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Sample records for manba mutation resulting

  1. IPEX as a result of mutations in FOXP3

    NARCIS (Netherlands)

    H.J. van der Vliet (Hans ); E.E.S. Nieuwenhuis (Edward)

    2007-01-01

    textabstractImmunodysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare disorder caused by mutations in the FOXP3 gene that result in the defective development of CD4+CD25+regulatory T cells which constitute an important T cell subset involved in immune homeostasis and p

  2. Mutation specific functions of EGFR result in a mutation-specific downstream pathway activation

    NARCIS (Netherlands)

    L. Eraslan-Erdem (Lale); Y. Gao; N.K. Kloosterhof (Nanne); Y. Atlasi (Yaser); J.A.A. Demmers (Jeroen); A. Sacchetti (Andrea); J.M. Kros (Johan); P.A.E. Sillevis Smitt (Peter); J.G.J.V. Aerts (Joachim); P.J. French (Pim)

    2015-01-01

    markdownabstractBackground: Epidermal growth factor receptor (EGFR) is frequently mutated in various types of cancer. Although all oncogenic mutations are considered activating, different tumour types have different mutation spectra. It is possible that functional differences underlie this tumour-ty

  3. The Genetic Equidistance Result of Molecular Evolution is Independent of Mutation Rates.

    Science.gov (United States)

    Huang, Shi

    2008-12-26

    The well-established genetic equidistance result shows that sister species are approximately equidistant to a simpler outgroup as measured by DNA or protein dissimilarity. The equidistance result is the most direct evidence, and remains the only evidence, for the constant mutation rate interpretation of this result, known as the molecular clock. However, data independent of the equidistance result have steadily accumulated in recent years that often violate a constant mutation rate. Many have automatically inferred non-equidistance whenever a non-constant mutation rate was observed, based on the unproven assumption that the equidistance result is an outcome of constant mutation rate. Here it is shown that the equidistance result remains valid even when different species can be independently shown to have different mutation rates. A random sampling of 50 proteins shows that nearly all proteins display the equidistance result despite the fact that many proteins have non-constant mutation rates. Therefore, the genetic equidistance result does not necessarily mean a constant mutation rate. Observations of different mutation rates do not invalidate the genetic equidistance result. New ideas are needed to explain the genetic equidistance result that must grant different mutation rates to different species and must be independently testable.

  4. Severe combined immunodeficiency resulting from mutations in MTHFD1.

    Science.gov (United States)

    Keller, Michael D; Ganesh, Jaya; Heltzer, Meredith; Paessler, Michele; Bergqvist, A G Christina; Baluarte, H Jorge; Watkins, David; Rosenblatt, David S; Orange, Jordan S

    2013-02-01

    Folate and vitamin B(12) metabolism are essential for de novo purine synthesis, and several defects in these pathways have been associated with immunodeficiency. Here we describe the occurrence of severe combined immunodeficiency (SCID) with megaloblastic anemia, leukopenia, atypical hemolytic uremic syndrome, and neurologic abnormalities in which hydroxocobalamin and folate therapy provided partial immune reconstitution. Whole exome sequencing identified compound heterozygous mutations in the MTHFD1 gene, which encodes a trifunctional protein essential for processing of single-carbon folate derivatives. We now report the immunologic details of this novel genetic cause of SCID and the response to targeted metabolic supplementation therapies. This finding expands the known metabolic causes of SCID and presents an important diagnostic consideration given the positive impact of therapy.

  5. Autosomal recessive transmission of MYBPC3 mutation results in malignant phenotype of hypertrophic cardiomyopathy.

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    Yilu Wang

    Full Text Available BACKGROUND: Hypertrophic cardiomyopathy (HCM due to mutations in genes encoding sarcomere proteins is most commonly inherited as an autosomal dominant trait. Since nearly 50% of HCM cases occur in the absence of a family history, a recessive inheritance pattern may be involved. METHODS: A pedigree was identified with suspected autosomal recessive transmission of HCM. Twenty-six HCM-related genes were comprehensively screened for mutations in the proband with targeted second generation sequencing, and the identified mutation was confirmed with bi-directional Sanger sequencing in all family members and 376 healthy controls. RESULTS: A novel missense mutation (c.1469G>T, p.Gly490Val in exon 17 of MYBPC3 was identified. Two siblings with HCM were homozygous for this mutation, whereas other family members were either heterozygous or wild type. Clinical evaluation showed that both homozygotes manifested a typical HCM presentation, but none of others, including 5 adult heterozygous mutation carriers up to 71 years of age, had any clinical evidence of HCM. CONCLUSIONS: Our data identified a MYBPC3 mutation in HCM, which appeared autosomal recessively inherited in this family. The absence of a family history of clinical HCM may be due to not only a de novo mutation, but also recessive mutations that failed to produce a clinical phenotype in heterozygous family members. Therefore, consideration of recessive mutations leading to HCM is essential for risk stratification and genetic counseling.

  6. Recessive mutations in the INS gene result in neonatal diabetes through reduced insulin biosynthesis.

    Science.gov (United States)

    Garin, Intza; Edghill, Emma L; Akerman, Ildem; Rubio-Cabezas, Oscar; Rica, Itxaso; Locke, Jonathan M; Maestro, Miguel Angel; Alshaikh, Adnan; Bundak, Ruveyde; del Castillo, Gabriel; Deeb, Asma; Deiss, Dorothee; Fernandez, Juan M; Godbole, Koumudi; Hussain, Khalid; O'Connell, Michele; Klupa, Thomasz; Kolouskova, Stanislava; Mohsin, Fauzia; Perlman, Kusiel; Sumnik, Zdenek; Rial, Jose M; Ugarte, Estibaliz; Vasanthi, Thiruvengadam; Johnstone, Karen; Flanagan, Sarah E; Martínez, Rosa; Castaño, Carlos; Patch, Ann-Marie; Fernández-Rebollo, Eduardo; Raile, Klemens; Morgan, Noel; Harries, Lorna W; Castaño, Luis; Ellard, Sian; Ferrer, Jorge; Perez de Nanclares, Guiomar; Hattersley, Andrew T

    2010-02-16

    Heterozygous coding mutations in the INS gene that encodes preproinsulin were recently shown to be an important cause of permanent neonatal diabetes. These dominantly acting mutations prevent normal folding of proinsulin, which leads to beta-cell death through endoplasmic reticulum stress and apoptosis. We now report 10 different recessive INS mutations in 15 probands with neonatal diabetes. Functional studies showed that recessive mutations resulted in diabetes because of decreased insulin biosynthesis through distinct mechanisms, including gene deletion, lack of the translation initiation signal, and altered mRNA stability because of the disruption of a polyadenylation signal. A subset of recessive mutations caused abnormal INS transcription, including the deletion of the C1 and E1 cis regulatory elements, or three different single base-pair substitutions in a CC dinucleotide sequence located between E1 and A1 elements. In keeping with an earlier and more severe beta-cell defect, patients with recessive INS mutations had a lower birth weight (-3.2 SD score vs. -2.0 SD score) and were diagnosed earlier (median 1 week vs. 10 weeks) compared to those with dominant INS mutations. Mutations in the insulin gene can therefore result in neonatal diabetes as a result of two contrasting pathogenic mechanisms. Moreover, the recessively inherited mutations provide a genetic demonstration of the essential role of multiple sequence elements that regulate the biosynthesis of insulin in man.

  7. Leptin Receptor Mutation Results in Defective Neutrophil Recruitment to the Colon during Entamoeba histolytica Infection

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    Naylor, Caitlin; Burgess, Stacey; Madan, Rajat; Buonomo, Erica; Razzaq, Khadija; Ralston, Katherine

    2014-01-01

    ABSTRACT Amebiasis is an enteric infection caused by Entamoeba histolytica, with symptoms ranging in severity from asymptomatic colonization to dysentery. Humans with the Q223R leptin receptor mutation have increased susceptibility to amebiasis, but the mechanism has been unclear. Using a mouse model expressing the mutation, we tested the impact of the Q223R mutation on the innate immune response to E. histolytica infection. The 223R mutation resulted in delayed clearance of amebae from the cecum, as had been previously observed. We found that neutrophil influx to the site of the infection was reduced 12 h after infection in 223R mice. Depletion of neutrophils with anti-Ly6G monoclonal antibody increased susceptibility of wild-type mice to infection, supporting the importance of neutrophils in innate defense. Leptin expression was increased in the cecum by E. histolytica infection, suggesting that leptin could serve as a homing signal for neutrophils to the gut. Interestingly, neutrophils from mice with the 223R mutation had diminished chemotaxis toward leptin. This impaired chemotaxis likely explained the reduced gut infiltration of neutrophils. The newly recognized effect of the leptin receptor Q223R mutation on neutrophil chemotaxis and the impact of this mutation on multiple infectious diseases suggest a broader impact of this mutation on susceptibility to disease. PMID:25516614

  8. β-Thalassemia gene mutations in Antalya, Turkey: results from a single centre study.

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    Kurtoğlu, Ayşegül; Karakuş, Volkan; Erkal, Özgür; Kurtoğlu, Erdal

    2016-11-01

    β-Thalassemia (β-thal) is a common autosomal recessive disorder resulting from over 300 different mutations of the β-globin genes. Our aim was to create a mutation map of β-thal in the province of Antalya, Turkey. In this study, mutation analysis of a total 146 of β-thal patients followed at the Thalassemia Center of the Antalya Education and Research Hospital, Antalya, Turkey, were included. Direct DNA sequence analysis was performed for mutation scanning of the β-globin gene. One hundred and forty-six patients with β-thal including all types were analyzed, and 14 different β-thal mutations were detected. The most frequently seen mutation was HBB: c.93 - 21G > A [IVS-I-110 (G > A)] (52.7%), followed by HBB: .c.92 + 6T > C [IVS-I-6 (T > C)] (14.4%), HBB: c.-80T > A [-30 (T > A)] (8.2%), HBB: c.315 + 1G > A [IVS-II-1 (G > A)] (8.2%), which made up 83.1% of the observed mutations. Our results indicate the importance of micromapping and epidemiology studies of thalassemia, which will assist in establishing the national prevention and control program in Turkey.

  9. Novel mutations in ACVR1 result in atypical features in two fibrodysplasia ossificans progressiva patients.

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    Kirsten A Petrie

    Full Text Available Fibrodysplasia Ossificans Progressiva (FOP is a rare, heritable condition typified by progression of extensive ossification within skeletal muscle, ligament and tendon together with defects in skeletal development. The condition is easily diagnosed by the presence of shortened great toes and there is severe advancement of disability with age. FOP has been shown to result from a point mutation (c.617G>A in the ACVR1 gene in almost all patients reported. Very recently two other mutations have been described in three FOP patients. We present here evidence for two further unique mutations (c.605G>T and c.983G>A in this gene in two FOP patients with some atypical digit abnormalities and other clinical features. The observation of disparate missense mutations mapped to the GS and kinase domains of the protein supports the disease model of mild kinase activation and provides a potential rationale for phenotypic variation.

  10. Parkinson's disease-related LRRK2 G2019S mutation results from independent mutational events in humans.

    OpenAIRE

    2010-01-01

    7 pages; International audience; Mutations in the leucine-rich-repeat kinase 2 (LRRK2) gene have been identified in families with autosomal dominant Parkinson's disease (PD) and in sporadic cases; the G2019S mutation is the single most frequent. Intriguingly, the frequency of this mutation in PD patients varies greatly among ethnic groups and geographic origins: it is present at

  11. The silent mutation nucleotide 744 G --> A, Lys172Lys, in exon 6 of BRCA2 results in exon skipping

    DEFF Research Database (Denmark)

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

    2009-01-01

    Germ-line mutations in BRCA2 predispose to breast and ovarian cancer. Mutations are widespread throughout the gene and include disease-causing mutations as frameshift, nonsense, splicing mutations and large genomic rearrangements. However a large number of mutations, including missense, silent...... and intron variants are of unknown significance. Here, we describe the functional characterization of a silent mutation (nucleotide 744 G --> A/c.516 G --> A, Lys172Lys) in exon 6 of BRCA2 in a Danish family with breast and ovarian cancer. Exon trapping analysis showed that the mutation results in skipping...... of exon 6 and/or both exon 5 and 6, which was verified by RT-PCR analysis on RNA isolated from whole blood of the affected patient. We therefore conclude that the BRCA2 silent mutation Lys172Lys is a disease-causing mutation....

  12. Homozygous FGF3 mutations result in congenital deafness with inner ear agenesis, microtia, and microdontia.

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    Tekin, M; Oztürkmen Akay, H; Fitoz, S; Birnbaum, S; Cengiz, F B; Sennaroğlu, L; Incesulu, A; Yüksel Konuk, E B; Hasanefendioğlu Bayrak, A; Sentürk, S; Cebeci, I; Utine, G E; Tunçbilek, E; Nance, W E; Duman, D

    2008-06-01

    Homozygous mutations in the fibroblast growth factor 3 (FGF3) gene have recently been discovered in an autosomal recessive form of syndromic deafness characterized by complete labyrinthine aplasia (Michel aplasia), microtia, and microdontia (OMIM 610706 - LAMM). In order to better characterize the phenotypic spectrum associated with FGF3 mutations, we sequenced the FGF3 gene in 10 unrelated families in which probands had congenital deafness associated with various inner ear anomalies, including Michel aplasia, with or without tooth or external ear anomalies. FGF3 sequence changes were not found in eight unrelated probands with isolated inner ear anomalies or with a cochlear malformation along with auricle and tooth anomalies. We identified two new homozygous FGF3 mutations, p.Leu6Pro (c.17T>C) and p. Ile85MetfsX15 (c.254delT), in four subjects from two unrelated families with LAMM. The p.Leu6Pro mutation occurred within the signal site of FGF3 and is predicted to impair its secretion. The c.254delT mutation results in truncation of FGF3. Both mutations completely co-segregated with the phenotype, and heterozygotes did not have any of the phenotypic findings of LAMM. Some affected children had large skin tags on the upper side of the auricles, which is a distinctive clinical component of the syndrome. Enlarged collateral emissary veins associated with stenosis of the jugular foramen were noted on computerized tomographies of most affected subjects with FGF3 mutations. However, similar venous anomalies were also detected in persons with non-syndromic Michel aplasia, suggesting that a direct causative role of impaired FGF3 signaling is unlikely.

  13. Isolation of a mutation resulting in constitutive synthesis of L-fucose catabolic enzymes.

    OpenAIRE

    Bartkus, J. M.; Mortlock, R P

    1986-01-01

    A ribitol-positive transductant of Escherichia coli K-12, JM2112, was used to facilitate the isolation and identification of mutations affecting the L-fucose catabolic pathway. Analysis of L-fucose-negative mutants of JM2112 enabled us to confirm that L-fucose-1-phosphate is the apparent inducer of the fucose catabolic enzymes. Plating of an L-fuculokinase-negative mutant of JM2112 on D-arabinose yielded an isolate containing a second fucose mutation which resulted in the constitutive synthes...

  14. Apert syndrome results from localized mutations of FGFR2 and is allelic with Crouzon syndrome.

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    Wilkie, A O; Slaney, S F; Oldridge, M; Poole, M D; Ashworth, G J; Hockley, A D; Hayward, R D; David, D J; Pulleyn, L J; Rutland, P

    1995-02-01

    Apert syndrome is a distinctive human malformation comprising craniosynostosis and severe syndactyly of the hands and feet. We have identified specific missense substitutions involving adjacent amino acids (Ser252Trp and Pro253Arg) in the linker between the second and third extracellular immunoglobulin (Ig) domains of fibroblast growth factor receptor 2 (FGFR2) in all 40 unrelated cases of Apert syndrome studied. Crouzon syndrome, characterized by craniosynostosis but normal limbs, was previously shown to result from allelic mutations of the third Ig domain of FGFR2. The contrasting effects of these mutations provide a genetic resource for dissecting the complex effects of signal transduction through FGFRs in cranial and limb morphogenesis.

  15. Parkinson's disease-related LRRK2 G2019S mutation results from independent mutational events in humans.

    Science.gov (United States)

    Lesage, Suzanne; Patin, Etienne; Condroyer, Christel; Leutenegger, Anne-Louise; Lohmann, Ebba; Giladi, Nir; Bar-Shira, Anat; Belarbi, Soraya; Hecham, Nassima; Pollak, Pierre; Ouvrard-Hernandez, Anne-Marie; Bardien, Soraya; Carr, Jonathan; Benhassine, Traki; Tomiyama, Hiroyuki; Pirkevi, Caroline; Hamadouche, Tarik; Cazeneuve, Cécile; Basak, A Nazli; Hattori, Nobutaka; Dürr, Alexandra; Tazir, Meriem; Orr-Urtreger, Avi; Quintana-Murci, Lluis; Brice, Alexis

    2010-05-15

    Mutations in the leucine-rich-repeat kinase 2 (LRRK2) gene have been identified in families with autosomal dominant Parkinson's disease (PD) and in sporadic cases; the G2019S mutation is the single most frequent. Intriguingly, the frequency of this mutation in PD patients varies greatly among ethnic groups and geographic origins: it is present at Jewish origin, mostly from Eastern Europe, one was from Japan, one from Turkey and two were of mixed origins. We found the G2019S mutation on three different haplotypes. Network analyses of the three carrier haplotypes showed that G2019S arose independently at least twice in humans. In addition, the population distribution of the intra-allelic diversity of the most widespread carrier haplotype, together with estimations of the age of G2019S determined by two different methods, suggests that one of the founding G2019S mutational events occurred in the Near East at least 4000 years ago.

  16. Ribosomal Protein Mutations Result in Constitutive p53 Protein Degradation through Impairment of the AKT Pathway

    NARCIS (Netherlands)

    Antunes, Ana T.; Goos, Yvonne J.; Pereboom, Tamara C.; Hermkens, Dorien; Wlodarski, Marcin W.; Da Costa, Lydie; MacInnes, Alyson W.

    Mutations in ribosomal protein (RP) genes can result in the loss of erythrocyte progenitor cells and cause severe anemia. This is seen in patients with Diamond-Blackfan anemia (DBA), a pure red cell aplasia and bone marrow failure syndrome that is almost exclusively linked to RP gene

  17. Ribosomal Protein Mutations Result in Constitutive p53 Protein Degradation through Impairment of the AKT Pathway.

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    Ana T Antunes

    2015-07-01

    Full Text Available Mutations in ribosomal protein (RP genes can result in the loss of erythrocyte progenitor cells and cause severe anemia. This is seen in patients with Diamond-Blackfan anemia (DBA, a pure red cell aplasia and bone marrow failure syndrome that is almost exclusively linked to RP gene haploinsufficiency. While the mechanisms underlying the cytopenia phenotype of patients with these mutations are not completely understood, it is believed that stabilization of the p53 tumor suppressor protein may induce apoptosis in the progenitor cells. In stark contrast, tumor cells from zebrafish with RP gene haploinsufficiency are unable to stabilize p53 even when exposed to acute DNA damage despite transcribing wild type p53 normally. In this work we demonstrate that p53 has a limited role in eliciting the anemia phenotype of zebrafish models of DBA. In fact, we find that RP-deficient embryos exhibit the same normal p53 transcription, absence of p53 protein, and impaired p53 response to DNA damage as RP haploinsufficient tumor cells. Recently we reported that RP mutations suppress activity of the AKT pathway, and we show here that this suppression results in proteasomal degradation of p53. By re-activating the AKT pathway or by inhibiting GSK-3, a downstream modifier that normally represses AKT signaling, we are able to restore the stabilization of p53. Our work indicates that the anemia phenotype of zebrafish models of DBA is dependent on factors other than p53, and may hold clinical significance for both DBA and the increasing number of cancers revealing spontaneous mutations in RP genes.

  18. Artifactual mutations resulting from DNA lesions limit detection levels in ultrasensitive sequencing applications.

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    Arbeithuber, Barbara; Makova, Kateryna D; Tiemann-Boege, Irene

    2016-12-01

    The need in cancer research or evolutionary biology to detect rare mutations or variants present at very low frequencies (DNA lesions introduce important error sources in ultrasensitive technologies such as single molecule PCR (smPCR) applications (e.g. droplet-digital PCR), or next-generation sequencing (NGS) based methods. Using templates with known amplifiable lesions (8-oxoguanine, deaminated 5-methylcytosine, uracil, and DNA heteroduplexes), we assessed with smPCR and duplex sequencing that templates with these lesions were amplified very efficiently by proofreading polymerases (except uracil), leading to G->T, and to a lesser extent, to unreported G->C substitutions at 8-oxoguanine lesions, and C->T transitions in amplified uracil containing templates. Long heat incubations common in many DNA extraction protocols significantly increased the number of G->T substitutions. Moreover, in ∼50-80% smPCR reactions we observed the random amplification preference of only one of both DNA strands explaining the known 'PCR jackpot effect', with the result that a lesion became indistinguishable from a true mutation or variant. Finally, we showed that artifactual mutations derived from uracil and 8-oxoguanine could be significantly reduced by DNA repair enzymes. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

  19. Papillorenal syndrome-causing missense mutations in PAX2/Pax2 result in hypomorphic alleles in mouse and human.

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    Ramakrishna P Alur

    2010-03-01

    Full Text Available Papillorenal syndrome (PRS, also known as renal-coloboma syndrome is an autosomal dominant disease characterized by potentially-blinding congenital optic nerve excavation and congenital kidney abnormalities. Many patients with PRS have mutations in the paired box transcription factor gene, PAX2. Although most mutations in PAX2 are predicted to result in complete loss of one allele's function, three missense mutations have been reported, raising the possibility that more subtle alterations in PAX2 function may be disease-causing. To date, the molecular behaviors of these mutations have not been explored. We describe a novel mouse model of PRS due to a missense mutation in a highly-conserved threonine residue in the paired domain of Pax2 (p.T74A that recapitulates the ocular and kidney findings of patients. This mutation is in the Pax2 paired domain at the same location as two human missense mutations. We show that all three missense mutations disrupt potentially critical hydrogen bonds in atomic models and result in reduced Pax2 transactivation, but do not affect nuclear localization, steady state mRNA levels, or the ability of Pax2 to bind its DNA consensus sequence. Moreover, these mutations show reduced steady-state levels of Pax2 protein in vitro and (for p.T74A in vivo, likely by reducing protein stability. These results suggest that hypomorphic alleles of PAX2/Pax2 can lead to significant disease in humans and mice.

  20. Functional analysis of the novel TBX5 c.1333delC mutation resulting in an extended TBX5 protein

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    Ekman-Joelsson Britt-Marie

    2008-10-01

    Full Text Available Abstract Background Autosomal dominant Holt-Oram syndrome (HOS is caused by mutations in the TBX5 gene and is characterized by congenital heart and preaxial radial ray upper limb defects. Most of the TBX5 mutations found in patients with HOS cause premature truncation of the primary TBX5 transcript. TBX5 missense mutations alter the three-dimensional structure of the protein and result in failed nuclear localization or reduced binding to target DNA. In this study we present our functional analyses of the novel and unusual c.1333delC mutation found in a patient with classical HOS. Methods The functional impact of this novel mutation was assessed by investigating the intracellular localization of the resulting TBX5 protein and its ability to activate the expression of its downstream target ANF. Results The deletion of the cytosine is the first TBX5 frameshift mutation predicted to result in an elongated TBX5 protein with 74 miscoding amino acids and 62 supernumerary C-terminal amino acids. The c.1333delC mutation affects neither the nuclear localization, nor its colocalization with SALL4, but severely affects the activation of the ANF promoter. Conclusion The mutation c.1333delC does not locate within functional domains, but impairs the activation of the downstream target. This suggests that misfolding of the protein prevents its biological function.

  1. bfb, a novel ENU-induced blebs mutant resulting from a missense mutation in Fras1.

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    Kerry A Miller

    Full Text Available Fras1 is an extracellular matrix associated protein with essential roles in adhesion of epithelia and mesenchyme during early embryonic development. The adhesive function of Fras1 is achieved through interaction with a group of related proteins, Frem 1-3, and a cytoplasmic adaptor protein Grip1. Mutation of each of these proteins results in characteristic epithelial blistering and have therefore become known as "blebs" proteins. Human Fraser syndrome presents with a similar phenotype and the blebs mice have been instrumental in identification of the genetic basis of Fraser syndrome. We have identified a new ENU-induced blebs allele resulting from a novel missense mutation in Fras1. The resulting mouse strain, blood filled blisters (bfb, presents with a classic blebs phenotype but does not exhibit embryonic lethality typical of other blebs mutants and in addition, we report novel palate and sternal defects. Analysis of the bfb phenotype confirms the presence of epithelial-mesenchymal adhesion defects but also supports the emerging role of blebs proteins in regulating signalling during organogenesis. The bfb strain provides new opportunities to investigate the role of Fras1 in development.

  2. The mutation-free embryo for in vitro fertilization selected by MALBAC-PGD resulted in a healthy live birth from a family carrying PKD 1 mutation.

    Science.gov (United States)

    Li, Wen; Ma, Yiyi; Yu, Shengqiang; Sun, Ningxia; Wang, Liang; Chen, Dongping; Yang, Guijiang; Lu, Sijia; Li, Yangyang; Yang, Bo; Mei, Changlin

    2017-08-19

    Autosomal dominant polycystic kidney disease (ADPKD, autosomal dominant PKD or adult-onset PKD) is the most prevalent and potentially lethal kidney disease that is hereditary and lacks effective treatment. Preimplantation genetic diagnosis (PGD) of embryos in assistant reproductive technology (ART) helps to select mutation-free embryos for blocking ADPKD inheritance from the parents to their offspring. However, there are multiple pseudogenes in the PKD1 coding region, which make blocking ADPKD inheritance by PGD complicated and difficult. Therefore, this technique has not been recommended and used routinely to ADPKD family plan. Here, we report a new strategy of performing PGD in screening (target-) mutation-free embryos. We firstly used a long-range PCR amplification and next generation sequencing to identify the potential PKD1 mutant(s). After pathogenic variants were detected, multiple annealing and looping-based amplification cycles (MALBAC), a recently developed whole genome amplification method, was used to screen embryo cells. We successfully distinguished the mutated allele among pseudogenes and obtained mutation-free embryos for implantation. The first embryo transfer attempt resulted in a healthy live birth free of ADPKD condition and chromosomal anomalies which was confirmed by aminocentesis at week 18 of gestation, and by performing live birth genetic screening. The first MALBAC-PGD attempt in ADPKD patient resulted in a healthy live birth free of ADPKD and chromosomal anomalies. MALBAC-PGD also enables selecting embryos without aneuploidy together and target gene mutation, thereby increasing implantation and live birth rates.

  3. Rapid adaptation of some phytoplankton species to osmium as a result of spontaneous mutations.

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    Marvá, Fernando; García-Balboa, Camino; Baselga-Cervera, Beatriz; Costas, Eduardo

    2014-03-01

    To understand the vulnerability of individual species to anthropogenic contamination, it is important to evaluate the different abilities of phytoplankton to respond to environmental changes induced by pollution. The ability of a species to adapt, rather than its initial tolerance, is the basis for survival under rapidly increasing levels of anthropogenic contamination. High doses of osmium (Os) cause massive destruction of diverse phytoplankton groups. In this study, we found that the coastal chlorophyte Tetraselmis suecica and the continental chlorophyte Dictyosphaerium chlorelloides were able to adapt to a lethal dose of Os. In these species, Os-resistant cells arose as a result of rare spontaneous mutations (at rates of approximately 10(-6) mutants per cell division) that occurred before exposure to Os. The mutants remained in the microalgal populations by means of mutation-selection balance. The huge size of phytoplankton populations ensures that there are always enough Os-resistant mutants to guarantee the survival of the population under Os pollution. In contrast, we observed that neither a haptophyte species from open ocean regions nor a cyanobacterium from continental freshwater were able to adapt to the lethal Os dose. Adaptation of phytoplankton to Os contamination is relevant because industrial activities are leading to a rapid increase in Os pollution worldwide.

  4. Epidermolytic palmoplantar keratoderma in a Hispanic kindred resulting from a mutation in the keratin 9 gene.

    Science.gov (United States)

    Warmuth, I; Cserhalmi-Friedman, P B; Schneiderman, P; Grossman, M E; Christiano, A M

    2000-05-01

    Epidermolytic palmoplantar keratoderma (EPPK) is a localized keratinization disorder caused by mutations in the highly conserved coil 1A domain of the keratin 9 gene, KRT9. We present a Hispanic pedigree spanning three generations, with affected individuals in all generations. Using polymerase chain reaction amplification and direct sequencing we demonstrated a previously reported missense mutation in KRT9, which is expressed almost exclusively in the skin of palms and soles. The C-->T missense mutation R162W changes a basic amino acid (arginine) to a neutral amino acid (tryptophan). We describe this mutation in a Hispanic pedigree with EPPK for the first time, extending the finding of this mutation in other genetic backgrounds, and demonstrating the prevalence of this mutation in diverse populations.

  5. Compound heterozygous desmoplakin mutations result in a phenotype with a combination of myocardial, skin, hair, and enamel abnormalities.

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    Mahoney, My G; Sadowski, Sara; Brennan, Donna; Pikander, Pekka; Saukko, Pekka; Wahl, James; Aho, Heikki; Heikinheimo, Kristiina; Bruckner-Tuderman, Leena; Fertala, Andrzej; Peltonen, Juha; Uitto, Jouni; Peltonen, Sirkku

    2010-04-01

    Desmoplakin (DP) anchors the intermediate filament cytoskeleton to the desmosomal cadherins and thereby confers structural stability to tissues. In this study, we present a patient with extensive mucocutaneous blisters, epidermolytic palmoplantar keratoderma, nail dystrophy, enamel dysplasia, and sparse woolly hair. The patient died at the age of 14 years from undiagnosed cardiomyopathy. The skin showed hyperplasia and acantholysis in the mid- and lower epidermal layers, whereas the heart showed extensive fibrosis and fibrofatty replacement in both ventricles. Immunofluorescence microscopy showed a reduction in the C-terminal domain of DP in the skin and oral mucosa. Sequencing of the DP gene showed undescribed mutations in the maternal and paternal alleles. Both mutations affected exon 24 encoding the C-terminal domain. The paternal mutation, c.6310delA, leads to a premature stop codon. The maternal mutation, c.7964 C to A, results in a substitution of an aspartic acid for a conserved alanine residue at amino acid 2655 (A2655D). Structural modeling indicated that this mutation changes the electrostatic potential of the mutated region of DP, possibly altering functions that depend on intermolecular interactions. To conclude, we describe a combination of DP mutation phenotypes affecting the skin, heart, hair, and teeth. This patient case emphasizes the importance of heart examination of patients with desmosomal genodermatoses.

  6. Computational Analysis Reveals the Association of Threonine 118 Methionine Mutation in PMP22 Resulting in CMT-1A

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    Chundi Vinay Kumar

    2014-01-01

    Full Text Available The T118M mutation in PMP22 gene is associated with Charcot Marie Tooth, type 1A (CMT1A. CMT1A is a form of Charcot-Marie-Tooth disease, the most common inherited disorder of the peripheral nervous system. Mutations in CMT related disorder are seen to increase the stability of the protein resulting in the diseased state. We performed SNP analysis for all the nsSNPs of PMP22 protein and carried out molecular dynamics simulation for T118M mutation to compare the stability difference between the wild type protein structure and the mutant protein structure. The mutation T118M resulted in the overall increase in the stability of the mutant protein. The superimposed structure shows marked structural variation between the wild type and the mutant protein structures.

  7. Kinetic Results for Mutations of Conserved Residues H304 and R309 of Human Sulfite Oxidase Point to Mechanistic Complexities

    Science.gov (United States)

    Davis, Amanda C.; Johnson-Winters, Kayunta; Arnold, Anna R.; Tollin, Gordon; Enemark, John H.

    2014-01-01

    Several point mutations in the gene of human sulfite oxidase (hSO) result in isolated sulfite oxidase deficiency, an inherited metabolic disorder. Three conserved residues (H304, R309, K322) are hydrogen bonded to the phosphate group of the molybdenum cofactor, and the R309H and K322R mutations are responsible for isolated sulfite oxidase deficiency. The kinetic effects of the K322R mutation have been previously reported (Rajapakshe et al. 2012, Chem. Biodiversity 9, 1621-1634); here we investigate several mutants of H304 and R309 by steady-state kinetics, laser flash photolysis studies of intramolecular electron transfer (IET), and spectroelectrochemistry. An unexpected result is that all of the mutants show decreased rates of IET but increased steady-state rates of catalysis. However, in all cases the rate of IET is greater than the overall turnover rate, showing that IET is not the rate determining step for any of the mutations. PMID:24968320

  8. Oxidative Stress Increases the Blood Brain Barrier Permeability Resulting in Increased Incidence of Brain Metastasis in BRCA Mutation Carriers

    Science.gov (United States)

    2014-08-01

    Increased Incidence of Brain Metastasis in BRCA Mutation Carriers PRINCIPAL INVESTIGATOR: Hava Avraham, Ph.D. CONTRACTING ORGANIZATION: Beth Israel...Permeability Resulting in Increased Incidence of Brain Metastasis in BRCA Mutation Carriers 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-11-1-0172 5c...significantly up-regulated with a decrease in cellular sensitivity to paclitaxel. Cells that harbor endogenous mutant or defective BRCA l (such as MDA-MB-436

  9. DNA Hydroxymethylation Profiling Reveals that WT1 Mutations Result in Loss of TET2 Function in Acute Myeloid Leukemia

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    Raajit Rampal

    2014-12-01

    Full Text Available Somatic mutations in IDH1/IDH2 and TET2 result in impaired TET2-mediated conversion of 5-methylcytosine (5mC to 5-hydroxymethylcytosine (5hmC. The observation that WT1 inactivating mutations anticorrelate with TET2/IDH1/IDH2 mutations in acute myeloid leukemia (AML led us to hypothesize that WT1 mutations may impact TET2 function. WT1 mutant AML patients have reduced 5hmC levels similar to TET2/IDH1/IDH2 mutant AML. These mutations are characterized by convergent, site-specific alterations in DNA hydroxymethylation, which drive differential gene expression more than alterations in DNA promoter methylation. WT1 overexpression increases global levels of 5hmC, and WT1 silencing reduced 5hmC levels. WT1 physically interacts with TET2 and TET3, and WT1 loss of function results in a similar hematopoietic differentiation phenotype as observed with TET2 deficiency. These data provide a role for WT1 in regulating DNA hydroxymethylation and suggest that TET2 IDH1/IDH2 and WT1 mutations define an AML subtype defined by dysregulated DNA hydroxymethylation.

