogenic. In addition, population frequency analysis showed the p.R1443W mutation was absent in 300 healthy controls.CONCLUSION: The identification of p.R1443W mutation cosegregating in a family with autosomal dominant RPSP highlights an atypical phenotype of the RP1 gene mutation, while RHO gene is not associated with the pathogenesis of RPSP in this study. To our knowledge, this is the fist mutation identified to associate with RPSP.

  5. Identification of a novel p.R1443W mutation in RP1 gene associated with retinitis pigmentosa sine pigmento.

    Science.gov (United States)

    Ma, Li; Sheng, Xun-Lun; Li, Hui-Ping; Zhang, Fang-Xia; Liu, Ya-Ni; Rong, Wei-Ning; Zhang, Jian-Ling

    2013-01-01

    To screen mutations in the retinitis pigmentosa 1 (RP1) gene and the rhodopsin (RHO) gene in Chinese patients with retinitis pigmentosa sine pigmento (RPSP) and describe the genotype-phenotype relationship of the mutations. Twenty affected, unrelated Chinese individuals with RPSP (4 autosomal dominant RPSP, 12 autosomal recessive RPSP and 4 unknown inheritance pattern) were recruited between 2009 and 2012. The clinical features were determined by complete ophthalmologic examinations. Polymerase chain reaction (PCR) and direct DNA sequencing were used to screen the entire coding region and splice junctions of the RP1 gene and the RHO gene. The cosegregation analysis and population frequency studies were performed for patients with identified mutations. Five variants in the RP1 gene and one in the RHO gene were detected in 20 probands. Four missense changes (rs444772, rs446227, rs414352, rs441800) and one non-coding variant (rs56340615) were common SNPs and none of them showed a significant relationship with RPSP. A missense mutation p.R1443W was identified in the RP1 gene in three affected individuals from a family with autosomal dominant RPSP and was found to cosegregate with the phenotype in this family, suggestive of pathogenic. In addition, population frequency analysis showed the p.R1443W mutation was absent in 300 healthy controls. The identification of p.R1443W mutation cosegregating in a family with autosomal dominant RPSP highlights an atypical phenotype of the RP1 gene mutation, while RHO gene is not associated with the pathogenesis of RPSP in this study. To our knowledge, this is the fist mutation identified to associate with RPSP.

  6. Heterozygous de novo and inherited mutations in the smooth muscle actin (ACTG2 gene underlie megacystis-microcolon-intestinal hypoperistalsis syndrome.

    Directory of Open Access Journals (Sweden)

    Michael F Wangler

    2014-03-01

    Full Text Available Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS is a rare disorder of enteric smooth muscle function affecting the intestine and bladder. Patients with this severe phenotype are dependent on total parenteral nutrition and urinary catheterization. The cause of this syndrome has remained a mystery since Berdon's initial description in 1976. No genes have been clearly linked to MMIHS. We used whole-exome sequencing for gene discovery followed by targeted Sanger sequencing in a cohort of patients with MMIHS and intestinal pseudo-obstruction. We identified heterozygous ACTG2 missense variants in 15 unrelated subjects, ten being apparent de novo mutations. Ten unique variants were detected, of which six affected CpG dinucleotides and resulted in missense mutations at arginine residues, perhaps related to biased usage of CpG containing codons within actin genes. We also found some of the same heterozygous mutations that we observed as apparent de novo mutations in MMIHS segregating in families with intestinal pseudo-obstruction, suggesting that ACTG2 is responsible for a spectrum of smooth muscle disease. ACTG2 encodes γ2 enteric actin and is the first gene to be clearly associated with MMIHS, suggesting an important role for contractile proteins in enteric smooth muscle disease.

  7. Novel and known MYOC exon 3 mutations in an admixed Peruvian primary open-angle glaucoma population.

    Science.gov (United States)

    Mendoza-Reinoso, Veronica; Patil, Teja S; Guevara-Fujita, Maria L; Fernández, Silvia; Vargas, Enrique; Castillo-Herrera, Wilder; Perez-Grossmann, Rodolfo; Lizaraso-Caparó, Frank; Richards, Julia E; Fujita, Ricardo

    2012-01-01

    The aim of this study was to characterize a representative sample of the Peruvian population suffering open-angle glaucoma (OAG) with respect to the myocilin gene (MYOC) mutations, glaucoma phenotype, and ancestry for future glaucoma risk assessment. DNA samples from 414 unrelated Peruvian subjects, including 205 open-angle glaucoma cases (10 juvenile glaucoma [JOAG], 19 normal-tension glaucoma [NTG], and 176 POAG) and 209 randomly sampled controls, were screened for nucleotide changes in MYOC exon 3 by conformational sensitive gel electrophoresis (CSGE) and mutation screening. We identified a probable causative novel MYOC missense mutation, Gly326Ser, in one POAG case and found a consistent genotype-phenotype correlation in eight of his relatives. We also found the known causative MYOC mutation Trp286Arg in one JOAG case and one POAG case. A known causative single base MYOC deletion, T1357, was found in one POAG case. Two previously reported silent polymorphisms, Thr325Thr and Tyr347Tyr, were found in both the case and the control populations. A novel missense variant, Met476Arg, was identified in two unrelated controls. The screening of exon 3 of MYOC in a representative sample of 205 independent POAG patients from Peru and 209 matched controls identified novel and previously reported mutations (both pathogenic and nonpathogenic) from other global regions. These results reflect the complex admixture of Amerindian and Old World ancestry in urban populations of Latin America, in general, and in Peru, in particular. It will be important to gather information about the ancestral origin of MYOC and other POAG gene mutations to develop screening panels and risk assessment for POAG in Peru.

  8. Identification of eight novel coagulation factor XIII subunit A mutations: implied consequences for structure and function.

    Science.gov (United States)

    Ivaskevicius, Vytautas; Biswas, Arijit; Bevans, Carville; Schroeder, Verena; Kohler, Hans Peter; Rott, Hannelore; Halimeh, Susan; Petrides, Petro E; Lenk, Harald; Krause, Manuele; Miterski, Bruno; Harbrecht, Ursula; Oldenburg, Johannes

    2010-06-01

    Severe hereditary coagulation factor XIII deficiency is a rare homozygous bleeding disorder affecting one person in every two million individuals. In contrast, heterozygous factor XIII deficiency is more common, but usually not associated with severe hemorrhage such as intracranial bleeding or hemarthrosis. In most cases, the disease is caused by F13A gene mutations. Causative mutations associated with the F13B gene are rarer. We analyzed ten index patients and three relatives for factor XIII activity using a photometric assay and sequenced their F13A and F13B genes. Additionally, structural analysis of the wild-type protein structure from a previously reported X-ray crystallographic model identified potential structural and functional effects of the missense mutations. All individuals except one were heterozygous for factor XIIIA mutations (average factor XIII activity 51%), while the remaining homozygous individual was found to have severe factor XIII deficiency (<5% of normal factor XIII activity). Eight of the 12 heterozygous patients exhibited a bleeding tendency upon provocation. The identified missense (Pro289Arg, Arg611His, Asp668Gly) and nonsense (Gly390X, Trp664X) mutations are causative for factor XIII deficiency. A Gly592Ser variant identified in three unrelated index patients, as well as in 200 healthy controls (minor allele frequency 0.005), and two further Tyr167Cys and Arg540Gln variants, represent possible candidates for rare F13A gene polymorphisms since they apparently do not have a significant influence on the structure of the factor XIIIA protein. Future in vitro expression studies of the factor XIII mutations are required to confirm their pathological mechanisms.

  9. Low prevalence of CHEK2 gene mutations in multiethnic cohorts of breast cancer patients in Malaysia.

    Science.gov (United States)

    Mohamad, Suriati; Isa, Nurismah Md; Muhammad, Rohaizak; Emran, Nor Aina; Kitan, Nor Mayah; Kang, Peter; Kang, In Nee; Taib, Nur Aishah Mohd; Teo, Soo Hwang; Akmal, Sharifah Noor

    2015-01-01

    CHEK2 is a protein kinase that is involved in cell-cycle checkpoint control after DNA damage. Germline mutations in CHEK2 gene have been associated with increase in breast cancer risk. The aim of this study is to identify the CHEK2 gene germline mutations among high-risk breast cancer patients and its contribution to the multiethnic population in Malaysia. We screened the entire coding region of CHEK2 gene on 59 high-risk breast cancer patients who tested negative for BRCA1/2 germline mutations from UKM Medical Centre (UKMMC), Hospital Kuala Lumpur (HKL) and Hospital Putrajaya (HPJ). Sequence variants identified were screened further in case-control cohorts consisting of 878 unselected invasive breast cancer patients (180 Malays, 526 Chinese and 172 Indian) and 270 healthy individuals (90 Malays, 90 Chinese and 90 Indian). By screening the entire coding region of the CHEK2 gene, two missense mutations, c.480A>G (p.I160M) and c.538C>T (p.R180C) were identified in two unrelated patients (3.4%). Further screening of these missense mutations on the case-control cohorts unveiled the variant p.I160M in 2/172 (1.1%) Indian cases and 1/90 (1.1%) Indian control, variant p.R180C in 2/526 (0.38%) Chinese cases and 0/90 Chinese control, and in 2/180 (1.1%) of Malay cases and 1/90 (1.1%) of Malay control. The results of this study suggest that CHEK2 mutations are rare among high-risk breast cancer patients and may play a minor contributing role in breast carcinogenesis among Malaysian population.

  10. Germline APC mutations in hepatoblastoma.

    Science.gov (United States)

    Yang, Adeline; Sisson, Rebecca; Gupta, Anita; Tiao, Greg; Geller, James I

    2018-04-01

    Conflicting reports on the frequency of germline adenomatous polyposis coli (APC) gene mutations in patients with hepatoblastoma (HB) have called into question the clinical value of APC mutation testing on apparently sporadic HB. An Institutional Review Board approved retrospective review of clinical data collected from patients with HB who received APC testing at our institution was conducted. All HB patients seen at Cincinnati Children's Hospital Medical Center were eligible for testing. Potential genotype/phenotype correlations were assessed. As of July 2015, 29 patients with HB had received constitutional APC testing. Four (14%) were found to have APC pathogenic truncations of the APC protein and in addition two (7%) had APC missense variants of unknown clinical significance. Two patients (7%) had family histories indicative of familial adenomatous polyposis (FAP). Response to chemotherapy tracked differently in APC pathogenic cases, with a slower imaging response despite an equivalent or slightly faster α-fetoprotein (AFP) response. The prevalence of pathogenic APC variants in apparently sporadic HB may be higher than previously detected. Differences in time to imaging response, despite similar AFP response, may impact surgical planning. All patients with HB warrant germline APC mutation testing for underlying FAP. © 2017 Wiley Periodicals, Inc.