  10. A novel mutation in IRF6 resulting in VWS-PPS spectrum disorder with renal aplasia.

    Science.gov (United States)

    de Medeiros, Filipe; Hansen, Lars; Mawlad, Evete; Eiberg, Hans; Asklund, Camilla; Tommerup, Niels; Jakobsen, Linda P

    2008-06-15

    Popliteal pterygium syndrome (PPS) and Van der Woude syndrome (VWS) are caused by mutations in the gene interferon regulatory factor 6 (IRF6). Skeletal, genital malformations and involvement of the skin occur in PPS and orofacial clefting and lip pits occur in both. We report on a patient with unilateral cleft lip and palate, ankyloblepharon, paramedian lip pits, unilateral renal aplasia, and a coronal hypospadias. By sequencing IRF6, we detected a novel missense mutation (Arg339Ile). The other family members were unaffected and had no IRF6 mutations, including the patient's brother who was also born with hypospadias. The patient and his brother were both conceived by in vitro fertilization (IVF). It is discussed whether the renal malformation in the patient is related to the IVF procedure or to the IRF6 mutation.

  11. Natural Mutations in Streptococcus agalactiae Resulting in Abrogation of β Antigen Production.

    Science.gov (United States)

    Vasilyeva, Anastasia; Santos Sanches, Ilda; Florindo, Carlos; Dmitriev, Alexander

    2015-01-01

    Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding for β antigen at transcriptional level. Inactivation of bgrR abrogated bac gene expression and increased virulence properties of S. agalactiae. In this study, a total of 140 strains were screened for the presence of bac gene, and the TCS bgrR and bgrS genes. A total of 53 strains carried the bac, bgrR and bgrS genes. Most of them (48 strains) expressed β antigen, while five strains did not express β antigen. Three strains, in which bac gene sequence was intact, while bgrR and/or bgrS genes had mutations, and expression of β antigen was absent, were complemented with a constructed plasmid pBgrRS(P) encoding functionally active bgrR and bgrS gene alleles. This procedure restored expression of β antigen indicating the crucial regulatory role of TCS BgrRS. The complemented strain A49V/BgrRS demonstrated attenuated virulence in intraperitoneal mice model of S. agalactiae infection compared to parental strain A49V. In conclusion we showed that disruption of β antigen expression is associated with: i) insertion of ISSa4 upstream the bac gene just after the ribosomal binding site; ii) point mutation G342A resulting a stop codon TGA within the bac gene and a truncated form of β antigen; iii) single deletion (G) in position 439 of the bgrR gene resulting in a frameshift and the loss of DNA-binding domain of the BgrR protein, and iv) single base substitutions in bgrR and bgrS genes causing single amino acid substitutions in BgrR (Arg187Lys) and BgrS (Arg252Gln). The fact that BgrRS negatively controls virulent properties of S. agalactiae gives a novel clue for understanding of S

  12. Natural Mutations in Streptococcus agalactiae Resulting in Abrogation of β Antigen Production

    Science.gov (United States)

    Vasilyeva, Anastasia; Santos Sanches, Ilda; Florindo, Carlos; Dmitriev, Alexander

    2015-01-01

    Streptococcus agalactiae genome encodes 21 two-component systems (TCS) and a variety of regulatory proteins in order to control gene expression. One of the TCS, BgrRS, comprising the BgrR DNA-binding regulatory protein and BgrS sensor histidine kinase, was discovered within a putative virulence island. BgrRS influences cell metabolism and positively control the expression of bac gene, coding for β antigen at transcriptional level. Inactivation of bgrR abrogated bac gene expression and increased virulence properties of S. agalactiae. In this study, a total of 140 strains were screened for the presence of bac gene, and the TCS bgrR and bgrS genes. A total of 53 strains carried the bac, bgrR and bgrS genes. Most of them (48 strains) expressed β antigen, while five strains did not express β antigen. Three strains, in which bac gene sequence was intact, while bgrR and/or bgrS genes had mutations, and expression of β antigen was absent, were complemented with a constructed plasmid pBgrRS(P) encoding functionally active bgrR and bgrS gene alleles. This procedure restored expression of β antigen indicating the crucial regulatory role of TCS BgrRS. The complemented strain A49V/BgrRS demonstrated attenuated virulence in intraperitoneal mice model of S. agalactiae infection compared to parental strain A49V. In conclusion we showed that disruption of β antigen expression is associated with: i) insertion of ISSa4 upstream the bac gene just after the ribosomal binding site; ii) point mutation G342A resulting a stop codon TGA within the bac gene and a truncated form of β antigen; iii) single deletion (G) in position 439 of the bgrR gene resulting in a frameshift and the loss of DNA-binding domain of the BgrR protein, and iv) single base substitutions in bgrR and bgrS genes causing single amino acid substitutions in BgrR (Arg187Lys) and BgrS (Arg252Gln). The fact that BgrRS negatively controls virulent properties of S. agalactiae gives a novel clue for understanding of S

  13. Life insurance and genetic test results: a mutation carrier's fight to achieve full cover.

    Science.gov (United States)

    Keogh, Louise A; Otlowski, Margaret F A

    2013-09-01

    Currently, there is debate about life insurance companies' use of genetic information for assessing applicants. In his early 20s, James (pseudonym) was denied full life insurance cover because he revealed that he had discussed genetic testing with a genetic counsellor. He was later tested and found to carry a mutation in the MSH6 gene; after disclosing this, he was denied cover for cancer by two other life insurance companies. Unsatisfied with the insurance companies' risk assessments, and based on his understanding that regular colonoscopy significantly reduced his risk of cancer, James made a complaint to the Australian Human Rights Commission. After informing the third insurance company that he had done so, he was offered full coverage, which suggests that the company did not have actuarial data to justify its decision. This case provides evidence of the high level of initiative and proactivity required for a consumer to achieve a fair result. Few Australians would be in a position to pursue the level of research and advocacy undertaken by James (a professional with scientific training). We call on a collaborative approach between industry, government and researchers to address the issues that James's case raises about genetic testing and life insurance.

  14. Oculofaciocardiodental and Lenz microphthalmia syndromes result from distinct classes of mutations in BCOR.

    Science.gov (United States)

    Ng, David; Thakker, Nalin; Corcoran, Connie M; Donnai, Dian; Perveen, Rahat; Schneider, Adele; Hadley, Donald W; Tifft, Cynthia; Zhang, Liqun; Wilkie, Andrew O M; van der Smagt, Jasper J; Gorlin, Robert J; Burgess, Shawn M; Bardwell, Vivian J; Black, Graeme C M; Biesecker, Leslie G

    2004-04-01

    Lenz microphthalmia is inherited in an X-linked recessive pattern and comprises microphthalmia, mental retardation, and skeletal and other anomalies. Two loci associated with this syndrome, MAA (microphthalmia with associated anomalies) and MAA2, are situated respectively at Xq27-q28 (refs. 1,2) and Xp11.4-p21.2 (ref. 3). We identified a substitution, nt 254C-->T; P85L, in BCOR (encoding BCL-6-interacting corepressor, BCOR) in affected males from the family with Lenz syndrome previously used to identify the MAA2 locus. Oculofaciocardiodental syndrome (OFCD; OMIM 300166) is inherited in an X-linked dominant pattern with presumed male lethality and comprises microphthalmia, congenital cataracts, radiculomegaly, and cardiac and digital abnormalities. Given their phenotypic overlap, we proposed that OFCD and MAA2-associated Lenz microphthalmia were allelic, and we found different frameshift, deletion and nonsense mutations in BCOR in seven families affected with OFCD. Like wild-type BCOR, BCOR P85L and an OFCD-mutant form of BCOR can interact with BCL-6 and efficiently repress transcription. This indicates that these syndromes are likely to result from defects in alternative functions of BCOR, such as interactions with transcriptional partners other than BCL-6. We cloned the zebrafish (Danio rerio) ortholog of BCOR and found that knock-down of this ortholog caused developmental perturbations of the eye, skeleton and central nervous system consistent with the human syndromes, confirming that BCOR is a key transcriptional regulator during early embryogenesis.

  15. Molecular analysis of beta-globin gene mutations among Thai beta-thalassemia children: results from a single center study

    Directory of Open Access Journals (Sweden)

    Boonyawat B

    2014-12-01

    Full Text Available Boonchai Boonyawat,1 Chalinee Monsereenusorn,2 Chanchai Traivaree2 1Division of Genetics, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand; 2Division of Hematology/Oncology, Department of Pediatrics, Phramongkutklao Hospital and College of Medicine, Bangkok, Thailand Background: Beta-thalassemia is one of the most common genetic disorders in Thailand. Clinical phenotype ranges from silent carrier to clinically manifested conditions including severe beta-thalassemia major and mild beta-thalassemia intermedia. Objective: This study aimed to characterize the spectrum of beta-globin gene mutations in pediatric patients who were followed-up in Phramongkutklao Hospital. Patients and methods: Eighty unrelated beta-thalassemia patients were enrolled in this study including 57 with beta-thalassemia/hemoglobin E, eight with homozygous beta-thalassemia, and 15 with heterozygous beta-thalassemia. Mutation analysis was performed by multiplex amplification refractory mutation system (M-ARMS, direct DNA sequencing of beta-globin gene, and gap polymerase chain reaction for 3.4 kb deletion detection, respectively. Results: A total of 13 different beta-thalassemia mutations were identified among 88 alleles. The most common mutation was codon 41/42 (-TCTT (37.5%, followed by codon 17 (A>T (26.1%, IVS-I-5 (G>C (8%, IVS-II-654 (C>T (6.8%, IVS-I-1 (G>T (4.5%, and codon 71/72 (+A (2.3%, and all these six common mutations (85.2% were detected by M-ARMS. Six uncommon mutations (10.2% were identified by DNA sequencing including 4.5% for codon 35 (C>A and 1.1% initiation codon mutation (ATG>AGG, codon 15 (G>A, codon 19 (A>G, codon 27/28 (+C, and codon 123/124/125 (-ACCCCACC, respectively. The 3.4 kb deletion was detected at 4.5%. The most common genotype of beta-thalassemia major patients was codon 41/42 (-TCTT/codon 26 (G>A or betaE accounting for 40%. Conclusion: All of the beta-thalassemia alleles have been characterized by

  16. Biosemiotic Entropy of the Genome: Mutations and Epigenetic Imbalances Resulting in Cancer

    Directory of Open Access Journals (Sweden)

    Samuel S. Shepard

    2013-01-01

    Full Text Available Biosemiotic entropy involves the deterioration of biological sign systems. The genome is a coded sign system that is connected to phenotypic outputs through the interpretive functions of the tRNA/ribosome machinery. This symbolic sign system (semiosis at the core of all biology has been termed “biosemiosis”. Layers of biosemiosis and cellular information management are analogous in varying degrees to the semiotics of computer programming, spoken, and written human languages. Biosemiotic entropy — an error or deviation from a healthy state — results from errors in copying functional information (mutations and errors in the appropriate context or quantity of gene expression (epigenetic imbalance. The concept of biosemiotic entropy is a deeply imbedded assumption in the study of cancer biology. Cells have a homeostatic, preprogrammed, ideal or healthy state that is rooted in genomics, strictly orchestrated by epigenetic regulation, and maintained by DNA repair mechanisms. Cancer is an eminent illustration of biosemiotic entropy, in which the corrosion of genetic information via substitutions, deletions, insertions, fusions, and aberrant regulation results in malignant phenotypes. However, little attention has been given to explicitly outlining the paradigm of biosemiotic entropy in the context of cancer. Herein we distill semiotic theory (from the familiar and well understood spheres of human language and computer code to draw analogies useful for understanding the operation of biological semiosis at the genetic level. We propose that the myriad checkpoints, error correcting mechanisms, and immunities are all systems whose primary role is to defend against the constant pressure of biosemiotic entropy, which malignancy must shut down in order to achieve advanced stages. In lieu of the narrower tumor suppressor/oncogene model, characterization of oncogenesis into the biosemiotic framework of sign, index, or object entropy may allow for more

  17. A knock-in Npm1 mutation in mice results in myeloproliferation and implies a perturbation in hematopoietic microenvironment.

    Directory of Open Access Journals (Sweden)

    Shiu-Huey Chou

    Full Text Available Somatic Nucleophosmin (NPM1 mutation frequently occurs in acute myeloid leukemia (AML, but its role in leukemogenesis remains unclear. This study reports the first "conventional" knock-in mouse model of Npm1 mutation, which was achieved by inserting TCTG after nucleotide c.857 (c.854_857dupTCTG to mimic human mutation without any "humanized" sequence. The resultant mutant peptide differed slightly different from that in humans but exhibited cytoplasmic pulling force. Homozygous (Npm1(c+/c+ mice showed embryonic lethality before day E8.5, wheras heterozygous (Npm1(wt/c+ mice appeared healthy at birth and were fertile. Approximately 36% of Npm1(wt/c+ mice developed myeloproliferative disease (MPD with extramedullary hematopoiesis. Those Npm1(wt/c+ mice that did not develop MPD nevertheless gradually developed monocytosis and showed increased numbers of marrow myeloid precursors. This second group of Npm1(wt/c+ mice also showed compromised cobblestone area formation, suggesting pathology in the hematopoietic niche. Microarray experiments and bioinformatic analysis on mice myeloid precursor cells and 227 human samples revealed the expression of CXCR4/CXCL12-related genes was significantly suppressed in mutant cells from both mice and humans. Thus, our mouse model demonstrated that Npm1 mutation can result in MPD, but is insufficient for leukemogenesis. Perturbation of hematopoietic niche in mutant hematopoietic stem cells (implied by underrepresentation of CXCR4/CXCL12-related genes may be important in the pathogenesis of NPM1 mutations.

  18. A mutation in TRPV4 results in altered chondrocyte calcium signaling in severe metatropic dysplasia.

    Science.gov (United States)

    Hurd, Lauren; Kirwin, Susan M; Boggs, Mary; Mackenzie, William G; Bober, Michael B; Funanage, Vicky L; Duncan, Randall L

    2015-10-01

    Transient receptor potential cation channel, subfamily V, member 4 (TRPV4) is a polymodal modulated non-selective cation channel required for normal development and maintenance of bone and cartilage. Heterozygous mutations of this channel cause a variety of channelopathies, including metatropic dysplasia (MD). We analyzed the effect of a novel TRPV4 mutation c.2398G>A, p.Gly800Asp on intracellular calcium ([Ca(2+) ]i ) regulation in chondrocytes and compared this response to chondrocytes with a frequently observed mutation, c.2396C>T, p.Pro799Leu. We observed temperature-dependent [Ca(2+) ]i oscillations in both intact and MD chondrocytes however, MD mutations exhibited increased peak magnitudes of [Ca(2+) ]i during oscillations. We also found increased baseline [Ca(2+) ]i in MD primary cells, as well as increased [Ca(2+) ]i response to either hypotonic swelling or the TRVP4-specific agonist, GSK1016790A. Oscillations and stimulation responses were blocked with the TRPV4-specific antagonist, GSK205. Analysis of [Ca(2+) ]i response kinetics showed that MD chondrocytes had increased frequency of temperature-sensitive oscillations, and the magnitude and duration of [Ca(2+) ]i responses to given stimuli. Duration of the response of the p.Gly800Asp mutation to stimulation was greater than for the p.Pro799Leu mutation. These experiments show that this region of the channel is essential for proper [Ca(2+) ]i regulation. These studies of primary cells from patients show how both mutant and WT TRPV4 channels regulate cartilage and bone development. © 2015 Wiley Periodicals, Inc.

  19. Mutation of the CH1 Domain in the Histone Acetyltransferase CREBBP Results in Autism-Relevant Behaviors in Mice.

    Science.gov (United States)

    Zheng, Fei; Kasper, Lawryn H; Bedford, David C; Lerach, Stephanie; Teubner, Brett J W; Brindle, Paul K

    2016-01-01

    Autism spectrum disorders (ASDs) are a group of neurodevelopmental afflictions characterized by repetitive behaviors, deficits in social interaction, and impaired communication skills. For most ASD patients, the underlying causes are unknown. Genetic mutations have been identified in about 25 percent of ASD cases, including mutations in epigenetic regulators, suggesting that dysregulated chromatin or DNA function is a critical component of ASD. Mutations in the histone acetyltransferase CREB binding protein (CBP, CREBBP) cause Rubinstein-Taybi Syndrome (RTS), a developmental disorder that includes ASD-like symptoms. Recently, genomic studies involving large numbers of ASD patient families have theoretically modeled CBP and its paralog p300 (EP300) as critical hubs in ASD-associated protein and gene interaction networks, and have identified de novo missense mutations in highly conserved residues of the CBP acetyltransferase and CH1 domains. Here we provide animal model evidence that supports this notion that CBP and its CH1 domain are relevant to autism. We show that mice with a deletion mutation in the CBP CH1 (TAZ1) domain (CBPΔCH1/ΔCH1) have an RTS-like phenotype that includes ASD-relevant repetitive behaviors, hyperactivity, social interaction deficits, motor dysfunction, impaired recognition memory, and abnormal synaptic plasticity. Our results therefore indicate that loss of CBP CH1 domain function contributes to RTS, and possibly ASD, and that this domain plays an essential role in normal motor function, cognition and social behavior. Although the key physiological functions affected by ASD-associated mutation of epigenetic regulators have been enigmatic, our findings are consistent with theoretical models involving CBP and p300 in ASD, and with a causative role for recently described ASD-associated CBP mutations.

  20. Multiple jejunal cancers resulting from combination of germline APC and MLH1 mutations.

    Science.gov (United States)

    Lindor, Noralane M; Smyrk, Tom C; Buehler, Sheila; Gunawardena, Shanaka R; Thomas, Brittany C; Limburg, Paul; Kirmani, Salman; Thibodeau, Stephen N

    2012-12-01

    Double heterozygotes for mutations in APC and a DNA mismatch repair gene are extremely rare. We report on an individual who had truncating mutations in APC and MLH1 whose clinical presentation initially resembled Familial Adenomatous Polyposis but then emerged as a novel phenotype with multiple jejunal carcinomas. We have reviewed the relevant literature on double heterozygotes and based on what has been reported to date, this phenotype was not anticipated. It may be useful for clinicians to be aware of this observation as clinical screening guidelines are proposed for such individuals.

  1. Two‑gene mutation in a single patient: Biochemical and functional analysis for a correct interpretation of exome results.

    Science.gov (United States)

    Bianco, Anna Monica; Faletra, Flavio; Vozzi, Diego; Girardelli, Martina; Knowles, Alessandra; Tommasini, Alberto; Zauli, Giorgio; Marcuzzi, Annalisa

    2015-10-01

    Next-generation sequencing (NGS) has generated a large amount of sequence data with the requirement of frequent critical revisions of reported mutations. This innovative tool has proved to be effective in detecting pathogenic mutations; however, it requires a certain degree of experience to identify incidental findings. In the present study, whole exome sequencing analysis was performed for the molecular diagnosis and correct genotype/phenotype correlation between parents and a patient presenting with an atypical phenotype. In addition, mevalonic acid quantification and frequency analysis of detected variants in public databases and X‑chromosome inactivation (XCI) studies on the patient's mother were performed. V377I as well as the S135L mutations were identified on the mevalonate kinase deficiency gene and the levels of mevalonic acid in the patient were 5,496 µg/ml. A D59G variation, reported in ESP6500 in two healthy individuals, was found on the Martin Probst syndrome gene (RAB40AL). Based on XCI studies on the patient's mother, it is likely that RAB40AL escapes XCI, while still remaining balanced. In conclusion, the results of the present study indicated that the Martin Probst syndrome is an X‑linked condition, which is probably not caused by RAB40AL mutations. Although NGS is a powerful tool to identify pathogenic mutations, the analysis of genetic data requires expert critical revision of all detected variants.

  2. Mutations in HNF1A result in marked alterations of plasma glycan profile

    DEFF Research Database (Denmark)

    Thanabalasingham, Gaya; Huffman, Jennifer E; Kattla, Jayesh J

    2013-01-01

    A recent genome-wide association study identified hepatocyte nuclear factor 1-α (HNF1A) as a key regulator of fucosylation. We hypothesized that loss-of-function HNF1A mutations causal for maturity-onset diabetes of the young (MODY) would display altered fucosylation of N-linked glycans on plasma...

  3. Functional categories of TP53 mutation in colorectal cancer: results of an International Collaborative Study.

    NARCIS (Netherlands)

    Iacopetta, B.; Russo, A.; Bazan, V.; Dardanoni, G.; Gebbia, N.; Soussi, T.; Kerr, D.J.; Elsaleh, H.; Soong, R.; Kandioler, D.; Janschek, E.; Kappel, S.; Lung, M.; Leung, C.S.; Ko, J.M.; Yuen, S.; Ho, J.; Leung, S.Y.; Crapez, E.; Duffour, J.; Ychou, M.; Leahy, D.T.; O'Donoghue, D.P.; Agnese, V.; Cascio, S.; Fede, G. Di; Chieco-Bianchi, L.; Bertorelle, R.; Belluco, C.; Giaretti, W.; Castagnola, P.; Ricevuto, E.; Ficorella, C.; Bosari, S.; Arizzi, C.D.; Miyaki, M.; Onda, M.; Kampman, E.; Diergaarde, B.; Royds, J.; Lothe, R.A.; Diep, C.B.; Meling, G.I.; Ostrowski, J.; Trzeciak, L.; Guzinska-Ustymowicz, K.; Zalewski, B.; Capella, G.M.; Moreno, V.; Peinado, M.A.; Lonnroth, C.; Lundholm, K.; Sun, X.F.; Jansson, A.; Bouzourene, H.; Hsieh, L.L.; Tang, R.; Smith, D.R.; Allen-Mersh, T.G.; Khan, Z.A.; Shorthouse, A.J.; Silverman, M.L.; Kato, S.; Ishioka, C.

    2006-01-01

    BACKGROUND: Loss of TP53 function through gene mutation is a critical event in the development and progression of many tumour types including colorectal cancer (CRC). In vitro studies have found considerable heterogeneity amongst different TP53 mutants in terms of their transactivating abilities. Th

  4. Functional categories of TP53 mutation in colorectal cancer: results of an International Collaborative Study

    NARCIS (Netherlands)

    Iacopetta, B.; Russo, A.; Bazan, V.; Kampman, E.; Diergaarde, B.

    2006-01-01

    Background: Loss of TP53 function through gene mutation is a critical event in the development and progression of many tumour types including colorectal cancer (CRC). In vitro studies have found considerable heterogeneity amongst different TP53 mutants in terms of their transactivating abilities. Th

  5. Fibrochondrogenesis results from mutations in the COL11A1 type XI collagen gene.

    Science.gov (United States)

    Tompson, Stuart W; Bacino, Carlos A; Safina, Nicole P; Bober, Michael B; Proud, Virginia K; Funari, Tara; Wangler, Michael F; Nevarez, Lisette; Ala-Kokko, Leena; Wilcox, William R; Eyre, David R; Krakow, Deborah; Cohn, Daniel H

    2010-11-12

    Fibrochondrogenesis is a severe, autosomal-recessive, short-limbed skeletal dysplasia. In a single case of fibrochondrogenesis, whole-genome SNP genotyping identified unknown ancestral consanguinity by detecting three autozygous regions. Because of the predominantly skeletal nature of the phenotype, the 389 genes localized to the autozygous intervals were prioritized for mutation analysis by correlation of their expression with known cartilage-selective genes via the UCLA Gene Expression Tool, UGET. The gene encoding the α1 chain of type XI collagen (COL11A1) was the only cartilage-selective gene among the three candidate intervals. Sequence analysis of COL11A1 in two genetically independent fibrochondrogenesis cases demonstrated that each was a compound heterozygote for a loss-of-function mutation on one allele and a mutation predicting substitution for a conserved triple-helical glycine residue on the other. The parents who were carriers of missense mutations had myopia. Early-onset hearing loss was noted in both parents who carried a loss-of-function allele, suggesting COL11A1 as a locus for mild, dominantly inherited hearing loss. These findings identify COL11A1 as a locus for fibrochondrogenesis and indicate that there might be phenotypic manifestations among carriers.

  6. Mutations in two regions of FLNB result in atelosteogenesis I and III

    NARCIS (Netherlands)

    Farrington-Rock, Claire; Firestein, Marc H.; Bicknell, Louise S.; Superti-Furga, Andrea; Bacino, Carlos A.; Cormier-Daire, Valerie; Le Merrer, Martine; Baumann, Clarisse; Roume, Joelle; Rump, Patrick; Verheij, Joke B. G. M.; Sweeney, Elizabeth; Rimoin, David L.; Lachman, Ralph S.; Robertson, Stephen P.; Cohn, Daniel H.; Krakow, Deborah

    2006-01-01

    The filamins are a family of cytoplasmic proteins that bind to and organize actin filaments, link membrane proteins to the cytoskeleton, and provide a scaffold for signaling molecules. Mutations in the gene encoding filamin B (FLNB) cause a spectrum of osteochondrodysplasias, including atelosteogene

  7. Mutations in MAB21L2 result in ocular Coloboma, microcornea and cataracts.

    Directory of Open Access Journals (Sweden)

    Brett Deml

    Full Text Available Ocular coloboma results from abnormal embryonic development and is often associated with additional ocular and systemic features. Coloboma is a highly heterogeneous disorder with many cases remaining unexplained. Whole exome sequencing from two cousins affected with dominant coloboma with microcornea, cataracts, and skeletal dysplasia identified a novel heterozygous allele in MAB21L2, c.151 C>G, p.(Arg51Gly; the mutation was present in all five family members with the disease and appeared de novo in the first affected generation of the three-generational pedigree. MAB21L2 encodes a protein similar to C. elegans mab-21 cell fate-determining factor; the molecular function of MAB21L2 is largely unknown. To further evaluate the role of MAB21L2, zebrafish mutants carrying a p.(Gln48Serfs*5 frameshift truncation (mab21l2Q48Sfs*5 and a p.(Arg51_Phe52del in-frame deletion (mab21l2R51_F52del were developed with TALEN technology. Homozygous zebrafish embryos from both lines developed variable lens and coloboma phenotypes: mab21l2Q48Sfs*5 embryos demonstrated severe lens and retinal defects with complete lethality while mab21l2R51_F52del mutants displayed a milder lens phenotype and severe coloboma with a small number of fish surviving to adulthood. Protein studies showed decreased stability for the human p.(Arg51Gly and zebrafish p.(Arg51_Phe52del mutant proteins and predicted a complete loss-of-function for the zebrafish p.(Gln48Serfs*5 frameshift truncation. Additionally, in contrast to wild-type human MAB21L2 transcript, mutant p.(Arg51Gly mRNA failed to efficiently rescue the ocular phenotype when injected into mab21l2Q48Sfs*5 embryos, suggesting this allele is functionally deficient. Histology, immunohistochemistry, and in situ hybridization experiments identified retinal invagination defects, an increase in cell death, abnormal proliferation patterns, and altered expression of several ocular markers in the mab21l2 mutants. These findings support the

  8. Disease Mutations in Rab7 Result in Unregulated Nucleotide Exchange and Inappropriate Activation

    Energy Technology Data Exchange (ETDEWEB)

    B McCray; E Skordalakes; J Taylor

    2011-12-31

    Rab GTPases are molecular switches that orchestrate vesicular trafficking, maturation and fusion by cycling between an active, GTP-bound form, and an inactive, GDP-bound form. The activity cycle is coupled to GTP hydrolysis and is tightly controlled by regulatory proteins. Missense mutations of the GTPase Rab7 cause a dominantly inherited axonal degeneration known as Charcot-Marie-Tooth type 2B through an unknown mechanism. We present the 2.8 A crystal structure of GTP-bound L129F mutant Rab7 which reveals normal conformations of the effector binding regions and catalytic site, but an alteration to the nucleotide binding pocket that is predicted to alter GTP binding. Through extensive biochemical analysis, we demonstrate that disease-associated mutations in Rab7 do not lead to an intrinsic GTPase defect, but permit unregulated nucleotide exchange leading to both excessive activation and hydrolysis-independent inactivation. Consistent with augmented activity, mutant Rab7 shows significantly enhanced interaction with a subset of effector proteins. In addition, dynamic imaging demonstrates that mutant Rab7 is abnormally retained on target membranes. However, we show that the increased activation of mutant Rab7 is counterbalanced by unregulated, GTP hydrolysis-independent membrane cycling. Notably, disease mutations are able to rescue the membrane cycling of a GTPase-deficient mutant. Thus, we demonstrate that disease mutations uncouple Rab7 from the spatial and temporal control normally imposed by regulatory proteins and cause disease not by a gain of novel toxic function, but by misregulation of native Rab7 activity.

  9. phuR intergenic mutation results in pleiotropic effects on global gene expression

    DEFF Research Database (Denmark)

    Khademi, Seyed Mohammad Hossein; Wassermann, Tina; Ciofu, Oana;

    2015-01-01

    We have previously found a positive selection for promoter mutations in Pseudomonas aeruginosa DK2 leading to increased expression of the phu (Pseudomonas heme utilization) system. By mimicking conditions of the CF airways in vitro, we experimentally demonstrated that increased expression of phu......R confers a growth advantage in the presence of hemoglobin, thus suggesting that P. aeruginosa evolves towards iron acquisition from hemoglobin....

  10. Autosomal recessive dilated cardiomyopathy due to DOLK mutations results from abnormal dystroglycan O-mannosylation.

    Directory of Open Access Journals (Sweden)

    Dirk J Lefeber

    2011-12-01

    Full Text Available Genetic causes for autosomal recessive forms of dilated cardiomyopathy (DCM are only rarely identified, although they are thought to contribute considerably to sudden cardiac death and heart failure, especially in young children. Here, we describe 11 young patients (5-13 years with a predominant presentation of dilated cardiomyopathy (DCM. Metabolic investigations showed deficient protein N-glycosylation, leading to a diagnosis of Congenital Disorders of Glycosylation (CDG. Homozygosity mapping in the consanguineous families showed a locus with two known genes in the N-glycosylation pathway. In all individuals, pathogenic mutations were identified in DOLK, encoding the dolichol kinase responsible for formation of dolichol-phosphate. Enzyme analysis in patients' fibroblasts confirmed a dolichol kinase deficiency in all families. In comparison with the generally multisystem presentation in CDG, the nonsyndromic DCM in several individuals was remarkable. Investigation of other dolichol-phosphate dependent glycosylation pathways in biopsied heart tissue indicated reduced O-mannosylation of alpha-dystroglycan with concomitant functional loss of its laminin-binding capacity, which has been linked to DCM. We thus identified a combined deficiency of protein N-glycosylation and alpha-dystroglycan O-mannosylation in patients with nonsyndromic DCM due to autosomal recessive DOLK mutations.

  11. Ultrastructural changes resulting from keratin-9 gene mutations in two families with epidermolytic palmoplantar keratoderma.

    Science.gov (United States)

    Navsaria, H A; Swensson, O; Ratnavel, R C; Shamsher, M; McLean, W H; Lane, E B; Griffiths, D; Eady, R A; Leigh, I M

    1995-03-01

    Palmoplantar keratoderma of Voerner type (or epidermolytic palmoplantar keratoderma) is an autosomal dominant inherited disorder of keratinization with histologic features of epidermolytic hyperkeratosis. We studied members of two large unrelated kindreds with epidermolytic palmoplantar keratoderma, and biopsy specimens of lesional palmar skin from both families confirmed the histologic changes of epidermolytic hyperkeratosis. Whorls of abnormally aggregated keratin filaments were seen ultrastructurally to be associated with signs of cellular disintegration in spinous and granular cells. Direct sequencing of genomic DNA samples obtained from several members of each family established the substitution of a highly conserved arginine by tryptophan (R162W) in the 1A region of the alpha-helical rod domain of keratin 9. This arginine residue in a highly conserved region of keratins 1 and 10 is affected by disruptive missense point mutations in many patients with bullous ichthyosiform erythroderma. An equivalent position in the sole and palm restricted keratin 9 appears to be the mutation hot spot in epidermolytic palmoplantar keratoderma. To date, R162W is the most prevalent genetic defect reported in this genodermatosis.

  12. A novel CACNA1A mutation results in episodic ataxia with migrainous features without headache.

    Science.gov (United States)

    Magis, Delphine; Boon, Elles; Coppola, Gianluca; Daron, Aurore; Schoenen, Jean

    2012-11-01

    The mechanisms subtending migrainous features, like sensoriphobia, remain poorly understood even though recent works have shed new light on their mechanisms. A 24-year-old woman consulted the headache clinic because of frequent paroxysmal attacks of strong sensoriphobia, digestive signs, moderate ataxia and a need to lie in the dark, without any headache. The symptoms had begun in infancy and the patient had been treated for hysteria, then for epilepsy. As she had some typical features of episodic ataxia type 2, an analysis of CACNA1A gene was performed and demonstrated a novel c3995 + 1G>A mutation. The same mutation was also discovered in her young son, who had an ataxia of unknown origin. Both remarkably improved under acetazolamide. This observation suggests that paroxysmal sensoriphobia and digestive signs can occur together in bouts in neurological conditions other than migraine, and in the absence of head pain. It raises interesting hypotheses about the central pathways driving these symptoms.

  13. Uniparental disomy of chromosome 2 resulting in lethal trifunctional protein deficiency due to homozygous alpha-subunit mutations.

    Science.gov (United States)

    Spiekerkoetter, Ute; Eeds, Angela; Yue, Zou; Haines, Jonathan; Strauss, Arnold W; Summar, Marshall

    2002-12-01

    The mitochondrial trifunctional protein (TFP) is an enzyme complex of the fatty acid beta-oxidation cycle composed of an alpha- and a beta-subunit. The two encoding genes are located in the same region on chromosome 2 (2p23). TFP deficiency due to either alpha- or beta-subunit mutations is characterized by mutational and phenotypic heterogeneity with severe, early-onset, cardiac forms and milder, later-onset, myopathic phenotypes. In two unrelated patients with lethal TFP deficiency, we delineated apparently homozygous alpha-subunit mutations that were present in heterozygous form in both mothers, but not in either biological father. We performed a microsatellite repeat analysis of both patients and their parents using seven chromosome 2-specific polymorphic DNA markers and four nonchromosome 2 markers. In both patients, two chromosome 2-specific markers demonstrated maternal isodisomy of chromosome 2. The other five chromosome 2-specific markers were noninformative in each patient. Inheritance of alleles from chromosomes 4, 5, and 7 was consistent with paternity. These results explain the apparently anomalous pattern of transmission. Six of our 12 known TFP-deficient patients with alpha-subunit mutations have disease due to homozygous changes and two of them via the mechanism of uniparental disomy (UPD) (16.7%). For very rare autosomal recessive diseases, UPD may represent a common mechanism. This study emphasizes the need to confirm mutations in parents whenever possible. TFP deficiency is another disorder that has become manifest due to isodisomy of chromosome 2. This information will impact genetic counseling for these families, reducing greatly the 25% risk normally used for recessive disorders.

  14. STUDIES ON PATHOGENESIS OF WAARDENBURG SYNDROME TYPE ⅡAND TIETZ SYNDROME RESULTING FROM MITF GENE MUTATIONS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua; LI Jiada; LUO Hunjin; CHEN Hongsheng; MEI Lingyun; HE Chufeng; JIANG Lu; FENG Yong

    2013-01-01

    Microphthalmia-associated transcription factor (MITF) controls melanocyte survival and differentiation through directly regulating the expression of the tyrosinase (TYR) and tyrosinase-related proteins 1 and 2 (TYRP1 and TYRP2) genes. MITF mutations have been reported to result in an abnormal melanocyte devel-opment and lead to Waardenburg syndrome type 2 (WS2), characterized by variable degrees of sensorineu-ral hearing loss and patchy regional distribution of hypopigmentation. Recently, MITF was also indicated as a causative gene for a more severe syndrome, the Tietz Syndrome (TS), characterized by generalized hy-popigmentation and complete hearing loss. However, few functional studies have been performed to com-pare the diseases-causing mutations. Here, we analyzed the in vitro activity of two recent identified WS2-as-sociated mutation (p.R217I and p.T192fsX18) and one TS-associated mutation p.N210K. The R217I MITF retained partial activity, normal DNA-binding ability and nuclear distribution, whereas the T192fsX18 MITF failed to activate TYR promoter due to loss of DNA-binding activity, and aberrant subcellular localization. The aberrant subcellular localization of T192fsX18 MITF may be caused by deletion of a putative nuclear localization signal (NLS) at aa 213-218 (ERRRRF). Indeed, MITF with deletion of the NLS fragment failed to translocate into the nucleus and activated the TYR promoter. Tagging this NLS to GFP promoted the green fluorescence protein (GFP) translocated into the nucleus. The surprising finding of our study is that a TS-as-sociated MITF mutation, N210K, showed comparable in vitro activity as WT. Thus, the possible involve-ment of MITF in TS and its underlying mechanisms still need further investigation.

  15. Multiple phenotypes resulting from a mutagenesis screen for pharynx muscle mutations in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Andrew Ferrier

    Full Text Available We describe a novel screen to isolate pharyngeal cell morphology mutants in Caenorhabditis elegans using myo-2::GFP to rapidly identify abnormally shaped pharynxes in EMS (Ethyl Methanesulfonate mutagenized worms. We observed over 83 C. elegans lines with distinctive pharyngeal phenotypes in worms surviving to the L1 larval stage, with phenotypes ranging from short pharynx, unattached pharynx, missing cells, asymmetric morphology, and non-adherent pharynx cells. Thirteen of these mutations have been chromosomally mapped using Single Nucleotide Polymorphisms (SNPs and deficiency strain complementation. Our studies have focused on genetically mapping and functionally testing two phenotypes, the short pharynx and the loss of muscle cohesion phenotypes. We have also identified new alleles of sma-1, and our screen suggests many genes directing pharynx assembly and structure may be either pharynx specific or less critical in other tissues.

  16. Mutation in E1, the ubiquitin activating enzyme, reduces Drosophila lifespan and results in motor impairment.

    Science.gov (United States)

    Liu, Hsiu-Yu; Pfleger, Cathie M

    2013-01-01

    Neurodegenerative diseases cause tremendous suffering for those afflicted and their families. Many of these diseases involve accumulation of mis-folded or aggregated proteins thought to play a causal role in disease pathology. Ubiquitinated proteins are often found in these protein aggregates, and the aggregates themselves have been shown to inhibit the activity of the proteasome. These and other alterations in the Ubiquitin Pathway observed in neurodegenerative diseases have led to the question of whether impairment of the Ubiquitin Pathway on its own can increase mortality or if ongoing neurodegeneration alters Ubiquitin Pathway function as a side-effect. To address the role of the Ubiquitin Pathway in vivo, we studied loss-of-function mutations in the Drosophila Ubiquitin Activating Enzyme, Uba1 or E1, the most upstream enzyme in the Ubiquitin Pathway. Loss of only one functional copy of E1 caused a significant reduction in adult lifespan. Rare homozygous hypomorphic E1 mutants reached adulthood. These mutants exhibited further reduced lifespan and showed inappropriate Ras activation in the brain. Removing just one functional copy of Ras restored the lifespan of heterozygous E1 mutants to that of wild-type flies and increased the survival of homozygous E1 mutants. E1 homozygous mutants also showed severe motor impairment. Our findings suggest that processes that impair the Ubiquitin Pathway are sufficient to cause early mortality. Reduced lifespan and motor impairment are seen in the human disease X-linked Infantile Spinal Muscular Atrophy, which is associated with mutation in human E1 warranting further analysis of these mutants as a potential animal model for study of this disease.

  17. Mutations in the DI-DII Linker of Human Parainfluenza Virus Type 3 Fusion Protein Result in Diminished Fusion Activity.

    Directory of Open Access Journals (Sweden)

    Wenyan Xie

    Full Text Available Human parainfluenza virus type 3 (HPIV3 can cause severe respiratory tract diseases in infants and young children, but no licensed vaccines or antiviral agents are currently available for treatment. Fusing the viral and target cell membranes is a prerequisite for its entry into host cells and is directly mediated by the fusion (F protein. Although several domains of F are known to have important effects on regulating the membrane fusion activity, the roles of the DI-DII linker (residues 369-374 of the HPIV3 F protein in the fusogenicity still remains ill-defined. To facilitate our understanding of the role of this domain might play in F-induced cell-cell fusion, nine single mutations were engineered into this domain by site-directed mutagenesis. A vaccinia virus-T7 RNA polymerase transient expression system was employed to express the wild-type or mutated F proteins. These mutants were analyzed for membrane fusion activity, cell surface expression, and interaction between F and HN protein. Each of the mutated F proteins in this domain has a cell surface expression level similar to that of wild-type F. All of them resulted in a significant reduction in fusogenic activity in all steps of membrane fusion. Furthermore, all these fusion-deficient mutants reduced the amount of the HN-F complexes at the cell surface. Together, the results of our work suggest that this region has an important effect on the fusogenic activity of F.

  18. MYH11 mutations result in a distinct vascular pathology driven by insulin-like growth factor 1 and angiotensin II

    Science.gov (United States)

    Pannu, Hariyadarshi; Tran-Fadulu, Van; Papke, Christina L.; Scherer, Steve; Liu, Yaozhong; Presley, Caroline; Guo, Dongchuan; Estrera, Anthony L.; Safi, Hazim J.; Brasier, Allan R.; Vick, G. Wesley; Marian, A.J.; Raman, C.S.; Buja, L. Maximilian; Milewicz, Dianna M.

    2010-01-01

    Non-syndromic thoracic aortic aneurysms and dissections (TAADs) are inherited in an autosomal dominant manner in ~20% of cases. Familial TAAD is genetically heterogeneous and four loci have been mapped for this disease to date, including a locus at 16p for TAAD associated with patent ductus arteriosus (PDA). The defective gene at the 16p locus has recently been identified as the smooth muscle cell (SMC)-specific myosin heavy chain gene (MYH11). On sequencing MYH11 in 93 families with TAAD alone and three families with TAAD/PDA, we identified novel mutations in two families with TAAD/PDA, but none in families with TAAD alone. Histopathological analysis of aortic sections from two individuals with MYH11 mutations revealed SMC disarray and focal hyperplasia of SMCs in the aortic media. SMC hyperplasia leading to significant lumen narrowing in some of the vessels of the adventitia was also observed. Insulin-like growth factor-1 (IGF-1) was upregulated in mutant aortas as well as explanted SMCs, but no increase in transforming growth factor-β expression or downstream targets was observed. Enhanced expression of angiotensin-converting enzyme and markers of Angiotensin II (Ang II) vascular inflammation (macrophage inflammatory protein-1α and β) were also found. These data suggest that MYH11 mutations are likely to be specific to the phenotype of TAAD/PDA and result in a distinct aortic and occlusive vascular pathology potentially driven by IGF-1 and Ang II. PMID:17666408

  19. A mutation in FBN1 disrupts profibrillin processing and results in isolated skeletal features of the Marfan syndrome.

    Science.gov (United States)

    Milewicz, D M; Grossfield, J; Cao, S N; Kielty, C; Covitz, W; Jewett, T

    1995-01-01

    Dermal fibroblasts from a 13-yr-old boy with isolated skeletal features of the Marfan syndrome were used to study fibrillin synthesis and processing. Only one half of the secreted profibrillin was proteolytically processed to fibrillin outside the cell and deposited into the extracellular matrix. Electron microscopic examination of rotary shadowed microfibrils made by the proband's fibroblasts were indistinguishable from control cells. Sequencing of the FBN1 gene revealed a heterozygous C to T transition at nucleotide 8176 resulting in the substitution of a tryptophan for an arginine (R2726W), at a site immediately adjacent to a consensus sequence recognized by a cellular protease. Six other individuals in the proband's family had the FBN1 mutation that segregated with tall stature. None of the affected individuals have cardiac or ocular manifestations of the Marfan syndrome. This mutation identifies a putative site for profibrillin to fibrillin processing, and is associated with isolated skeletal features of the Marfan syndrome, indicating that the FBN1 gene is one of the genes that determines height in the general population. The cellular effect of the mutation may be equivalent to a "null" FBN1 allele and may define the phenotype associated with FBN1 "null" alleles. Images PMID:7738200

  20. Mutations in Two Genes Encoding Different Subunits of a Receptor Signaling Complex Result in an Identical Disease Phenotype

    Science.gov (United States)

    Paloneva, Juha; Manninen, Tuula; Christman, Grant; Hovanes, Karine; Mandelin, Jami; Adolfsson, Rolf; Bianchin, Marino; Bird, Thomas; Miranda, Roxana; Salmaggi, Andrea; Tranebjærg, Lisbeth; Konttinen, Yrjö; Peltonen, Leena

    2002-01-01

    Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), also known as “Nasu-Hakola disease,” is a globally distributed recessively inherited disease leading to death during the 5th decade of life and is characterized by early-onset progressive dementia and bone cysts. Elsewhere, we have identified PLOSL mutations in TYROBP (DAP12), which codes for a membrane receptor component in natural-killer and myeloid cells, and also have identified genetic heterogeneity in PLOSL, with some patients carrying no mutations in TYROBP. Here we complete the molecular pathology of PLOSL by identifying TREM2 as the second PLOSL gene. TREM2 forms a receptor signaling complex with TYROBP and triggers activation of the immune responses in macrophages and dendritic cells. Patients with PLOSL have no defects in cell-mediated immunity, suggesting a remarkable capacity of the human immune system to compensate for the inactive TYROBP-mediated activation pathway. Our data imply that the TYROBP-mediated signaling pathway plays a significant role in human brain and bone tissue and provide an interesting example of how mutations in two different subunits of a multisubunit receptor complex result in an identical human disease phenotype. PMID:12080485

  1. Mutation of the diamond-blackfan anemia gene Rps7 in mouse results in morphological and neuroanatomical phenotypes.

    Directory of Open Access Journals (Sweden)

    Dawn E Watkins-Chow

    Full Text Available The ribosome is an evolutionarily conserved organelle essential for cellular function. Ribosome construction requires assembly of approximately 80 different ribosomal proteins (RPs and four different species of rRNA. As RPs co-assemble into one multi-subunit complex, mutation of the genes that encode RPs might be expected to give rise to phenocopies, in which the same phenotype is associated with loss-of-function of each individual gene. However, a more complex picture is emerging in which, in addition to a group of shared phenotypes, diverse RP gene-specific phenotypes are observed. Here we report the first two mouse mutations (Rps7(Mtu and Rps7(Zma of ribosomal protein S7 (Rps7, a gene that has been implicated in Diamond-Blackfan anemia. Rps7 disruption results in decreased body size, abnormal skeletal morphology, mid-ventral white spotting, and eye malformations. These phenotypes are reported in other murine RP mutants and, as demonstrated for some other RP mutations, are ameliorated by Trp53 deficiency. Interestingly, Rps7 mutants have additional overt malformations of the developing central nervous system and deficits in working memory, phenotypes that are not reported in murine or human RP gene mutants. Conversely, Rps7 mouse mutants show no anemia or hyperpigmentation, phenotypes associated with mutation of human RPS7 and other murine RPs, respectively. We provide two novel RP mouse models and expand the repertoire of potential phenotypes that should be examined in RP mutants to further explore the concept of RP gene-specific phenotypes.

  2. Development of a Tool to Guide Parents Carrying a BRCA1/2 Mutation Share Genetic Results with Underage Children.

    Science.gov (United States)

    Santerre-Theil, Ariane; Bouchard, Karine; St-Pierre, Dominique; Drolet, Anne-Marie; Chiquette, Jocelyne; Dorval, Michel

    2016-11-02

    Although most parents carrying a BRCA1/2 genetic mutation share their test result with their underage children, they report needing support to decide if, when, and how to share risk information and what reactions to expect from their children. We developed a tool to guide parents carrying a BRCA1/2 mutation share their genetic result with underage children. Here, we report on the development of this tool using a qualitative methodology. A tool prototype was developed based on the International Patient Decision Aids Standards Collaboration framework. Content was assessed using feedback from focus groups, individual interviews, and a 12-item reading grid. Participants were nine BRCA1/2 mutation carriers with underage children and three cancer genetics health professionals. Thematic content analysis was conducted on interview transcripts. The tool was developed using an iterative process until saturation of data. An independent advisory committee was involved in all steps of tool development until reaching consensus. Rather than a decision aid per se (to communicate or not), the parents wanted a more comprehensive tool to help them communicate genetic test result to their children. To meet parents' needs, a communication guidance booklet was developed, setting out the pros and cons of communication, steps to prepare sharing the test result, communication tips, and parents' testimonies. This communication tool responds to a significant unmet need faced by parents carrying a genetic predisposition to cancer. Future studies are needed to assess how the information from the parent's genetic test result impacts the child's development, health behaviors, and relationship with the parent.

  3. XLMR in MRX families 29, 32, 33 and 38 results from the dup24 mutation in the ARX (Aristaless related homeobox gene

    Directory of Open Access Journals (Sweden)

    MacMillan Andrée

    2005-04-01

    Full Text Available Abstract Background X-linked mental retardation (XLMR is the leading cause of mental retardation in males. Mutations in the ARX gene in Xp22.1 have been found in numerous families with both nonsyndromic and syndromic XLMR. The most frequent mutation in this gene is a 24 bp duplication in exon 2. Based on this fact, a panel of XLMR families linked to Xp22 was tested for this particular ARX mutation. Methods Genomic DNA from XLMR families linked to Xp22.1 was amplified for exon 2 in ARX using a Cy5 labeled primer pair. The resulting amplicons were sized using the ALFexpress automated sequencer. Results A panel of 11 families with X-linked mental retardation was screened for the ARX 24dup mutation. Four nonsyndromic XLMR families – MRX29, MRX32, MRX33 and MRX38 – were found to have this particular gene mutation. Conclusion We have identified 4 additional XLMR families with the ARX dup24 mutation from a panel of 11 XLMR families linked to Xp22.1. This finding makes the ARX dup24 mutation the most common mutation in nonsyndromic XLMR families linked to Xp22.1. As this mutation can be readily tested for using an automated sequencer, screening should be considered for any male with nonsyndromic MR of unknown etiology.

  4. The Spectrum of SLC17A5-Gene Mutations Resulting in Free Sialic Acid–Storage Diseases Indicates Some Genotype-Phenotype Correlation

    Science.gov (United States)

    Aula, Nina; Salomäki, Pirjo; Timonen, Ritva; Verheijen, Frans; Mancini, Grazia; Månsson, Jan-Eric; Aula, Pertti; Peltonen, Leena

    2000-01-01

    Lysosomal free sialic acid–storage diseases include the allelic disorders Salla disease (SD) and infantile sialic acid–storage disease (ISSD). The defective gene, SLC17A5, coding for the lysosomal free sialic acid transporter was recently isolated by positional cloning. In the present study, we have identified a large number of mutations in SLC17A5 in patients presenting with either Salla disease or the ISSD phenotype. We also report for the first time the exon-intron boundaries of SLC17A5. All Finnish patients with SD (n=80) had a missense mutation changing a highly conserved arginine to cysteine (R39C); 91% of them were homozygotes for this old founder mutation. The compound-heterozygote patients, with the founder mutation in only one allele, presented with a more severe phenotype than did the homozygote patients. The same R39C mutation was also found both in most of the Swedish patients with SD and in a heterozygous form in five patients from central Europe who presented with an unusually severe (intermediate) SD phenotype. Ten different mutations, including deletions, insertions, and missense and nonsense mutations, were identified in patients with the most severe ISSD phenotype, most of whom were compound heterozygotes. Our results indicate some genotype-phenotype correlation in free sialic acid–storage diseases, suggesting that the phenotype associated with the homozygote R39C mutation is milder than that associated with other mutations. PMID:10947946

  5. Adaptation of cancer cells from different entities to the MDM2 inhibitor nutlin-3 results in the emergence of p53-mutated multi-drug-resistant cancer cells

    NARCIS (Netherlands)

    Michaelis, M.; Rothweiler, F.; Barth, S.; Cinatl, J.; van Rikxoort, M.; Loeschmann, N.; Voges, Y.; Breitling, R.; von Deimling, A.; Roedel, F.; Weber, K.; Fehse, B.; Mack, E.; Stiewe, T.; Doerr, H. W.; Speidel, D.; Cinatl, J.; Cinatl jr., J.; Stephanou, A.

    2011-01-01

    Six p53 wild-type cancer cell lines from infrequently p53-mutated entities (neuroblastoma, rhabdomyosarcoma, and melanoma) were continuously exposed to increasing concentrations of the murine double minute 2 inhibitor nutlin-3, resulting in the emergence of nutlin-3-resistant, p53-mutated sublines d

  6. Homozygosity for a single base-pair mutation in the oocyte-specific GDF9 gene results in sterility in Thoka sheep

    DEFF Research Database (Denmark)

    Nicel, Linda; Bishop, Stephen; Pong-Wong, Richardo;

    2009-01-01

    ovulation rate, although in some cases homozygous ewes are infertile. In the present study we present a detailed characterisation of a novel mutation in growth differentiation factor 9 (GDF9), found in Icelandic Thoka sheep. This mutation is a single base change (A1279C) resulting in a non...

  7. BRCA1 and BRCA2 mutations in males with familial breast and ovarian cancer syndrome. Results of a Spanish multicenter study.

    Science.gov (United States)

    de Juan, Inmaculada; Palanca, Sarai; Domenech, Asunción; Feliubadaló, Lidia; Segura, Ángel; Osorio, Ana; Chirivella, Isabel; de la Hoya, Miguel; Sánchez, Ana Beatriz; Infante, Mar; Tena, Isabel; Díez, Orland; Garcia-Casado, Zaida; Vega, Ana; Teulé, Àlex; Barroso, Alicia; Pérez, Pedro; Durán, Mercedes; Carrasco, Estela; Juan-Fita, M José; Murria, Rosa; Llop, Marta; Barragan, Eva; Izquierdo, Ángel; Benítez, Javier; Caldés, Trinidad; Salas, Dolores; Bolufer, Pascual

    2015-12-01

    Male breast cancer (MBC) is a rare disease that represents breast cancers (BCs). We analyze the results of a multicenter study performed in Spanish familial MBC including family history of hereditary breast and ovarian cancer syndrome (HBOCS) and clinicopathological features. We also study the relationship between BRCA1/BRCA2 mutational status in male relatives affected with cancer (MAC) and, family history and tumor types. The study included 312 men index cases with family history of HBOCS and 61 MAC BRCA1/2 mutation-carriers. Family history, histological grade (HG), clinicopathological and immunohistochemistry data were collected. BRCA1/2 mutation analyses were performed by direct sequencing or screening methods and the large rearrangements by multiplex ligation dependent probe amplification. We found 49 mutation-carriers (15.7%), 95.9% with BRCA2 mutations. BRCA2 mutation-carriers were associated with families with at least one MBC and one BC in female (type II; p = 0.05). Strong association were found between the presence of pathogenic mutations in MBCs and the advanced HG (p = 0.003). c.658_659delTG, c.2808_2811delACAA, c.6275_6276delTT and c.9026_9030delATCAT were the most prevalent mutations. In 61 MAC we found 20 mutations in BRCA1 and 41 in BRCA2. For MAC we show that mutational status was differentially associated with family history (p = 0.018) and tumor type, being BRCA2 mutations linked with BC and prostatic cancer (p = 0.018). MBC caused by BRCA1/2 mutations define two types of MBCs. The most frequent caused by BRCA2 mutation linked to type II families and the rarest one attributed to BRCA1 mutation. Tumor associated with MAC suggest that only BRCA2 mutations have to do with a specific type of cancer (BC and prostatic cancer); but the linkage to tumors is questionable for BRCA1 mutations .

  8. Gene mutations and genomic rearrangements in the mouse as a result of transposon mobilization from chromosomal concatemers.

    Directory of Open Access Journals (Sweden)

    Aron M Geurts

    2006-09-01

    Full Text Available Previous studies of the Sleeping Beauty (SB transposon system, as an insertional mutagen in the germline of mice, have used reverse genetic approaches. These studies have led to its proposed use for regional saturation mutagenesis by taking a forward-genetic approach. Thus, we used the SB system to mutate a region of mouse Chromosome 11 in a forward-genetic screen for recessive lethal and viable phenotypes. This work represents the first reported use of an insertional mutagen in a phenotype-driven approach. The phenotype-driven approach was successful in both recovering visible and behavioral mutants, including dominant limb and recessive behavioral phenotypes, and allowing for the rapid identification of candidate gene disruptions. In addition, a high frequency of recessive lethal mutations arose as a result of genomic rearrangements near the site of transposition, resulting from transposon mobilization. The results suggest that the SB system could be used in a forward-genetic approach to recover interesting phenotypes, but that local chromosomal rearrangements should be anticipated in conjunction with single-copy, local transposon insertions in chromosomes. Additionally, these mice may serve as a model for chromosome rearrangements caused by transposable elements during the evolution of vertebrate genomes.

  9. Consensus for EGFR mutation testing in non-small cell lung cancer: results from a European workshop

    DEFF Research Database (Denmark)

    Pirker, Robert; Herth, Felix J F; Kerr, Keith M;

    2010-01-01

    Activating somatic mutations of the tyrosine kinase domain of epidermal growth factor receptor (EGFR) have recently been characterized in a subset of patients with advanced non-small cell lung cancer (NSCLC). Patients harboring these mutations in their tumors show excellent response to EGFR...... tyrosine kinase inhibitors (EGFR-TKIs). The EGFR-TKI gefitinib has been approved in Europe for the treatment of adult patients with locally advanced or metastatic NSCLC with activating mutations of the EGFR TK. Because EGFR mutation testing is not yet well established across Europe, biomarker......-directed therapy only slowly emerges for the subset of NSCLC patients most likely to benefit: those with EGFR mutations....

  10. Nonsense Mutations in SMPX, Encoding a Protein Responsive to Physical Force, Result in X-Chromosomal Hearing Loss

    Science.gov (United States)

    Huebner, Antje K.; Gandia, Marta; Frommolt, Peter; Maak, Anika; Wicklein, Eva M.; Thiele, Holger; Altmüller, Janine; Wagner, Florian; Viñuela, Antonio; Aguirre, Luis A.; Moreno, Felipe; Maier, Hannes; Rau, Isabella; Gießelmann, Sebastian; Nürnberg, Gudrun; Gal, Andreas; Nürnberg, Peter; Hübner, Christian A.; del Castillo, Ignacio; Kurth, Ingo

    2011-01-01

    The fact that hereditary hearing loss is the most common sensory disorder in humans is reflected by, among other things, an extraordinary allelic and nonallelic genetic heterogeneity. X-chromosomal hearing impairment represents only a minor fraction of all cases. In a study of a Spanish family the locus for one of the X-chromosomal forms was assigned to Xp22 (DFNX4). We mapped the disease locus in the same chromosomal region in a large German pedigree with X-chromosomal nonsyndromic hearing impairment by using genome-wide linkage analysis. Males presented with postlingual hearing loss and onset at ages 3–7, whereas onset in female carriers was in the second to third decades. Targeted DNA capture with high-throughput sequencing detected a nonsense mutation in the small muscle protein, X-linked (SMPX) of affected individuals. We identified another nonsense mutation in SMPX in patients from the Spanish family who were previously analyzed to map DFNX4. SMPX encodes an 88 amino acid, cytoskeleton-associated protein that is responsive to mechanical stress. The presence of Smpx in hair cells and supporting cells of the murine cochlea indicates its role in the inner ear. The nonsense mutations detected in the two families suggest a loss-of-function mechanism underlying this form of hearing impairment. Results obtained after heterologous overexpression of SMPX proteins were compatible with this assumption. Because responsivity to physical force is a characteristic feature of the protein, we propose that long-term maintenance of mechanically stressed inner-ear cells critically depends on SMPX function. PMID:21549336

  11. DEPENDENCE OF YKL-40 mRNA TISSUE LEVELS ON KRAS MUTATION STATUS IN COLORECTAL CANCER - PRELIMINARY RESULTS

    Directory of Open Access Journals (Sweden)

    Yana Feodorova

    2015-08-01

    Full Text Available Colorectal cancer (CRC is one of the most deadly cancers worldwide. Despite the introduction of targeted molecular therapies in the last 10 years, overall survival has not increased substantially. CRC progression is accompanied by numerous genetic and epigenetic alterations and dysregulation of several signaling pathways, among which activation of Wnt and inactivation of TGF-β signaling. The molecular heterogeneity of CRC, however, hinders the molecular subtyping of CRC and thus the identification of common biomarkers for this pathology. The only three well established biomarkers for advanced-colorectal-cancer drug treatment are negative biomarkers. These are mutations in the genes KRAS, NRAS and BRAF which determine resistance to therapy with anti-EGFR antibodies. YKL-40 is a chitin-binding glycoprotein that has been shown to play a role in extracellular tissue remodeling, angiogenesis, cell migration and inflammation. Increased serum levels of this protein have been detected in patients with CRC but the role of YKL-40 in this neoplastic disease has not been studied extensively and the precise function of YKL-40 in CRC progression is not known. In the present study we determined the KRAS mutation status and measured the mRNA levels of YKL-40 of 24 patients with sporadic CRC. In addition, we assessed the association between these two parameters by statistical analysis. We are the first to show that in CRC YKL-40 mRNA levels are dependent on the presence of KRAS mutations, being prominently elevated in the wild type background. Our results indicate the potential role of YKL-40 as a target molecule for CRC therapy.

  12. A mutation in NFkB interacting protein 1 results in cardiomyopathy and abnormal skin development in wa3 mice.

    Science.gov (United States)

    Herron, Bruce J; Rao, Cherie; Liu, Shanming; Laprade, Lisa; Richardson, James A; Olivieri, Emily; Semsarian, Chris; Millar, Sarah E; Stubbs, Lisa; Beier, David R

    2005-03-01

    We have identified waved 3 (wa3), a novel recessive mutation that causes abnormalities of the heart and skin. The cardiac defect results in a severe and rapidly progressive dilated cardiomyopathy. We identified the gene mutated in these mice, which we call NFkB interacting protein1 (Nkip1), using positional cloning. Nkip1 is expressed in skin, heart and vascular endothelium and shares homology with a small family of proteins that play a role in the regulation of transcription factors. A C-terminal fragment of this protein was previously identified as the RelA associated inhibitor (RAI). We show that the full-length protein is larger than previously described, and we confirm that it interacts with NFkB in vivo. Expression analysis of genes known to be regulated by NFkB revealed that Intercellular adhesion molecule 1 (Icam1) expression is consistently elevated in mutant mice. This result suggests that wa3 mutant mice represent a potentially important model for the analysis of the role of inflammatory processes in heart disease.

  13. A splice site mutation in laminin-α2 results in a severe muscular dystrophy and growth abnormalities in zebrafish.

    Directory of Open Access Journals (Sweden)

    Vandana A Gupta

    Full Text Available Congenital muscular dystrophy (CMD is a clinically and genetically heterogeneous group of inherited muscle disorders. In patients, muscle weakness is usually present at or shortly after birth and is progressive in nature. Merosin deficient congenital muscular dystrophy (MDC1A is a form of CMD caused by a defect in the laminin-α2 gene (LAMA2. Laminin-α2 is an extracellular matrix protein that interacts with the dystrophin-dystroglycan (DGC complex in membranes providing stability to muscle fibers. In an N-ethyl-N-nitrosourea mutagenesis screen to develop zebrafish models of neuromuscular diseases, we identified a mutant fish that exhibits severe muscular dystrophy early in development. Genetic mapping identified a splice site mutation in the lama2 gene. This splice site is highly conserved in humans and this mutation results in mis-splicing of RNA and a loss of protein function. Homozygous lama2 mutant zebrafish, designated lama2(cl501/cl501, exhibited reduced motor function and progressive degeneration of skeletal muscles and died at 8-15 days post fertilization. The skeletal muscles exhibited damaged myosepta and detachment of myofibers in the affected fish. Laminin-α2 deficiency also resulted in growth defects in the brain and eye of the mutant fish. This laminin-α2 deficient mutant fish represents a novel disease model to develop therapies for modulating splicing defects in congenital muscular dystrophies and to restore the muscle function in human patients with CMD.

  14. Fibrinogen geneva II: a new congenitally abnormal fibrinogen alpha chain (Gly17Asp) with a review of similar mutations resulting in abnormal knob A.

    Science.gov (United States)

    Casini, Alessandro; De Maistre, Emmanuel; Casini-Stuppi, Virginie; Fontana, Pierre; Neerman-Arbez, Marguerite; de Moerloose, Philippe

    2014-04-01

    Congenital dysfibrinogenemias are characterized by biosynthesis of a structurally abnormal fibrinogen molecule that exhibits reduced functional levels compared with the level of fibrinogen antigen. To date a large number of mutations have been identified in patients with dysfibrinogenemia. Mutations occurring at the thrombin cleavage site (Arg16-Gly17 in the mature alpha-chain) at the amino-terminal end of the fibrinogen alpha chain are a common cause of the disease. These mutations causing abnormal fibrin polymerization are associated with different phenotypes. Here, we report the identification of a novel heterozygous missense mutation of Glycine 17 (Gly17Asp) in a female patient with mild bleeding manifestations, and compare it with other previously reported mutations also resulting in abnormal knob A.

  15. Targeted prostate cancer screening in men with mutations in BRCA1 and BRCA2 detects aggressive prostate cancer: preliminary analysis of the results of the IMPACT study

    DEFF Research Database (Denmark)

    Mitra, Anita V; Bancroft, Elizabeth K; Barbachano, Yolanda;

    2011-01-01

    Study Type - Diagnostic (validating cohort)
Level of Evidence 1b OBJECTIVES: To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening...... in BRCA1/2 mutation carriers and controls), was established. This is the first multicentre screening study targeted at men with a known genetic predisposition to prostate cancer. A preliminary analysis of the data is reported. MATERIALS AND METHODS: Men aged 40-69 years from families with BRCA1 or BRCA2...... mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA >3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation. RESULTS: In total, 300 men were recruited (205 mutation carriers; 89 BRCA1, 116 BRCA2...

  16. A gain-of-function mutation in the sodium channel gene Scn2a results in seizures and behavioral abnormalities.

    Science.gov (United States)

    Kearney, J A; Plummer, N W; Smith, M R; Kapur, J; Cummins, T R; Waxman, S G; Goldin, A L; Meisler, M H

    2001-01-01

    The GAL879-881QQQ mutation in the cytoplasmic S4-S5 linker of domain 2 of the rat brain IIA sodium channel (Na(v)1.2) results in slowed inactivation and increased persistent current when expressed in Xenopus oocytes. The neuron-specific enolase promoter was used to direct in vivo expression of the mutated channel in transgenic mice. Three transgenic lines exhibited seizures, and line Q54 was characterized in detail. The seizures in these mice began at two months of age and were accompanied by behavioral arrest and stereotyped repetitive behaviors. Continuous electroencephalogram monitoring detected focal seizure activity in the hippocampus, which in some instances generalized to involve the cortex. Hippocampal CA1 neurons isolated from presymptomatic Q54 mice exhibited increased persistent sodium current which may underlie hyperexcitability in the hippocampus. During the progression of the disorder there was extensive cell loss and gliosis within the hippocampus in areas CA1, CA2, CA3 and the hilus. The lifespan of Q54 mice was shortened and only 25% of the mice survived beyond six months of age. Four independent transgenic lines expressing the wild-type sodium channel were examined and did not exhibit any abnormalities. The transgenic Q54 mice provide a genetic model that will be useful for testing the effect of pharmacological intervention on progression of seizures caused by sodium channel dysfunction. The human ortholog, SCN2A, is a candidate gene for seizure disorders mapped to chromosome 2q22-24.

  17. Axonemal dynein intermediate-chain gene (DNAI1) mutations result in situs inversus and primary ciliary dyskinesia (Kartagener syndrome).

    Science.gov (United States)

    Guichard, C; Harricane, M C; Lafitte, J J; Godard, P; Zaegel, M; Tack, V; Lalau, G; Bouvagnet, P

    2001-04-01

    Kartagener syndrome (KS) is a trilogy of symptoms (nasal polyps, bronchiectasis, and situs inversus totalis) that is associated with ultrastructural anomalies of cilia of epithelial cells covering the upper and lower respiratory tracts and spermatozoa flagellae. The axonemal dynein intermediate-chain gene 1 (DNAI1), which has been demonstrated to be responsible for a case of primary ciliary dyskinesia (PCD) without situs inversus, was screened for mutation in a series of 34 patients with KS. We identified compound heterozygous DNAI1 gene defects in three independent patients and in two of their siblings who presented with PCD and situs solitus (i.e., normal position of inner organs). Strikingly, these five patients share one mutant allele (splice defect), which is identical to one of the mutant DNAI1 alleles found in the patient with PCD, reported elsewhere. Finally, this study demonstrates a link between ciliary function and situs determination, since compound mutation heterozygosity in DNAI1 results in PCD with situs solitus or situs inversus (KS).

  18. Mutation of zebrafish dihydrolipoamide branched-chain transacylase E2 results in motor dysfunction and models maple syrup urine disease

    Directory of Open Access Journals (Sweden)

    Timo Friedrich

    2012-03-01

    Analysis of zebrafish mutants that demonstrate abnormal locomotive behavior can elucidate the molecular requirements for neural network function and provide new models of human disease. Here, we show that zebrafish quetschkommode (que mutant larvae exhibit a progressive locomotor defect that culminates in unusual nose-to-tail compressions and an inability to swim. Correspondingly, extracellular peripheral nerve recordings show that que mutants demonstrate abnormal locomotor output to the axial muscles used for swimming. Using positional cloning and candidate gene analysis, we reveal that a point mutation disrupts the gene encoding dihydrolipoamide branched-chain transacylase E2 (Dbt, a component of a mitochondrial enzyme complex, to generate the que phenotype. In humans, mutation of the DBT gene causes maple syrup urine disease (MSUD, a disorder of branched-chain amino acid metabolism that can result in mental retardation, severe dystonia, profound neurological damage and death. que mutants harbor abnormal amino acid levels, similar to MSUD patients and consistent with an error in branched-chain amino acid metabolism. que mutants also contain markedly reduced levels of the neurotransmitter glutamate within the brain and spinal cord, which probably contributes to their abnormal spinal cord locomotor output and aberrant motility behavior, a trait that probably represents severe dystonia in larval zebrafish. Taken together, these data illustrate how defects in branched-chain amino acid metabolism can disrupt nervous system development and/or function, and establish zebrafish que mutants as a model to better understand MSUD.