  11. The novel C-terminal KCNQ1 mutation M520R alters protein trafficking

    DEFF Research Database (Denmark)

    Schmitt, Nicole; Calloe, Kirstine; Nielsen, Nathalie Hélix

    2007-01-01

    The long QT-syndrome is characterized by a prolongation of the QT-interval and tachyarrhythmias causing syncopes and sudden death. We identified the missense mutation M520R in the calmodulin binding domain of the Kv7.1 channel from a German family with long QT-syndrome. Heterologous expression...... an immunopositive labeling of the plasma membrane. For M520R no plasma membrane staining was visible, instead a strong signal in the ER was observed. These results indicate that the LQT1 mutation M520R leads to ER-retention and dysfunctional trafficking of the mutant channel resulting in haploinsufficiency...

  12. Café-au-lait macules and pediatric malignancy caused by biallelic mutations in the DNA mismatch repair (MMR) gene PMS2.

    Science.gov (United States)

    Jackson, Carl-Christian; Holter, Spring; Pollett, Aaron; Clendenning, Mark; Chou, Shirley; Senter, Leigha; Ramphal, Raveena; Gallinger, Steven; Boycott, Kym

    2008-06-01

    A 14-year-old male presented with a T4 sigmoid adenocarcinoma, PMS2 protein and high frequency microsatellite instability. Germline analysis identified biallelic PMS2 missense mutations. A new cancer syndrome caused by biallelic mutations in the mismatch repair genes, including PMS2, is now emerging and is characterized by café-au-lait macules, colonic polyps and a distinctive tumor spectrum. (c) 2007 Wiley-Liss, Inc.

  13. BRCA2 hypomorphic missense variants confer moderate risks of breast cancer

    OpenAIRE

    Shimelis, Hermela; Mesman, Romy L.s.; Von Nicolai, Catharina; Ehlen, Asa; Guidugli, Lucia; Martin, Charlotte; Calleja, Fabienne Mgr; Meeks, Huong; Hallberg, Emily; Hinton, Jamie; Lilyquist, Jenna; Hu, Chunling; Aalfs, Cora M; Aittomaki, Kristiina; Andrulis, Irene L.

    2017-01-01

    Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case–control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine studies of Asian ances...

  14. The somatic FAH C.1061C>A change counteracts the frequent FAH c.1062+5G>A mutation and permits U1snRNA-based splicing correction.

    Science.gov (United States)

    Scalet, Daniela; Sacchetto, Claudia; Bernardi, Francesco; Pinotti, Mirko; van de Graaf, Stan F J; Balestra, Dario

    2018-05-01

    In tyrosinaemia type 1(HT1), a mosaic pattern of fumarylacetoacetase (FAH) immunopositive or immunonegative nodules in liver tissue has been reported in many patients. This aspect is generally explained by a spontaneous reversion of the mutation into a normal genotype. In one HT1 patient carrying the frequent FAH c.1062+5G>A mutation, a second somatic change (c.1061C>A) has been reported in the same allele, and found in immunopositive nodules. Here, we demonstrated that the c.1062+5G>A prevents usage of the exon 12 5' splice site (ss), even when forced by an engineered U1snRNA specifically designed on the FAH 5'ss to strengthen its recognition. Noticeably the new somatic c.1061C>A change, in linkage with the c.1062+5G>A mutation, partially rescues the defective 5'ss and is associated to trace level (~5%) of correct transcripts. Interestingly, this combined genetic condition strongly favored the rescue by the engineered U1snRNA, with correct transcripts reaching up to 60%. Altogether, these findings elucidate the molecular basis of HT1 caused by the frequent FAH c.1062+5G>A mutation, and demonstrate the compensatory effect of the c.1061C>A change in promoting exon definition, thus unraveling a rare mechanism leading to FAH immune-reactive mosaicism.

  15. Identification of Novel Mutations in FAH Gene and Prenatal Diagnosis of Tyrosinemia in Indian Family

    Directory of Open Access Journals (Sweden)

    Jayesh J. Sheth

    2012-01-01

    Full Text Available Carrier of tyrosinemia type I was diagnosed by sequencing FAH (fumarylacetoacetate hydrolase gene. It leads to the identification of heterozygous status for both c.648C>G (p.Ile216Met and c.1159G>A (p.Gly387Arg mutations in exons 8 and 13, respectively, in the parents. The experimental program PolyPhen, SIFT, and MT predicts former missense point mutation as “benign” that creates a potential donor splice site and later one as “probably damaging” which disrupts secondary structure of protein.

  16. A novel homozygous missense variant in NECTIN4 (PVRL4) causing ectodermal dysplasia cutaneous syndactyly syndrome.

    Science.gov (United States)

    Ahmad, Farooq; Nasir, Abdul; Thiele, Holger; Umair, Muhammad; Borck, Guntram; Ahmad, Wasim

    2018-02-12

    Ectodermal dysplasia syndactyly syndrome 1 (EDSS1) is a rare form of ectodermal dysplasia including anomalies of hair, nails, and teeth along with bilateral cutaneous syndactyly of hands and feet. In the present report, we performed a clinical and genetic characterization of a consanguineous Pakistani family with four individuals affected by EDSS1. We performed exome sequencing using DNA of one affected individual. Exome data analysis identified a novel homozygous missense variant (c.242T>C; p.(Leu81Pro)) in NECTIN4 (PVRL4). Sanger sequencing validated this variant and confirmed its cosegregation with the disease phenotype in the family members. Thus, our report adds a novel variant to the NECTIN4 mutation spectrum and contributes to the NECTIN4-related clinical characterization. © 2018 John Wiley & Sons Ltd/University College London.

  17. Haplotype analysis suggest that the MLH1 c.2059C > T mutation is a Swedish founder mutation.

    Science.gov (United States)

    von Salomé, Jenny; Liu, Tao; Keihäs, Markku; Morak, Moni; Holinski-Feder, Elke; Berry, Ian R; Moilanen, Jukka S; Baert-Desurmont, Stéphanie; Lindblom, Annika; Lagerstedt-Robinson, Kristina

    2017-12-29

    Lynch syndrome (LS) predisposes to a spectrum of cancers and increases the lifetime risk of developing colorectal- or endometrial cancer to over 50%. Lynch syndrome is dominantly inherited and is caused by defects in DNA mismatch-repair genes MLH1, MSH2, MSH6 or PMS2, with the vast majority detected in MLH1 and MSH2. Recurrent LS-associated variants observed in apparently unrelated individuals, have either arisen de novo in different families due to mutation hotspots, or are inherited from a founder (a common ancestor) that lived several generations back. There are variants that recur in some populations while also acting as founders in other ethnic groups. Testing for founder mutations can facilitate molecular diagnosis of Lynch Syndrome more efficiently and more cost effective than screening for all possible mutations. Here we report a study of the missense mutation MLH1 c.2059C > T (p.Arg687Trp), a potential founder mutation identified in eight Swedish families and one Finnish family with Swedish ancestors. Haplotype analysis confirmed that the Finnish and Swedish families shared a haplotype of between 0.9 and 2.8 Mb. While MLH1 c.2059C > T exists worldwide, the Swedish haplotype was not found among mutation carriers from Germany or France, which indicates a common founder in the Swedish population. The geographic distribution of MLH1 c.2059C > T in Sweden suggests a single, ancient mutational event in the northern part of Sweden.

  18. Frequent topoisomerase IV mutations associated with fluoroquinolone resistance in Ureaplasma species.

    Science.gov (United States)

    Song, Jingjuan; Qiao, Yingli; Kong, Yingying; Ruan, Zhi; Huang, Jun; Song, Tiejun; Zhang, Jun; Xie, Xinyou

    2015-11-01

    This study aimed to investigate the role of quinolone resistance-determining regions (QRDRs) of DNA gyrase (encoded by gyrA and gyrB) and topoisomerase IV (encoded by parC and parE) associated with fluoroquinolone resistance. A total of 114 Ureaplasma spp. strains, isolated from clinical female patients with symptomatic infection, were tested for species distribution and susceptibility to four fluoroquinolones. Moreover, we analysed the QRDRs and compared these with 14 ATCC reference strains of Ureaplasma spp. serovars to identify mutations that caused antimicrobial resistance. Our study indicated that moxifloxacin was the most effective fluoroquinolone against Ureaplasma spp. (MIC range: 0.125-32 μg ml⁻¹). However, extremely high MICs were estimated for ciprofloxacin (MIC range: 1-256 μg ml⁻¹) and ofloxacin (MIC range: 0.5-128 μg ml⁻¹), followed by levofloxacin (MIC range: 0.5-64 μg ml⁻¹). Seven amino acid substitutions were discovered in GyrB, ParC and ParE, but not in GyrA. Ser-83 → Leu/Trp (C248T/G) in ParC and Arg-448 → Lys (G1343A) in ParE, which were potentially responsible for fluoroquinolone resistance, were observed in 89 (77.2 %) and three (2.6 %) strains, respectively. Pro-462 → Ser (C1384T), Asn-481 → Ser (A1442G) and Ala-493 → Val (C1478T) in GyrB and Met-105 → Ile (G315T) in ParC seemed to be neutral polymorphisms, and were observed and occurred along with the amino acid change of Ser-83 → Leu (C248T) in ParC. Interestingly, two novel mutations of ParC and ParE were independently found in four strains. These observations suggest that amino acid mutation in topoisomerase IV appears to be the leading cause of fluoroquinolone resistance, especially the mutation of Ser-83 → Leu (C248T) in ParC. Moxifloxacin had the best activity against strains with Ser-83 → Leu mutation.

  19. Functional assays for analysis of variants of uncertain significance in BRCA2

    DEFF Research Database (Denmark)

    Guidugli, Lucia; Carreira, Aura; Caputo, Sandrine M

    2014-01-01

    Missense variants in the BRCA2 gene are routinely detected during clinical screening for pathogenic mutations in patients with a family history of breast and ovarian cancer. These subtle changes frequently remain of unknown clinical significance because of the lack of genetic information that may...... of uncertain significance analyzed, and describe a validation set of (genetically) proven pathogenic and neutral missense variants to serve as a golden standard for the validation of each assay. Guidelines are proposed to enable implementation of laboratory-based methods to assess the impact of the variant...

  20. Panel-based whole exome sequencing identifies novel mutations in microphthalmia and anophthalmia patients showing complex Mendelian inheritance patterns.