  19. Pseudomonas aeruginosa mutations in lasl and rhll quorum sensing systems result in milder chronic lung infection

    DEFF Research Database (Denmark)

    Wu, H.; Song, Z.J.; Givskov, Michael Christian

    2001-01-01

    . The rat model of P. aeruginosa lung infection was used in the present study. The rats were killed on days 3, 7, 14 and 28 after infection with the P. aeruginosa strains. The results showed that during the early stages of infection, the PAO1 double mutant induced a stronger serum antibody response, higher...

  20. Evolutionary loss of the rdar morphotype in Salmonella as a result of high mutation rates during laboratory passage.

    Science.gov (United States)

    Davidson, Carla J; White, Aaron P; Surette, Michael G

    2008-03-01

    Rapid evolution of microbes under laboratory conditions can lead to domestication of environmental or clinical strains. In this work, we show that domestication due to laboratory passage in rich medium is extremely rapid. Passaging of wild-type Salmonella in rich medium led to diversification of genotypes contributing to the loss of a spatial phenotype, called the rdar morphotype, within days. Gene expression analysis of the rdar regulatory network demonstrated that mutations were primarily within rpoS, indicating that the selection pressure for scavenging during stationary phase had the secondary effect of impairing this highly conserved phenotype. If stationary phase was omitted from the experiment, radiation of genotypes and loss of the rdar morphotype was also demonstrated, but due to mutations within the cellulose biosynthesis pathway and also in an unknown upstream regulator. Thus regardless of the selection pressure, rapid regulatory changes can be observed on laboratory timescales. The speed of accumulation of rpoS mutations during daily passaging could not be explained by measured fitness and mutation rates. A model of mutation accumulation suggests that to generate the observed accumulation of sigma 38 mutations, this locus must experience a mutation rate of approximately 10(-4) mutations/gene/generation. Sequencing and gene expression of population isolates indicated that there were a wide variety of sigma 38 phenotypes within each population. This suggests that the rpoS locus is highly mutable by an unknown pathway, and that these mutations accumulate rapidly under common laboratory conditions.

  1. Afatinib in first-line setting for NSCLC harbouring common EGFR mutations: new light after the preliminary results of LUX-Lung 7?

    Science.gov (United States)

    Passaro, Antonio; Pochesci, Alessia; Spitaleri, Gianluca; Catania, Chiara; Noberasco, Cristina; Del Signore, Ester; de Marinis, Filippo

    2016-03-01

    The development of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) changed dramatically the history of non-small cell lung cancer (NSCLC) harboring EGFR sensitive mutations. Several randomized prospective trials confirmed the superiority of these target agents about survival and response rate when comparing with platinum-based chemotherapy. Knowledge about EGFR mutations increased gradually during the development of target agents and different clinical trials. EGFR mutations cannot be considered all equal, but different entities should be considered in our clinical practice: exon 19 deletions, exon 21 mutation (L858R) and uncommon mutation (exon 20, exon 18 and double mutation). Nowadays, we dispose of three different EGFR TKIs (afatinib, erlotinib and gefitinib) approved for the treatment for first-line treatment of patients di NSCLC carrying EGFR, that was compared only by indirect analysis, producing data not always clear and convincing. This research highlight is an overview of data about EGFR TKIs in first-line setting, focusing on differences about exon 19 deletions and L585R mutation in patients treated with different TKIs. In addition, we report the preliminary results of the first head-to-head randomized clinical trial between two different EGFR TKIs, the LUX-Lung 7 (LL7) that compared afatinib and gefitinib showing interesting results.

  2. A de novo germline MLH1 mutation in a Lynch syndrome patient with discordant immunohistochemical and molecular biology test results

    Institute of Scientific and Technical Information of China (English)

    Fabrice Airaud; Sébastien Küry; Isabelle Valo; Ingrid Maury; Dominique Bonneau; Olivier Ingster; Stéphane Bezieau

    2012-01-01

    We describe a patient with a Homo sapiens mutL homolog 1 (MLH1)-associated Lynch syndrome with previous diagnoses of two distinct primary cancers:a sigmoid colon cancer at the age of 39 years,and a right colon cancer at the age of 50 years.The mutation identified in his blood and buccal cells,c.1771delG,p.Asp591Ilefs*25,appears to be a de novo event,as it was not transmitted by either of his parents.This type of de novo event is rare in MLH1 as only three cases have been reported in the literature so far.Furthermore,the discordant results observed between replication error phenotyping and immunohistochemistry highlight the importance of the systematic use of both pre-screening tests in the molecular diagnosis of Lynch syndrome.

  3. Kinked collagen VI tetramers and reduced microfibril formation as a result of Bethlem myopathy and introduced triple helical glycine mutations

    NARCIS (Netherlands)

    Lamande, [No Value; Morgelin, M; Selan, C; Jobsis, GJ; Baas, F; Bateman, JF

    2002-01-01

    Mutations in the genes that code for collagen VI subunits, COL6A1, COL6A2, and COL6A3, are the cause of the dominantly inherited disorder, Bethlem myopathy. Glycine mutations that interrupt the Gly-X-Y repetitive amino acid sequence that forms the characteristic collagen triple helix have been defin

  4. Filaggrin null mutations and association with contact allergy and allergic contact dermatitis: results from a tertiary dermatology clinic

    DEFF Research Database (Denmark)

    Carlsen, Berit Christina; Johansen, Jeanne Duus; Menné, Torkil

    2010-01-01

    Filaggrin null (FLG) mutations lead to skin barrier disruption with a reduced resistance towards exogenous agents and also influence the course of disease in atopic dermatitis.......Filaggrin null (FLG) mutations lead to skin barrier disruption with a reduced resistance towards exogenous agents and also influence the course of disease in atopic dermatitis....

  5. Local amino acid sequence patterns dominate the heterogeneous phenotype for the collagen connective tissue disease Osteogenesis Imperfecta resulting from Gly mutations.

    Science.gov (United States)

    Xiao, Jianxi; Yang, Zhangfu; Sun, Xiuxia; Addabbo, Rayna; Baum, Jean

    2015-10-01

    Osteogenesis Imperfecta (OI), a hereditary connective tissue disease in collagen that arises from a single Gly → X mutation in the collagen chain, varies widely in phenotype from perinatal lethal to mild. It is unclear why there is such a large variation in the severity of the disease considering the repeating (Gly-X-Y)n sequence and the uniform rod-like structure of collagen. We systematically evaluate the effect of local (Gly-X-Y)n sequence around the mutation site on OI phenotype using integrated bio-statistical approaches, including odds ratio analysis and decision tree modeling. We show that different Gly → X mutations have different local sequence patterns that are correlated with lethal and nonlethal phenotypes providing a mechanism for understanding the sensitivity of local context in defining lethal and non-lethal OI. A number of important trends about which factors are related to OI phenotypes are revealed by the bio-statistical analyses; most striking is the complementary relationship between the placement of Pro residues and small residues and their correlation to OI phenotype. When Pro is present or small flexible residues are absent nearby a mutation site, the OI case tends to be lethal; when Pro is present or small flexible residues are absent further away from the mutation site, the OI case tends to be nonlethal. The analysis also reveals the dominant role of local sequence around mutation sites in the Major Ligand Binding Regions that are primarily responsible for collagen binding to its receptors and shows that non-lethal mutations are highly predicted by local sequence considerations alone whereas lethal mutations are not as easily predicted and may be a result of more complex interactions. Understanding the sequence determinants of OI mutations will enhance genetic counseling and help establish which steps in the collagen hierarchy to target for drug therapy.

  6. Four mutations in SH2 and SH3 domains of Bruton`s tyrosine kinase (BTK) resulting in classic X-linked agammaglobulinemia (XLA)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.H.; Zhang, M.; Zhu, Q.; Scott, C.R.; Och, H.D. [Univ. of Washington, Seattle, WA (United States)

    1994-09-01

    XLA is an X-linked immunodeficient disease in man resulted from mutations in the BTK gene. BTK contains a unique amino-region of unknown function, SH2 and SH3 (src homology) domains, and a carboxyl-terminal kinase (SH1) domain. We have studied the normal genomic organizations of the SH2 and SH3 domains and found the regions containing 6 exons are about 3000 bp in length. We also carried out sequence analyses of cDNA and genomic DNA of XLA patients to identify mutations. Four of fourteen families with XLA were found to have mutations within the regions. (1) A point mutation G to T in codon 240 resulted in a stop codon. (2) A transition mutation (g to a) at first nucleotide of intron 8 resulted in exon 8 skipping, missing 21 codons and shorter polypeptide but with normal kinase activity and ATP binding ability. (3) An a to t transversion at one of the invariant dinucleotides (ag) of the 3{prime} end of intron 11 resulted in alternative splicing at a position 13 nucleotides downstream from the normal one. The mutation produced mRNA with 13 nucleotide deletion and presumably resulted in a frameshift at codon 372 leading to a stop codon at 398. (4) A 16 nucleotide duplication (1248 to 1263 of the cDNA sequence) consistently present in mRNA of three brothers with XLA. However, genomic sequence of patient DNA of the regions did not reveal the anormaly. The observation that mutations within SH2 and SH3 causing severe B-cell defects typical for XLA suggests that these two domains are crucial for the function of BTK, possibly by regulating the interaction of cytoplasmic proteins involved in signal transduction.

  7. Decreased gene expression activity as a result of a mutation in the calreticulin gene promoter in a family case of schizoaffective disorder.

    Science.gov (United States)

    Farashi, S; Ohadi, M; Hosseinkhani, S; Darvish, H; Mirabzadeh, A

    2016-06-01

    Accumulating evidence of population association studies support the hypothesis that the high heritability of major psychiatric disorders is a combination of relatively common alleles of modest effect, and rare alleles some with relatively larger effects. We have previously reported low frequency mutations in the proximal promoter of the human calreticulin (CALR) gene that co-occur with the spectrum of major psychiatric disorders. One of those mutations at -205C>T (rs556992558) was detected in an isolate case of schizoaffective disorder. In the current study, the functional implication of mutation -205T is studied in the human neuronal cell lines LAN-5, BE(2)-C and HEK-293. In contrast with other mutations in the promoter region which increase gene expression activity, the -205T mutation significantly decreased gene expression in those cell lines in comparison with the wild-type -205C nucleotide (p expression activity in the mutant -205T versus the wild-type -205C construct. VPA increased gene expression activity in both constructs, while a significantly higher expression activity was observed in the mutant construct (p < 0.01), indicative of the creation of a positive effector binding site for VPA as a result of the -205T mutation. We conclude that deviation from normalcy in the level of CALR in either direction is associated with major psychiatric disorders.

  8. Mutations in paralogous Hox genes result in overlapping homeotic transformations of the axial skeleton: evidence for unique and redundant function.

    Science.gov (United States)

    Horan, G S; Kovàcs, E N; Behringer, R R; Featherstone, M S

    1995-05-01

    Hoxd-4 (previously known as Hox-4.2 and -5.1) is a mouse homeobox-containing gene homologous to the Drosophila homeotic gene Deformed. During embryogenesis, Hoxd-4 is expressed in the presumptive hindbrain and spinal cord, prevertebrae, and other tissues. In the adult, Hoxd-4 transcripts are expressed predominantly in the testis and kidney, and to a lesser extent in intestine and heart. To understand the role of Hoxd-4 during mouse embryogenesis, we generated Hoxd-4 mutant mice. Mice heterozygous or homozygous for the Hoxd-4 mutation exhibit homeotic transformations of the second cervical vertebrae (C2) to the first cervical vertebrae (C1) and malformations of the neural arches of C1 to C3 and of the basioccipital bone. The phenotype was incompletely penetrant and showed variable expressivity on both an F2 hybrid and 129 inbred genetic background. The mutant phenotype was detected in the cartilaginous skeleton of 14.5-day (E14.5) mutant embryos but no apparent differences were detected in the somites of E9.5 mutant embryos, suggesting that the abnormalities develop after E9.5 perhaps during or after resegmentation of the somites to form the prevertebrae. These results suggest that Hoxd-4 plays a role in conferring position information along the anteroposterior axis in the skeleton. The phenotypic similarities and differences between Hoxd-4 and previously reported Hoxa-4 and Hoxb-4 mutant mice suggest that Hox gene paralogs have both redundant and unique functions.

  9. Novel Homozygous Missense Mutation in SPG20 Gene Results in Troyer Syndrome Associated with Mitochondrial Cytochrome c Oxidase Deficiency.

    Science.gov (United States)

    Spiegel, Ronen; Soiferman, Devorah; Shaag, Avraham; Shalev, Stavit; Elpeleg, Orly; Saada, Ann

    2016-08-19

    Troyer syndrome is an autosomal recessive form of hereditary spastic paraplegia (HSP) caused by deleterious mutations in the SPG20 gene. Although the disease is associated with a loss of function mechanism of spartin, the protein encoded by SPG20, the precise pathogenesis is yet to be elucidated. Recent data indicated an important role for spartin in both mitochondrial maintenance and function. Here we report a child presenting with progressive spastic paraparesis, generalized muscle weakness, dysarthria, impaired growth, and severe isolated decrease in muscle cytochrome c oxidase (COX) activity. Whole exome sequencing identified the homozygous c.988A>G variant in SPG20 gene (p.Met330Val) resulting in almost complete loss of spartin in skeletal muscle. Further analyses demonstrated significant tissue specific reduction of COX 4, a nuclear encoded subunit of COX, in muscle suggesting a role for spartin in proper mitochondrial respiratory chain function mediated by COX activity. Our findings need to be verified in other Troyer syndrome patients in order to classify it as a form of HSP caused by mitochondrial dysfunction.

  10. Expression of A2V-mutated Aβ in Caenorhabditis elegans results in oligomer formation and toxicity☆

    Science.gov (United States)

    Diomede, Luisa; Di Fede, Giuseppe; Romeo, Margherita; Bagnati, Renzo; Ghidoni, Roberta; Fiordaliso, Fabio; Salio, Monica; Rossi, Alessandro; Catania, Marcella; Paterlini, Anna; Benussi, Luisa; Bastone, Antonio; Stravalaci, Matteo; Gobbi, Marco; Tagliavini, Fabrizio; Salmona, Mario

    2014-01-01

    Although Alzheimer's disease (AD) is usually sporadic, in a small proportion of cases it is familial and can be linked to mutations in β-amyloid precursor protein (APP). Unlike the other genetic defects, the mutation [alanine-673→valine-673] (A673V) causes the disease only in the homozygous condition with enhanced amyloid β (Aβ) production and aggregation; heterozygous carriers remain unaffected. It is not clear how misfolding and aggregation of Aβ is affected in vivo by this mutation and whether this correlates with its toxic effects. No animal models over-expressing the A673V–APP gene or alanine-2-valine (A2V) mutated human Aβ protein are currently available. Using the invertebrate Caenorhabditis elegans, we generated the first transgenic animal model to express the human Aβ1–40 wild-type (WT) in neurons or possess the A2V mutation (Aβ1–40A2V). Insertion of an Aβ-mutated gene into this nematode reproduced the homozygous state of the human pathology. Functional and biochemical characteristics found in the A2V strain were compared to those of transgenic C. elegans expressing Aβ1–40WT. The expression of both WT and A2V Aβ1–40 specifically reduced the nematode's lifespan, causing behavioral defects and neurotransmission impairment which were worse in A2V worms. Mutant animals were more resistant than WT to paralysis induced by the cholinergic agonist levamisole, indicating that the locomotor defect was specifically linked to postsynaptic dysfunctions. The toxicity caused by the mutated protein was associated with a high propensity to form oligomeric assemblies which accumulate in the neurons, suggesting this to be the central event involved in the postsynaptic damage and early onset of the disease in homozygous human A673V carriers. PMID:24184799

  11. Two novel mutations on exon 8 and intron 65 of COL7A1 gene in two Chinese brothers result in recessive dystrophic epidermolysis bullosa.

    Directory of Open Access Journals (Sweden)

    Ying Lin

    Full Text Available Dystrophic epidermolysis bullosa is an inherited bullous dermatosis caused by the COL7A1 gene mutation in autosomal dominant or recessive mode. COL7A1 gene encodes type VII collagen - the main component of the anchoring fibrils at the dermal-epidermal junction. Besides the 730 mutations reported, we identified two novel COL7A1 gene mutations in a Chinese family, which caused recessive dystrophic epidermolysis bullosa (RDEB. The diagnosis was established histopathologically and ultrastructurally. After genomic DNA extraction from the peripheral blood sample of all subjects (5 pedigree members and 136 unrelated control individuals, COL7A1 gene screening was performed by polymerase chain reaction amplification and direct DNA sequencing of the whole coding exons and flanking intronic regions. Genetic analysis of the COL7A1 gene in affected individuals revealed compound heterozygotes with identical novel mutations. The maternal mutation is a 2-bp deletion at exon 8 (c.1006_1007delCA, leading to a subsequent reading frame-shift and producing a premature termination codon located 48 amino acids downstream in exon 9 (p.Q336EfsX48, consequently resulting in the truncation of 2561 amino acids downstream. This was only present in two affected brothers, but not in the other unaffected family members. The paternal mutation is a 1-bp deletion occurring at the first base of intron 65 (c.IVS5568+1delG that deductively changes the strongly conserved GT dinucleotide at the 5' donor splice site, results in subsequent reading-through into intron 65, and creates a stop codon immediately following the amino acids encoded by exon 65 (GTAA→TAA. This is predicted to produce a truncated protein lacking of 1089 C-terminal amino acids downstream. The latter mutation was found in all family members except one of the two unaffected sisters. Both mutations were observed concurrently only in the two affected brothers. Neither mutation was discovered in 136 unrelated Chinese

  12. Mutations in CRADD Result in Reduced Caspase-2-Mediated Neuronal Apoptosis and Cause Megalencephaly with a Rare Lissencephaly Variant.

    Science.gov (United States)

    Di Donato, Nataliya; Jean, Ying Y; Maga, A Murat; Krewson, Briana D; Shupp, Alison B; Avrutsky, Maria I; Roy, Achira; Collins, Sarah; Olds, Carissa; Willert, Rebecca A; Czaja, Agnieszka M; Johnson, Rachel; Stover, Jessi A; Gottlieb, Steven; Bartholdi, Deborah; Rauch, Anita; Goldstein, Amy; Boyd-Kyle, Victoria; Aldinger, Kimberly A; Mirzaa, Ghayda M; Nissen, Anke; Brigatti, Karlla W; Puffenberger, Erik G; Millen, Kathleen J; Strauss, Kevin A; Dobyns, William B; Troy, Carol M; Jinks, Robert N

    2016-11-03

    Lissencephaly is a malformation of cortical development typically caused by deficient neuronal migration resulting in cortical thickening and reduced gyration. Here we describe a "thin" lissencephaly (TLIS) variant characterized by megalencephaly, frontal predominant pachygyria, intellectual disability, and seizures. Trio-based whole-exome sequencing and targeted re-sequencing identified recessive mutations of CRADD in six individuals with TLIS from four unrelated families of diverse ethnic backgrounds. CRADD (also known as RAIDD) is a death-domain-containing adaptor protein that oligomerizes with PIDD and caspase-2 to initiate apoptosis. TLIS variants cluster in the CRADD death domain, a platform for interaction with other death-domain-containing proteins including PIDD. Although caspase-2 is expressed in the developing mammalian brain, little is known about its role in cortical development. CRADD/caspase-2 signaling is implicated in neurotrophic factor withdrawal- and amyloid-β-induced dendritic spine collapse and neuronal apoptosis, suggesting a role in cortical sculpting and plasticity. TLIS-associated CRADD variants do not disrupt interactions with caspase-2 or PIDD in co-immunoprecipitation assays, but still abolish CRADD's ability to activate caspase-2, resulting in reduced neuronal apoptosis in vitro. Homozygous Cradd knockout mice display megalencephaly and seizures without obvious defects in cortical lamination, supporting a role for CRADD/caspase-2 signaling in mammalian brain development. Megalencephaly and lissencephaly associated with defective programmed cell death from loss of CRADD function in humans implicate reduced apoptosis as an important pathophysiological mechanism of cortical malformation. Our data suggest that CRADD/caspase-2 signaling is critical for normal gyration of the developing human neocortex and for normal cognitive ability. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  13. Hepatitis E virus mutations associated with ribavirin treatment failure result in altered viral fitness and ribavirin sensitivity.

    Science.gov (United States)

    Debing, Yannick; Ramière, Christophe; Dallmeier, Kai; Piorkowski, Géraldine; Trabaud, Mary-Anne; Lebossé, Fanny; Scholtès, Caroline; Roche, Magali; Legras-Lachuer, Catherine; de Lamballerie, Xavier; André, Patrice; Neyts, Johan

    2016-09-01

    Ribavirin monotherapy is the preferred treatment for chronic hepatitis E, although occasional treatment failure occurs. We present a patient with chronic hepatitis E experiencing ribavirin treatment failure with a completely resistant phenotype. We aimed to identify viral mutations associated with treatment failure and explore the underlying mechanisms. Viral genomes were deep-sequenced at different time points and the role of identified mutations was assessed in vitro using mutant replicons, antiviral assays, cell culture of patient-derived virus and deep-sequencing. Ribavirin resistance was associated with Y1320H, K1383N and G1634R mutations in the viral polymerase, but also an insertion in the hypervariable region comprising a duplication and a polymerase-derived fragment. Analysis of these genome alterations in vitro revealed replication-increasing roles for Y1320H and G1634R mutations and the hypervariable region insertion. In contrast, the K1383N mutation in the polymerase F1-motif suppressed viral replication and increased the in vitro sensitivity to ribavirin, contrary to the clinical phenotype. Analysis of the replication of mutant full-length virus and in vitro culturing of patient-derived virus confirmed that sensitivity to ribavirin was retained. Finally, deep-sequencing of hepatitis E virus genomes revealed that ribavirin is mutagenic to viral replication in vitro and in vivo. Mutations Y1320H, G1634R and the hypervariable region insertion compensated for K1383N-associated replication defects. The specific role of the K1383N mutation remains enigmatic, but it appears to be of importance for the ribavirin resistant phenotype in this patient. Ribavirin is the most common treatment for chronic hepatitis E and is mostly effective, although some cases of ribavirin treatment failure have been described. Here, we report on a particular case of ribavirin resistance and investigate the underlying causes of treatment failure. Mutations in the viral polymerase

  14. A Single Mutation at the Sheet Switch Region Results in Conformational Changes Favoring 6 Light-Chain Fibrillogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Hernández-Santoyo, A.; Del Pozo Yauner, L; Fuentes-Silva, D; Ortiz, E; Rudiño-Piñera, E; Sánchez-López, R; Horjales, E; Becerril, B; Rodríguez-Romero, A

    2010-01-01

    Systemic amyloid light-chain (LC) amyloidosis is a disease process characterized by the pathological deposition of monoclonal LCs in tissue. All LC subtypes are capable of fibril formation although {lambda} chains, particularly those belonging to the {lambda}6 type, are overrepresented. Here, we report the thermodynamic and in vitro fibrillogenic properties of several mutants of the {lambda}6 protein 6aJL2 in which Pro7 and/or His8 was substituted by Ser or Pro. The H8P and H8S mutants were almost as stable as the wild-type protein and were poorly fibrillogenic. In contrast, the P7S mutation decreased the thermodynamic stability of 6aJL2 and greatly enhanced its capacity to form amyloid-like fibrils in vitro. The crystal structure of the P7S mutant showed that the substitution induced both local and long-distance effects, such as the rearrangement of the VL (variable region of the light chain)-VL interface. This mutant crystallized in two orthorhombic polymorphs, P2{sub 1}2{sub 1}2{sub 1} and C222{sub 1}. In the latter, a monomer that was not arranged in the typical Bence-Jones dimer was observed for the first time. Crystal-packing analysis of the C222{sub 1} lattice showed the establishment of intermolecular {beta}-{beta} interactions that involved the N-terminus and {beta}-strand B and that these could be relevant in the mechanism of LC fibril formation. Our results strongly suggest that Pro7 is a key residue in the conformation of the N-terminal sheet switch motif and, through long-distance interactions, is also critically involved in the contacts that stabilized the VL interface in {lambda}6 LCs.

  15. Neonatal progeroid variant of Marfan syndrome with congenital lipodystrophy results from mutations at the 3' end of FBN1 gene.

    Science.gov (United States)

    Jacquinet, Adeline; Verloes, Alain; Callewaert, Bert; Coremans, Christine; Coucke, Paul; de Paepe, Anne; Kornak, Uwe; Lebrun, Frederic; Lombet, Jacques; Piérard, Gérald E; Robinson, Peter N; Symoens, Sofie; Van Maldergem, Lionel; Debray, François-Guillaume

    2014-04-01

    We report a 16-year-old girl with neonatal progeroid features and congenital lipodystrophy who was considered at birth as a possible variant of Wiedemann-Rautenstrauch syndrome. The emergence of additional clinical signs (marfanoid habitus, severe myopia and dilatation of the aortic bulb) lead to consider the diagnosis of the progeroid variant of Marfan syndrome. A de novo donor splice-site mutation (c.8226+1G>A) was identified in FBN1. We show that this mutation leads to exon 64 skipping and to the production of a stable mRNA that should allow synthesis of a truncated profibrillin-1, in which the C-terminal furin cleavage site is altered. FBN1 mutations associated with a similar phenotype have only been reported in four other patients. We confirm the correlation between marfanoid phenotype with congenital lipodystrophy and neonatal progeroid features (marfanoid-progeroid-lipodystrophy syndrome) and frameshift mutations at the 3' end of FBN1. This syndrome should be considered in differential diagnosis of neonatal progeroid syndromes.

  16. A combination of sbmA and tolC mutations in Escherichia coli K-12 Tn10-carrying strains results in hypersusceptibility to tetracycline.

    Science.gov (United States)

    de Cristóbal, Ricardo E; Vincent, Paula A; Salomón, Raúl A

    2008-02-01

    Previously, we demonstrated that Escherichia coli tolC mutations reduce the high-level resistance to tetracycline afforded by the transposon Tn10-encoded TetA pump from resistance at 200 microg/ml to resistance at 40 microg/ml. In this study, we found that the addition of an sbmA mutation to a tolC::Tn10 mutant exacerbates this phenotype: the double mutant did not form colonies, even in the presence of tetracycline at a concentration as low as 5 microg/ml. Inactivation of sbmA alone partially inhibited high-level tetracycline resistance, from resistance at 200 microg/ml to resistance at 120 microg/ml. There thus appears to be an additive effect of the mutations, resulting in almost complete suppression of the phenotypic expression of Tn10 tetracycline resistance.

  17. Retinal degeneration associated with RDH12 mutations results from decreased 11-cis retinal synthesis due to disruption of the visual cycle.

    NARCIS (Netherlands)

    Thompson, D.A.; Janecke, A.R.; Lange, J. de; Feathers, K.L.; Hubner, C.; McHenry, C.; Stockton, D.W.; Rammesmayer, G.; Lupski, J.R.; Antinolo, G.; Ayuso, C.; Baiget, M.; Gouras, P.; Heckenlively, J.R.; Hollander, A.I. den; Jacobson, S.G.; Lewis, R.A.; Sieving, P.A.; Wissinger, B.; IJzer, S.; Zrenner, E.; Utermann, G.; Gal, A.

    2005-01-01

    Retinoid dehydrogenases/reductases catalyze key oxidation-reduction reactions in the visual cycle that converts vitamin A to 11-cis retinal, the chromophore of the rod and cone photoreceptors. It has recently been shown that mutations in RDH12, encoding a retinol dehydrogenase, result in severe and

  18. MeCP2 mutation results in compartment-specific reductions in dendritic branching and spine density in layer 5 motor cortical neurons of YFP-H mice.

    Directory of Open Access Journals (Sweden)

    David P Stuss

    Full Text Available Rett Syndrome (RTT is a neurodevelopmental disorder predominantly caused by mutations in the X-linked gene MECP2. A primary feature of the syndrome is the impaired maturation and maintenance of excitatory synapses in the central nervous system (CNS. Different RTT mouse models have shown that particular Mecp2 mutations have highly variable effects on neuronal architecture. Distinguishing MeCP2 mutant cellular phenotypes therefore demands analysis of specific mutations in well-defined neuronal subpopulations. We examined a transgenically labeled subset of cortical neurons in YFP-H mice crossed with the Mecp2(tm1.1Jae mutant line. YFP(+ Layer 5 pyramidal neurons in the motor cortex of wildtype and hemizygous mutant male mice were examined for differences in dendrite morphology and spine density. Total basal dendritic length was decreased by 18.6% due to both shorter dendrites and reduced branching proximal to the soma. Tangential dendrite lengths in the apical tuft were reduced by up to 26.6%. Spine density was reduced by 47.4% in the apical tuft and 54.5% in secondary apical dendrites, but remained unaffected in primary apical and proximal basal dendrites. We also found that MeCP2 mutation reduced the number of YFP(+ cells in YFP-H mice by up to 72% in various cortical regions without affecting the intensity of YFP expression in individual cells. Our results support the view that the effects of MeCP2 mutation are highly context-dependent and cannot be generalized across mutation types and cell populations.

  19. SORT1 Mutation Resulting in Sortilin Deficiency and p75NTR Upregulation in a Family With Essential Tremor

    Science.gov (United States)

    Sánchez, Elena; Bergareche, Alberto; Krebs, Catharine E.; Gorostidi, Ana; Makarov, Vladimir; Ruiz-Martinez, Javier; Chorny, Alejo; Lopez de Munain, Adolfo; Marti-Masso, Jose Felix

    2015-01-01

    *These authors contributed equally to this work.Essential tremor (ET) is the most prevalent movement disorder affecting millions of people in the United States. Although a positive family history is one of the most important risk factors for ET, the genetic causes of ET remain unknown. In this study, whole exome sequencing and subsequent approaches were performed in a family with an autosomal dominant form of early-onset ET. Functional analyses including mutagenesis, cell culture, gene expression, enzyme-linked immunosorbent, and apoptosis assays were also performed. A disease-segregating mutation (p.Gly171Ala), absent in normal population, was identified in the SORT1 gene. The p.Gly171Ala mutation was shown not only to impair the expression of its encoding protein sortilin but also the mRNA levels of its binding partner p75 neurotrophin receptor that is known to be implicated in brain injury, neuronal apoptosis, and neurotransmission. PMID:26297037

  20. SORT1 Mutation Resulting in Sortilin Deficiency and p75NTR Upregulation in a Family With Essential Tremor

    Directory of Open Access Journals (Sweden)

    Elena Sánchez

    2015-08-01

    Full Text Available *These authors contributed equally to this work.Essential tremor (ET is the most prevalent movement disorder affecting millions of people in the United States. Although a positive family history is one of the most important risk factors for ET, the genetic causes of ET remain unknown. In this study, whole exome sequencing and subsequent approaches were performed in a family with an autosomal dominant form of early-onset ET. Functional analyses including mutagenesis, cell culture, gene expression, enzyme-linked immunosorbent, and apoptosis assays were also performed. A disease-segregating mutation (p.Gly171Ala, absent in normal population, was identified in the SORT1 gene. The p.Gly171Ala mutation was shown not only to impair the expression of its encoding protein sortilin but also the mRNA levels of its binding partner p75 neurotrophin receptor that is known to be implicated in brain injury, neuronal apoptosis, and neurotransmission.

  1. Conformational alterations resulting from mutations in cytoplasmic domains of the alpha subunit of the Na,K-ATPase

    DEFF Research Database (Denmark)

    Blostein, R; Daly, S E; MacAulay, Nanna;

    1998-01-01

    , and decreased sensitivity to inhibition by vanadate. The striking changes observed with alpha 1M32E233K suggests interactions between the N-terminus, the beta-strand in the M2-M3 loop and the catalytic phosphorylation site. The behavior of these mutants contrasts with that of least one mutant involving......This paper summarizes experiments concerned with the functional consequences of mutations in cytoplasmic regions of the alpha 1 subunit of the Na,K-ATPase, in particular the amino terminus, the first cytoplasmic loop between transmembrane segments M2 and M3, and the major cytoplasmic loop between M......4 and M5. In the first mutation (alpha 1M32), 32 residues were removed from the N-terminus. The second mutation (E233K) was in the putative beta strand of M2-M3 loop and the third, comprised the replacement of the amino terminal half of loop M4-M5 of the Na,K-ATPase with the homologous segment...

  2. Charcot-Marie-Tooth Disease Type 4H Resulting from Compound Heterozygous Mutations in FGD4 from Nonconsanguineous Korean Families.

    Science.gov (United States)

    Hyun, Young Se; Lee, Jinho; Kim, Hye Jin; Hong, Young Bin; Koo, Heasoo; Smith, Alec S T; Kim, Deok-Ho; Choi, Byung-Ok; Chung, Ki Wha

    2015-11-01

    Charcot-Marie-Tooth disease type 4H (CMT4H) is an autosomal recessive demyelinating subtype of peripheral enuropathies caused by mutations in the FGD4 gene. Most CMT4H patients are in consanguineous Mediterranean families characterized by early onset and slow progression. We identified two CMT4H patients from a Korean CMT cohort, and performed a detailed genetic and clinical analysis in both cases. Both patients from nonconsanguineous families showed characteristic clinical manifestations of CMT4H including early onset, scoliosis, areflexia, and slow disease progression. Exome sequencing revealed novel compound heterozygous mutations in FGD4 as the underlying cause in both families (p.Arg468Gln and c.1512-2A>C in FC73, p.Met345Thr and c.2043+1G>A (p.Trp663Trpfs*30) in FC646). The missense mutations were located in highly conserved RhoGEF and PH domains which were predicted to be pathogenic in nature by in silico modeling. The CMT4H occurrence frequency was calculated to 0.7% in the Korean demyelinating CMT patients. This study is the first report of CMT4H in Korea. FGD4 assay could be considered as a means of molecular diagnosis for sporadic cases of demyelinating CMT with slow progression. © 2015 John Wiley & Sons Ltd/University College London.

  3. Mutation in Torenia fournieri Lind. UFO homolog confers loss of TfLFY interaction and results in a petal to sepal transformation.

    Science.gov (United States)

    Sasaki, Katsutomo; Yamaguchi, Hiroyasu; Aida, Ryutaro; Shikata, Masahito; Abe, Tomoko; Ohtsubo, Norihiro

    2012-09-01

    We identified a Torenia fournieri Lind. mutant (no. 252) that exhibited a sepaloid phenotype in which the second whorls were changed to sepal-like organs. This mutant had no stamens, and the floral organs consisted of sepals and carpels. Although the expression of a torenia class B MADS-box gene, GLOBOSA (TfGLO), was abolished in the 252 mutant, no mutation of TfGLO was found. Among torenia homologs such as APETALA1 (AP1), LEAFY (LFY), and UNUSUAL FLORAL ORGANS (UFO), which regulate expression of class B genes in Arabidopsis, only accumulation of the TfUFO transcript was diminished in the 252 mutant. Furthermore, a missense mutation was found in the coding region of the mutant TfUFO. Intact TfUFO complemented the mutant phenotype whereas mutated TfUFO did not; in addition, the transgenic phenotype of TfUFO-knockdown torenias coincided with the mutant phenotype. Yeast two-hybrid analysis revealed that the mutated TfUFO lost its ability to interact with TfLFY protein. In situ hybridization analysis indicated that the transcripts of TfUFO and TfLFY were partially accumulated in the same region. These results clearly demonstrate that the defect in TfUFO caused the sepaloid phenotype in the 252 mutant due to the loss of interaction with TfLFY. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.

  4. XPC branch-point sequence mutations disrupt U2 snRNP binding, resulting in abnormal pre-mRNA splicing in xeroderma pigmentosum patients.

    Science.gov (United States)

    Khan, Sikandar G; Yamanegi, Koji; Zheng, Zhi-Ming; Boyle, Jennifer; Imoto, Kyoko; Oh, Kyu-Seon; Baker, Carl C; Gozukara, Engin; Metin, Ahmet; Kraemer, Kenneth H

    2010-02-01

    Mutations in two branch-point sequences (BPS) in intron 3 of the XPC DNA repair gene affect pre-mRNA splicing in association with xeroderma pigmentosum (XP) with many skin cancers (XP101TMA) or no skin cancer (XP72TMA), respectively. To investigate the mechanism of these abnormalities we now report that transfection of minigenes with these mutations revealed abnormal XPC pre-mRNA splicing that mimicked pre-mRNA splicing in the patients' cells. DNA oligonucleotide-directed RNase H digestion demonstrated that mutations in these BPS disrupt U2 snRNP-BPS interaction. XP101TMA cells had no detectable XPC protein but XP72TMA had 29% of normal levels. A small amount of XPC protein was detected at sites of localized ultraviolet (UV)-damaged DNA in XP72TMA cells which then recruited other nucleotide excision repair (NER) proteins. In contrast, XP101TMA cells had no detectable recruitment of XPC or other NER proteins. Post-UV survival and photoproduct assays revealed greater reduction in DNA repair in XP101TMA cells than in XP72TMA. Thus mutations in XPC BPS resulted in disruption of U2 snRNP-BPS interaction leading to abnormal pre-mRNA splicing and reduced XPC protein. At the cellular level these changes were associated with features of reduced DNA repair including diminished NER protein recruitment, reduced post-UV survival and impaired photoproduct removal.

  5. Retinal degeneration associated with RDH12 mutations results from decreased 11-cis retinal synthesis due to disruption of the visual cycle.

    Science.gov (United States)

    Thompson, Debra A; Janecke, Andreas R; Lange, Jessica; Feathers, Kecia L; Hübner, Christian A; McHenry, Christina L; Stockton, David W; Rammesmayer, Gabriele; Lupski, James R; Antinolo, Guillermo; Ayuso, Carmen; Baiget, Montserrat; Gouras, Peter; Heckenlively, John R; den Hollander, Anneke; Jacobson, Samuel G; Lewis, Richard A; Sieving, Paul A; Wissinger, Bernd; Yzer, Suzanne; Zrenner, Eberhart; Utermann, Gerd; Gal, Andreas

    2005-12-15

    Retinoid dehydrogenases/reductases catalyze key oxidation-reduction reactions in the visual cycle that converts vitamin A to 11-cis retinal, the chromophore of the rod and cone photoreceptors. It has recently been shown that mutations in RDH12, encoding a retinol dehydrogenase, result in severe and early-onset autosomal recessive retinal dystrophy (arRD). In a cohort of 1011 individuals diagnosed with arRD, we have now identified 20 different disease-associated RDH12 mutations, of which 16 are novel, in a total of 22 individuals (2.2%). Haplotype analysis suggested a founder mutation for each of the three common mutations: p.L99I, p.T155I and c.806_810delCCCTG. Patients typically presented with early disease that affected the function of both rods and cones and progressed to legal blindness in early adulthood. Eleven of the missense variants identified in our study exhibited profound loss of catalytic activity when expressed in transiently transfected COS-7 cells and assayed for ability to convert all-trans retinal to all-trans retinol. Loss-of-function appeared to result from decreased protein stability, as expression levels were significantly reduced. For the p.T49M variant, differing activity profiles were associated with each of the alleles of the common p.R161Q RDH12 polymorphism, suggesting that genetic background may act as a modifier of mutation effect. A locus (LCA3) for Leber congenital amaurosis, a severe, early-onset form of arRD, maps close to RDH12 on chromosome 14q24. Haplotype analysis in the family in which LCA3 was mapped excluded RDH12 as the LCA3 gene and thus suggests the presence of a novel arRD gene in this region.

  6. Targeted Prostate Cancer Screening in BRCA1 and BRCA2 Mutation Carriers: Results from the Initial Screening Round of the IMPACT Study

    Science.gov (United States)

    Bancroft, Elizabeth K.; Page, Elizabeth C.; Castro, Elena; Lilja, Hans; Vickers, Andrew; Sjoberg, Daniel; Assel, Melissa; Foster, Christopher S.; Mitchell, Gillian; Drew, Kate; Mæhle, Lovise; Axcrona, Karol; Evans, D. Gareth; Bulman, Barbara; Eccles, Diana; McBride, Donna; van Asperen, Christi; Vasen, Hans; Kiemeney, Lambertus A.; Ringelberg, Janneke; Cybulski, Cezary; Wokolorczyk, Dominika; Selkirk, Christina; Hulick, Peter J.; Bojesen, Anders; Skytte, Anne-Bine; Lam, Jimmy; Taylor, Louise; Oldenburg, Rogier; Cremers, Ruben; Verhaegh, Gerald; van Zelst-Stams, Wendy A.; Oosterwijk, Jan C.; Blanco, Ignacio; Salinas, Monica; Cook, Jackie; Rosario, Derek J.; Buys, Saundra; Conner, Tom; Ausems, Margreet G.; Ong, Kai-ren; Hoffman, Jonathan; Domchek, Susan; Powers, Jacquelyn; Teixeira, Manuel R.; Maia, Sofia; Foulkes, William D.; Taherian, Nassim; Ruijs, Marielle; den Enden, Apollonia T. Helderman-van; Izatt, Louise; Davidson, Rosemarie; Adank, Muriel A.; Walker, Lisa; Schmutzler, Rita; Tucker, Kathy; Kirk, Judy; Hodgson, Shirley; Harris, Marion; Douglas, Fiona; Lindeman, Geoffrey J.; Zgajnar, Janez; Tischkowitz, Marc; Clowes, Virginia E.; Susman, Rachel; Ramón y Cajal, Teresa; Patcher, Nicholas; Gadea, Neus; Spigelman, Allan; van Os, Theo; Liljegren, Annelie; Side, Lucy; Brewer, Carole; Brady, Angela F.; Donaldson, Alan; Stefansdottir, Vigdis; Friedman, Eitan; Chen-Shtoyerman, Rakefet; Amor, David J.; Copakova, Lucia; Barwell, Julian; Giri, Veda N.; Murthy, Vedang; Nicolai, Nicola; Teo, Soo-Hwang; Greenhalgh, Lynn; Strom, Sara; Henderson, Alex; McGrath, John; Gallagher, David; Aaronson, Neil; Ardern-Jones, Audrey; Bangma, Chris; Dearnaley, David; Costello, Philandra; Eyfjord, Jorunn; Rothwell, Jeanette; Falconer, Alison; Gronberg, Henrik; Hamdy, Freddie C.; Johannsson, Oskar; Khoo, Vincent; Kote-Jarai, Zsofia; Lubinski, Jan; Axcrona, Ulrika; Melia, Jane; McKinley, Joanne; Mitra, Anita V.; Moynihan, Clare; Rennert, Gad; Suri, Mohnish; Wilson, Penny; Killick, Emma; Moss, Sue; Eeles, Rosalind A.

    2014-01-01

    Background Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls) is an international consortium of 62 centres in 20 countries evaluating the use of targeted PCa screening in men with BRCA1/2 mutations. Objective To report the first year's screening results for all men at enrolment in the study. Design, setting and participants We recruited men aged 40–69 yr with germline BRCA1/2 mutations and a control group of men who have tested negative for a pathogenic BRCA1 or BRCA2 mutation known to be present in their families. All men underwent prostate-specific antigen (PSA) testing at enrolment, and those men with PSA >3 ng/ml were offered prostate biopsy. Outcome measurements and statistical analysis PSA levels, PCa incidence, and tumour characteristics were evaluated. The Fisher exact test was used to compare the number of PCa cases among groups and the differences among disease types. Results and limitations We recruited 2481 men (791 BRCA1 carriers, 531 BRCA1 controls; 731 BRCA2 carriers, 428 BRCA2 controls). A total of 199 men (8%) presented with PSA >3.0 ng/ml, 162 biopsies were performed, and 59 PCas were diagnosed (18 BRCA1 carriers, 10 BRCA1 controls; 24 BRCA2 carriers, 7 BRCA2 controls); 66% of the tumours were classified as intermediate- or high-risk disease. The positive predictive value (PPV) for biopsy using a PSA threshold of 3.0 ng/ml in BRCA2 mutation carriers was 48%—double the PPV reported in population screening studies. A significant difference in detecting intermediate- or high-risk disease was observed in BRCA2 carriers. Ninety-five percent of the men were white, thus the results cannot be generalised to all ethnic groups. Conclusions The IMPACT screening network will be useful

  7. Parallel Mutations Result in a Wide Range of Cooperation and Community Consequences in a Two-Species Bacterial Consortium.

    Science.gov (United States)

    Douglas, Sarah M; Chubiz, Lon M; Harcombe, William R; Ytreberg, F Marty; Marx, Christopher J

    2016-01-01

    Multi-species microbial communities play a critical role in human health, industry, and waste remediation. Recently, the evolution of synthetic consortia in the laboratory has enabled adaptation to be addressed in the context of interacting species. Using an engineered bacterial consortium, we repeatedly evolved cooperative genotypes and examined both the predictability of evolution and the phenotypes that determine community dynamics. Eight Salmonella enterica serovar Typhimurium strains evolved methionine excretion sufficient to support growth of an Escherichia coli methionine auxotroph, from whom they required excreted growth substrates. Non-synonymous mutations in metA, encoding homoserine trans-succinylase (HTS), were detected in each evolved S. enterica methionine cooperator and were shown to be necessary for cooperative consortia growth. Molecular modeling was used to predict that most of the non-synonymous mutations slightly increase the binding affinity for HTS homodimer formation. Despite this genetic parallelism and trend of increasing protein binding stability, these metA alleles gave rise to a wide range of phenotypic diversity in terms of individual versus group benefit. The cooperators with the highest methionine excretion permitted nearly two-fold faster consortia growth and supported the highest fraction of E. coli, yet also had the slowest individual growth rates compared to less cooperative strains. Thus, although the genetic basis of adaptation was quite similar across independent origins of cooperative phenotypes, quantitative measurements of metabolite production were required to predict either the individual-level growth consequences or how these propagate to community-level behavior.

  8. Insulin gene mutations resulting in early-onset diabetes: marked differences in clinical presentation, metabolic status, and pathogenic effect through endoplasmic reticulum retention

    DEFF Research Database (Denmark)

    Meur, Gargi; Simon, Albane; Harun, Nasret

    2009-01-01

    the molecular mechanisms involved. RESEARCH DESIGN AND METHODS: The INS gene was sequenced in 16 French probands with unexplained MODY, 95 patients with nonautoimmune early-onset diabetes (diagnosed at ... quantitated by real-time PCR. RESULTS: A novel coding mutation, L30M, potentially affecting insulin multimerization, was identified in five diabetic individuals (diabetes onset 17-36 years) in a single family. L30M preproinsulin-GFP fluorescence largely associated with the endoplasmic reticulum (ER) in MIN6...

  9. Mutation of the Na-K-Cl co-transporter gene Slc12a2 results in deafness in mice.

    Science.gov (United States)

    Dixon, M J; Gazzard, J; Chaudhry, S S; Sampson, N; Schulte, B A; Steel, K P

    1999-08-01

    Hearing impairment is a common human condition, but we know little about the molecular basis of cochlear function. Shaker-with-syndactylism (sy) is a classic deaf mouse mutant and we show here that a second allele, sy(ns), is associated with abnormal production of endolymph, the fluid bathing sensory hair cells. Using a positional candidate approach, we demonstrate that mutations in the gene encoding the basolateral Na-K-Cl co-transporter Slc12a2 (Nkcc1, mBSC2) cause the deafness observed in sy and sy(ns) mice. This finding provides the molecular basis of another link in the chain of K+recycling in the cochlea, a process essential for normal cochlear function.

  10. Suppression of signal sequence defects and azide resistance in Escherichia coli commonly result from the same mutations in secA.

    Science.gov (United States)

    Huie, J L; Silhavy, T J

    1995-06-01

    The SecA protein of Escherichia coli is required for protein translocation from the cytoplasm. The complexity of SecA function is reflected by missense mutations in the secA gene that confer several different phenotypes: (i) conditional-lethal alleles cause a generalized block in protein secretion, resulting in the cytoplasmic accumulation of the precursor forms of secreted proteins; (ii) azi alleles confer resistance to azide at concentrations up to 4 mM; and (iii) prlD alleles suppress a number of signal sequence mutations in several different genes. To gain further insights into the role of SecA in protein secretion, we have isolated and characterized a large number of prlD mutations, reasoning that these mutations alter a normal function of wild-type SecA. Our results reveal a striking coincidence of signal sequence suppression and azide resistance: the majority of prlD alleles also confer azide resistance, and all azi alleles tested are suppressors. We suggest that this correlation reflects the mechanism(s) of signal sequence suppression. There are two particularly interesting subclasses of prlD and azi alleles. First, four of the prlD and azi alleles exhibit special properties: (i) as suppressors they are potent enough to allow PrlD (SecA) inactivation by a toxic LacZ fusion protein marked with a signal sequence mutation (suppressor-directed inactivation), (ii) they confer azide resistance, and (iii) they cause modest defects in the secretion of wild-type proteins. Sequence analysis reveals that all four of these alleles alter Tyr-134 in SecA, changing it to Ser, Cys, or Asn. The second subclass consists of seven prlD alleles that confer azide supersensitivity, and sequence analysis reveals that six of these alleles are changes of Ala-507 to Val. Both of the affected amino acids are located within different putative ATP-binding regions of SecA and thus may affect ATPase activities of SecA. We suggest that the four azide-resistant mutations slow an ATPase

  11. Transgene silencing of the Hutchinson-Gilford progeria syndrome mutation results in a reversible bone phenotype, whereas resveratrol treatment does not show overall beneficial effects

    DEFF Research Database (Denmark)

    Strandgren, Charlotte; Nasser, Hasina Abdul; McKenna, Tomás

    2015-01-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder that is most commonly caused by a de novo point mutation in exon 11 of the LMNA gene, c.1824C>T, which results in an increased production of a truncated form of lamin A known as progerin. In this study, we used a mouse...... model to study the possibility of recovering from HGPS bone disease upon silencing of the HGPS mutation, and the potential benefits from treatment with resveratrol. We show that complete silencing of the transgenic expression of progerin normalized bone morphology and mineralization already after 7...... weeks. The improvements included lower frequencies of rib fractures and callus formation, an increased number of osteocytes in remodeled bone, and normalized dentinogenesis. The beneficial effects from resveratrol treatment were less significant and to a large extent similar to mice treated with sucrose...

  12. NGS-based BRCA1/2 mutation testing of high-grade serous ovarian cancer tissue: results and conclusions of the first international round robin trial.

    Science.gov (United States)

    Endris, Volker; Stenzinger, Albrecht; Pfarr, Nicole; Penzel, Roland; Möbs, Markus; Lenze, Dido; Darb-Esfahani, Silvia; Hummel, Michael; Sabine-Merkelbach-Bruse; Jung, Andreas; Lehmann, Ulrich; Kreipe, Hans; Kirchner, Thomas; Büttner, Reinhard; Jochum, Wolfram; Höfler, Gerald; Dietel, Manfred; Weichert, Wilko; Schirmacher, Peter

    2016-06-01

    With the approval of olaparib as monotherapy treatment in platinum-sensitive, relapsed high-grade serous ovarian cancer by the European Medical Agency (EMA), comprehensive genotyping of BRCA1 and BRCA2 in tumor tissue has become a mandatory pre-therapeutic test. This requires significant advances in routine tumor test methodologies due to the large size of both genes and the lack of mutational hot spots. Classical focused screening approaches, like Sanger sequencing, do not allow for a sensitive, rapid, and economic analysis of tumor tissue. Next-generation sequencing (NGS) approaches employing targeted panels for BRCA1/2 to interrogate formalin-fixed and paraffin-embedded tumor samples from either surgical resection or biopsy specimens can overcome these limitations. Although focused NGS methods have been implemented by few centers in routine molecular diagnostics for the analysis of some druggable oncogenic mutations, the reliable diagnostic testing of the entire coding regions of BRCA1 and BRCA2 was a new challenge requiring extensive technological improvement and quality management. Here, we describe the implementation and results of the first round robin trial for BRCA1/2 mutation testing in tumor tissue that was conducted in central Europe on May 2015, shortly after the approval and prior to the official release of olaparib. The high success rate of 81 % (21/26 test centers) demonstrates that BRCA1/2 multicenter mutation testing is well feasible in FFPE tumor tissue, extending to other tumor entities beyond ovarian cancer. The high number of test centers passing the trial demonstrates the success of the concerted efforts by German, Swiss, and Austrian pathology centers to ensure quality-controlled NGS-based testing and proves the potential of this technology in routine molecular pathology. On the basis of our results, we provide recommendations for predictive testing of tumor tissue for BRCA1/2 to clinical decision making in ovarian cancer patients.

  13. A multiplex single nucleotide polymorphism typing assay for detecting mutations that result in decreased fluoroquinolone susceptibility in Salmonella enterica serovars Typhi and Paratyphi A.

    LENUS (Irish Health Repository)

    Song, Yajun

    2010-08-01

    OBJECTIVES: Decreased susceptibility to fluoroquinolones has become a major problem for the successful therapy of human infections caused by Salmonella enterica, especially the life-threatening typhoid and paratyphoid fevers. METHODS: By using Luminex xTAG beads, we developed a rapid, reliable and cost-effective multiplexed genotyping assay for simultaneously detecting 11 mutations in gyrA, gyrB and parE of S. enterica serovars Typhi and Paratyphi A that result in nalidixic acid resistance (Nal(R)) and\\/or decreased susceptibility to fluoroquinolones. RESULTS: This assay yielded unambiguous single nucleotide polymorphism calls on extracted DNA from 292 isolates of Salmonella Typhi (Nal(R) = 223 and Nal(S) = 69) and 106 isolates of Salmonella Paratyphi A (Nal(R) = 24 and Nal(S) = 82). All of the 247 Nal(R) Salmonella Typhi and Salmonella Paratyphi A isolates were found to harbour at least one of the target mutations, with GyrA Phe-83 as the most common one (143\\/223 for Salmonella Typhi and 18\\/24 for Salmonella Paratyphi A). We also identified three GyrB mutations in eight Nal(S) Salmonella Typhi isolates (six for GyrB Phe-464, one for GyrB Leu-465 and one for GyrB Asp-466), and mutations GyrB Phe-464 and GyrB Asp-466 seem to be related to the decreased ciprofloxacin susceptibility phenotype in Salmonella Typhi. This assay can also be used directly on boiled single colonies. CONCLUSIONS: The assay presented here would be useful for clinical and reference laboratories to rapidly screen quinolone-resistant isolates of Salmonella Typhi and Salmonella Paratyphi A, and decipher the underlying genetic changes for epidemiological purposes.

  14. Limb-girdle muscular dystrophy type 2A resulting from homozygous G2338C transversion mutation in the calpain-3 gene.

    Science.gov (United States)

    Peddareddygari, Leema Reddy; Surgan, Victoria; Grewal, Raji P

    2010-12-01

    Limb-girdle muscular dystrophy represents a clinically and genetically heterogeneous group of myopathies. Limb-girdle muscular dystrophy Type 2A, which is transmitted in an autosomal-recessive pattern, is caused by mutations in the calpain-3 (CAPN3) gene. A number of mutations have been reported in patients from throughout the world but not in the Asian-Indian population. We describe a genotype/phenotype analysis of an Asian-Indian patient with a history, neurologic examination, and investigations consistent with muscular dystrophy. Genetic analysis of this patient showed a homozygous G2338C transversion resulting in an amino acid change from aspartic acid 780 histidine in the CAPN3 gene confirming Limb-girdle muscular dystrophy Type 2A. Subsequent testing of the patient's family revealed that his parents and sister were heterozygous unaffected carriers. The G2338C transversion was detected as a compound heterozygous mutation in one patient in Germany. We report a homozygous case and expand the clinical spectrum of limb-girdle muscular dystrophy Type 2A to include Asian-Indians.

  15. A dominant negative heterozygous G87R mutation in the zinc transporter, ZnT-2 (SLC30A2), results in transient neonatal zinc deficiency.

    Science.gov (United States)

    Lasry, Inbal; Seo, Young Ah; Ityel, Hadas; Shalva, Nechama; Pode-Shakked, Ben; Glaser, Fabian; Berman, Bluma; Berezovsky, Igor; Goncearenco, Alexander; Klar, Aharon; Levy, Jacob; Anikster, Yair; Kelleher, Shannon L; Assaraf, Yehuda G

    2012-08-24

    Zinc is an essential mineral, and infants are particularly vulnerable to zinc deficiency as they require large amounts of zinc for their normal growth and development. We have recently described the first loss-of-function mutation (H54R) in the zinc transporter ZnT-2 (SLC30A2) in mothers with infants harboring transient neonatal zinc deficiency (TNZD). Here we identified and characterized a novel heterozygous G87R ZnT-2 mutation in two unrelated Ashkenazi Jewish mothers with infants displaying TNZD. Transient transfection of G87R ZnT-2 resulted in endoplasmic reticulum-Golgi retention, whereas the WT transporter properly localized to intracellular secretory vesicles in HC11 and MCF-7 cells. Consequently, G87R ZnT-2 showed decreased stability compared with WT ZnT-2 as revealed by Western blot analysis. Three-dimensional homology modeling based on the crystal structure of YiiP, a close zinc transporter homologue from Escherichia coli, revealed that the basic arginine residue of the mutant G87R points toward the membrane lipid core, suggesting misfolding and possible loss-of-function. Indeed, functional assays including vesicular zinc accumulation, zinc secretion, and cytoplasmic zinc pool assessment revealed markedly impaired zinc transport in G87R ZnT-2 transfectants. Moreover, co-transfection experiments with both mutant and WT transporters revealed a dominant negative effect of G87R ZnT-2 over the WT ZnT-2; this was associated with mislocalization, decreased stability, and loss of zinc transport activity of the WT ZnT-2 due to homodimerization observed upon immunoprecipitation experiments. These findings establish that inactivating ZnT-2 mutations are an underlying basis of TNZD and provide the first evidence for the dominant inheritance of heterozygous ZnT-2 mutations via negative dominance due to homodimer formation.

  16. Physiological Levels of Pik3caH1047R Mutation in the Mouse Mammary Gland Results in Ductal Hyperplasia and Formation of ERα-Positive Tumors

    Science.gov (United States)

    Tikoo, Anjali; Roh, Vincent; Montgomery, Karen G.; Ivetac, Ivan; Waring, Paul; Pelzer, Rebecca; Hare, Lauren; Shackleton, Mark; Humbert, Patrick; Phillips, Wayne A.

    2012-01-01

    PIK3CA, the gene coding for the p110α subunit of phosphoinositide 3-kinase, is frequently mutated in a variety of human tumors including breast cancers. To better understand the role of mutant PIK3CA in the initiation and/or progression of breast cancer, we have generated mice with a conditional knock-in of the common activating mutation, Pik3caH1047R, into one allele of the endogenous gene in the mammary gland. These mice developed a ductal anaplasia and hyperplasia by 6 weeks of age characterized by multi-layering of the epithelial lining of the mammary ducts and expansion of the luminal progenitor (Lin−; CD29lo; CD24+; CD61+) cell population. The Pik3caH1047R expressing mice eventually develop mammary tumors with 100% penetrance but with a long latency (>12 months). This is significantly longer than has been reported for transgenic models where expression of the mutant Pik3ca is driven by an exogenous promoter. Histological analysis of the tumors formed revealed predominantly ERα-positive fibroadenomas, carcinosarcomas and sarcomas. In vitro induction of Pik3caH1047R in immortalized mammary epithelial cells also resulted in tumor formation when injected into the mammary fat pad of immunodeficient recipient mice. This novel model, which reproduces the scenario of a heterozygous somatic mutation occurring in the endogenous PIK3CA gene, will thus be a valuable tool for investigating the role of Pik3caH1047R mutation in mammary tumorigenesis both in vivo and in vitro. PMID:22666336

  17. Physiological levels of Pik3ca(H1047R) mutation in the mouse mammary gland results in ductal hyperplasia and formation of ERα-positive tumors.

    Science.gov (United States)

    Tikoo, Anjali; Roh, Vincent; Montgomery, Karen G; Ivetac, Ivan; Waring, Paul; Pelzer, Rebecca; Hare, Lauren; Shackleton, Mark; Humbert, Patrick; Phillips, Wayne A

    2012-01-01

    PIK3CA, the gene coding for the p110α subunit of phosphoinositide 3-kinase, is frequently mutated in a variety of human tumors including breast cancers. To better understand the role of mutant PIK3CA in the initiation and/or progression of breast cancer, we have generated mice with a conditional knock-in of the common activating mutation, Pik3ca(H1047R), into one allele of the endogenous gene in the mammary gland. These mice developed a ductal anaplasia and hyperplasia by 6 weeks of age characterized by multi-layering of the epithelial lining of the mammary ducts and expansion of the luminal progenitor (Lin(-); CD29(lo); CD24(+); CD61(+)) cell population. The Pik3ca(H1047R) expressing mice eventually develop mammary tumors with 100% penetrance but with a long latency (>12 months). This is significantly longer than has been reported for transgenic models where expression of the mutant Pik3ca is driven by an exogenous promoter. Histological analysis of the tumors formed revealed predominantly ERα-positive fibroadenomas, carcinosarcomas and sarcomas. In vitro induction of Pik3ca(H1047R) in immortalized mammary epithelial cells also resulted in tumor formation when injected into the mammary fat pad of immunodeficient recipient mice. This novel model, which reproduces the scenario of a heterozygous somatic mutation occurring in the endogenous PIK3CA gene, will thus be a valuable tool for investigating the role of Pik3ca(H1047R) mutation in mammary tumorigenesis both in vivo and in vitro.

  18. Mutations in Hedgehog acyltransferase (Hhat perturb Hedgehog signaling, resulting in severe acrania-holoprosencephaly-agnathia craniofacial defects.

    Directory of Open Access Journals (Sweden)

    Jennifer F Dennis

    Full Text Available Holoprosencephaly (HPE is a failure of the forebrain to bifurcate and is the most common structural malformation of the embryonic brain. Mutations in SHH underlie most familial (17% cases of HPE; and, consistent with this, Shh is expressed in midline embryonic cells and tissues and their derivatives that are affected in HPE. It has long been recognized that a graded series of facial anomalies occurs within the clinical spectrum of HPE, as HPE is often found in patients together with other malformations such as acrania, anencephaly, and agnathia. However, it is not known if these phenotypes arise through a common etiology and pathogenesis. Here we demonstrate for the first time using mouse models that Hedgehog acyltransferase (Hhat loss-of-function leads to holoprosencephaly together with acrania and agnathia, which mimics the severe condition observed in humans. Hhat is required for post-translational palmitoylation of Hedgehog (Hh proteins; and, in the absence of Hhat, Hh secretion from producing cells is diminished. We show through downregulation of the Hh receptor Ptch1 that loss of Hhat perturbs long-range Hh signaling, which in turn disrupts Fgf, Bmp and Erk signaling. Collectively, this leads to abnormal patterning and extensive apoptosis within the craniofacial primordial, together with defects in cartilage and bone differentiation. Therefore our work shows that Hhat loss-of-function underscrores HPE; but more importantly it provides a mechanism for the co-occurrence of acrania, holoprosencephaly, and agnathia. Future genetic studies should include HHAT as a potential candidate in the etiology and pathogenesis of HPE and its associated disorders.

  19. Mutation of the BRCA1 SQ-cluster results in aberrant mitosis, reduced homologous recombination, and a compensatory increase in non-homologous end joining.

    Science.gov (United States)

    Beckta, Jason M; Dever, Seth M; Gnawali, Nisha; Khalil, Ashraf; Sule, Amrita; Golding, Sarah E; Rosenberg, Elizabeth; Narayanan, Aarthi; Kehn-Hall, Kylene; Xu, Bo; Povirk, Lawrence F; Valerie, Kristoffer

    2015-09-29

    Mutations in the breast cancer susceptibility 1 (BRCA1) gene are catalysts for breast and ovarian cancers. Most mutations are associated with the BRCA1 N- and C-terminal domains linked to DNA double-strand break (DSB) repair. However, little is known about the role of the intervening serine-glutamine (SQ) - cluster in the DNA damage response beyond its importance in regulating cell cycle checkpoints. We show that serine-to-alanine alterations at critical residues within the SQ-cluster known to be phosphorylated by ATM and ATR result in reduced homologous recombination repair (HRR) and aberrant mitosis. While a S1387A BRCA1 mutant - previously shown to abrogate S-phase arrest in response to radiation - resulted in only a modest decrease in HRR, S1387A together with an additional alteration, S1423A (BRCA12P), reduced HRR to vector control levels and similar to a quadruple mutant also including S1457A and S1524A (BRCA14P). These effects appeared to be independent of PALB2. Furthermore, we found that BRCA14P promoted a prolonged and struggling HRR late in the cell cycle and shifted DSB repair from HRR to non-homologous end joining which, in the face of irreparable chromosomal damage, resulted in mitotic catastrophe. Altogether, SQ-cluster phosphorylation is critical for allowing adequate time for completing normal HRR prior to mitosis and preventing cells from entering G1 prematurely resulting in gross chromosomal aberrations.

  20. Mutations in FKBP10, which result in Bruck syndrome and recessive forms of osteogenesis imperfecta, inhibit the hydroxylation of telopeptide lysines in bone collagen

    NARCIS (Netherlands)

    Schwarze, Ulrike; Cundy, Tim; Pyott, Shawna M.; Christiansen, Helena E.; Hegde, Madhuri R.; Bank, Ruud A.; Pals, Gerard; Ankala, Arunkanth; Conneely, Karen; Seaver, Laurie; Yandow, Suzanne M.; Raney, Ellen; Babovic-Vuksanovic, Dusica; Stoler, Joan; Ben-Neriah, Ziva; Segel, Reeval; Lieberman, Sari; Siderius, Liesbeth; Al-Aqeel, Aida; Hannibal, Mark; Hudgins, Louanne; McPherson, Elizabeth; Clemens, Michele; Sussman, Michael D.; Steiner, Robert D.; Mahan, John; Smith, Rosemarie; Anyane-Yeboa, Kwame; Wynn, Julia; Chong, Karen; Uster, Tami; Aftimos, Salim; Sutton, V. Reid; Davis, Elaine C.; Kim, Lammy S.; Weis, Mary Ann; Eyre, David; Byers, Peter H.

    2013-01-01

    Although biallelic mutations in non-collagen genes account for 10 of individuals with osteogenesis imperfecta, the characterization of these genes has identified new pathways and potential interventions that could benefit even those with mutations in type I collagen genes. We identified mutations in

  1. Factor V Leiden mutation, prothrombin gene mutation, and deficiencies in coagulation inhibitors associated with Budd-Chiari syndrome and portal vein thrombosis: results of a case-control study

    NARCIS (Netherlands)

    H.L.A. Janssen (Harry); J.P. Vandenbroucke; F.R. Rosendaal (Frits); B. van Hoek (Bart); J.R. Meinardi; F.P. Vleggaar (Frank); S.H. van Uum; E.B. Haagsma (Els); F.J.M. van der Meer; J. van Hattum (Jan); R.A. Chamuleau; R.P.R. Adang (Rob)

    2000-01-01

    textabstractIn a collaborative multicenter case-control study, we investigated the effect of factor V Leiden mutation, prothrombin gene mutation, and inherited deficiencies of protein C, protein S, and antithrombin on the risk of Budd-Chiari syndrome (BCS) and portal vein thrombosi

  2. Defective Proteolytic Processing of Fibrillar Procollagens and Prodecorin Due to Biallelic BMP1 Mutations Results in a Severe, Progressive Form of Osteogenesis Imperfecta.

    Science.gov (United States)

    Syx, Delfien; Guillemyn, Brecht; Symoens, Sofie; Sousa, Ana Berta; Medeira, Ana; Whiteford, Margo; Hermanns-Lê, Trinh; Coucke, Paul J; De Paepe, Anne; Malfait, Fransiska

    2015-08-01

    Whereas the vast majority of osteogenesis imperfecta (OI) is caused by autosomal dominant defects in the genes encoding type I procollagen, mutations in a myriad of genes affecting type I procollagen biosynthesis or bone formation and homeostasis have now been associated with rare autosomal recessive OI forms. Recently, homozygous or compound heterozygous mutations in BMP1, encoding the metalloproteases bone morphogenetic protein-1 (BMP1) and its longer isoform mammalian Tolloid (mTLD), were identified in 5 children with a severe autosomal recessive form of OI and in 4 individuals with mild to moderate bone fragility. BMP1/mTLD functions as the procollagen carboxy-(C)-proteinase for types I to III procollagen but was also suggested to participate in amino-(N)-propeptide cleavage of types V and XI procollagens and in proteolytic trimming of other extracellular matrix (ECM) substrates. We report the phenotypic characteristics and natural history of 4 adults with severe, progressive OI characterized by numerous fractures, short stature with rhizomelic shortening, and deformity of the limbs and variable kyphoscoliosis, in whom we identified novel biallelic missense and frameshift mutations in BMP1. We show that BMP1/mTLD-deficiency in humans not only results in delayed cleavage of the type I procollagen C-propeptide but also hampers the processing of the small leucine-rich proteoglycan prodecorin, a regulator of collagen fibrillogenesis. Immunofluorescent staining of types I and V collagen and transmission electron microscopy of the dermis show impaired assembly of heterotypic type I/V collagen fibrils in the ECM. Our study thus highlights the severe and progressive nature of BMP1-associated OI in adults and broadens insights into the functional consequences of BMP1/mTLD-deficiency on ECM organization.