    Science.gov (United States)

    Riera, Marina; Wert, Ana; Nieto, Isabel; Pomares, Esther

    2017-11-01

    Microphthalmia and anophthalmia (MA) are congenital eye abnormalities that show an extremely high clinical and genetic complexity. In this study, we evaluated the implementation of whole exome sequencing (WES) for the genetic analysis of MA patients. This approach was used to investigate three unrelated families in which previous single-gene analyses failed to identify the molecular cause. A total of 47 genes previously associated with nonsyndromic MA were included in our panel. WES was performed in one affected patient from each family using the AmpliSeq TM Exome technology and the Ion Proton TM platform. A novel heterozygous OTX2 missense mutation was identified in a patient showing bilateral anophthalmia who inherited the variant from a parent who was a carrier, but showed no sign of the condition. We also describe a new PAX6 missense variant in an autosomal-dominant pedigree affected by mild bilateral microphthalmia showing high intrafamiliar variability, with germline mosaicism determined to be the most plausible molecular cause of the disease. Finally, a heterozygous missense mutation in RBP4 was found to be responsible in an isolated case of bilateral complex microphthalmia. This study highlights that panel-based WES is a reliable and effective strategy for the genetic diagnosis of MA. Furthermore, using this technique, the mutational spectrum of these diseases was broadened, with novel variants identified in each of the OTX2, PAX6, and RBP4 genes. Moreover, we report new cases of reduced penetrance, mosaicism, and variable phenotypic expressivity associated with MA, further demonstrating the heterogeneity of such disorders. © 2017 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.

  1. Mutations in the Norrie disease gene.

    Science.gov (United States)

    Schuback, D E; Chen, Z Y; Craig, I W; Breakefield, X O; Sims, K B

    1995-01-01

    We report our experience to date in mutation identification in the Norrie disease (ND) gene. We carried out mutational analysis in 26 kindreds in an attempt to identify regions presumed critical to protein function and potentially correlated with generation of the disease phenotype. All coding exons, as well as noncoding regions of exons 1 and 2, 636 nucleotides in the noncoding region of exon 3, and 197 nucleotides of 5' flanking sequence, were analyzed for single-strand conformation polymorphisms (SSCP) by polymerase chain reaction (PCR) amplification of genomic DNA. DNA fragments that showed altered SSCP band mobilities were sequenced to locate the specific mutations. In addition to three previously described submicroscopic deletions encompassing the entire ND gene, we have now identified 6 intragenic deletions, 8 missense (seven point mutations, one 9-bp deletion), 6 nonsense (three point mutations, three single bp deletions/frameshift) and one 10-bp insertion, creating an expanded repeat in the 5' noncoding region of exon 1. Thus, mutations have been identified in a total of 24 of 26 (92%) of the kindreds we have studied to date. With the exception of two different mutations, each found in two apparently unrelated kindreds, these mutations are unique and expand the genotype database. Localization of the majority of point mutations at or near cysteine residues, potentially critical in protein tertiary structure, supports a previous protein model for norrin as member of a cystine knot growth factor family (Meitinger et al., 1993). Genotype-phenotype correlations were not evident with the limited clinical data available, except in the cases of larger submicroscopic deletions associated with a more severe neurologic syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. A novel mutation in the WFS1 gene identified in a Taiwanese family with low-frequency hearing impairment

    Directory of Open Access Journals (Sweden)

    Chung Shing-Fang

    2007-05-01

    Full Text Available Abstract Background Wolfram syndrome gene 1 (WFS1 accounts for most of the familial nonsyndromic low-frequency sensorineural hearing loss (LFSNHL which is characterized by sensorineural hearing losses equal to and below 2000 Hz. The current study aimed to contribute to our understanding of the molecular basis of LFSNHL in an affected Taiwanese family. Methods The Taiwanese family with LFSNHL was phenotypically characterized using audiologic examination and pedigree analysis. Genetic characterization was performed by direct sequencing of WFS1 and mutation analysis. Results Pure tone audiometry confirmed that the family members affected with LFSNHL had a bilateral sensorineural hearing loss equal to or below 2000 Hz. The hearing loss threshold of the affected members showed no progression, a characteristic that was consistent with a mutation in the WFS1 gene located in the DFNA6/14/38 locus. Pedigree analysis showed a hereditarily autosomal dominant pattern characterized by a full penetrance. Among several polymorphisms, a missense mutation Y669H (2005T>C in exon 8 of WFS1 was identified in members of a Taiwanese family diagnosed with LFSNHL but not in any of the control subjects. Conclusion We discovered a novel heterozygous missense mutation in exon 8 of WFS1 (i.e., Y669H which is likely responsible for the LFSNHL phenotype in this particular Taiwanese family.

  3. Novel CLCN7 compound heterozygous mutations in intermediate autosomal recessive osteopetrosis.

    Science.gov (United States)

    Okamoto, Nana; Kohmoto, Tomohiro; Naruto, Takuya; Masuda, Kiyoshi; Komori, Takahide; Imoto, Issei

    2017-01-01

    Osteopetrosis is a heritable disorder of the skeleton that is characterized by increased bone density on radiographs caused by defects in osteoclast formation and function. Mutations in >10 genes are identified as causative for this clinically and genetically heterogeneous disease in humans. We report two novel missense variations in a compound heterozygous state in the CLCN7 gene, detected through targeted exome sequencing, in a 15-year-old Japanese female with intermediate autosomal recessive osteopetrosis.

  4. Factor VII deficiency: a novel missense variant and genotype-phenotype correlation in patients from Southern Italy.

    Science.gov (United States)

    Tiscia, Giovanni; Favuzzi, Giovanni; Chinni, Elena; Colaizzo, Donatella; Fischetti, Lucia; Intrieri, Mariano; Margaglione, Maurizio; Grandone, Elvira

    2017-01-01

    This study aimed at attempting to correlate genotype and phenotype in factor VII deficiency. Here, we present molecular and clinical findings of 10 patients with factor VII deficiency. From 2013 to 2016, 10 subjects were referred to our center because of a prolonged prothrombin time identified during routine or presurgery examinations or after a laboratory assessment of a bleeding episode. Mutation characterization was performed using the bioinformatics applications PROMO, SIFT, and Polyphen-2. Structural changes in the factor VII protein were analyzed using the SPDB viewer tool. Of the 10 variants we identified, 1 was responsible for a novel missense change (c.1199G>C, p.Cys400Ser); in 2 cases we identified the c.-54G>A and c.509G>A (p.Arg170His) polymorphic variants in the 5'-upstream region of the factor VII gene and exon 6, respectively. To our knowledge, neither of these polymorphic variants has been described previously in factor VII-deficient patients. In silico predictions showed differences in binding sites for transcription factors caused by the c.-54G>A variant and a probable damaging effect of the p.Cys400Ser missense change on factor VII active conformation, leading to breaking of the Cys400-Cys428 disulfide bridge. Our findings further suggest that, independently of factor VII levels and of variants potentially affecting factor VII levels, environmental factors, e.g., trauma, could heavily influence the clinical phenotype of factor VII-deficient patients.

  5. Novel mutations in the homogentisate 1,2 dioxygenase gene identified in Jordanian patients with alkaptonuria.

    Science.gov (United States)

    Al-sbou, Mohammed

    2012-06-01

    This study was conducted to identify mutations in the homogentisate 1,2 dioxygenase gene (HGD) in alkaptonuria patients among Jordanian population. Blood samples were collected from four alkaptonuria patients, four carriers, and two healthy volunteers. DNA was isolated from peripheral blood. All 14 exons of the HGD gene were amplified using the polymerase chain reaction (PCR) technique. The PCR products were then purified and analyzed by sequencing. Five mutations were identified in our samples. Four of them were novel C1273A, T1046G, 551-552insG, T533G and had not been previously reported, and one mutation T847C has been described before. The types of mutations identified were two missense mutations, one splice site mutation, one frameshift mutation, and one polymorphism. We present the first molecular study of the HGD gene in Jordanian alkaptonuria patients. This study provides valuable information about the molecular basis of alkaptonuria in Jordanian population.

  6. Severe neonatal epileptic encephalopathy and KCNQ2 mutation: neuropathological substrate?

    Directory of Open Access Journals (Sweden)

    Charlotte eDalen Meurs-Van Der Schoor

    2014-12-01

    Full Text Available Background:Neonatal convulsions are clinical manifestations in a heterogeneous group of disorders with different etiology and outcome. They are attributed to several genetic causes. Methods:We describe a patient with intractable neonatal seizures who died from respiratory compromise during a status epilepticus. Results:This case report provides EEG, MRI, genetic analysis and neuropathological data. Genetic analysis revealed a de novo heterozygous missense mutation in the KCNQ2 gene, which encodes a subunit of a voltage-gated potassium channel. KCNQ2 gene mutation is associated with intractable neonatal seizures. EEG, MRI data as well as mutation analysis have been described in other KCNQ2 cases. Postmortem neuropathologic investigation revealed mild malformation of cortical development with increased heterotopic neurons in the deep white matter compared to an age-matched control subject. The new finding of this study is the combination of a KCNQ2 mutation and the cortical abnormalities. Conclusions:KCNQ2 mutations should be considered in neonates with refractory epilepsy of unknown cause. The mild cortical malformation is an important new finding, though it remains unknown whether these cortical abnormalities are due to the KCNQ2 mutation or are secondary to the refractory seizures.

  7. Calibration of Multiple In Silico Tools for Predicting Pathogenicity of Mismatch Repair Gene Missense Substitutions

    Science.gov (United States)

    Thompson, Bryony A.; Greenblatt, Marc S.; Vallee, Maxime P.; Herkert, Johanna C.; Tessereau, Chloe; Young, Erin L.; Adzhubey, Ivan A.; Li, Biao; Bell, Russell; Feng, Bingjian; Mooney, Sean D.; Radivojac, Predrag; Sunyaev, Shamil R.; Frebourg, Thierry; Hofstra, Robert M.W.; Sijmons, Rolf H.; Boucher, Ken; Thomas, Alun; Goldgar, David E.; Spurdle, Amanda B.; Tavtigian, Sean V.