  3. Transgene silencing of the Hutchinson-Gilford progeria syndrome mutation results in a reversible bone phenotype, whereas resveratrol treatment does not show overall beneficial effects.

    Science.gov (United States)

    Strandgren, Charlotte; Nasser, Hasina Abdul; McKenna, Tomás; Koskela, Antti; Tuukkanen, Juha; Ohlsson, Claes; Rozell, Björn; Eriksson, Maria

    2015-08-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disorder that is most commonly caused by a de novo point mutation in exon 11 of the LMNA gene, c.1824C>T, which results in an increased production of a truncated form of lamin A known as progerin. In this study, we used a mouse model to study the possibility of recovering from HGPS bone disease upon silencing of the HGPS mutation, and the potential benefits from treatment with resveratrol. We show that complete silencing of the transgenic expression of progerin normalized bone morphology and mineralization already after 7 weeks. The improvements included lower frequencies of rib fractures and callus formation, an increased number of osteocytes in remodeled bone, and normalized dentinogenesis. The beneficial effects from resveratrol treatment were less significant and to a large extent similar to mice treated with sucrose alone. However, the reversal of the dental phenotype of overgrown and laterally displaced lower incisors in HGPS mice could be attributed to resveratrol. Our results indicate that the HGPS bone defects were reversible upon suppressed transgenic expression and suggest that treatments targeting aberrant progerin splicing give hope to patients who are affected by HGPS.

  4. A New Variant of Charcot-Marie-Tooth Disease Type 2 Is Probably the Result of a Mutation in the Neurofilament-Light Gene

    Science.gov (United States)

    Mersiyanova, Irina V.; Perepelov, Alexander V.; Polyakov, Alexander V.; Sitnikov, Vladimir F.; Dadali, Elena L.; Oparin, Roman B.; Petrin, Alexander N.; Evgrafov, Oleg V.

    2000-01-01

    Charcot-Marie-Tooth (CMT) disease is the most common inherited motor and sensory neuropathy. The axonal form of the disease is designated as “CMT type 2” (CMT2). Although four loci known to be implicated in autosomal dominant CMT2 have been mapped thus far (on 1p35-p36, 3q13.1, 3q13-q22, and 7p14), no one causative gene is yet known. A large Russian family with CMT2 was found in the Mordovian Republic (Russia). Affected members had the typical CMT2 phenotype. Additionally, several patients suffered from hyperkeratosis, although the association, if any, between the two disorders is not clear. Linkage with the CMT loci already known (CMT1A, CMT1B, CMT2A, CMT2B, CMT2D, and a number of other CMT-related loci) was excluded. Genomewide screening pinpointed the disease locus in this family to chromosome 8p21, within a 16-cM interval between markers D8S136 and D8S1769. A maximum two-point LOD score of 5.93 was yielded by a microsatellite from the 5′ region of the neurofilament-light gene (NF-L). Neurofilament proteins play an important role in axonal structure and are implicated in several neuronal disorders. Screening of affected family members for mutations in the NF-L gene and in the tightly linked neurofilament-medium gene (NF-M) revealed the only DNA alteration linked with the disease: a A998C transversion in the first exon of NF-L, which converts a conserved Gln333 amino acid to proline. This alteration was not found in 180 normal chromosomes. Twenty unrelated CMT2 patients, as well as 26 others with an undetermined form of CMT, also were screened for mutations in NF-L, but no additional mutations were found. It is suggested that Gln333Pro represents a rare disease-causing mutation, which results in the CMT2 phenotype. PMID:10841809

  5. Centrosomal-ciliary gene CEP290/NPHP6 mutations result in blindness with unexpected sparing of photoreceptors and visual brain: implications for therapy of Leber congenital amaurosis.

    Science.gov (United States)

    Cideciyan, Artur V; Aleman, Tomas S; Jacobson, Samuel G; Khanna, Hemant; Sumaroka, Alexander; Aguirre, Geoffrey K; Schwartz, Sharon B; Windsor, Elizabeth A M; He, Shirley; Chang, Bo; Stone, Edwin M; Swaroop, Anand

    2007-11-01

    Mutations in the centrosomal-ciliary gene CEP290/NPHP6 are associated with Joubert syndrome and are the most common cause of the childhood recessive blindness known as Leber congenital amaurosis (LCA). An in-frame deletion in Cep290 shows rapid degeneration in the rod-rich mouse retina. To explore the mechanisms of the human retinal disease, we studied CEP290-LCA in patients of different ages (7-48 years) and compared results to Cep290-mutant mice. Unexpectedly, blind CEP290-mutant human retinas retained photoreceptor and inner laminar architecture in the cone-rich central retina, independent of severity of visual loss. Surrounding the cone-rich island was photoreceptor loss and distorted retina, suggesting neural-glial remodeling. The mutant mouse retina at 4-6 weeks of age showed similar features of retinal remodeling, with altered neural and synaptic laminae and Muller glial activation. The visual brain pathways in CEP290-LCA were anatomically intact. Our findings of preserved foveal cones and visual brain anatomy in LCA with CEP290 mutations, despite severe blindness and rapid rod cell death, suggest an opportunity for visual restoration of central vision in this common form of inherited blindness.

  6. Conformational alterations resulting from mutations in cytoplasmic domains of the alpha subunit of the Na,K-ATPase

    DEFF Research Database (Denmark)

    Blostein, R; Daly, S E; MacAulay, Nanna

    1998-01-01

    substitution of a residue in the putative cation binding pocket, namely S775A in the fifth transmembrane segment (Arguello, J.M., & Lingrel, J. B. J. Biol. Chem. 270: 22764-22771, 1995). Although its K+/ATP antagonism resembles that of the foregoing cytoplasmic mutants, its vanadate sensitivity is unaltered...... in the presence or absence of Na+ and at low versus high pH indicate a marked alteration in cation affinity and/or selectivity. This results suggests coupling of an alteration in the large M4-M5 cytoplasmic domain to cation binding in, presumably, the juxtapositioned transmembrane domain....

  7. Deficiency of patched 1-induced Gli1 signal transduction results in astrogenesis in Swedish mutated APP transgenic mice.

    Science.gov (United States)

    He, Ping; Staufenbiel, Matthias; Li, Rena; Shen, Yong

    2014-12-15

    Normally, sonic hedgehog (Shh) signaling induces high levels of Patched 1 (Ptc1) and its associated transcription factor Gli1 with genesis of specific neuronal progeny. But their roles in the neural stem cells (NSCs), including glial precursor cells (GPCs), of Alzheimer's disease (AD) are unclear. Here, we show that Ptc1 and Gli1 are significantly deficits in the hippocampus of an aged AD transgenic mouse mode, whereas these two molecules are highly elevated at young ages. Our similar findings in autopsied AD brains validate the discovery in AD mouse models. To examine whether Aβ peptides, which are a main component of the amyloid plaques in AD brains, affected Ptc1-Gli1 signaling, we treated GPCs with Aβ peptides, we found that high dose of Aβ1-42 but not Aβ1-40 significantly decreased Ptc1-Gli1, while Shh itself was elevated in hippocampal NSCs/GPCs. Furthermore, we found that deficits of Ptc1-Gli1 signaling induced NSCs/GPCs into asymmetric division, which results in an increase in the number of dividing cells including transit-amplifying cells and neuroblasts. These precursor cells commit to apoptosis-like death under the toxic conditions. By this way, adult neural precursor cell pool is exhausted and defective neurogenesis happens in AD brains. Our findings suggest that Ptc1-Gli1 signaling deregulation resulting abnormal loss of GPCs may contribute to a cognition decline in AD brains. The novel findings elucidate a new molecular mechanism of adult NSCs/GPCs on neurogenesis and demonstrate a regulatory role for Ptc1-Gli1 in adult neural circuit integrity of the brain.

  8. Point mutation in the NF2 gene of HEI-193 human schwannoma cells results in the expression of a merlin isoform with attenuated growth suppressive activity

    Energy Technology Data Exchange (ETDEWEB)

    Lepont, Pierig; Stickney, John T.; Foster, Lauren A.; Meng, Jin-Jun; Hennigan, Robert F. [Department of Cell and Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267-0521 (United States); Ip, Wallace [Department of Cell and Cancer Biology, Vontz Center for Molecular Studies, University of Cincinnati College of Medicine, 3125 Eden Avenue, Cincinnati, OH 45267-0521 (United States)], E-mail: wallace.ip@uc.edu

    2008-01-01

    Neurofibromatosis type 2 (NF2) is a genetic disorder characterized by the formation of bilateral schwannomas of the eighth cranial nerve. Although the protein product of the NF2 gene (merlin) is a classical tumor suppressor, the mechanism by which merlin suppresses cell proliferation is not fully understood. The availability of isolated tumor cells would facilitate a better understanding of the molecular function of merlin, but primary schwannoma cells obtained from patients grow slowly and do not yield adequate numbers for biochemical analysis. In this study, we have examined the NF2 mutation in HEI-193 cells, an immortalized cell line derived from the schwannoma of an NF2 patient. Previous work showed that the NF2 mutation in HEI-193 cells causes a splicing defect in the NF2 transcript. We have confirmed this result and further identified the resultant protein product as an isoform of merlin previously designated as isoform 3. The level of isoform 3 proteins in HEI-193 cells is comparable to the levels of merlin isoforms 1 and 2 in normal human Schwann cells and several other immortalized cell lines. In contrast to many mutant forms of merlin, isoform 3 is as resistant to proteasomal degradation as isoforms 1 and 2 and can interact with each of these isoforms in vivo. Cell proliferation assays showed that, in NF2{sup -/-} mouse embryonic fibroblasts, exogenously expressed merlin isoform 3 does exhibit growth suppressive activity although it is significantly lower than that of identically expressed merlin isoform 1. These results indicate that, although HEI-193 cells have undetectable levels of merlin isoforms 1 and 2, they are, in fact, not a merlin-null model because they express the moderately active growth suppressive merlin isoform 3.

  9. Mice carrying a knock-in mutation of Aicda resulting in a defect in somatic hypermutation have impaired gut homeostasis and compromised mucosal defense.

    Science.gov (United States)

    Wei, Min; Shinkura, Reiko; Doi, Yasuko; Maruya, Mikako; Fagarasan, Sidonia; Honjo, Tasuku

    2011-03-01

    To elucidate the specific role of somatic hypermutation (SHM) in mucosal immunity, we generated mice carrying a knock-in point mutation in Aicda, which encodes activation-induced cytidine deaminase (AID), an enzyme essential to SHM and class-switch recombination (CSR). These mutant AID(G23S) mice had much less SHM but had normal amounts of immunoglobulin in both serum and intestinal secretions. AID(G23S) mice developed hyperplasia of germinal center B cells in gut-associated lymphoid tissues, accompanied by expansion of microflora in the small intestine. Moreover, AID(G23S) mice had more translocation of Yersinia enterocolitica into mesenteric lymph nodes and were more susceptible than wild-type mice to oral challenge with cholera toxin. Together our results indicate that SHM is critical in maintaining intestinal homeostasis and efficient mucosal defense.

  10. Angiotensin I-converting enzyme Gln1069Arg mutation impairs trafficking to the cell surface resulting in selective denaturation of the C-domain.

    Directory of Open Access Journals (Sweden)

    Sergei M Danilov

    Full Text Available BACKGROUND: Angiotensin-converting enzyme (ACE; Kininase II; CD143 hydrolyzes small peptides such as angiotensin I, bradykinin, substance P, LH-RH and several others and thus plays a key role in blood pressure regulation and vascular remodeling. Complete absence of ACE in humans leads to renal tubular dysgenesis (RTD, a severe disorder of renal tubule development characterized by persistent fetal anuria and perinatal death. METHODOLOGY/PRINCIPAL FINDINGS: Patient with RTD in Lisbon, Portugal, maintained by peritoneal dialysis since birth, was found to have a homozygous substitution of Arg for Glu at position 1069 in the C-terminal domain of ACE (Q1069R resulting in absence of plasma ACE activity; both parents and a brother who are heterozygous carriers of this mutation had exactly half-normal plasma ACE activity compared to healthy individuals. We hypothesized that the Q1069R substitution impaired ACE trafficking to the cell surface and led to accumulation of catalytically inactive ACE in the cell cytoplasm. CHO cells expressing wild-type (WT vs. Q1069R-ACE demonstrated the mutant accumulates intracellularly and also that it is significantly degraded by intracellular proteases. Q1069R-ACE retained catalytic and immunological characteristics of WT-ACE N domain whereas it had 10-20% of the nativity of the WT-ACE C domain. A combination of chemical (sodium butyrate or pharmacological (ACE inhibitor chaperones with proteasome inhibitors (MG 132 or bortezomib significantly restored trafficking of Q1069R-ACE to the cell surface and increased ACE activity in the cell culture media 4-fold. CONCLUSIONS/SIGNIFICANCE: Homozygous Q1069R substitution results in an ACE trafficking and processing defect which can be rescued, at least in cell culture, by a combination of chaperones and proteasome inhibitors. Further studies are required to determine whether similar treatment of individuals with this ACE mutation would provide therapeutic benefits such as

  11. Heterozygous mutation of eEF1A1b resulted in spermatogenesis arrest and infertility in male tilapia, Oreochromis niloticus

    Science.gov (United States)

    Chen, Jinlin; Jiang, Dongneng; Tan, Dejie; Fan, Zheng; Wei, Yingying; Li, Minghui; Wang, Deshou

    2017-01-01

    Eukaryotic elongation factor 1 alpha (eEF1A) is an essential component of the translational apparatus. In the present study, eEF1A1b was isolated from the Nile tilapia. Real-time PCR and Western blot revealed that eEF1A1b was expressed highly in the testis from 90 dah (days after hatching) onwards. In situ hybridization and immunohistochemistry analyses showed that eEF1A1b was highly expressed in the spermatogonia of the testis. CRISPR/Cas9 mediated mutation of eEF1A1b resulted in spermatogenesis arrest and infertility in the F0 XY fish. Consistently, heterozygous mutation of eEF1A1b (eEF1A1b+/−) resulted in an absence of spermatocytes at 90 dah, very few spermatocytes, spermatids and spermatozoa at 180 dah, and decreased Cyp11b2 and serum 11-ketotestosterone level at both stages. Further examination of the fertilization capacity of the sperm indicated that the eEF1A1b+/− XY fish were infertile due to abnormal spermiogenesis. Transcriptomic analyses of the eEF1A1b+/− testis from 180 dah XY fish revealed that key elements involved in spermatogenesis, steroidogenesis and sperm motility were significantly down-regulated compared with the control XY. Transgenic overexpression of eEF1A1b rescued the spermatogenesis arrest phenotype of the eEF1A1b+/− testis. Taken together, our data suggested that eEF1A1b is crucial for spermatogenesis and male fertility in the Nile tilapia. PMID:28266557

  12. Pathology of Breast and Ovarian Cancers among BRCA1 and BRCA2 Mutation Carriers: Results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

    DEFF Research Database (Denmark)

    Mavaddat, Nasim; Barrowdale, Daniel; Andrulis, Irene L

    2012-01-01

    BACKGROUND: Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. METHODS: We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the path...

  13. The NOD2 3020insC Mutation in Women with Breast Cancer from the Bydgoszcz Region in Poland. First Results

    Directory of Open Access Journals (Sweden)

    Janiszewska Hanna

    2006-01-01

    Full Text Available Abstract The frameshift NOD2 gene mutation 3020insC is predominantly associated with Crohn's disease, but predisposes to many types of common cancers as well. We studied the frequency of this mutant NOD2 allele in 148 breast cancer women from the Bydgoszcz region in Poland. The NOD2 mutation was present in 8.8% of the patients. The mean age at breast cancer diagnosis of the mutation carriers was 43 years. We did not find any mutation in patients diagnosed with breast cancer after the age of 50 years. There was no association of the NOD2 mutation with a strong family history of breast cancer. On the contrary, the mutation frequency (11.4% was two times higher in women from families with a single case of breast cancer and with aggregation of other common types of cancer, especially digestive tract cancers. Low risk of breast cancer in the mutation carriers seems to be confirmed by finding the 3020insC mutation in three healthy parents of probands aged 73, 74 and 83 years, from three separate families.

  14. Pathology of breast and ovarian cancers among BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA).

    NARCIS (Netherlands)

    Mavaddat, N.; Barrowdale, D.; Andrulis, I.L.; Domchek, S.M.; Eccles, D.; Nevanlinna, H.; Ramus, S.J.; Spurdle, A.; Robson, M.; Sherman, M.; Mulligan, A.M.; Couch, F.J.; Engel, C.; McGuffog, L.; Healey, S.; Sinilnikova, O.M.; Southey, M.C.; Terry, M.B.; Goldgar, D.; O'Malley, F.; John, E.M.; Janavicius, R.; Tihomirova, L.; Hansen, T.V.; Nielsen, F.C.; Osorio, A.; Stavropoulou, A.; Benitez, J.; Manoukian, S.; Peissel, B.; Barile, M.; Volorio, S.; Pasini, B.; Dolcetti, R.; Putignano, A.L.; Ottini, L.; Radice, P.; Hamann, U.; Rashid, M.U.; Hogervorst, F.B.L.; Kriege, M.; Luijt, R.B. van der; Peock, S.; Frost, D.; Evans, D.G.; Brewer, C.; Walker, L.; Rogers, M.T.; Side, L.E.; Houghton, C.; Weaver, J.; Godwin, A.K.; Schmutzler, R.K.; Wappenschmidt, B.; Meindl, A.; Kast, K.; Arnold, N.; Niederacher, D.; Sutter, C.; Deissler, H.; Gadzicki, D.; Preisler-Adams, S.; Varon-Mateeva, R.; Schonbuchner, I.; Gevensleben, H.; Stoppa-Lyonnet, D.; Belotti, M.; Barjhoux, L.; Isaacs, C.; Peshkin, B.N.; Caldes, T.; Hoya, M. de la; Canadas, C.; Heikkinen, T.; Heikkila, P.; Aittomaki, K.; Blanco, I.; Lazaro, C.; Brunet, J.; Agnarsson, B.A.; Arason, A.; Barkardottir, R.B.; Dumont, M.; Simard, J.; Montagna, M.; Agata, S.; D'Andrea, E.; Yan, M.; Fox, S.; Rebbeck, T.R.; Rubinstein, W.; Tung, N.; Garber, J.E.; Wang, X.; Fredericksen, Z.; Pankratz, V.S.; Lindor, N.M.; Szabo, C.; Offit, K.; Sakr, R.; Gaudet, M.M.; Singer, C.F.; Tea, M.K.; Rappaport, C.; Mai, P.L.; Greene, M.H.; Sokolenko, A.; Imyanitov, E.; Toland, A.E.; Senter, L.; Sweet, K.; Thomassen, M.; Gerdes, A.M.; Kruse, T.; Caligo, M.; Aretini, P.; Rantala, J.; Wachenfeld, A. von; Henriksson, K.; Steele, L.; Neuhausen, S.L.; Nussbaum, R.; Beattie, M.; Odunsi, K.; Sucheston, L.; Gayther, S.A.; Nathanson, K.; Gross, J.; Walsh, C.; Karlan, B.; Chenevix-Trench, G.; Easton, D.F.; Antoniou, A.C.; Ligtenberg, M.J.L.; Hoogerbrugge, N.

    2012-01-01

    BACKGROUND: Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. METHODS: We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the patholo

  15. Pathology of Breast and Ovarian Cancers among BRCA1 and BRCA2 Mutation Carriers : Results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

    NARCIS (Netherlands)

    Mavaddat, Nasim; Barrowdale, Daniel; Andrulis, Irene L.; Domchek, Susan M.; Eccles, Diana; Nevanlinna, Heli; Ramus, Susan J.; Spurdle, Amanda; Robson, Mark; Sherman, Mark; Mulligan, Anna Marie; Couch, Fergus J.; Engel, Christoph; McGuffog, Lesley; Healey, Sue; Sinilnikova, Olga M.; Southey, Melissa C.; Terry, Mary Beth; Goldgar, David; O'Malley, Frances; John, Esther M.; Janavicius, Ramunas; Tihomirova, Laima; Hansen, Thomas V. O.; Nielsen, Finn C.; Osorio, Ana; Stavropoulou, Alexandra; Benitez, Javier; Manoukian, Siranoush; Peissel, Bernard; Barile, Monica; Volorio, Sara; Pasini, Barbara; Dolcetti, Riccardo; Putignano, Anna Laura; Ottini, Laura; Radice, Paolo; Hamann, Ute; Rashid, Muhammad U.; Hogervorst, Frans B.; Kriege, Mieke; van der Luijt, Rob B.; Peock, Susan; Frost, Debra; Evans, D. Gareth; Brewer, Carole; Walker, Lisa; Rogers, Mark T.; Side, Lucy E.; Houghton, Catherine; Weaver, JoEllen; Godwin, Andrew K.; Schmutzler, Rita K.; Wappenschmidt, Barbara; Meindl, Alfons; Kast, Karin; Arnold, Norbert; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Doroteha; Preisler-Adams, Sabine; Varon-Mateeva, Raymonda; Schoenbuchner, Ines; Gevensleben, Heidrun; Stoppa-Lyonnet, Dominique; Belotti, Muriel; Barjhoux, Laure; Isaacs, Claudine; Peshkin, Beth N.; Caldes, Trinidad; de la Hoya, Miguel; Canadas, Carmen; Heikkinen, Tuomas; Heikkila, Paivi; Aittomaki, Kristiina; Blanco, Ignacio; Lazaro, Conxi; Brunet, Joan; Agnarsson, Bjarni A.; Arason, Adalgeir; Barkardottir, Rosa B.; Dumont, Martine; Simard, Jacques; Montagna, Marco; Agata, Simona; D'Andrea, Emma; Yan, Max; Fox, Stephen; Rebbeck, Timothy R.; Rubinstein, Wendy; Tung, Nadine; Garber, Judy E.; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S.; Lindor, Noralane M.; Szabo, Csilla; Offit, Kenneth; Sakr, Rita; Gaudet, Mia M.; Singer, Christian F.; Tea, Muy-Kheng; Rappaport, Christine; Mai, Phuong L.; Greene, Mark H.; Sokolenko, Anna; Imyanitov, Evgeny; Toland, Amanda Ewart; Senter, Leigha; Sweet, Kevin; Thomassen, Mads; Gerdes, Anne-Marie; Kruse, Torben; Caligo, Maria; Aretini, Paolo; Rantala, Johanna; von Wachenfeld, Anna; Henriksson, Karin; Steele, Linda; Neuhausen, Susan L.; Nussbaum, Robert; Beattie, Mary; Odunsi, Kunle; Sucheston, Lara; Gayther, Simon A.; Nathanson, Kate; Gross, Jenny; Walsh, Christine; Karlan, Beth; Chenevix-Trench, Georgia; Easton, Douglas F.; Antoniou, Antonis C.

    2012-01-01

    Background: Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. Methods: We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the patholo

  16. Recessive mutations in SLC13A5 result in a loss of citrate transport and cause neonatal epilepsy, developmental delay and teeth hypoplasia

    DEFF Research Database (Denmark)

    Hardies, Katia; de Kovel, Carolien G F; Weckhuysen, Sarah

    2015-01-01

    . Occasionally recessive mutations are identified: a recent publication described a distinct neonatal epileptic encephalopathy (MIM 615905) caused by autosomal recessive mutations in the SLC13A5 gene. Here, we report eight additional patients belonging to four different families with autosomal recessive...

  17. Pathology of Breast and Ovarian Cancers among BRCA1 and BRCA2 Mutation Carriers : Results from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA)

    NARCIS (Netherlands)

    Mavaddat, Nasim; Barrowdale, Daniel; Andrulis, Irene L.; Domchek, Susan M.; Eccles, Diana; Nevanlinna, Heli; Ramus, Susan J.; Spurdle, Amanda; Robson, Mark; Sherman, Mark; Mulligan, Anna Marie; Couch, Fergus J.; Engel, Christoph; McGuffog, Lesley; Healey, Sue; Sinilnikova, Olga M.; Southey, Melissa C.; Terry, Mary Beth; Goldgar, David; O'Malley, Frances; John, Esther M.; Janavicius, Ramunas; Tihomirova, Laima; Hansen, Thomas V. O.; Nielsen, Finn C.; Osorio, Ana; Stavropoulou, Alexandra; Benitez, Javier; Manoukian, Siranoush; Peissel, Bernard; Barile, Monica; Volorio, Sara; Pasini, Barbara; Dolcetti, Riccardo; Putignano, Anna Laura; Ottini, Laura; Radice, Paolo; Hamann, Ute; Rashid, Muhammad U.; Hogervorst, Frans B.; Kriege, Mieke; van der Luijt, Rob B.; Peock, Susan; Frost, Debra; Evans, D. Gareth; Brewer, Carole; Walker, Lisa; Rogers, Mark T.; Side, Lucy E.; Houghton, Catherine; Weaver, JoEllen; Godwin, Andrew K.; Schmutzler, Rita K.; Wappenschmidt, Barbara; Meindl, Alfons; Kast, Karin; Arnold, Norbert; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Doroteha; Preisler-Adams, Sabine; Varon-Mateeva, Raymonda; Schoenbuchner, Ines; Gevensleben, Heidrun; Stoppa-Lyonnet, Dominique; Belotti, Muriel; Barjhoux, Laure; Isaacs, Claudine; Peshkin, Beth N.; Caldes, Trinidad; de la Hoya, Miguel; Canadas, Carmen; Heikkinen, Tuomas; Heikkila, Paivi; Aittomaki, Kristiina; Blanco, Ignacio; Lazaro, Conxi; Brunet, Joan; Agnarsson, Bjarni A.; Arason, Adalgeir; Barkardottir, Rosa B.; Dumont, Martine; Simard, Jacques; Montagna, Marco; Agata, Simona; D'Andrea, Emma; Yan, Max; Fox, Stephen; Rebbeck, Timothy R.; Rubinstein, Wendy; Tung, Nadine; Garber, Judy E.; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S.; Lindor, Noralane M.; Szabo, Csilla; Offit, Kenneth; Sakr, Rita; Gaudet, Mia M.; Singer, Christian F.; Tea, Muy-Kheng; Rappaport, Christine; Mai, Phuong L.; Greene, Mark H.; Sokolenko, Anna; Imyanitov, Evgeny; Toland, Amanda Ewart; Senter, Leigha; Sweet, Kevin; Thomassen, Mads; Gerdes, Anne-Marie; Kruse, Torben; Caligo, Maria; Aretini, Paolo; Rantala, Johanna; von Wachenfeld, Anna; Henriksson, Karin; Steele, Linda; Neuhausen, Susan L.; Nussbaum, Robert; Beattie, Mary; Odunsi, Kunle; Sucheston, Lara; Gayther, Simon A.; Nathanson, Kate; Gross, Jenny; Walsh, Christine; Karlan, Beth; Chenevix-Trench, Georgia; Easton, Douglas F.; Antoniou, Antonis C.

    2012-01-01

    Background: Previously, small studies have found that BRCA1 and BRCA2 breast tumors differ in their pathology. Analysis of larger datasets of mutation carriers should allow further tumor characterization. Methods: We used data from 4,325 BRCA1 and 2,568 BRCA2 mutation carriers to analyze the patholo

  18. Twenty year results on application of induced mutation in soybean (Glycine max (L.) Merr.) breeding at Agricultural Genetics Institute (AGI), Hanoi, Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Mai Quang Vinh; Phan Phai; Ngo Phuong Thinh; Tran Dinh Dong; Tran Thuy Oanh [Agricultural Genetics Institute (AGI), Hanoi (Viet Nam)

    2001-03-01

    Research on application of the induced mutation method combined with crossing in soybean breeding for 20 years (1980-2000) plays an important role in research work at AGI, (Ministry of Agriculture and Rural Development of Vietnam). 23 soybean varieties and hybrid lines (including 6 local cultivars, 14 selected and introduced varieties, 3 hybrid lines) were treated with Roentgen ray irradiation, Gamma Ray {sup 60}Co with doses 7, 10, 12, 15, 18, 20 krad, and with chemical mutagens: EI, NMU, DNMU, DES, EMS, DEU with various concentrations 0.008, 0.02, 0.04, 0.06, 0.08%. As the results, we obtained the important conclusions about the rule of induced mutation process in soybean in the natural conditions of Vietnam. 8 mutant varieties [1 National varieties (DT84) and 6 regional production varieties (DT83, DT90, DT94, DT95, DT99, AK06 (DT-55))]. Several promising varieties were selected and released for farmers to produce in the large areas that occupied 50-90% percentage of soybean cultivated areas in Vietnam. These varieties have high-yield 1.5-3.5 tons/ha, short growth duration 75-100 days, tolerance to cold and hot temperature and can be planted in 3 crops per year (Winter, Spring and Summer season) over 35-40 thousands ha/year. At present, the mutagens are being used for defect-orientated repair of some promising hybrid lines, in order to contribute new good varieties to soybean production in Vietnam. (author)

  19. Results on prognostic value of mutations in localized gastrointestinal stromal tumors (GIST: in one single center Valor pronóstico de las mutaciones en tumores estromales gastrointestinales localizados (GIST: resultados de un solo centro

    Directory of Open Access Journals (Sweden)

    Marina Garcés-Albir

    2012-08-01

    Full Text Available Introduction: to study the prognostic value of mutations in KIT or PDGFRA in gastrointestinal stromal tumors (GIST managed in our department. Materials and methods: forty five patients with localized GIST underwent surgery between 1998 and 2010. Thirty six patients were enrolled in a retrospective study. DNA was isolated from 3 to 5 µm sections of fixed and paraffin-embedded tissue. Exon 9, 11, 13 and 17 of c-kit gene and exon 12 and 18 of PDGFRA were amplified by PCR and sequenced. Results: tumors with mutations were larger at the surgery and showed higher mitotic count (p 50 mitosis/HPF (42 vs. 88%, p < 0.03. Multivariate analyses indicated that the mutations, mitotic counts, and tumor size were independent prognostic factors for survival in patients with localized GIST. Conclusions: in this series, having a detected mutation is a poor prognostic factor with significantly increased recurrence rate and shortens survival.

  20. Mutational spectrum drives the rise of mutator bacteria.

    Directory of Open Access Journals (Sweden)

    Alejandro Couce

    Full Text Available Understanding how mutator strains emerge in bacterial populations is relevant both to evolutionary theory and to reduce the threat they pose in clinical settings. The rise of mutator alleles is understood as a result of their hitchhiking with linked beneficial mutations, although the factors that govern this process remain unclear. A prominent but underappreciated fact is that each mutator allele increases only a specific spectrum of mutational changes. This spectrum has been speculated to alter the distribution of fitness effects of beneficial mutations, potentially affecting hitchhiking. To study this possibility, we analyzed the fitness distribution of beneficial mutations generated from different mutator and wild-type Escherichia coli strains. Using antibiotic resistance as a model system, we show that mutational spectra can alter these distributions substantially, ultimately determining the competitive ability of each strain across environments. Computer simulation showed that the effect of mutational spectrum on hitchhiking dynamics follows a non-linear function, implying that even slight spectrum-dependent fitness differences are sufficient to alter mutator success frequency by several orders of magnitude. These results indicate an unanticipated central role for the mutational spectrum in the evolution of bacterial mutation rates. At a practical level, this study indicates that knowledge of the molecular details of resistance determinants is crucial for minimizing mutator evolution during antibiotic therapy.

  1. Two novel variants of human medium chain acyl-CoA dehydrogenase (MCAD). K364R, a folding mutation, and R256T, a catalytic-site mutation resulting in a well-folded but totally inactive protein

    DEFF Research Database (Denmark)

    O'Reilly, Linda P; Andresen, Brage S; Engel, Paul C

    2005-01-01

    Two novel rare mutations, MCAD approximately 842G-->C (R256T) and MCAD approximately 1166A-->G (K364R), have been investigated to assess how far the biochemical properties of the mutant proteins correlate with the clinical phenotype of medium chain acyl-CoA dehydrogenase (MCAD) deficiency. When t...

  2. NATURAL MUTATION IN THE GENE OF RESPONSE REGULATOR BgrR RESULTING IN REPRESSION OF Bac PROTEIN SYNTHESIS, A PATHOGENICITY FACTOR OF STREPTOCOCCUS AGALACTIAE

    Directory of Open Access Journals (Sweden)

    A. S. Rozhdestvenskaya

    2013-01-01

    Full Text Available Abstract. Streptococcus agalactiae can cause variety of diseases of newborns and adults. For successful colonization of different human tissues and organs as well as for suppression of the host immune system S. agalactiae expresses numerous virulence factors. For coordinated expression of the virulence genes S. agalactiae employs regulatory molecules including regulatory proteins of two-component systems. Results of the present study demonstrated that in S. agalactiae strain A49V the natural mutation in the brgR gene encoding for BgrR regulatory protein, which is component of regulatory system BgrRS, resulted in the repression of Bac protein synthesis, a virulence factor of S. agalactiae. A single nucleotide deletion in the bgrR gene has caused a shift of the reading frame and the changes in the primary, secondary and tertiary structures of the BgrR protein. The loss of functional activity of BgrR protein in A49V strain and repression of Bac protein synthesis have increased virulence of the strain in experimental animal streptococcal infection.

  3. Filaggrin null mutations increase the risk and persistence of hand eczema in subjects with atopic dermatitis: results from a general population study

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Carlsen, B C; Menné, Torkil

    2010-01-01

    Hand eczema is prevalent in the general population. It remains unclear whether or not filaggrin gene (FLG) null mutations increase the overall risk of hand eczema or only increase the risk of hand eczema in subjects with atopic dermatitis.......Hand eczema is prevalent in the general population. It remains unclear whether or not filaggrin gene (FLG) null mutations increase the overall risk of hand eczema or only increase the risk of hand eczema in subjects with atopic dermatitis....

  4. A Recessive Mutation Resulting in a Disabling Amino Acid Substitution (T194R) in the LHX3 Homeodomain Causes Combined Pituitary Hormone Deficiency

    OpenAIRE

    Bechtold-Dalla Pozza, Susanne; Hiedl, Stefan; Roeb, Julia; Lohse, Peter; Malik, Raleigh E.; Park, Soyoung; Duran-Prado, Mario; Rhodes, Simon J.

    2012-01-01

    Background/Aims: Recessive mutations in the LHX3 homeodomain transcription factor gene are associated with developmental disorders affecting the pituitary and nervous system. We describe pediatric patients with combined pituitary hormone deficiency (CPHD) who harbor a novel mutation in LHX3. Methods: Two female siblings from related parents were examined. Both patients had neonatal complications. The index patient had CPHD featuring deficiencies of GH, LH, FSH, PRL, and TSH, with later onset ...

  5. Discrimination of three mutational events that result in a disruption of the R122 primary autolysis site of the human cationic trypsinogen (PRSS1 by denaturing high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Férec Claude

    2001-11-01

    Full Text Available Abstract Background R122, the primary autolysis site of the human cationic trypsinogen (PRSS1, constitutes an important "self-destruct" or "fail-safe" defensive mechanism against premature trypsin activation within the pancreas. Disruption of this site by a missense mutation, R122H, was found to cause hereditary pancreatitis. In addition to a c.365G>A (CGC>CAC single nucleotide substitution, a c.365~366GC>AT (CGC>CAT gene conversion event in exon 3 of PRSS1 was also found to result in a R122H mutation. This imposes a serious concern on the genotyping of pancreatitis by a widely used polymerase chain reaction-restriction fragment length polymorphism assay, which could only detect the commonest c.365G>A variant. Materials and methods DNA samples containing either the known c.365G>A or c.365~366GC>AT variant in exon 3 of PRSS1 were used as positive controls to establish a denaturing high performance liquid chromatography (DHPLC assay. Results DHPLC could readily discriminate the two known different mutational events resulting in the R122H mutation. More importantly, under the same experimental conditions, it identified a further mutational event that also occurs in the R122 primary autolysis site but results in a different amino acid substitution: c.364C>T (CGC>TGC; R122C. Conclusions A rapid, simple, and low-cost assay for detecting both the known and new mutations occuring in the R122 primary autolysis site of PRSS1 was established. In addition, the newly found R122C variant represents a likely pancreatitis-predisposing mutation.

  6. Mutations in the Gene Encoding the Ancillary Pilin Subunit of the Streptococcus suis srtF Cluster Result in Pili Formed by the Major Subunit Only

    Science.gov (United States)

    Fittipaldi, Nahuel; Takamatsu, Daisuke; la Cruz Domínguez-Punaro, María de; Lecours, Marie-Pier; Montpetit, Diane; Osaki, Makoto; Sekizaki, Tsutomu; Gottschalk, Marcelo

    2010-01-01

    Pili have been shown to contribute to the virulence of different Gram-positive pathogenic species. Among other critical steps of bacterial pathogenesis, these structures participate in adherence to host cells, colonization and systemic virulence. Recently, the presence of at least four discrete gene clusters encoding putative pili has been revealed in the major swine pathogen and emerging zoonotic agent Streptococcus suis. However, pili production by this species has not yet been demonstrated. In this study, we investigated the functionality of one of these pili clusters, known as the srtF pilus cluster, by the construction of mutant strains for each of the four genes of the cluster as well as by the generation of antibodies against the putative pilin subunits. Results revealed that the S. suis serotype 2 strain P1/7, as well as several other highly virulent invasive S. suis serotype 2 isolates express pili from this cluster. However, in most cases tested, and as a result of nonsense mutations at the 5′ end of the gene encoding the minor pilin subunit (a putative adhesin), pili were formed by the major pilin subunit only. We then evaluated the role these pili play in S. suis virulence. Abolishment of the expression of srtF cluster-encoded pili did not result in impaired interactions of S. suis with porcine brain microvascular endothelial cells. Furthermore, non-piliated mutants were as virulent as the wild type strain when evaluated in a murine model of S. suis sepsis. Our results show that srtF cluster-encoded, S. suis pili are atypical compared to other Gram-positive pili. In addition, since the highly virulent strains under investigation are unlikely to produce other pili, our results suggest that pili might be dispensable for critical steps of the S. suis pathogenesis of infection. PMID:20052283

  7. Mutation of the aspartic acid residues of the GDD sequence motif of poliovirus RNA-dependent RNA polymerase results in enzymes with altered metal ion requirements for activity.

    Science.gov (United States)

    Jablonski, S A; Morrow, C D

    1995-01-01

    different metal ions. Surprisingly, the transfection of the cDNA containing the 3D-N-329 mutation resulted in the production of virus at a low frequency in the presence of FeSO4 or CoCl2. The virus derived from transfection in the presence of FeSO4 grew slowly, while the viruses recovered from transfection in CoCl2 grew at a rate which was similar to that of the wild-type poliovirus.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:7853486

  8. Baseline results from the UK SIGNIFY study: a whole-body MRI screening study in TP53 mutation carriers and matched controls.

    Science.gov (United States)

    Saya, Sibel; Killick, Emma; Thomas, Sarah; Taylor, Natalie; Bancroft, Elizabeth K; Rothwell, Jeanette; Benafif, Sarah; Dias, Alexander; Mikropoulos, Christos; Pope, Jenny; Chamberlain, Anthony; Gunapala, Ranga; Izatt, Louise; Side, Lucy; Walker, Lisa; Tomkins, Susan; Cook, Jackie; Barwell, Julian; Wiles, Vicki; Limb, Lauren; Eccles, Diana; Leach, Martin O; Shanley, Susan; Gilbert, Fiona J; Hanson, Helen; Gallagher, David; Rajashanker, Bala; Whitehouse, Richard W; Koh, Dow-Mu; Sohaib, S Aslam; Evans, D Gareth; Eeles, Rosalind A

    2017-01-16

    In the United Kingdom, current screening guidelines for TP53 germline mutation carriers solely recommends annual breast MRI, despite the wide spectrum of malignancies typically seen in this group. This study sought to investigate the role of one-off non-contrast whole-body MRI (WB MRI) in the screening of asymptomatic TP53 mutation carriers. 44 TP53 mutation carriers and 44 population controls were recruited. Scans were read by radiologists blinded to participant carrier status. The incidence of malignancies diagnosed in TP53 mutation carriers against general population controls was calculated. The incidences of non-malignant relevant disease and irrelevant disease were measured, as well as the number of investigations required to determine relevance of findings. In TP53 mutation carriers, 6 of 44 (13.6, 95% CI 5.2-27.4%) participants were diagnosed with cancer during the study, all of which would be considered life threatening if untreated. Two were found to have two primary cancers. Two participants with cancer had abnormalities on the MRI which were initially thought to be benign (a pericardial cyst and a uterine fibroid) but transpired to be sarcomas. No controls were diagnosed with cancer. Fifteen carriers (34.1, 95% CI 20.5-49.9%) and seven controls (15.9, 95% CI 6.7-30.1%) underwent further investigations following the WB MRI for abnormalities that transpired to be benign (p = 0.049). The cancer detection rate in this group justifies a minimum baseline non-contrast WB MRI in germline TP53 mutation carriers. This should be adopted into national guidelines for management of adult TP53 mutation carriers in addition to the current practice of contrast enhanced breast MRI imaging.

  9. Mutation-induced quisqualic acid and ibotenic acid affinity at the metabotropic glutamate receptor subtype 4: ligand selectivity results from a synergy of several amino acid residues

    DEFF Research Database (Denmark)

    Hermit, Mette B; Greenwood, Jeremy R; Bräuner-Osborne, Hans

    2004-01-01

    resides. In this study, we have identified four non-conserved amino acid residues that are essential for differentiating mGluR1 from mGluR4. Our approach has been to increase the affinity of the classic mGluR1 agonists, quisqualic acid and ibotenic acid, at mGluR4 by making various point mutations...... that mimicked mGluR1 residues. Based on ligand docking to homology models, the non-conserved residues, Lys-74, Glu-287, Ser-313, and Lys-317, were chosen for the mutational studies and all of the mutations proved capable of partially or completely restoring the affinities of the ligands. In particular......, the mutations K74Y and K317R induced dramatic triple-order-of-magnitude increases in the affinity of ibotenic acid at mGluR4, making the affinity equivalent to that of mGluR1. Furthermore, the affinity of quisqualic acid at mGluR4 was increased to the same level as mGluR1 by the two double mutations, K74Y/K317R...

  10. A rare CYP 21 mutation (p.E431K) induced deactivation of CYP 21A2 and resulted in congenital adrenal hyperplasia.

    Science.gov (United States)

    Kawashima, Yuki; Usui, Takeshi; Fujimoto, Masanobu; Miyahara, Naoki; Nishimura, Rei; Hanaki, Keiichi; Kanzaki, Susumu

    2015-01-01

    Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is caused by mutations in the CYP21A2 gene. The residual enzyme activity is strongly associated with the phenotype. We describe a rare case of CAH with a rare CYP21A2 mutation. The patient was a one-year-old Japanese boy. At 16 days old, he was referred to our hospital because of elevated serum 17-OH-progesterone (17-OHP) levels in neonatal screening. The compound heterozygous mutations (IVS2-13 A/C>G, and p.E431K) in CYP21A2 were identified at 2 months old, and we diagnosed non-classical CAH, since he did not have significant physical signs (pigmentation and salt-wasting). However, his body weight decreased, and his serum 17-OHP level (99.5 ng/mL) was elevated at 3 months old. Steroid replacement therapy was started at 3 months old. Our patient's clinical course resembled simple virilizing (SV) CAH, but classification was difficult because the patient showed increased renin activity indicating an aldosterone deficiency, and late onset of symptoms. While the IVS 2-13 A/C>G mutation is common in the classical form of CAH, p.E431K is a rare point mutation. Functional analysis revealed that the residual enzyme activity of p.E431L was 5.08±2.55% for 17-OHP and 4.12±2.37% for progesterone, which is consistent with SV CAH. p.E431 is localized in the L-helix near the heme-binding site. The mutation might interfere with heme binding, leading to deactivation of CYP21A2. This report showed that CYP21A2 p.E431 has an important effect on enzyme activity.

  11. RAD51 135G-->C modifies breast cancer risk among BRCA2 mutation carriers: results from a combined analysis of 19 studies.

    Science.gov (United States)

    Antoniou, Antonis C; Sinilnikova, Olga M; Simard, Jacques; Léoné, Mélanie; Dumont, Martine; Neuhausen, Susan L; Struewing, Jeffery P; Stoppa-Lyonnet, Dominique; Barjhoux, Laure; Hughes, David J; Coupier, Isabelle; Belotti, Muriel; Lasset, Christine; Bonadona, Valérie; Bignon, Yves-Jean; Rebbeck, Timothy R; Wagner, Theresa; Lynch, Henry T; Domchek, Susan M; Nathanson, Katherine L; Garber, Judy E; Weitzel, Jeffrey; Narod, Steven A; Tomlinson, Gail; Olopade, Olufunmilayo I; Godwin, Andrew; Isaacs, Claudine; Jakubowska, Anna; Lubinski, Jan; Gronwald, Jacek; Górski, Bohdan; Byrski, Tomasz; Huzarski, Tomasz; Peock, Susan; Cook, Margaret; Baynes, Caroline; Murray, Alexandra; Rogers, Mark; Daly, Peter A; Dorkins, Huw; Schmutzler, Rita K; Versmold, Beatrix; Engel, Christoph; Meindl, Alfons; Arnold, Norbert; Niederacher, Dieter; Deissler, Helmut; Spurdle, Amanda B; Chen, Xiaoqing; Waddell, Nicola; Cloonan, Nicole; Kirchhoff, Tomas; Offit, Kenneth; Friedman, Eitan; Kaufmann, Bella; Laitman, Yael; Galore, Gilli; Rennert, Gad; Lejbkowicz, Flavio; Raskin, Leon; Andrulis, Irene L; Ilyushik, Eduard; Ozcelik, Hilmi; Devilee, Peter; Vreeswijk, Maaike P G; Greene, Mark H; Prindiville, Sheila A; Osorio, Ana; Benitez, Javier; Zikan, Michal; Szabo, Csilla I; Kilpivaara, Outi; Nevanlinna, Heli; Hamann, Ute; Durocher, Francine; Arason, Adalgeir; Couch, Fergus J; Easton, Douglas F; Chenevix-Trench, Georgia

    2007-12-01

    RAD51 is an important component of double-stranded DNA-repair mechanisms that interacts with both BRCA1 and BRCA2. A single-nucleotide polymorphism (SNP) in the 5' untranslated region (UTR) of RAD51, 135G-->C, has been suggested as a possible modifier of breast cancer risk in BRCA1 and BRCA2 mutation carriers. We pooled genotype data for 8,512 female mutation carriers from 19 studies for the RAD51 135G-->C SNP. We found evidence of an increased breast cancer risk in CC homozygotes (hazard ratio [HR] 1.92 [95% confidence interval {CI} 1.25-2.94) but not in heterozygotes (HR 0.95 [95% CI 0.83-1.07]; P=.002, by heterogeneity test with 2 degrees of freedom [df]). When BRCA1 and BRCA2 mutation carriers were analyzed separately, the increased risk was statistically significant only among BRCA2 mutation carriers, in whom we observed HRs of 1.17 (95% CI 0.91-1.51) among heterozygotes and 3.18 (95% CI 1.39-7.27) among rare homozygotes (P=.0007, by heterogeneity test with 2 df). In addition, we determined that the 135G-->C variant affects RAD51 splicing within the 5' UTR. Thus, 135G-->C may modify the risk of breast cancer in BRCA2 mutation carriers by altering the expression of RAD51. RAD51 is the first gene to be reliably identified as a modifier of risk among BRCA1/2 mutation carriers.

  12. RAD51 135G→C Modifies Breast Cancer Risk among BRCA2 Mutation Carriers: Results from a Combined Analysis of 19 Studies

    Science.gov (United States)

    Antoniou, Antonis C. ; Sinilnikova, Olga M. ; Simard, Jacques ; Léoné, Mélanie ; Dumont, Martine ; Neuhausen, Susan L. ; Struewing, Jeffery P. ; Stoppa-Lyonnet, Dominique ; Barjhoux, Laure ; Hughes, David J. ; Coupier, Isabelle ; Belotti, Muriel ; Lasset, Christine ; Bonadona, Valérie ; Bignon, Yves-Jean ; Rebbeck, Timothy R. ; Wagner, Theresa ; Lynch, Henry T. ; Domchek, Susan M. ; Nathanson, Katherine L. ; Garber, Judy E. ; Weitzel, Jeffrey ; Narod, Steven A. ; Tomlinson, Gail ; Olopade, Olufunmilayo I. ; Godwin, Andrew ; Isaacs, Claudine ; Jakubowska, Anna ; Lubinski, Jan ; Gronwald, Jacek ; Górski, Bohdan ; Byrski, Tomasz ; Huzarski, Tomasz ; Peock, Susan ; Cook, Margaret ; Baynes, Caroline ; Murray, Alexandra ; Rogers, Mark ; Daly, Peter A. ; Dorkins, Huw ; Schmutzler, Rita K. ; Versmold, Beatrix ; Engel, Christoph ; Meindl, Alfons ; Arnold, Norbert ; Niederacher, Dieter ; Deissler, Helmut ; Spurdle, Amanda B. ; Chen, Xiaoqing ; Waddell, Nicola ; Cloonan, Nicole ; Kirchhoff, Tomas ; Offit, Kenneth ; Friedman, Eitan ; Kaufmann, Bella ; Laitman, Yael ; Galore, Gilli ; Rennert, Gad ; Lejbkowicz, Flavio ; Raskin, Leon ; Andrulis, Irene L. ; Ilyushik, Eduard ; Ozcelik, Hilmi ; Devilee, Peter ; Vreeswijk, Maaike P. G. ; Greene, Mark H. ; Prindiville, Sheila A. ; Osorio, Ana ; Benítez, Javier ; Zikan, Michal ; Szabo, Csilla I. ; Kilpivaara, Outi ; Nevanlinna, Heli ; Hamann, Ute ; Durocher, Francine ; Arason, Adalgeir ; Couch, Fergus J. ; Easton, Douglas F. ; Chenevix-Trench, Georgia 

    2007-01-01

    RAD51 is an important component of double-stranded DNA–repair mechanisms that interacts with both BRCA1 and BRCA2. A single-nucleotide polymorphism (SNP) in the 5′ untranslated region (UTR) of RAD51, 135G→C, has been suggested as a possible modifier of breast cancer risk in BRCA1 and BRCA2 mutation carriers. We pooled genotype data for 8,512 female mutation carriers from 19 studies for the RAD51 135G→C SNP. We found evidence of an increased breast cancer risk in CC homozygotes (hazard ratio [HR] 1.92 [95% confidence interval {CI} 1.25–2.94) but not in heterozygotes (HR 0.95 [95% CI 0.83–1.07]; P=.002, by heterogeneity test with 2 degrees of freedom [df]). When BRCA1 and BRCA2 mutation carriers were analyzed separately, the increased risk was statistically significant only among BRCA2 mutation carriers, in whom we observed HRs of 1.17 (95% CI 0.91–1.51) among heterozygotes and 3.18 (95% CI 1.39–7.27) among rare homozygotes (P=.0007, by heterogeneity test with 2 df). In addition, we determined that the 135G→C variant affects RAD51 splicing within the 5′ UTR. Thus, 135G→C may modify the risk of breast cancer in BRCA2 mutation carriers by altering the expression of RAD51. RAD51 is the first gene to be reliably identified as a modifier of risk among BRCA1/2 mutation carriers. PMID:17999359

  13. Mutations in zebrafish lrp2 result in adult-onset ocular pathogenesis that models myopia and other risk factors for glaucoma.

    Directory of Open Access Journals (Sweden)

    Kerry N Veth

    2011-02-01

    Full Text Available The glaucomas comprise a genetically complex group of retinal neuropathies that typically occur late in life and are characterized by progressive pathology of the optic nerve head and degeneration of retinal ganglion cells. In addition to age and family history, other significant risk factors for glaucoma include elevated intraocular pressure (IOP and myopia. The complexity of glaucoma has made it difficult to model in animals, but also challenging to identify responsible genes. We have used zebrafish to identify a genetically complex, recessive mutant that shows risk factors for glaucoma including adult onset severe myopia, elevated IOP, and progressive retinal ganglion cell pathology. Positional cloning and analysis of a non-complementing allele indicated that non-sense mutations in low density lipoprotein receptor-related protein 2 (lrp2 underlie the mutant phenotype. Lrp2, previously named Megalin, functions as an endocytic receptor for a wide-variety of bioactive molecules including Sonic hedgehog, bone morphogenic protein 4, retinol-binding protein, vitamin D-binding protein, and apolipoprotein E, among others. Detailed phenotype analyses indicated that as lrp2 mutant fish age, many individuals--but not all--develop high IOP and severe myopia with obviously enlarged eye globes. This results in retinal stretch and prolonged stress to retinal ganglion cells, which ultimately show signs of pathogenesis. Our studies implicate altered Lrp2-mediated homeostasis as important for myopia and other risk factors for glaucoma in humans and establish a new genetic model for further study of phenotypes associated with this disease.

  14. X-linked CHARGE-like Abruzzo-Erickson syndrome and classic cleft palate with ankyloglossia result from TBX22 splicing mutations.

    Science.gov (United States)

    Pauws, E; Peskett, E; Boissin, C; Hoshino, A; Mengrelis, K; Carta, E; Abruzzo, M A; Lees, M; Moore, G E; Erickson, R P; Stanier, P

    2013-04-01

    X-linked cleft palate (CPX) is caused by mutations in the gene encoding the TBX22 transcription factor and is known to exhibit phenotypic variability, usually involving either a complete, partial or submucous cleft palate, with or without ankyloglossia. This study hypothesized a possible involvement of TBX22 in a family with X-linked, CHARGE-like Abruzzo-Erickson syndrome, of unknown etiology. The phenotype extends to additional features including sensorineural deafness and coloboma, which are suggested by the Tbx22 developmental expression pattern but not previously associated in CPX patients. A novel TBX22 splice acceptor mutation (c.593-5T>A) was identified that tracked with the phenotype in this family. A novel splice donor variant (c.767+5G>A) and a known canonical splice donor mutation (c.767+1G>A) affecting the same exon were identified in patients with classic CPX phenotypes and were comparatively analyzed using both in silico and in vitro splicing studies. All three variants were predicted to abolish normal mRNA splicing and an in vitro assay indicated that use of alternative splice sites was a likely outcome. Collectively, the data showed the functional effect of several novel intronic splice site variants but most importantly confirms that TBX22 is the gene underlying Abruzzo-Erickson syndrome, expanding the phenotypic spectrum of TBX22 mutations. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  15. Mutation in the phosphoribosylpyrophosphate synthetase gene (prs) that results in simultaneous requirements for purine and pyrimidine nucleosides, nicotinamide nucleotide, histidine, and tryptophan in Escherichia coli

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne

    1988-01-01

    , histidine, tryptophan, and nicotinamide mononucleotide were all added to the growth medium. Viability of the strain was dependent upon mutations in genes of the nucleoside salvage pathways that improved the utilization of exogenous nucleosides. The properties of the strain are those expected of a PRPP...

  16. Targeted Prostate Cancer Screening in BRCA1 and BRCA2 Mutation Carriers : Results from the Initial Screening Round of the IMPACT Study

    NARCIS (Netherlands)

    Bancroft, Elizabeth K.; Page, Elizabeth C.; Castro, Elena; Lilja, Hans; Vickers, Andrew; Sjoberg, Daniel; Assel, Melissa; Foster, Christopher S.; Mitchell, Gillian; Drew, Kate; Maehle, Lovise; Axcrona, Karol; Evans, D. Gareth; Bulman, Barbara; Eccles, Diana; McBride, Donna; van Asperen, Christi; Vasen, Hans; Kiemeney, Lambertus A.; Ringelberg, Janneke; Cybulski, Cezary; Wokolorczyk, Dominika; Selkirk, Christina; Hulick, Peter J.; Bojesen, Anders; Skytte, Anne-Bine; Lam, Jimmy; Taylor, Louise; Oldenburg, Rogier; Cremers, Ruben; Verhaegh, Gerald; van Zelst-Stams, Wendy A.; Oosterwijk, Jan C.; Blanco, Ignacio; Salinas, Monica; Cook, Jackie; Rosario, Derek J.; Buys, Saundra; Conner, Tom; Ausems, Margreet G.; Ong, Kai-ren; Hoffman, Jonathan; Domchek, Susan; Powers, Jacquelyn; Teixeira, Manuel R.; Maia, Sofia; Foulkes, William D.; Taherian, Nassim; Ruijs, Marielle; Helderman-van den Enden, Apollonia T.; Izatt, Louise; Davidson, Rosemarie; Adank, Muriel A.; Walker, Lisa; Schmutzler, Rita; Tucker, Kathy; Kirk, Judy; Hodgson, Shirley; Harris, Marion; Douglas, Fiona; Lindeman, Geoffrey J.; Zgajnar, Janez; Tischkowitz, Marc; Clowes, Virginia E.; Susman, Rachel; Ramon y Cajal, Teresa; Patcher, Nicholas; Gadea, Neus; Spigelman, Allan; van Os, Theo; Liljegren, Annelie; Side, Lucy; Brewer, Carole; Brady, Angela F.; Donaldson, Alan; Stefansdottir, Vigdis; Friedman, Eitan; Chen-Shtoyerman, Rakefet; Amor, David J.; Copakova, Lucia; Barwell, Julian; Giri, Veda N.; Murthy, Vedang; Nicolai, Nicola; Teo, Soo-Hwang; Greenhalgh, Lynn; Strom, Sara; Henderson, Alex; McGrath, John; Gallagher, David; Aaronson, Neil; Ardern-Jones, Audrey; Bangma, Chris; Dearnaley, David; Costello, Philandra; Eyfjord, Jorunn; Rothwell, Jeanette; Falconer, Alison; Gronberg, Henrik; Hamdy, Freddie C.; Johannsson, Oskar; Khoo, Vincent; Kote-Jarai, Zsofia; Lubinski, Jan; Axcrona, Ulrika; Melia, Jane; McKinley, Joanne; Mitra, Anita V.; Moynihan, Clare; Rennert, Gad; Suri, Mohnish; Wilson, Penny; Killick, Emma; Moss, Sue; Eeles, Rosalind A.

    Background: Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in

  17. Targeted prostate cancer screening in BRCA1 and BRCA2 mutation carriers: Results from the initial screening round of the IMPACT study

    NARCIS (Netherlands)

    E. Bancroft (Elizabeth); E. Page (Elizabeth); E. Castro (Elena); H. Lilja (Hans); A.J. Vickers (Andrew); D. Sjoberg (Daniel); M. Assel (Matthias); C.S. Foster; G. Mitchell (Gillian); K. Drew (Kate); L. Maehle; K. Axcrona; D.G. Evans (Gareth); B. Bulman; D. Eccles (Diana); D. McBride (Donna); C.J. van Asperen (Christi); H. Vasen (Hans); L.A.L.M. Kiemeney (Bart); J. Ringelberg (Janneke); C. Cybulski (Cezary); D. Wokolorczyk (Dominika); C.G. Selkirk (Christina); P.J. Hulick (Peter); S.E. Bojesen (Stig); A.-B. Skytte (Anne-Bine); J. Lam (Jimmy); L. Taylor (Lorne); R.A. Oldenburg (Rogier); R.G.H.M. Cremers; G. Verhaegh (Gerald); W.A. van Zelst-Stams; J.C. Oosterwijk (Jan); I. Blanco (Ignacio); M. Salinas; J. Cook (Jackie); K. Rosario (Karyna); S.S. Buys (Saundra); T. Conner (Tom); M.G.E.M. Ausems (Margreet); K.-R. Ong (Kai-Ren); J. Hoffman (Jonathan); S.M. Domchek (Susan); J. Powers (Jacquelyn); P.J. Teixeira; S. Maia (Sofia); W.D. Foulkes (William); N. Taherian (Nassim); M.W.G. Ruijs (Marielle); A.T.H.-V. den Enden (Apollonia T. Helderman-Van); L. Izatt (Louise); R. Davidson (Rosemarie); M.A. Adank (Muriel); L.J. Walker (Lisa); R.K. Schmutzler (Rita); K. Tucker (Kathryn); J. Kirk (Judy); S.V. Hodgson (Shirley); M. Harris (Marion); F. Douglas (Fiona); G.J. Lindeman; J. Zgajnar (Janez); M. Tischkowitz (Marc); V. Clowes; R. Susman (Rachel); T. Ramon Y Cajal; N. Patcher (Nicholas); N. Gadea (Neus); A. Spigelman; T.A.M. van Os (Theo); A. Liljegren (Annelie); L. Side (Lucy); C. Brewer (Carole); A.F. Brady (Angela); A. Donaldson (Alan); V. Stefansdottir (Vigdis); E. Friedman (Eitan); R. Chen-Shtoyerman (Rakefet); D. Amor (David); L. Copakova (Lucia); J. Barwell (Julian); V.N. Giri (Veda); A.C. Murthy (Adeline C.); N. Nicolai (Nicola); S.-H. Teo; T. Greenhalgh (Trisha); S. Strom; A. Henderson (Alex); J. McGrath (John); D. Gallagher (David); N.K. Aaronson (Neil); A. Ardern-Jones (Audrey); C.H. Bangma (Chris); D. Dearnaley (David); A. Costello (Anthony); J. Eyfjord; J. Rothwell (Jeanette); A. Falconer; H. Grönberg (Henrik); F. Hamdy (Freddie); O.T. Johannson (Oskar); V. Khoo; Z. Kote-Jarai; J. Lubinski (Jan); K. Axcrona; J. Melia; E.T. McKinley (Enid); A. Mitra (Anita); C. Moynihan; G. Rennert (Gad); M. Suri (Mohnish); P. Wilson; S.R. Killick; S.M. Moss (Sue); R. Eeles (Rosalind)

    2014-01-01

    textabstractBackground Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted

  18. RAS testing practices and RAS mutation prevalence among patients with metastatic colorectal cancer: results from a Europe-wide survey of pathology centres

    NARCIS (Netherlands)

    Boleij, A.; Tack, V.; Taylor, A.; Kafatos, G.; Jenkins-Anderson, S.; Tembuyser, L.; Dequeker, E.; Krieken, J.H.J.M. van

    2016-01-01

    BACKGROUND: Treatment options for patients with metastatic colorectal cancer (mCRC) include anti-epithelial growth factor therapies, which, in Europe, are indicated in patients with RAS wild-type tumours only and require prior mutation testing of "hot-spot" codons in exons 2, 3 and 4 of KRAS and

  19. Targeted Prostate Cancer Screening in BRCA1 and BRCA2 Mutation Carriers: Results from the Initial Screening Round of the IMPACT Study

    NARCIS (Netherlands)

    Bancroft, E.K.; Page, E.C.; Castro, E.; Lilja, H.; Vickers, A.; Sjoberg, D.; Assel, M.; Foster, C.S.; Mitchell, G.; Drew, K.; Maehle, L.; Axcrona, K.; Evans, D.G.; Bulman, B.; Eccles, D.; McBride, D.; Asperen, C. van; Vasen, H.; Kiemeney, B.; Ringelberg, J.; Cybulski, C.; Wokolorczyk, D.; Selkirk, C.; Hulick, P.J.; Bojesen, A.; Skytte, A.B.; Lam, J.; Taylor, L.; Oldenburg, R.; Cremers, R.; Verhaegh, G.; Zelst-Stams, W.A.G. van; Oosterwijk, J.C.; Blanco, I.; Salinas, M.; Cook, J.; Rosario, D.J.; Buys, S.; Conner, T.; Ausems, M.G.; Ong, K.R.; Hoffman, J.; Domchek, S.; Powers, J.; Teixeira, M.R.; Maia, S.; Foulkes, W.D.; Taherian, N.; Ruijs, M.; Enden, A.T. den; Izatt, L.; Davidson, R.; Adank, M.A.; Walker, L.; Schmutzler, R.; Tucker, K.; Kirk, J.; Hodgson, S.; Harris, M.; Douglas, F.; Lindeman, G.J.; Zgajnar, J.; Tischkowitz, M.; Clowes, V.E.; Susman, R.; Ramon, Y.C.T.; Patcher, N.; Gadea, N.; Spigelman, A.; Os, T. van; Liljegren, A.; Side, L.; Brewer, C.; Brady, A.F.; Donaldson, A.; Stefansdottir, V.; Friedman, E.; Chen-Shtoyerman, R.; Amor, D.J.; Copakova, L.; Barwell, J.; Giri, V.N.; Murthy, V.; Nicolai, N.; Teo, S.H.; Greenhalgh, L.; Strom, S.; Henderson, A.; McGrath, J.; Gallagher, D.; Aaronson, N.; Ardern-Jones, A.; Bangma, C.; Dearnaley, D.; Costello, P.; Eyfjord, J.; Rothwell, J.; Falconer, A.; Gronberg, H.; Hamdy, F.C.

    2014-01-01

    BACKGROUND: Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in

  20. Targeted prostate cancer screening in BRCA1 and BRCA2 mutation carriers: Results from the initial screening round of the IMPACT study

    NARCIS (Netherlands)

    Bancroft, E.K.; Page, E.C.; Castro, E.; Lilja, H.; Vickers, A.; Sjoberg, D.; Assel, M.; Foster, C.S.; Mitchell, G.; Drew, K.; Maehle, L.; Axcrona, K.; Evans, D.G.; Bulman, B.; Eccles, D.; McBride, D.; van Asperen, C.; Vasen, H.; Kiemeney, L.A.; Ringelberg, J.; Cybulski, C.; Wokolorczyk, D.; Selkirk, C.; Hulick, P.J.; Bojesen, A.; Skytte, A.B.; Lam, J.; Taylor, L.; Oldenburg, R.; Cremers, R.; Verhaegh, G.; van Zelst-Stams, W.A.; Oosterwijk, J.C.; Blanco, I.; Salinas, M.; Cook, J.; Rosario, D.J.; Buys, S.; Conner, T.; Ausems, M.G.; Ong, K.R.; Hoffman, J.; Domchek, S.; Powers, J.; Teixeira, M.R.; Maia, S.; Foulkes, W.D.; Taherian, N.; Ruijs, M.; den Enden, A.T.; Izatt, L.; Davidson, R.; Adank, M.A.; Walker, L.; Schmutzler, R.; Tucker, K.; Kirk, J.; Hodgson, S.; Harris, M.; Douglas, F.; Lindeman, G.J.; Zgajnar, J.; Tischkowitz, M.; Clowes, V.E.; Susman, R.; Ramón Y Cajal, T.; Patcher, N.; Gadea, N.; Spigelman, A.; van Os, T.; Liljegren, A.; Side, L.; Brewer, C.; Brady, A.F.; Donaldson, A.; Stefansdottir, V.; Friedman, E.; Chen-Shtoyerman, R.; Amor, D.J.; Copakova, L.; Barwell, J.; Giri, V.N.; Murthy, V.; Nicolai, N.; Teo, S.H.; Greenhalgh, L.; Strom, S.; Henderson, A.; McGrath, J.; Gallagher, D.; Aaronson, N.K.; Ardern-Jones, A.; Bangma, C.; Dearnaley, D.; Costello, P.; Eyfjord, J.; Rothwell, J.; Falconer, A.; Gronberg, H.; Hamdy, F.C.; Johannsson, O.; Khoo, V.; Kote-Jarai, Z.; Lubinski, J.; Axcrona, U.; Melia, J.; McKinley, J.; Mitra, A.V.; Moynihan, C.; Rennert, G.; Suri, M.; Wilson, P.; Killick, E.; Moss, S.; Eeles, R.A.

    2014-01-01

    Background: Men with germline breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) gene mutations have a higher risk of developing prostate cancer (PCa) than noncarriers. IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in

  1. Recessive mutations in SLC13A5 result in a loss of citrate transport and cause neonatal epilepsy, developmental delay and teeth hypoplasia

    NARCIS (Netherlands)

    Hardies, Katia; de Kovel, Carolien G F; Weckhuysen, Sarah; Asselbergh, Bob; Geuens, Thomas; Deconinck, Tine; Azmi, Abdelkrim; May, Patrick; Brilstra, Eva; Becker, Felicitas; Barisic, Nina; Craiu, Dana; Braun, Kees P J; Lal, Dennis; Thiele, Holger; Schubert, Julian; Weber, Yvonne; van 't Slot, Ruben; Nürnberg, Peter; Balling, Rudi; Timmerman, Vincent; Lerche, Holger; Maudsley, Stuart; Helbig, Ingo; Suls, Arvid; Koeleman, Bobby P C; De Jonghe, Peter

    2015-01-01

    The epileptic encephalopathies are a clinically and aetiologically heterogeneous subgroup of epilepsy syndromes. Most epileptic encephalopathies have a genetic cause and patients are often found to carry a heterozygous de novo mutation in one of the genes associated with the disease entity. Occasion

  2. Defective i6A37 modification of mitochondrial and cytosolic tRNAs results from pathogenic mutations in TRIT1 and its substrate tRNA.