    2015-01-01

    Classification of rare missense substitutions observed during genetic testing for patient management is a considerable problem in clinical genetics. The Bayesian integrated evaluation of unclassified variants is a solution originally developed for BRCA1/2. Here, we take a step toward an analogous system for the mismatch repair (MMR) genes (MLH1, MSH2, MSH6, and PMS2) that confer colon cancer susceptibility in Lynch syndrome by calibrating in silico tools to estimate prior probabilities of pathogenicity for MMR gene missense substitutions. A qualitative five-class classification system was developed and applied to 143 MMR missense variants. This identified 74 missense substitutions suitable for calibration. These substitutions were scored using six different in silico tools (Align-Grantham Variation Grantham Deviation, multivariate analysis of protein polymorphisms [MAPP], Mut-Pred, PolyPhen-2.1, Sorting Intolerant From Tolerant, and Xvar), using curated MMR multiple sequence alignments where possible. The output from each tool was calibrated by regression against the classifications of the 74 missense substitutions; these calibrated outputs are interpretable as prior probabilities of pathogenicity. MAPP was the most accurate tool and MAPP + PolyPhen-2.1 provided the best-combined model (R2 = 0.62 and area under receiver operating characteristic = 0.93). The MAPP + PolyPhen-2.1 output is sufficiently predictive to feed as a continuous variable into the quantitative Bayesian integrated evaluation for clinical classification of MMR gene missense substitutions. PMID:22949387

  8. Mutations in LOXHD1, a Recessive-Deafness Locus, Cause Dominant Late-Onset Fuchs Corneal Dystrophy

    Science.gov (United States)

    Riazuddin, S. Amer; Parker, David S.; McGlumphy, Elyse J.; Oh, Edwin C.; Iliff, Benjamin W.; Schmedt, Thore; Jurkunas, Ula; Schleif, Robert; Katsanis, Nicholas; Gottsch, John D.

    2012-01-01

    Fuchs corneal dystrophy (FCD) is a genetic disorder of the corneal endothelium and is the most common cause of corneal transplantation in the United States. Previously, we mapped a late-onset FCD locus, FCD2, on chromosome 18q. Here, we present next-generation sequencing of all coding exons in the FCD2 critical interval in a multigenerational pedigree in which FCD segregates as an autosomal-dominant trait. We identified a missense change in LOXHD1, a gene causing progressive hearing loss in humans, as the sole variant capable of explaining the phenotype in this pedigree. We observed LOXHD1 mRNA in cultured human corneal endothelial cells, whereas antibody staining of both human and mouse corneas showed staining in the corneal epithelium and endothelium. Corneal sections of the original proband were stained for LOXHD1 and demonstrated a distinct increase in antibody punctate staining in the endothelium and Descemet membrane; punctate staining was absent from both normal corneas and FCD corneas negative for causal LOXHD1 mutations. Subsequent interrogation of a cohort of >200 sporadic affected individuals identified another 15 heterozygous missense mutations that were absent from >800 control chromosomes. Furthermore, in silico analyses predicted that these mutations reside on the surface of the protein and are likely to affect the protein's interface and protein-protein interactions. Finally, expression of the familial LOXHD1 mutant allele as well as two sporadic mutations in cells revealed prominent cytoplasmic aggregates reminiscent of the corneal phenotype. All together, our data implicate rare alleles in LOXHD1 in the pathogenesis of FCD and highlight how different mutations in the same locus can potentially produce diverse phenotypes. PMID:22341973

  9. Severe hypertriglyceridemia in a patient heterozygous for a lipoprotein lipase gene allele with two novel missense variants.

    Science.gov (United States)

    Kassner, Ursula; Salewsky, Bastian; Wühle-Demuth, Marion; Szijarto, Istvan Andras; Grenkowitz, Thomas; Binner, Priska; März, Winfried; Steinhagen-Thiessen, Elisabeth; Demuth, Ilja

    2015-09-01

    Rare monogenic hyperchylomicronemia is caused by loss-of-function mutations in genes involved in the catabolism of triglyceride-rich lipoproteins, including the lipoprotein lipase gene, LPL. Clinical hallmarks of this condition are eruptive xanthomas, recurrent pancreatitis and abdominal pain. Patients with LPL deficiency and severe or recurrent pancreatitis are eligible for the first gene therapy treatment approved by the European Union. Therefore the precise molecular diagnosis of familial hyperchylomicronemia may affect treatment decisions. We present a 57-year-old male patient with excessive hypertriglyceridemia despite intensive lipid-lowering therapy. Abdominal sonography showed signs of chronic pancreatitis. Direct DNA sequencing and cloning revealed two novel missense variants, c.1302A>T and c.1306G>A, in exon 8 of the LPL gene coexisting on the same allele. The variants result in the amino-acid exchanges p.(Lys434Asn) and p.(Gly436Arg). They are located in the carboxy-terminal domain of lipoprotein lipase that interacts with the glycosylphosphatidylinositol-anchored HDL-binding protein (GPIHBP1) and are likely of functional relevance. No further relevant mutations were found by direct sequencing of the genes for APOA5, APOC2, LMF1 and GPIHBP1. We conclude that heterozygosity for damaging mutations of LPL may be sufficient to produce severe hypertriglyceridemia and that chylomicronemia may be transmitted in a dominant manner, at least in some families.

  10. Mutational status of synchronous and metachronous tumor samples in patients with metastatic non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Quéré, Gilles; Descourt, Renaud; Robinet, Gilles; Autret, Sandrine; Raguenes, Odile; Fercot, Brigitte; Alemany, Pierre; Uguen, Arnaud; Férec, Claude; Quintin-Roué, Isabelle; Le Gac, Gérald

    2016-01-01

    Despite reported discordance between the mutational status of primary lung cancers and their metastases, metastatic sites are rarely biopsied and targeted therapy is guided by genetic biomarkers detected in the primary tumor. This situation is mostly explained by the apparent stability of EGFR-activating mutations. Given the dramatic increase in the range of candidate drugs and high rates of drug resistance, rebiopsy or liquid biopsy may become widespread. The purpose of this study was to test genetic biomarkers used in clinical practice (EGFR, ALK) and candidate biomarkers identified by the French National Cancer Institute (KRAS, BRAF, PIK3CA, HER2) in patients with metastatic non-small-cell lung cancer for whom two tumor samples were available. A retrospective study identified 88 tumor samples collected synchronously or metachronously, from the same or two different sites, in 44 patients. Mutation analysis used SNaPshot (EGFR, KRAS, BRAF missense mutations), pyrosequencing (EGFR and PIK3CA missense mutations), sizing assays (EGFR and HER2 indels) and IHC and/or FISH (ALK rearrangements). About half the patients (52 %) harbored at least one mutation. Five patients had an activating mutation of EGFR in both the primary tumor and the metastasis. The T790M resistance mutation was detected in metastases in 3 patients with acquired resistance to EGFR tyrosine kinase inhibitors. FISH showed discordance in ALK status between a small biopsy sample and the surgical specimen. KRAS mutations were observed in 36 % of samples, six patients (14 %) having discordant genotypes; all discordances concerned sampling from different sites. Two patients (5 %) showed PI3KCA mutations. One metastasis harbored both PI3KCA and KRAS mutations, while the synchronously sampled primary tumor was mutation free. No mutations were detected in BRAF and HER2. This study highlighted noteworthy intra-individual discordance in KRAS mutational status, whereas EGFR status was stable. Intratumoral

  11. X-linked hydrocephalus : A novel missense mutation in the L1CAM gene

    NARCIS (Netherlands)

    Sztriha, L; Vos, YJ; Verlind, E; Johansen, J; Berg, B

    2002-01-01

    X-linked hydrocephalus is associated with mutations in the L1 neuronal cell adhesion molecule gene. L1 protein plays a key role in neurite outgrowth, axonal guidance, and pathfinding during the development of the nervous system. A male is described with X-linked hydrocephalus who had multiple small

  12. Systematic Analysis of Splice-Site-Creating Mutations in Cancer

    Directory of Open Access Journals (Sweden)

    Reyka G. Jayasinghe

    2018-04-01

    Full Text Available Summary: For the past decade, cancer genomic studies have focused on mutations leading to splice-site disruption, overlooking those having splice-creating potential. Here, we applied a bioinformatic tool, MiSplice, for the large-scale discovery of splice-site-creating mutations (SCMs across 8,656 TCGA tumors. We report 1,964 originally mis-annotated mutations having clear evidence of creating alternative splice junctions. TP53 and GATA3 have 26 and 18 SCMs, respectively, and ATRX has 5 from lower-grade gliomas. Mutations in 11 genes, including PARP1, BRCA1, and BAP1, were experimentally validated for splice-site-creating function. Notably, we found that neoantigens induced by SCMs are likely several folds more immunogenic compared to missense mutations, exemplified by the recurrent GATA3 SCM. Further, high expression of PD-1 and PD-L1 was observed in tumors with SCMs, suggesting candidates for immune blockade therapy. Our work highlights the importance of integrating DNA and RNA data for understanding the functional and the clinical implications of mutations in human diseases. : Jayasinghe et al. identify nearly 2,000 splice-site-creating mutations (SCMs from over 8,000 tumor samples across 33 cancer types. They provide a more accurate interpretation of previously mis-annotated mutations, highlighting the importance of integrating data types to understand the functional and the clinical implications of splicing mutations in human disease. Keywords: splicing, RNA, mutations of clinical relevance

  13. X-Linked Hypohidrotic Ectodermal Dysplasia: New Features and a Novel EDA Gene Mutation.

    Science.gov (United States)

    Savasta, Salvatore; Carlone, Giorgia; Castagnoli, Riccardo; Chiappe, Francesca; Bassanese, Francesco; Piras, Roberta; Salpietro, Vincenzo; Brazzelli, Valeria; Verrotti, Alberto; Marseglia, Gian L

    2017-01-01

    We described a 5-year-old male with hypodontia, hypohidrosis, and facial dysmorphisms characterized by a depressed nasal bridge, maxillary hypoplasia, and protuberant lips. Chromosomal analysis revealed a normal 46,XY male karyotype. Due to the presence of clinical features of hypohidrotic ectodermal dysplasia (HED), the EDA gene, located at Xq12q13.1, of the patient and his family was sequenced. Analysis of the proband's sequence revealed a missense mutation (T to A transversion) in hemizygosity state at nucleotide position 158 in exon 1 of the EDA gene, which changes codon 53 from leucine to histidine, while heterozygosity at this position was detected in the slightly affected mother; moreover, this mutation was not found in the publically available Human Gene Mutation Database. To date, our findings indicate that a novel mutation in EDA is associated with X-linked HED, adding it to the repertoire of EDA mutations. © 2017 S. Karger AG, Basel.

  14. FANCA Gene Mutations with 8 Novel Molecular Changes in Indian Fanconi Anemia Patients.

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    Avani Solanki

    Full Text Available Fanconi anemia (FA, a rare heterogeneous genetic disorder, is known to be associated with 19 genes and a spectrum of clinical features. We studied FANCA molecular changes in 34 unrelated and 2 siblings of Indian patients with FA and have identified 26 different molecular changes of FANCA gene, of which 8 were novel mutations (a small deletion c.2500delC, 4 non-sense mutations c.2182C>T, c.2630C>G, c.3677C>G, c.3189G>A; and 3 missense mutations; c.1273G>C, c.3679 G>C, and c.3992 T>C. Among these only 16 patients could be assigned FA-A complementation group, because we could not confirm single exon deletions detected by MLPA or cDNA amplification by secondary confirmation method and due to presence of heterozygous non-pathogenic variations or heterozygous pathogenic mutations. An effective molecular screening strategy should be developed for confirmation of these mutations and determining the breakpoints for single exon deletions.

  15. FANCA Gene Mutations with 8 Novel Molecular Changes in Indian Fanconi Anemia Patients.

    Science.gov (United States)

    Solanki, Avani; Mohanty, Purvi; Shukla, Pallavi; Rao, Anita; Ghosh, Kanjaksha; Vundinti, Babu Rao

    2016-01-01

    Fanconi anemia (FA), a rare heterogeneous genetic disorder, is known to be associated with 19 genes and a spectrum of clinical features. We studied FANCA molecular changes in 34 unrelated and 2 siblings of Indian patients with FA and have identified 26 different molecular changes of FANCA gene, of which 8 were novel mutations (a small deletion c.2500delC, 4 non-sense mutations c.2182C>T, c.2630C>G, c.3677C>G, c.3189G>A; and 3 missense mutations; c.1273G>C, c.3679 G>C, and c.3992 T>C). Among these only 16 patients could be assigned FA-A complementation group, because we could not confirm single exon deletions detected by MLPA or cDNA amplification by secondary confirmation method and due to presence of heterozygous non-pathogenic variations or heterozygous pathogenic mutations. An effective molecular screening strategy should be developed for confirmation of these mutations and determining the breakpoints for single exon deletions.

  16. Reciprocal sign epistasis between frequently experimentally evolved adaptive mutations causes a rugged fitness landscape.

    Directory of Open Access Journals (Sweden)

    Daniel J Kvitek

    2011-04-01

    Full Text Available The fitness landscape captures the relationship between genotype and evolutionary fitness and is a pervasive metaphor used to describe the possible evolutionary trajectories of adaptation. However, little is known about the actual shape of fitness landscapes, including whether valleys of low fitness create local fitness optima, acting as barriers to adaptive change. Here we provide evidence of a rugged molecular fitness landscape arising during an evolution experiment in an asexual population of Saccharomyces cerevisiae. We identify the mutations that arose during the evolution using whole-genome sequencing and use competitive fitness assays to describe the mutations individually responsible for adaptation. In addition, we find that a fitness valley between two adaptive mutations in the genes MTH1 and HXT6/HXT7 is caused by reciprocal sign epistasis, where the fitness cost of the double mutant prohibits the two mutations from being selected in the same genetic background. The constraint enforced by reciprocal sign epistasis causes the mutations to remain mutually exclusive during the experiment, even though adaptive mutations in these two genes occur several times in independent lineages during the experiment. Our results show that epistasis plays a key role during adaptation and that inter-genic interactions can act as barriers between adaptive solutions. These results also provide a new interpretation on the classic Dobzhansky-Muller model of reproductive isolation and display some surprising parallels with mutations in genes often associated with tumors.

  17. Differential functional readthrough over homozygous nonsense mutations contributes to the bleeding phenotype in coagulation factor VII deficiency.

    Science.gov (United States)

    Branchini, A; Ferrarese, M; Lombardi, S; Mari, R; Bernardi, F; Pinotti, M

    2016-10-01

    Essentials Potentially null homozygous Factor(F)7 nonsense mutations are associated to variable bleeding symptoms. Readthrough of p.Ser112X (life-threatening) and p.Cys132X (moderate) stop codons was investigated. Readthrough-mediated insertion of wild-type or tolerated residues produce functional proteins. Functional readthrough over homozygous F7 nonsense mutations contributes to the bleeding phenotype. Background Whereas the rare homozygous nonsense mutations causing factor (F)VII deficiency may predict null conditions that are almost completely incompatible with life, they are associated with appreciable differences in hemorrhagic symptoms. The misrecognition of premature stop codons (readthrough) may account for variable levels of functional full-length proteins. Objectives To experimentally evaluate the basal and drug-induced levels of FVII resulting from the homozygous p.Cys132X and p.Ser112X nonsense mutations that are associated with moderate (132X) or life-threatening (112X) symptoms, and that are predicted to undergo readthrough with (132X) or without (112X) production of wild-type FVII. Methods We transiently expressed recombinant FVII (rFVII) nonsense and missense variants in human embryonic kidney 293 cells, and evaluated secreted FVII protein and functional levels by ELISA, activated FX generation, and coagulation assays. Results The levels of functional FVII produced by p.Cys132X and p.Ser112X mutants (rFVII-132X, 1.1% ± 0.2% of wild-type rFVII; rFVII-112X, 0.5% ± 0.1% of wild-type rFVII) were compatible with the occurrence of spontaneous readthrough, which was magnified by the addition of G418 - up to 12% of the wild-type value for the rFVII-132X nonsense variant. The predicted missense variants arising from readthrough abolished (rFVII-132Trp/Arg) or reduced (rFVII-112Trp/Cys/Arg, 22-45% of wild-type levels) secretion and function. These data suggest that the appreciable rescue of p.Cys132X function was driven by reinsertion of the wild

  18. Deletions and de novo mutations of SOX11 are associated with a neurodevelopmental disorder with features of Coffin–Siris syndrome

    Science.gov (United States)

    Hempel, Annmarie; Pagnamenta, Alistair T; Blyth, Moira; Mansour, Sahar; McConnell, Vivienne; Kou, Ikuyo; Ikegawa, Shiro; Tsurusaki, Yoshinori; Matsumoto, Naomichi; Lo-Castro, Adriana; Plessis, Ghislaine; Albrecht, Beate; Battaglia, Agatino; Taylor, Jenny C; Howard, Malcolm F; Keays, David; Sohal, Aman Singh; Kühl, Susanne J; Kini, Usha; McNeill, Alisdair

    2016-01-01

    Background SOX11 is a transcription factor proposed to play a role in brain development. The relevance of SOX11 to human developmental disorders was suggested by a recent report of SOX11 mutations in two patients with Coffin–Siris syndrome. Here we further investigate the role of SOX11 variants in neurodevelopmental disorders. Methods We used array based comparative genomic hybridisation and trio exome sequencing to identify children with intellectual disability who have deletions or de novo point mutations disrupting SOX11. The pathogenicity of the SOX11 mutations was assessed using an in vitro gene expression reporter system. Loss-of-function experiments were performed in xenopus by knockdown of Sox11 expression. Results We identified seven individuals with chromosome 2p25 deletions involving SOX11. Trio exome sequencing identified three de novo SOX11 variants, two missense (p.K50N; p.P120H) and one nonsense (p.C29*). The biological consequences of the missense mutations were assessed using an in vitro gene expression system. These individuals had microcephaly, developmental delay and shared dysmorphic features compatible with mild Coffin–Siris syndrome. To further investigate the function of SOX11, we knocked down the orthologous gene in xenopus. Morphants had significant reduction in head size compared with controls. This suggests that SOX11 loss of function can be associated with microcephaly. Conclusions We thus propose that SOX11 deletion or mutation can present with a Coffin–Siris phenotype. PMID:26543203

  19. Identification of a novel CLRN1 gene mutation in Usher syndrome type 3: two case reports.

    Science.gov (United States)

    Yoshimura, Hidekane; Oshikawa, Chie; Nakayama, Jun; Moteki, Hideaki; Usami, Shin-Ichi

    2015-05-01

    This study examines the CLRN1 gene mutation analysis in Japanese patients who were diagnosed with Usher syndrome type 3 (USH3) on the basis of clinical findings. Genetic analysis using massively parallel DNA sequencing (MPS) was conducted to search for 9 causative USH genes in 2 USH3 patients. We identified the novel pathogenic mutation in the CLRN1 gene in 2 patients. The missense mutation was confirmed by functional prediction software and segregation analysis. Both patients were diagnosed as having USH3 caused by the CLRN1 gene mutation. This is the first report of USH3 with a CLRN1 gene mutation in Asian populations. Validating the presence of clinical findings is imperative for properly differentiating among USH subtypes. In addition, mutation screening using MPS enables the identification of causative mutations in USH. The clinical diagnosis of this phenotypically variable disease can then be confirmed. © The Author(s) 2015.

  20. Spectrum of ABCA4 (ABCR) gene mutations in Spanish patients with autosomal recessive macular dystrophies.

    Science.gov (United States)

    Paloma, E; Martínez-Mir, A; Vilageliu, L; Gonzàlez-Duarte, R; Balcells, S

    2001-06-01

    The ABCA4 gene has been involved in several forms of inherited macular dystrophy. In order to further characterize the complex genotype-phenotype relationships involving this gene, we have performed a mutation analysis of ABCA4 in 14 Spanish patients comprising eight STGD (Stargardt), four FFM (fundus flavimaculatus), and two CRD (Cone-rod dystrophy) patients. SSCP (single-strand conformation polymorphism) analysis and DNA sequencing of the coding and 5' upstream regions of this gene allowed the identification of 16 putatively pathogenic alterations, nine of which are novel. Most of these were missense changes, and no patient was found to carry two null alleles. Overall, the new data agree with a working model relating the different pathogenic phenotypes to the severity of the mutations. When considering the information presented here together with that of previous reports, a picture of the geographic distribution of three particular mutations emerges. The R212C change has been found in French, Italian, Dutch, German, and Spanish but not in British patients. In the Spanish collection, R212C was found in a CRD patient, indicating that it may be a rather severe change. In contrast, c.2588G>C, a very common mild allele in the Dutch population, is rarely found in Southern Europe. Interestingly, the c.2588G>C mutation has been found in a double mutant allele together with the missense R1055W. Finally, the newly described L1940P was found in two unrelated Spanish patients, and may be a moderate to severe allele. Copyright 2001 Wiley-Liss, Inc.

  1. The refractive state of the eye in Icelandic horses with the Silver mutation.

    Science.gov (United States)

    Johansson, Maria K; Jäderkvist Fegraeus, Kim; Lindgren, Gabriella; Ekesten, Björn

    2017-06-02

    The syndrome Multiple Congenital Ocular Anomalies (MCOA) is a congenital eye disorder in horses. Both the MCOA syndrome and the Silver coat colour in horses are caused by the same missense mutation in the premelanosome protein (PMEL) gene. Horses homozygous for the Silver mutation (TT) are affected by multiple ocular defects causing visual impairment or blindness. Horses heterozygous for the Silver mutation (CT) have less severe clinical signs, usually cysts arising from the ciliary body iris or retina temporally. It is still unknown if the vision is impaired in horses heterozygous for the Silver mutation. A recent study reported that Comtois horses carrying the Silver mutation had significantly deeper anterior chambers of the eye compared to wild-type horses. This could potentially cause refractive errors. The purpose of the present study was to investigate if Icelandic horses with the Silver mutation have refractive errors compared to wild-type horses. One hundred and fifty-two Icelandic horses were included in the study, 71 CT horses and five TT horses. All horses were genotyped for the missense mutation in PMEL. Each CT and TT horse was matched by a wild-type (CC) horse of the same age ± 1 year. Skiascopy and a brief ophthalmic examination were performed in all horses. Association between refraction and age, eye, genotype and sex was tested by linear mixed-effect model analysis. TT horses with controls were not included in the statistical analyses as they were too few. The interaction between age and genotype had a significant impact on the refractive state (P = 0.0001). CT horses older than 16 years were on average more myopic than wild-type horses of the same age. No difference in the refractive state could be observed between genotypes (CT and CC) in horses younger than 16 years. TT horses were myopic (-2 D or more) in one or both eyes regardless of age. Our results indicate that an elderly Icelandic horse (older than 16 years) carrying the Silver

  2. TARDBP mutations in individuals with sporadic and familial amyotrophic lateral sclerosis.

    Science.gov (United States)

    Kabashi, Edor; Valdmanis, Paul N; Dion, Patrick; Spiegelman, Dan; McConkey, Brendan J; Vande Velde, Christine; Bouchard, Jean-Pierre; Lacomblez, Lucette; Pochigaeva, Ksenia; Salachas, Francois; Pradat, Pierre-Francois; Camu, William; Meininger, Vincent; Dupre, Nicolas; Rouleau, Guy A

    2008-05-01

    Recently, TDP-43 was identified as a key component of ubiquitinated aggregates in amyotrophic lateral sclerosis (ALS), an adult-onset neurological disorder that leads to the degeneration of motor neurons. Here we report eight missense mutations in nine individuals--six from individuals with sporadic ALS (SALS) and three from those with familial ALS (FALS)--and a concurring increase of a smaller TDP-43 product. These findings further corroborate that TDP-43 is involved in ALS pathogenesis.

  3. Identification of a Novel Mutation in a Pseudohypoparathyroidism Family

    Directory of Open Access Journals (Sweden)

    Zhi-Min Miao

    2011-01-01

    Full Text Available Pseudohypoparathyroidism type Ia (PHP Ia is defined as a series of disorders characterized by multihormone resistance in end-organs and Albright hereditary osteodystrophy (AHO phenotype. PHP Ia is caused by heterozygous inactivating mutations in GNAS, which encodes the stimulatory G-protein alpha subunit (Gsa. A patient with typical clinical manifestations of pseudohypoparathyroidism (PHP (round face, short stature, centripetal obesity, brachydactyly, and multi-hormone resistance: parathyroid hormone (PTH, thyroid-stimulating hormone (TSH, and gonadotropins presented at our center. The sequence of the GNAS gene from the patient and her families revealed a novel missense mutation (Y318H in the proband and her mother. An in vitro Gsa functional study showed that Gsa function was significantly impaired. These results stress the importance of GNAS gene investigation.

  4. Growth Hormone Receptor Mutations Related to Individual Dwarfism

    Science.gov (United States)

    Li, Charles; Zhang, Xiquan

    2018-01-01

    Growth hormone (GH) promotes body growth by binding with two GH receptors (GHRs) at the cell surface. GHRs interact with Janus kinase, signal transducers, and transcription activators to stimulate metabolic effects and insulin-like growth factor (IGF) synthesis. However, process dysfunctions in the GH–GHR–IGF-1 axis cause animal dwarfism. If, during the GH process, GHR is not successfully recognized and/or bound, or GHR fails to transmit the GH signal to IGF-1, the GH dysfunction occurs. The goal of this review was to focus on the GHR mutations that lead to failures in the GH–GHR–IGF-1 signal transaction process in the dwarf phenotype. Until now, more than 90 GHR mutations relevant to human short stature (Laron syndrome and idiopathic short stature), including deletions, missense, nonsense, frameshift, and splice site mutations, and four GHR defects associated with chicken dwarfism, have been described. Among the 93 identified mutations of human GHR, 68 occur extracellularly, 13 occur in GHR introns, 10 occur intracellularly, and two occur in the transmembrane. These mutations interfere with the interaction between GH and GHRs, GHR dimerization, downstream signaling, and the expression of GHR. These mutations cause aberrant functioning in the GH-GHR-IGF-1 axis, resulting in defects in the number and diameter of muscle fibers as well as bone development. PMID:29748515

  5. Growth Hormone Receptor Mutations Related to Individual Dwarfism

    Directory of Open Access Journals (Sweden)

    Shudai Lin

    2018-05-01

    Full Text Available Growth hormone (GH promotes body growth by binding with two GH receptors (GHRs at the cell surface. GHRs interact with Janus kinase, signal transducers, and transcription activators to stimulate metabolic effects and insulin‐like growth factor (IGF synthesis. However, process dysfunctions in the GH–GHR–IGF-1 axis cause animal dwarfism. If, during the GH process, GHR is not successfully recognized and/or bound, or GHR fails to transmit the GH signal to IGF-1, the GH dysfunction occurs. The goal of this review was to focus on the GHR mutations that lead to failures in the GH–GHR–IGF-1 signal transaction process in the dwarf phenotype. Until now, more than 90 GHR mutations relevant to human short stature (Laron syndrome and idiopathic short stature, including deletions, missense, nonsense, frameshift, and splice site mutations, and four GHR defects associated with chicken dwarfism, have been described. Among the 93 identified mutations of human GHR, 68 occur extracellularly, 13 occur in GHR introns, 10 occur intracellularly, and two occur in the transmembrane. These mutations interfere with the interaction between GH and GHRs, GHR dimerization, downstream signaling, and the expression of GHR. These mutations cause aberrant functioning in the GH-GHR-IGF-1 axis, resulting in defects in the number and diameter of muscle fibers as well as bone development.

  6. A negative screen for mutations in calstabin 1 and 2 genes in patients with dilated cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Biagi Diogo G

    2012-01-01

    Full Text Available Abstract Background Calstabins 1 and 2 bind to Ryanodine receptors regulating muscle excitation-contraction coupling. Mutations in Ryanodine receptors affecting their interaction with calstabins lead to different cardiac pathologies. Animal studies suggest the involvement of calstabins with dilated cardiomyopathy. Results We tested the hypothesis that calstabins mutations may cause dilated cardiomyopathy in humans screening 186 patients with idiopathic dilated cardiomyopathy for genetic alterations in calstabins 1 and 2 genes (FKBP12 and FKBP12.6. No missense variant was found. Five no-coding variations were found but not related to the disease. Conclusions These data corroborate other studies suggesting that mutations in FKBP12 and FKBP12.6 genes are not commonly related to cardiac diseases.

  7. Over-Expression of Porcine Myostatin Missense Mutant Leads to A Gender Difference in Skeletal Muscle Growth between Transgenic Male and Female Mice.

    Science.gov (United States)

    Ma, Dezun; Gao, Pengfei; Qian, Lili; Wang, Qingqing; Cai, Chunbo; Jiang, Shengwang; Xiao, Gaojun; Cui, Wentao

    2015-08-24

    Myostatin, a transforming growth factor-β family member, is a negative regulator of skeletal muscle development and growth. Piedmontese cattle breeds have a missense mutation, which results in a cysteine to tyrosine substitution in the mature myostatin protein (C313Y). This loss-of-function mutation in myostatin results in a double-muscled phenotype in cattle. Myostatin propeptide is an inhibitor of myostatin activity and is considered a potential agent to stimulate muscle growth in livestock. In this study, we generated transgenic mice overexpressing porcine myostatin missense mutant (pmMS), C313Y, and wild-type porcine myostatin propeptide (ppMS), respectively, to examine their effects on muscle growth in mice. Enhanced muscle growth was observed in both pmMS and ppMS transgenic female mice and also in ppMS transgenic male mice. However, there was no enhanced muscle growth observed in pmMS transgenic male mice. To explore why there is such a big difference in muscle growth between pmMS and ppMS transgenic male mice, the expression level of androgen receptor (AR) mutant AR45 was measured by Western blot. Results indicated that AR45 expression significantly increased in pmMS transgenic male mice while it decreased dramatically in ppMS transgenic male mice. Our data demonstrate that both pmMS and ppMS act as myostatin inhibitors in the regulation of muscle growth, but the effect of pmMS in male mice is reversed by an increased AR45 expression. These results provide useful insight and basic theory to future studies on improving pork quality by genetically manipulating myostatin expression or by regulating myostatin activity.

  8. Genetic basis for correction of very-long-chain acyl-coenzyme A dehydrogenase deficiency by bezafibrate in patient fibroblasts

    DEFF Research Database (Denmark)

    Gobin-Limballe, S; Djouadi, F; Aubey, F

    2007-01-01

    there is no established treatment. Recent data suggest that bezafibrate could improve the FAO capacities in beta-oxidation-deficient cells, by enhancing the residual level of mutant enzyme activity via gene-expression stimulation. Since VLCAD-deficient patients frequently harbor missense mutations with unpredictable...... values, for 21 genotypes that mainly corresponded to patients with the myopathic phenotype. In contrast, bezafibrate induced no changes in FAO for 11 genotypes corresponding to severe neonatal or infantile phenotypes. This pattern of response was not due to differential inductions of VLCAD messenger RNA......, as shown by quantitative real-time polymerase chain reaction, but reflected variable increases in measured VLCAD residual enzyme activity in response to bezafibrate. Genotype cross-analysis allowed the identification of alleles carrying missense mutations, which could account for these different...

  9. Screening for Ataxia-Telangiectasia Mutations in a Population-Based Sample of Women with Early-Onset Breast Cancer

    Science.gov (United States)

    1999-09-01

    and xeroderma pigmentosum in Britain. Cancer Res 1988;48:2929-32. 18 13. Stankovic T, Kidd AMJ, Sutcliffe A, McGuire GM, Robinson P, Weber P, et al...nested-PCR products of ATM nucleotide po - Nonsense and Missense Mutations with Indirect Effects sitions 500-1191 from cDNAs of AT113LA, AT140LA, and

  10. Case Report Identification of a novel SLC45A2 mutation in albinism by targeted next-generation sequencing.

    Science.gov (United States)

    Xue, J J; Xue, J F; Xue, H Q; Guo, Y Y; Liu, Y; Ouyang, N

    2016-09-19

    Albinism is a diverse group of hypopigmentary disorders caused by multiple-genetic defects. The genetic diagnosis of patients affected with albinism by Sanger sequencing is often complex, expensive, and time-consuming. In this study, we performed targeted next-generation sequencing to screen for 16 genes in a patient with albinism, and identified 21 genetic variants, including 19 known single nucleotide polymorphisms, one novel missense mutation (c.1456 G>A), and one disease-causing mutation (c.478 G>C). The novel mutation was not observed in 100 controls, and was predicted to be a damaging mutation by SIFT and Polyphen. Thus, we identified a novel mutation in SLC45A2 in a Chinese family, expanding the mutational spectrum of albinism. Our results also demonstrate that targeted next-generation sequencing is an effective genetic test for albinism.

  11. Variable expressivity of FGF3 mutations associated with deafness and LAMM syndrome

    Directory of Open Access Journals (Sweden)

    Griffith Andrew J

    2011-02-01

    Full Text Available Abstract Background Recessive mutations of fibroblast growth factor 3 (FGF3 can cause LAMM syndrome (OMIM 610706, characterized by fully penetrant complete labyrinthine aplasia, microtia and microdontia. Methods We performed a prospective molecular genetic and clinical study of families segregating hearing loss linked to FGF3 mutations. Ten affected individuals from three large Pakistani families segregating FGF3 mutations were imaged with CT, MRI, or both to detect inner ear abnormalities. We also modeled the three dimensional structure of FGF3 to better understand the structural consequences of the three missense mutations. Results Two families segregated reported mutations (p.R104X and p.R95W and one family segregated a novel mutation (p.R132GfsX26 of FGF3. All individuals homozygous for p.R104X or p.R132GfsX26 had fully penetrant features of LAMM syndrome. However, recessive p.R95W mutations were associated with nearly normal looking auricles and variable inner ear structural phenotypes, similar to that reported for a Somali family also segregating p.R95W. This suggests that the mild phenotype is not entirely due to genetic background. Molecular modeling result suggests a less drastic effect of p.R95W on FGF3 function compared with known missense mutations detected in fully penetrant LAMM syndrome. Since we detected significant intrafamilial variability of the inner ear structural phenotype in the family segregating p.R95W, we also sequenced FGF10 as a likely candidate for a modifier. However, we did not find any sequence variation, pointing out that a larger sample size will be needed to map and identify a modifier. We also observed a mild to moderate bilateral conductive hearing loss in three carriers of p.R95W, suggesting either a semi-dominant effect of this mutant allele of FGF3, otitis media, or a consequence of genetic background in these three family members. Conclusions We noted a less prominent dental and external ear phenotype in

  12. Agrin mutations lead to a congenital myasthenic syndrome with distal muscle weakness and atrophy.

    Science.gov (United States)

    Nicole, Sophie; Chaouch, Amina; Torbergsen, Torberg; Bauché, Stéphanie; de Bruyckere, Elodie; Fontenille, Marie-Joséphine; Horn, Morten A; van Ghelue, Marijke; Løseth, Sissel; Issop, Yasmin; Cox, Daniel; Müller, Juliane S; Evangelista, Teresinha; Stålberg, Erik; Ioos, Christine; Barois, Annie; Brochier, Guy; Sternberg, Damien; Fournier, Emmanuel; Hantaï, Daniel; Abicht, Angela; Dusl, Marina; Laval, Steven H; Griffin, Helen; Eymard, Bruno; Lochmüller, Hanns

    2014-09-01

    Congenital myasthenic syndromes are a clinically and genetically heterogeneous group of rare diseases resulting from impaired neuromuscular transmission. Their clinical hallmark is fatigable muscle weakness associated with a decremental muscle response to repetitive nerve stimulation and frequently related to postsynaptic defects. Distal myopathies form another clinically and genetically heterogeneous group of primary muscle disorders where weakness and atrophy are restricted to distal muscles, at least initially. In both congenital myasthenic syndromes and distal myopathies, a significant number of patients remain genetically undiagnosed. Here, we report five patients from three unrelated families with a strikingly homogenous clinical entity combining congenital myasthenia with distal muscle weakness and atrophy reminiscent of a distal myopathy. MRI and neurophysiological studies were compatible with mild myopathy restricted to distal limb muscles, but decrement (up to 72%) in response to 3 Hz repetitive nerve stimulation pointed towards a neuromuscular transmission defect. Post-exercise increment (up to 285%) was observed in the distal limb muscles in all cases suggesting presynaptic congenital myasthenic syndrome. Immunofluorescence and ultrastructural analyses of muscle end-plate regions showed synaptic remodelling with denervation-reinnervation events. We performed whole-exome sequencing in two kinships and Sanger sequencing in one isolated case and identified five new recessive mutations in the gene encoding agrin. This synaptic proteoglycan with critical function at the neuromuscular junction was previously found mutated in more typical forms of congenital myasthenic syndrome. In our patients, we found two missense mutations residing in the N-terminal agrin domain, which reduced acetylcholine receptors clustering activity of agrin in vitro. Our findings expand the spectrum of congenital myasthenic syndromes due to agrin mutations and show an unexpected

  13. Molecular Genetic Analysis of the PLP1 Gene in 38 Families with PLP1-related disorders: Identification and Functional Characterization of 11 Novel PLP1 Mutations

    Directory of Open Access Journals (Sweden)

    Marchiani Valentina

    2011-06-01

    Full Text Available Abstract Background The breadth of the clinical spectrum underlying Pelizaeus-Merzbacher disease and spastic paraplegia type 2 is due to the extensive allelic heterogeneity in the X-linked PLP1 gene encoding myelin proteolipid protein (PLP. PLP1 mutations range from gene duplications of variable size found in 60-70% of patients to intragenic lesions present in 15-20% of patients. Methods Forty-eight male patients from 38 unrelated families with a PLP1-related disorder were studied. All DNA samples were screened for PLP1 gene duplications using real-time PCR. PLP1 gene sequencing analysis was performed on patients negative for the duplication. The mutational status of all 14 potential carrier mothers of the familial PLP1 gene mutation was determined as well as 15/24 potential carrier mothers of the PLP1 duplication. Results and Conclusions PLP1 gene duplications were identified in 24 of the unrelated patients whereas a variety of intragenic PLP1 mutations were found in the remaining 14 patients. Of the 14 different intragenic lesions, 11 were novel; these included one nonsense and 7 missense mutations, a 657-bp deletion, a microdeletion and a microduplication. The functional significance of the novel PLP1 missense mutations, all occurring at evolutionarily conserved residues, was analysed by the MutPred tool whereas their potential effect on splicing was ascertained using the Skippy algorithm and a neural network. Although MutPred predicted that all 7 novel missense mutations would be likely to be deleterious, in silico analysis indicated that four of them (p.Leu146Val, p.Leu159Pro, p.Thr230Ile, p.Ala247Asp might cause exon skipping by altering exonic splicing elements. These predictions were then investigated in vitro for both p.Leu146Val and p.Thr230Ile by means of RNA or minigene studies and were subsequently confirmed in the case of p.Leu146Val. Peripheral neuropathy was noted in four patients harbouring intragenic mutations that altered RNA

  14. Gain-of-function SOS1 mutations cause a distinctive form of noonansyndrome

    Energy Technology Data Exchange (ETDEWEB)

    Tartaglia, Marco; Pennacchio, Len A.; Zhao, Chen; Yadav, KamleshK.; Fodale, Valentina; Sarkozy, Anna; Pandit, Bhaswati; Oishi, Kimihiko; Martinelli, Simone; Schackwitz, Wendy; Ustaszewska, Anna; Martin, Joes; Bristow, James; Carta, Claudio; Lepri, Francesca; Neri, Cinzia; Vasta,Isabella; Gibson, Kate; Curry, Cynthia J.; Lopez Siguero, Juan Pedro; Digilio, Maria Cristina; Zampino, Giuseppe; Dallapiccola, Bruno; Bar-Sagi, Dafna; Gelb, Brude D.

    2006-09-01

    Noonan syndrome (NS) is a developmental disordercharacterized by short stature, facial dysmorphia, congenital heartdefects and skeletal anomalies1. Increased RAS-mitogenactivated proteinkinase (MAPK) signaling due to PTPN11 and KRAS mutations cause 50 percentof NS2-6. Here, we report that 22 of 129 NS patients without PTPN11 orKRAS mutation (17 percent) have missense mutations in SOS1, which encodesa RAS-specific guanine nucleotide exchange factor (GEF). SOS1 mutationscluster at residues implicated in the maintenance of SOS1 in itsautoinhibited form and ectopic expression of two NS-associated mutantsinduced enhanced RAS activation. The phenotype associated with SOS1defects is distinctive, although within NS spectrum, with a highprevalence of ectodermal abnormalities but generally normal developmentand linear growth. Our findings implicate for the first timegain-of-function mutations in a RAS GEF in inherited disease and define anew mechanism by which upregulation of the RAS pathway can profoundlychange human development.

  15. Diverse growth hormone receptor gene mutations in Laron syndrome.

    Science.gov (United States)

    Berg, M A; Argente, J; Chernausek, S; Gracia, R; Guevara-Aguirre, J; Hopp, M; Pérez-Jurado, L; Rosenbloom, A; Toledo, S P; Francke, U

    1993-01-01

    To better understand the molecular genetic basis and genetic epidemiology of Laron syndrome (growth-hormone insensitivity syndrome), we analyzed the growth-hormone receptor (GHR) genes of seven unrelated affected individuals from the United States, South America, Europe, and Africa. We amplified all nine GHR gene exons and splice junctions from these individuals by PCR and screened the products for mutations by using denaturing gradient gel electrophoresis (DGGE). We identified a single GHR gene fragment with abnormal DGGE results for each affected individual, sequenced this fragment, and, in each case, identified a mutation likely to cause Laron syndrome, including two nonsense mutations (R43X and R217X), two splice-junction mutations, (189-1 G to T and 71 + 1 G to A), and two frameshift mutations (46 del TT and 230 del TA or AT). Only one of these mutations, R43X, has been previously reported. Using haplotype analysis, we determined that this mutation, which involves a CpG dinucleotide hot spot, likely arose as a separate event in this case, relative to the two prior reports of R43X. Aside from R43X, the mutations we identified are unique to patients from particular geographic regions. Ten GHR gene mutations have now been described in this disorder. We conclude that Laron syndrome is caused by diverse GHR gene mutations, including deletions, RNA processing defects, translational stop codons, and missense codons. All the identified mutations involve the extracellular domain of the receptor, and most are unique to particular families or geographic areas. Images Figure 1 Figure 2 PMID:8488849

  16. Mutations in DDX3X Are a Common Cause of Unexplained Intellectual Disability with Gender-Specific Effects on Wnt Signaling.

    Science.gov (United States)

    Snijders Blok, Lot; Madsen, Erik; Juusola, Jane; Gilissen, Christian; Baralle, Diana; Reijnders, Margot R F; Venselaar, Hanka; Helsmoortel, Céline; Cho, Megan T; Hoischen, Alexander; Vissers, Lisenka E L M; Koemans, Tom S; Wissink-Lindhout, Willemijn; Eichler, Evan E; Romano, Corrado; Van Esch, Hilde; Stumpel, Connie; Vreeburg, Maaike; Smeets, Eric; Oberndorff, Karin; van Bon, Bregje W M; Shaw, Marie; Gecz, Jozef; Haan, Eric; Bienek, Melanie; Jensen, Corinna; Loeys, Bart L; Van Dijck, Anke; Innes, A Micheil; Racher, Hilary; Vermeer, Sascha; Di Donato, Nataliya; Rump, Andreas; Tatton-Brown, Katrina; Parker, Michael J; Henderson, Alex; Lynch, Sally A; Fryer, Alan; Ross, Alison; Vasudevan, Pradeep; Kini, Usha; Newbury-Ecob, Ruth; Chandler, Kate; Male, Alison; Dijkstra, Sybe; Schieving, Jolanda; Giltay, Jacques; van Gassen, Koen L I; Schuurs-Hoeijmakers, Janneke; Tan, Perciliz L; Pediaditakis, Igor; Haas, Stefan A; Retterer, Kyle; Reed, Patrick; Monaghan, Kristin G; Haverfield, Eden; Natowicz, Marvin; Myers, Angela; Kruer, Michael C; Stein, Quinn; Strauss, Kevin A; Brigatti, Karlla W; Keating, Katherine; Burton, Barbara K; Kim, Katherine H; Charrow, Joel; Norman, Jennifer; Foster-Barber, Audrey; Kline, Antonie D; Kimball, Amy; Zackai, Elaine; Harr, Margaret; Fox, Joyce; McLaughlin, Julie; Lindstrom, Kristin; Haude, Katrina M; van Roozendaal, Kees; Brunner, Han; Chung, Wendy K; Kooy, R Frank; Pfundt, Rolph; Kalscheuer, Vera; Mehta, Sarju G; Katsanis, Nicholas; Kleefstra, Tjitske

    2015-08-06

    Intellectual disability (ID) affects approximately 1%-3% of humans with a gender bias toward males. Previous studies have identified mutations in more than 100 genes on the X chromosome in males with ID, but there is less evidence for de novo mutations on the X chromosome causing ID in females. In this study we present 35 unique deleterious de novo mutations in DDX3X identified by whole exome sequencing in 38 females with ID and various other features including hypotonia, movement disorders, behavior problems, corpus callosum hypoplasia, and epilepsy. Based on our findings, mutations in DDX3X are one of the more common causes of ID, accounting for 1%-3% of unexplained ID in females. Although no de novo DDX3X mutations were identified in males, we present three families with segregating missense mutations in DDX3X, suggestive of an X-linked recessive inheritance pattern. In these families, all males with the DDX3X variant had ID, whereas carrier females were unaffected. To explore the pathogenic mechanisms accounting for the differences in disease transmission and phenotype between affected females and affected males with DDX3X missense variants, we used canonical Wnt defects in zebrafish as a surrogate measure of DDX3X function in vivo. We demonstrate a consistent loss-of-function effect of all tested de novo mutations on the Wnt pathway, and we further show a differential effect by gender. The differential activity possibly reflects a dose-dependent effect of DDX3X expression in the context of functional mosaic females versus one-copy males, which reflects the complex biological nature of DDX3X mutations. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  17. Mutations of the aminoacyl-tRNA-synthetases SARS and WARS2 are implicated in the etiology of autosomal recessive intellectual disability.

    Science.gov (United States)

    Musante, Luciana; Püttmann, Lucia; Kahrizi, Kimia; Garshasbi, Masoud; Hu, Hao; Stehr, Henning; Lipkowitz, Bettina; Otto, Sabine; Jensen, Lars R; Tzschach, Andreas; Jamali, Payman; Wienker, Thomas; Najmabadi, Hossein; Ropers, Hans Hilger; Kuss, Andreas W

    2017-06-01

    Intellectual disability (ID) is the hallmark of an extremely heterogeneous group of disorders that comprises a wide variety of syndromic and non-syndromic phenotypes. Here, we report on mutations in two aminoacyl-tRNA synthetases that are associated with ID in two unrelated Iranian families. In the first family, we identified a homozygous missense mutation (c.514G>A, p.Asp172Asn) in the cytoplasmic seryl-tRNA synthetase (SARS) gene. The mutation affects the enzymatic core domain of the protein and impairs its enzymatic activity, probably leading to reduced cytoplasmic tRNA Ser concentrations. The mutant protein was predicted to be unstable, which could be substantiated by investigating ectopic mutant SARS in transfected HEK293T cells. In the second family, we found a compound heterozygous genotype of the mitochondrial tryptophanyl-tRNA synthetase (WARS2) gene, comprising a nonsense mutation (c.325delA, p.Ser109Alafs*15), which very likely entails nonsense-mediated mRNA decay and a missense mutation (c.37T>G, p.Trp13Gly). The latter affects the mitochondrial localization signal of WARS2, causing protein mislocalization. Including AIMP1, which we have recently implicated in the etiology of ID, three genes with a role in tRNA-aminoacylation are now associated with this condition. We therefore suggest that the functional integrity of tRNAs in general is an important factor in the development and maintenance of human cognitive functions. © 2017 Wiley Periodicals, Inc.

  18. Novel mutations in the long isoform of the USH2A gene in patients with Usher syndrome type II or non-syndromic retinitis pigmentosa.

    Science.gov (United States)

    McGee, Terri L; Seyedahmadi, Babak Jian; Sweeney, Meredith O; Dryja, Thaddeus P; Berson, Eliot L

    2010-07-01

    Usher syndrome type II (USH2) is an autosomal recessive disorder characterised by retinitis pigmentosa (RP) and mild to moderate sensorineural hearing loss. Mutations in the USH2A gene are the most common cause of USH2 and are also a cause of some forms of RP without hearing loss (ie, non-syndromic RP). The USH2A gene was initially identified as a transcript comprised of 21 exons but subsequently a longer isoform containing 72 exons was identified. The 51 exons unique to the long isoform of USH2A were screened for mutations among a core set of 108 patients diagnosed with USH2 and 80 patients with non-syndromic RP who were all included in a previously reported screen of the short isoform of USH2A. For several exons, additional patients were screened. In total, 35 deleterious mutations were identified including 17 nonsense mutations, 9 frameshift mutations, 5 splice-site mutations, and 4 small in-frame deletions or insertions. Twenty-seven mutations were novel. In addition, 65 rare missense changes were identified. A method of classifying the deleterious effect of the missense changes was developed using the summed results of four different mutation assessment algorithms, SIFT, pMUT, PolyPhen, and AGVGD. This system classified 8 of the 65 changes as 'likely deleterious' and 9 as 'possibly deleterious'. At least one mutation was identified in 57-63% of USH2 cases and 19-23% of cases of non-syndromic recessive RP (calculated without and including probable/possible deleterious changes) thus supporting that USH2A is the most common known cause of RP in the USA.

  19. Mutation spectrum of RB1 mutations in retinoblastoma cases from Singapore with implications for genetic management and counselling.

    Directory of Open Access Journals (Sweden)

    Swati Tomar

    Full Text Available Retinoblastoma (RB is a rare childhood malignant disorder caused by the biallelic inactivation of RB1 gene. Early diagnosis and identification of carriers of heritable RB1 mutations can improve disease outcome and management. In this study, mutational analysis was conducted on fifty-nine matched tumor and peripheral blood samples from 18 bilateral and 41 unilateral unrelated RB cases by a combinatorial approach of Multiplex Ligation-dependent Probe Amplification (MLPA assay, deletion screening, direct sequencing, copy number gene dosage analysis and methylation assays. Screening of both blood and tumor samples yielded a mutation detection rate of 94.9% (56/59 while only 42.4% (25/59 of mutations were detected if blood samples alone were analyzed. Biallelic mutations were observed in 43/59 (72.9% of tumors screened. There were 3 cases (5.1% in which no mutations could be detected and germline mutations were detected in 19.5% (8/41 of unilateral cases. A total of 61 point mutations were identified, of which 10 were novel. There was a high incidence of previously reported recurrent mutations, occurring at 38.98% (23/59 of all cases. Of interest were three cases of mosaic RB1 mutations detected in the blood from patients with unilateral retinoblastoma. Additionally, two germline mutations previously reported to be associated with low-penetrance phenotypes: missense-c.1981C>T and splice variant-c.607+1G>T, were observed in a bilateral and a unilateral proband, respectively. These findings have implications for genetic counselling and risk prediction for the affected families. This is the first published report on the spectrum of mutations in RB patients from Singapore and shows that further improved mutation screening strategies are required in order to provide a definitive molecular diagnosis for every case of RB. Our findings also underscore the importance of genetic testing in supporting individualized disease management plans for patients and

  20. A Review of the Giant Protein Titin in Clinical Molecular Diagnostics of Cardiomyopathies

    Directory of Open Access Journals (Sweden)

    Marta Gigli

    2016-07-01

    Full Text Available Titin (TTN is known as the largest sarcomeric protein that resides within the heart muscle. Due to alternative splicing of TTN the heart expresses two major isoforms (N2B and N2BA that incorporate four distinct regions termed the Z-line, I-band, A-band, and M-line. Next-generation sequencing allows a large number of genes to be sequenced simultaneously and provides the opportunity to easily analyze giant genes such as TTN. Mutations in the TTN gene can cause cardiomyopathies, in particular dilated cardiomyopathy (DCM. DCM is the most common form of cardiomyopathy and it is characterized by systolic dysfunction and dilation of the left ventricle. TTN truncating variants have been described as the most common cause of DCM while the real impact of TTN missense variants in the pathogenesis of DCM is still unclear. In a recent population screening study, rare missense variants potentially pathogenic based on bioinformatic filtering represented only 12.6% of the several hundred rare TTN missense variants found, suggesting that missense variants are very common in TTN and frequently benign. The aim of this review is to understand the clinical role of TTN mutations in DCM and in other cardiomyopathies. Whereas TTN truncations are common in DCM, there is evidence that TTN truncations are rare in the HCM phenotype. Furthermore TTN mutations can also cause arrhythmogenic right ventricular cardiomyopathy (ARVC with distinct clinical features and outcomes. Finally, the identification of a rare missense variant in TTN cosegregating with the restrictive cardiomyopathy (RCM phenotype suggests that TTN is a novel gene in this disease. Clinical diagnostic testing is currently able to analyze over 100 cardiomyopathy genes, including TTN, however, the size and presence of extensive genetic variation in TTN presents clinical challenges in determining significant disease-causing mutations. This review discusses the current knowledge of TTN genetic variations in