    Directory of Open Access Journals (Sweden)

    John W Yarham

    2014-06-01

    Full Text Available Identifying the genetic basis for mitochondrial diseases is technically challenging given the size of the mitochondrial proteome and the heterogeneity of disease presentations. Using next-generation exome sequencing, we identified in a patient with severe combined mitochondrial respiratory chain defects and corresponding perturbation in mitochondrial protein synthesis, a homozygous p.Arg323Gln mutation in TRIT1. This gene encodes human tRNA isopentenyltransferase, which is responsible for i6A37 modification of the anticodon loops of a small subset of cytosolic and mitochondrial tRNAs. Deficiency of i6A37 was previously shown in yeast to decrease translational efficiency and fidelity in a codon-specific manner. Modelling of the p.Arg323Gln mutation on the co-crystal structure of the homologous yeast isopentenyltransferase bound to a substrate tRNA, indicates that it is one of a series of adjacent basic side chains that interact with the tRNA backbone of the anticodon stem, somewhat removed from the catalytic center. We show that patient cells bearing the p.Arg323Gln TRIT1 mutation are severely deficient in i6A37 in both cytosolic and mitochondrial tRNAs. Complete complementation of the i6A37 deficiency of both cytosolic and mitochondrial tRNAs was achieved by transduction of patient fibroblasts with wild-type TRIT1. Moreover, we show that a previously-reported pathogenic m.7480A>G mt-tRNASer(UCN mutation in the anticodon loop sequence A36A37A38 recognised by TRIT1 causes a loss of i6A37 modification. These data demonstrate that deficiencies of i6A37 tRNA modification should be considered a potential mechanism of human disease caused by both nuclear gene and mitochondrial DNA mutations while providing insight into the structure and function of TRIT1 in the modification of cytosolic and mitochondrial tRNAs.

  3. Defective i6A37 modification of mitochondrial and cytosolic tRNAs results from pathogenic mutations in TRIT1 and its substrate tRNA.

    Science.gov (United States)

    Yarham, John W; Lamichhane, Tek N; Pyle, Angela; Mattijssen, Sandy; Baruffini, Enrico; Bruni, Francesco; Donnini, Claudia; Vassilev, Alex; He, Langping; Blakely, Emma L; Griffin, Helen; Santibanez-Koref, Mauro; Bindoff, Laurence A; Ferrero, Ileana; Chinnery, Patrick F; McFarland, Robert; Maraia, Richard J; Taylor, Robert W

    2014-06-01

    Identifying the genetic basis for mitochondrial diseases is technically challenging given the size of the mitochondrial proteome and the heterogeneity of disease presentations. Using next-generation exome sequencing, we identified in a patient with severe combined mitochondrial respiratory chain defects and corresponding perturbation in mitochondrial protein synthesis, a homozygous p.Arg323Gln mutation in TRIT1. This gene encodes human tRNA isopentenyltransferase, which is responsible for i6A37 modification of the anticodon loops of a small subset of cytosolic and mitochondrial tRNAs. Deficiency of i6A37 was previously shown in yeast to decrease translational efficiency and fidelity in a codon-specific manner. Modelling of the p.Arg323Gln mutation on the co-crystal structure of the homologous yeast isopentenyltransferase bound to a substrate tRNA, indicates that it is one of a series of adjacent basic side chains that interact with the tRNA backbone of the anticodon stem, somewhat removed from the catalytic center. We show that patient cells bearing the p.Arg323Gln TRIT1 mutation are severely deficient in i6A37 in both cytosolic and mitochondrial tRNAs. Complete complementation of the i6A37 deficiency of both cytosolic and mitochondrial tRNAs was achieved by transduction of patient fibroblasts with wild-type TRIT1. Moreover, we show that a previously-reported pathogenic m.7480A>G mt-tRNASer(UCN) mutation in the anticodon loop sequence A36A37A38 recognised by TRIT1 causes a loss of i6A37 modification. These data demonstrate that deficiencies of i6A37 tRNA modification should be considered a potential mechanism of human disease caused by both nuclear gene and mitochondrial DNA mutations while providing insight into the structure and function of TRIT1 in the modification of cytosolic and mitochondrial tRNAs.

  4. Comparative Evaluation of Sloppy Molecular Beacon and Dual-Labeled Probe Melting Temperature Assays to Identify Mutations in Mycobacterium tuberculosis Resulting in Rifampin, Fluoroquinolone and Aminoglycoside Resistance

    Science.gov (United States)

    Lee, Jong Seok; Via, Laura E.; Barry, Clifton E.; Alland, David; Chakravorty, Soumitesh

    2015-01-01

    Several molecular assays to detect resistance to Rifampin, the Fluoroquinolones, and Aminoglycosides in Mycobacterium tuberculosis (M. tuberculosis) have been recently described. A systematic approach for comparing these assays in the laboratory is needed in order to determine the relative advantage of each assay and to decide which ones should be advanced to evaluation. We performed an analytic comparison of a Sloppy Molecular Beacon (SMB) melting temperature (Tm) assay and a Dual labeled probe (DLP) Tm assay. Both assays targeted the M. tuberculosis rpoB, gyrA, rrs genes and the eis promoter region. The sensitivity and specificity to detect mutations, analytic limit of detection (LOD) and the detection of heteroresistance were tested using a panel of 56 clinical DNA samples from drug resistant M. tuberculosis strains. Both SMB and DLP assays detected 29/29 (100%) samples with rpoB RRDR mutations and 3/3 (100%) samples with eis promoter mutations correctly. The SMB assay detected all 17/17 gyrA mutants and 22/22 rrs mutants, while the DLP assay detected 16/17 (94%) gyrA mutants and 12/22 (55%) rrs mutants. Both assays showed comparable LODs for detecting rpoB and eis mutations; however, the SMB assay LODs were at least two logs better for detecting wild type and mutants in gyrA and rrs targets. The SMB assay was also moderately better at detecting heteroresistance. In summary, both assays appeared to be promising methods to detect drug resistance associated mutations in M. tuberculosis; however, the relative advantage of each assay varied under each test condition. PMID:25938476

  5. Comparative Evaluation of Sloppy Molecular Beacon and Dual-Labeled Probe Melting Temperature Assays to Identify Mutations in Mycobacterium tuberculosis Resulting in Rifampin, Fluoroquinolone and Aminoglycoside Resistance.

    Directory of Open Access Journals (Sweden)

    Sandy S Roh

    Full Text Available Several molecular assays to detect resistance to Rifampin, the Fluoroquinolones, and Aminoglycosides in Mycobacterium tuberculosis (M. tuberculosis have been recently described. A systematic approach for comparing these assays in the laboratory is needed in order to determine the relative advantage of each assay and to decide which ones should be advanced to evaluation. We performed an analytic comparison of a Sloppy Molecular Beacon (SMB melting temperature (Tm assay and a Dual labeled probe (DLP Tm assay. Both assays targeted the M. tuberculosis rpoB, gyrA, rrs genes and the eis promoter region. The sensitivity and specificity to detect mutations, analytic limit of detection (LOD and the detection of heteroresistance were tested using a panel of 56 clinical DNA samples from drug resistant M. tuberculosis strains. Both SMB and DLP assays detected 29/29 (100% samples with rpoB RRDR mutations and 3/3 (100% samples with eis promoter mutations correctly. The SMB assay detected all 17/17 gyrA mutants and 22/22 rrs mutants, while the DLP assay detected 16/17 (94% gyrA mutants and 12/22 (55% rrs mutants. Both assays showed comparable LODs for detecting rpoB and eis mutations; however, the SMB assay LODs were at least two logs better for detecting wild type and mutants in gyrA and rrs targets. The SMB assay was also moderately better at detecting heteroresistance. In summary, both assays appeared to be promising methods to detect drug resistance associated mutations in M. tuberculosis; however, the relative advantage of each assay varied under each test condition.

  6. Filaggrin loss-of-function mutation R501X and 2282del4 carrier status is associated with fissured skin on the hands: results from a cross-sectional population study

    DEFF Research Database (Denmark)

    Thyssen, J P; Ross-Hansen, K; Johansen, J D

    2012-01-01

    tested. Results: In an adjusted logistic regression analysis, filaggrin mutation status was significantly associated with fissured skin on the hands and/or fingers in adults (OR=1.93; CI95%=1.05-3.55) and a near significant negative interaction with atopic dermatitis (p=0.055), suggesting the effect...... was predominantly in subjects without AD. Conclusions: Filaggrin loss-of-function mutations seem not only to increase the risk of atopic dermatitis and dry skin but also the risk of fissures on the hands and/or fingers in subjects without atopic dermatitis. Prophylactic emollient therapy should be particularly...

  7. Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)

    DEFF Research Database (Denmark)

    Osorio, A.; Milne, R.L.; Pita, G.

    2009-01-01

    genotyped rs744154 in 9408 BRCA1 and 5632 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and assessed its association with breast cancer risk using a retrospective weighted cohort approach. RESULTS: We found no evidence of association with breast cancer risk...

  8. Allelic variants of the amylose extender mutation of maize demonstrate phenotypic variation in starch structure resulting from modified protein–protein interactions

    Science.gov (United States)

    Liu, Fushan; Ahmed, Zaheer; Lee, Elizabeth A.; Donner, Elizabeth; Liu, Qiang; Ahmed, Regina; Morell, Matthew K.; Emes, Michael J.; Tetlow, Ian J.

    2012-01-01

    amylose extender (ae−) starches characteristically have modified starch granule morphology resulting from amylopectin with reduced branch frequency and longer glucan chains in clusters, caused by the loss of activity of the major starch branching enzyme (SBE), which in maize endosperm is SBEIIb. A recent study with ae− maize lacking the SBEIIb protein (termed ae1.1 herein) showed that novel protein–protein interactions between enzymes of starch biosynthesis in the amyloplast could explain the starch phenotype of the ae1.1 mutant. The present study examined an allelic variant of the ae− mutation, ae1.2, which expresses a catalytically inactive form of SBEIIb. The catalytically inactive SBEIIb in ae1.2 lacks a 28 amino acid peptide (Val272–Pro299) and is unable to bind to amylopectin. Analysis of starch from ae1.2 revealed altered granule morphology and physicochemical characteristics distinct from those of the ae1.1 mutant as well as the wild-type, including altered apparent amylose content and gelatinization properties. Starch from ae1.2 had fewer intermediate length glucan chains (degree of polymerization 16–20) than ae1.1. Biochemical analysis of ae1.2 showed that there were differences in the organization and assembly of protein complexes of starch biosynthetic enzymes in comparison with ae1.1 (and wild-type) amyloplasts, which were also reflected in the composition of starch granule-bound proteins. The formation of stromal protein complexes in the wild-type and ae1.2 was strongly enhanced by ATP, and broken by phosphatase treatment, indicating a role for protein phosphorylation in their assembly. Labelling experiments with [γ-32P]ATP showed that the inactive form of SBEIIb in ae1.2 was phosphorylated, both in the monomeric form and in association with starch synthase isoforms. Although the inactive SBEIIb was unable to bind starch directly, it was strongly associated with the starch granule, reinforcing the conclusion that its presence in the

  9. Generalized Arterial Calcification in a Recipient Twin: Discordant Fetal Hemodynamics Result in Differing Phenotypes in Monozygotic Twins with an ABCC6 Mutation.

    Science.gov (United States)

    Votava-Smith, Jodie K; Pitukcheewanont, Pisit; Randolph, Linda M; Chmait, Ramen H

    2017-01-01

    Recipients of the twin-twin transfusion syndrome (TTTS) often develop cardiac manifestations, but arterial calcification has rarely been reported. Generalized arterial calcification of infancy (GACI) is a genetic disorder with high infantile mortality. We report the case of a TTTS recipient with moderate cardiomyopathy at diagnosis who developed progressive calcification of the pulmonary arteries and aorta after successful in utero laser therapy. Postnatally, both twins were diagnosed with a heterozygous ABCC6 gene mutation associated with GACI. The recipient had progressive supravalvular pulmonary and aortic stenosis, was treated with bisphosphonate therapy, and successfully underwent cardiac surgery at 4 months of age. The donor twin with the same mutation remained phenotypically normal at 15 months of age. This case illustrates monozygotic fetuses with discordant in utero hemodynamics, with subsequent development of phenotypic differences. TTTS recipients with arterial calcifications should undergo genetic testing for GACI. © 2016 S. Karger AG, Basel.

  10. A novel gain-of-function STAT1 mutation resulting in basal phosphorylation of STAT1 and increased distal IFN-γ-mediated responses in chronic mucocutaneous candidiasis.

    Science.gov (United States)

    Martinez-Martinez, Laura; Martinez-Saavedra, Maria Teresa; Fuentes-Prior, Pablo; Barnadas, Maria; Rubiales, Maria Victoria; Noda, Judith; Badell, Isabel; Rodríguez-Gallego, Carlos; de la Calle-Martin, Oscar

    2015-12-01

    Gain-of-function STAT1 mutations have recently been associated with autosomal dominant chronic mucocutaneous candidiasis (CMC). The purpose of this study was to characterize the three members of a non-consanguineous family, the father and his two sons, who presented with recurrent oral thrush and ocular candidiasis since early childhood. The three patients had reduced levels of IL-17-producing T cells. This reduction affected specifically IL-17(+)IFN-γ(-) T cells, because the levels of IL-17(+)IFN-γ(+) T cells were similar to controls. We found that PBMC (peripheral blood mononuclear cells) from the patients did not respond to Candida albicans ex vivo. Moreover, after polyclonal activation, patients' PBMC produced lower levels of IL-17 and IL-6 and higher levels of IL-4 than healthy controls. Genetic analyses showed that the three patients were heterozygous for a new mutation in STAT1 (c.894A>C, p.K298N) that affects a highly conserved residue of the coiled-coil domain of STAT1. STAT1 phosphorylation levels were significantly higher in patients' cells than in healthy controls, both in basal conditions and after IFN-γ stimulation, suggesting a permanent activation of STAT1. Cells from the patients also presented increased IFN-γ-mediated responses measured as MIG and IP-10 production. In conclusion, we report a novel gain-of-function mutation in the coiled-coil domain of STAT1, which increases STAT1 phosphorylation and impairs IL-17-mediated immunity. The mutation is responsible for CMC in this family with autosomal dominant inheritance of the disease.

  11. A Novel Mutation within the Central Listeria monocytogenes Regulator PrfA That Results in Constitutive Expression of Virulence Gene Products

    OpenAIRE

    Wong, Kendy K. Y.; Freitag, Nancy E.

    2004-01-01

    The PrfA protein of Listeria monocytogenes functions as a key regulatory factor for the coordinated expression of many virulence genes during bacterial infection of host cells. PrfA activity is controlled by multiple regulatory mechanisms, including an apparent requirement for either the presence of a cofactor or some form of posttranslational modification that regulates the activation of PrfA. In this study, we describe the identification and characterization of a novel PrfA mutation that re...

  12. Prevalence and contribution of BRCA1 mutations in breast cancer and ovarian cancer: Results from three US population-based case-control studies of ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Whittemore, A.S.; Gong, G.; Itnyre, J. [Stanford Univ. School of Medicine, CA (United States)

    1997-03-01

    We investigate the familial risks of cancers of the breast and ovary, using data pooled from three population-based case-control studies of ovarian cancer that were conducted in the United States. We base estimates of the frequency of mutations of BRCA1 (and possibly other genes) on the reported occurrence of breast cancer and ovarian cancer in the mothers and sisters of 922 women with incident ovarian cancer (cases) and in 922 women with no history of ovarian cancer (controls). Segregation analysis and goodness-of-fit testing of genetic models suggest that rare mutations (frequency .0014; 95% confidence interval .0002-.011) account for all the observed aggregation of breast cancer and ovarian cancer in these families. The estimated risk of breast cancer by age 80 years is 73.5% in mutation carriers and 6.8% in noncarriers. The corresponding estimates for ovarian cancer are 27.8% in carriers and 1.8% in noncarriers. For cancer risk in carriers, these estimates are lower than those obtained from families selected for high cancer prevalence. The estimated proportion of all U.S. cancer diagnoses, by age 80 years, that are due to germ-line BRCA1 mutations is 3.0% for breast cancer and 4.4% for ovarian cancer. Aggregation of breast cancer and ovarian cancer was less evident in the families of 169 cases with borderline ovarian cancers than in the families of cases with invasive cancers. Familial aggregation did not differ by the ethnicity of the probands, although the number of non-White and Hispanic cases (N = 99) was sparse. 14 refs., 3 figs., 6 tabs.

  13. Modeling the human MTM1 p.R69C mutation in murine Mtm1 results in exon 4 skipping and a less severe myotubular myopathy phenotype

    Science.gov (United States)

    Pierson, Christopher R.; Dulin-Smith, Ashley N.; Durban, Ashley N.; Marshall, Morgan L.; Marshall, Jordan T.; Snyder, Andrew D.; Naiyer, Nada; Gladman, Jordan T.; Chandler, Dawn S.; Lawlor, Michael W.; Buj-Bello, Anna; Dowling, James J.; Beggs, Alan H.

    2012-01-01

    X-linked myotubular myopathy (MTM) is a severe neuromuscular disease of infancy caused by mutations of MTM1, which encodes the phosphoinositide lipid phosphatase, myotubularin. The Mtm1 knockout (KO) mouse has a severe phenotype and its short lifespan (8 weeks) makes it a challenge to use as a model in the testing of certain preclinical therapeutics. Many MTM patients succumb early in life, but some have a more favorable prognosis. We used human genotype–phenotype correlation data to develop a myotubularin-deficient mouse model with a less severe phenotype than is seen in Mtm1 KO mice. We modeled the human c.205C>T point mutation in Mtm1 exon 4, which is predicted to introduce the p.R69C missense change in myotubularin. Hemizygous male Mtm1 p.R69C mice develop early muscle atrophy prior to the onset of weakness at 2 months. The median survival period is 66 weeks. Histopathology shows small myofibers with centrally placed nuclei. Myotubularin protein is undetectably low because the introduced c.205C>T base change induced exon 4 skipping in most mRNAs, leading to premature termination of myotubularin translation. Some full-length Mtm1 mRNA bearing the mutation is present, which provides enough myotubularin activity to account for the relatively mild phenotype, as Mtm1 KO and Mtm1 p.R69C mice have similar muscle phosphatidylinositol 3-phosphate levels. These data explain the basis for phenotypic variability among human patients with MTM1 p.R69C mutations and establish the Mtm1 p.R69C mouse as a valuable model for the disease, as its less severe phenotype will expand the scope of testable preclinical therapies. PMID:22068590

  14. HIV-1 drug resistance mutations among antiretroviral-naive HIV-1-infected patients in Asia: results from the TREAT Asia Studies to Evaluate Resistance-Monitoring Study.

    Science.gov (United States)

    Sungkanuparph, Somnuek; Oyomopito, Rebecca; Sirivichayakul, Sunee; Sirisanthana, Thira; Li, Patrick C K; Kantipong, Pacharee; Lee, Christopher K C; Kamarulzaman, Adeeba; Messerschmidt, Liesl; Law, Matthew G; Phanuphak, Praphan

    2011-04-15

    Of 682 antiretroviral-naïve patients initiating antiretroviral therapy in a prospective, multicenter human immunodeficiency virus type 1 (HIV-1) drug resistance monitoring study involving 8 sites in Hong Kong, Malaysia, and Thailand, the prevalence of patients with ≥1 drug resistance mutation was 13.8%. Primary HIV drug resistance is emerging after rapid scaling-up of antiretroviral therapy use in Asia.

  15. Selective FLT3 inhibition of FLT3-ITD+ acute myeloid leukaemia resulting in secondary D835Y mutation: a model for emerging clinical resistance patterns.

    Science.gov (United States)

    Moore, A S; Faisal, A; Gonzalez de Castro, D; Bavetsias, V; Sun, C; Atrash, B; Valenti, M; de Haven Brandon, A; Avery, S; Mair, D; Mirabella, F; Swansbury, J; Pearson, A D J; Workman, P; Blagg, J; Raynaud, F I; Eccles, S A; Linardopoulos, S

    2012-07-01

    Acquired resistance to selective FLT3 inhibitors is an emerging clinical problem in the treatment of FLT3-ITD(+) acute myeloid leukaemia (AML). The paucity of valid pre-clinical models has restricted investigations to determine the mechanism of acquired therapeutic resistance, thereby limiting the development of effective treatments. We generated selective FLT3 inhibitor-resistant cells by treating the FLT3-ITD(+) human AML cell line MOLM-13 in vitro with the FLT3-selective inhibitor MLN518, and validated the resistant phenotype in vivo and in vitro. The resistant cells, MOLM-13-RES, harboured a new D835Y tyrosine kinase domain (TKD) mutation on the FLT3-ITD(+) allele. Acquired TKD mutations, including D835Y, have recently been identified in FLT3-ITD(+) patients relapsing after treatment with the novel FLT3 inhibitor, AC220. Consistent with this clinical pattern of resistance, MOLM-13-RES cells displayed high relative resistance to AC220 and Sorafenib. Furthermore, treatment of MOLM-13-RES cells with AC220 lead to loss of the FLT3 wild-type allele and the duplication of the FLT3-ITD-D835Y allele. Our FLT3-Aurora kinase inhibitor, CCT137690, successfully inhibited growth of FLT3-ITD-D835Y cells in vitro and in vivo, suggesting that dual FLT3-Aurora inhibition may overcome selective FLT3 inhibitor resistance, in part due to inhibition of Aurora kinase, and may benefit patients with FLT3-mutated AML.

  16. Identification of two novel critical mutations in PCNT gene resulting in microcephalic osteodysplastic primordial dwarfism type II associated with multiple intracranial aneurysms.

    Science.gov (United States)

    Li, Fei-Feng; Wang, Xu-Dong; Zhu, Min-Wei; Lou, Zhi-Hong; Zhang, Qiong; Zhu, Chun-Yu; Feng, Hong-Lin; Lin, Zhi-Guo; Liu, Shu-Lin

    2015-12-01

    Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is a highly detrimental human autosomal inherited recessive disorder. The hallmark characteristics of this disease are intrauterine and postnatal growth restrictions, with some patients also having cerebrovascular problems such as cerebral aneurysms. The genomic basis behind most clinical features of MOPD II remains largely unclear. The aim of this work was to identify the genetic defects in a Chinese family with MOPD II associated with multiple intracranial aneurysms. The patient had typical MOPD II syndrome, with subarachnoid hemorrhage and multiple intracranial aneurysms. We identified three novel mutations in the PCNT gene, including one single base alteration (9842A>C in exon 45) and two deletions (Del-C in exon 30 and Del-16 in exon 41). The deletions were co-segregated with the affected individual in the family and were not present in the control population. Computer modeling demonstrated that the deletions may cause drastic changes on the secondary and tertiary structures, affecting the hydrophilicity and hydrophobicity of the mutant proteins. In conclusion, we identified two novel mutations in the PCNT gene associated with MOPD II and intracranial aneurysms, and the mutations were expected to alter the stability and functioning of the protein by computer modeling.

  17. A novel point mutation (G[sup [minus]1] to T) in a 5[prime] splice donor site of intron 13 of the dystrophin gene results in exon skipping and is responsible for Becker Muscular Dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Hagiwara, Yoko; Nishio, Hisahide; Kitoh, Yoshihiko; Takeshima, Yasuhiro; Narita, Naoko; Wada, Hiroko; Yokoyama, Mitsuhiro; Nakamura, Hajime; Matsuo, Masafumi (Kobe Univ. School of Medicine (Japan))

    1994-01-01

    The mutations in one-third of Duchenne and Becker muscular dystrophy patients remain unknown, as they do not involve gross rearrangements of the dystrophin gene. The authors now report a defect in the splicing of precursor mRNA (pre-mRNA), resulting from a maternally inherited mutation of the dystrophin gene in a patient with Becker muscular dystrophy. This defect results from a G-to-T transversion at the terminal nucleotide of exon 13, within the 5[prime] splice site of intron 13, and causes complete skipping of exon 13 during processing of dystrophin pre-mRNA. The predicted polypeptide encoded by the aberrant mRNA is a truncated dystrophin lacking 40 amino acids from the amino-proximal end of the rod domain. This is the first report of an intraexon point mutation that completely inactivates a 5[prime] splice donor site in dystrophin pre-mRNA. Analysis of the genomic context of the G[sup [minus]1]-to-T mutation at the 5[prime] splice site supports the exon-definition model of pre-mRNA splicing and contributes to the understanding of splice-site selection. 48 refs., 5 figs.

  18. Mutations in GABRB3

    DEFF Research Database (Denmark)

    Møller, Rikke S; Wuttke, Thomas V; Helbig, Ingo

    2017-01-01

    OBJECTIVE: To examine the role of mutations in GABRB3 encoding the β3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. METHODS: We performed massive parallel sequencing...... of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs. RESULTS: We identified 22 patients with heterozygous mutations in GABRB3, including 3...... probands from multiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy with myoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies...

  19. Immunohistochemically detected p53 mutations in epithelial tumors and results of treatment with chemotherapy and radiotherapy. A treatment-specific overview of the clinical data

    Energy Technology Data Exchange (ETDEWEB)

    Thames, H.D. [University of Texas, Houston, TX (United States); Petersen, C.; Baumann, M. [University Hospital Dresden (Germany); Petersen, S. [Hospital Dresden-Friedrichstadt (Germany); Nieder, C. [Klinikum rechts der Isar, Munich (Germany)

    2002-08-01

    Background: The aim was to ascertain whether many hundreds of clinical reports over the last decade are consistent with the prediction of a poorer outcome in cancer patients with p53 abnormalities treated with cytotoxic drugs and radiation. Material and method: There are 301 studies on the influence of p53 overexpression published through summer 2000, in which chemotherapy or radiotherapy was used alone or in combination with surgery. From 45 reports meeting stringent selection rules, comparison groups are identified in whom the same measure of outcome was reported for the same treatment applied to the same tumor, with results corrected for important prognostic factors. Metaanalysis techniques are then applied to the comparison groups. Attention was limited to reports using immunohistochemical techniques, to form comparison groups of sufficient size. Results: Four comparison groups were identified by treatment and endpoint: (1) Stage-I-III breast cancer (surgery and chemotherapy, disease-free survival, seven studies); (2) stage I-III breast cancer (surgery and chemotherapy, overall survival, six studies); (3) stage II-IV head and neck cancer (radiotherapy and chemotherapy, overall survival, five studies); (4) FIGO I-IV ovarian cancer (surgery and chemotherapy, overall survival, six studies). In the breast (disease-free survival) and ovarian (overall survival) comparison groups, the hazard ratio for a deleterious effect of p53 overexpression was significant or marginally significant, depending on assumed ranges for unreported hazard ratios in non-significant studies. Conclusions: Despite the many caveats related to metaanalysis applied to retrospective data, high variability of immunohistochemical technique, etc., a nearly significant negative effect of p53 overexpression on outcome of treatment with cytotoxic drugs and radiation emerges in the few studies where heterogeneity can be sufficiently reduced or accounted for. (orig.) [German] Hintergrund: Es sollte

  20. Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)

    DEFF Research Database (Denmark)

    Osorio, A; Milne, R L; Pita, G;

    2009-01-01

    Background:In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers.Methods:We have...... genotyped rs744154 in 9408 BRCA1 and 5632 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and assessed its association with breast cancer risk using a retrospective weighted cohort approach.Results:We found no evidence of association with breast cancer risk...... for BRCA1 (per-allele HR: 0.98, 95% CI: 0.93-1.04, P=0.5) or BRCA2 (per-allele HR: 0.97, 95% CI: 0.89-1.06, P=0.5) mutation carriers.Conclusion:This SNP is not a significant modifier of breast cancer risk for mutation carriers, though weak associations cannot be ruled out.British Journal of Cancer advance...

  1. Five years results after intrafamilial kidney post-transplant in a case of familial hypomagnesemia due to a claudin-19 mutation

    Directory of Open Access Journals (Sweden)

    Jorge Reis Almeida

    2014-09-01

    Full Text Available Introduction: Familial Hypomagnesaemia with hypercalciuria and nephrocalcinosis, with severe ocular impairment secondary to claudin-19 mutation, is a rare recessive autossomic disorder. Its spectrum includes renal Mg2+ wasting, medullary nephrocalcinosis and progressive chronic renal failure in young people. Objective: To report a case of kidney transplantation father to daughter in a familial occurrence of severe bilateral nephrocalcinosis associated with ocular impairment in a non-consanguineous Brazilian family, in which two daughters had nephrocalcinosis and severe retinopathy. Methods: The index case, a 19 years-old female, had long-lasting past medical history of recurrent urinary tract infections, and the abdominal X-ray revealed bilateral multiple renal calcifications as well as ureteral lithiasis, and she was under haemodialysis. She had the diagnosis of retinitis pigmentosa in the early neonatal period. The other daughter (13 years-old had also nephrocalcinosis with preserved kidney function, retinopathy with severe visual impairment, and in addition, she exhibited hypomagnesaemia = 0.5 mg/dL and hypercalciuria. The other family members (mother, father and son had no clinical disease manifestation. Mutation analysis at claudin-19 revealed two heterozygous missense mutations (P28L and G20D in both affected daughters. The other family members exhibited mutant monoallelic status. In despite of that, the index case underwent intrafamilial living donor kidney transplantation (father. Conclusion: In conclusion, the disease was characterized by an autosomal recessive compound heterozygous status and, after five years of donation the renal graft function remained stable without recurrence of metabolic disturbances or nephrocalcinosis. Besides, donor single kidney Mg2+ and Ca2+ homeostasis associated to monoallelic status did not affect the safety and the usual living donor post-transplant clinical course.

  2. Characterisation of clinical meticillin-resistant Staphylococcus epidermidis demonstrating high levels of linezolid resistance (>256 μg/ml) resulting from transmissible and mutational mechanisms.

    Science.gov (United States)

    Gabriel, Emma M; Fitzgibbon, Siobhan; Clair, James; Coffey, Aidan; O'Mahony, Jim M

    2015-07-01

    Staphylococcus epidermidis (S. epidermidis), one of the leading etiological agents of nosocomial infections poses a significant economic burden globally. Introduced in 2000, linezolid (LZD) has become an important antibiotic, used in nearly seventy countries worldwide to treat infections caused by Gram-positive pathogens such as meticillin-resistant Staphylococcus and Streptococcus species along with vancomycin-resistant enterococci. Resistance to LZD in clinical settings remains rare. Here, we report the emergence of meticillin resistant S. epidermidis (MRSE) clinical isolates from two voluntary general acute hospitals exhibiting higher than typically reported levels of LZD resistance (MIC>256 μg/ml). The MRSE ST-2 clone isolated from eight patients (2010-2011) not only possessed resistance-conferring mutations such as G2576T in domain V of 23S rRNA gene (as determined by HRM-PCR analysis) and R172C substitution in the ribosomal protein L3, but also carried the cfr gene (the only known transmissible mechanism of LZD resistance). All isolates possessed several key biofilm-associated genes (such as icaA, icaD, aap and atlE) and resistance to multiple clinically significant antibiotics was recorded. This study reports the earliest incidence (2010) of clinical MRSE in the Republic of Ireland demonstrating multiple LZD resistance mechanisms both mutational and potentially transmissible, and characterises this emerging resistance from a molecular perspective.

  3. Expression of the Hutchinson-Gilford Progeria Mutation during Osteoblast Development Results in Loss of Osteocytes, Irregular Mineralization, and Poor Biomechanical Properties*

    Science.gov (United States)

    Schmidt, Eva; Nilsson, Ola; Koskela, Antti; Tuukkanen, Juha; Ohlsson, Claes; Rozell, Björn; Eriksson, Maria

    2012-01-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a very rare genetic disorder that is characterized by multiple features of premature aging and largely affects tissues of mesenchymal origin. In this study, we describe the development of a tissue-specific mouse model that overexpresses the most common HGPS mutation (LMNA, c.1824C>T, p.G608G) in osteoblasts. Already at the age of 5 weeks, HGPS mutant mice show growth retardation, imbalanced gait and spontaneous fractures. Histopathological examination revealed an irregular bone structure, characterized by widespread loss of osteocytes, defects in mineralization, and a hypocellular red bone marrow. Computerized tomography analysis demonstrated impaired skeletal geometry and altered bone structure. The skeletal defects, which resemble the clinical features reported for bone disease in HGPS patients, was associated with an abnormal osteoblast differentiation. The osteoblast-specific expression of the HGPS mutation increased DNA damage and affected Wnt signaling. In the teeth, irregular dentin formation, as was previously demonstrated in human progeria cases, caused severe dental abnormalities affecting the incisors. The observed phenotype also shows similarities to reported bone abnormalities in aging mice and may therefore help to uncover general principles of the aging process. PMID:22893709

  4. Expression of the Hutchinson-Gilford progeria mutation during osteoblast development results in loss of osteocytes, irregular mineralization, and poor biomechanical properties.

    Science.gov (United States)

    Schmidt, Eva; Nilsson, Ola; Koskela, Antti; Tuukkanen, Juha; Ohlsson, Claes; Rozell, Björn; Eriksson, Maria

    2012-09-28

    Hutchinson-Gilford progeria syndrome (HGPS) is a very rare genetic disorder that is characterized by multiple features of premature aging and largely affects tissues of mesenchymal origin. In this study, we describe the development of a tissue-specific mouse model that overexpresses the most common HGPS mutation (LMNA, c.1824C>T, p.G608G) in osteoblasts. Already at the age of 5 weeks, HGPS mutant mice show growth retardation, imbalanced gait and spontaneous fractures. Histopathological examination revealed an irregular bone structure, characterized by widespread loss of osteocytes, defects in mineralization, and a hypocellular red bone marrow. Computerized tomography analysis demonstrated impaired skeletal geometry and altered bone structure. The skeletal defects, which resemble the clinical features reported for bone disease in HGPS patients, was associated with an abnormal osteoblast differentiation. The osteoblast-specific expression of the HGPS mutation increased DNA damage and affected Wnt signaling. In the teeth, irregular dentin formation, as was previously demonstrated in human progeria cases, caused severe dental abnormalities affecting the incisors. The observed phenotype also shows similarities to reported bone abnormalities in aging mice and may therefore help to uncover general principles of the aging process.

  5. Accumulation of Krebs cycle intermediates and over-expression of HIF1alpha in tumours which result from germline FH and SDH mutations.

    Science.gov (United States)

    Pollard, P J; Brière, J J; Alam, N A; Barwell, J; Barclay, E; Wortham, N C; Hunt, T; Mitchell, M; Olpin, S; Moat, S J; Hargreaves, I P; Heales, S J; Chung, Y L; Griffiths, J R; Dalgleish, A; McGrath, J A; Gleeson, M J; Hodgson, S V; Poulsom, R; Rustin, P; Tomlinson, I P M

    2005-08-01

    The nuclear-encoded Krebs cycle enzymes, fumarate hydratase (FH) and succinate dehydrogenase (SDHB, -C and -D), act as tumour suppressors. Germline mutations in FH predispose individuals to leiomyomas and renal cell cancer (HLRCC), whereas mutations in SDH cause paragangliomas and phaeochromocytomas (HPGL). In this study, we have shown that FH-deficient cells and tumours accumulate fumarate and, to a lesser extent, succinate. SDH-deficient tumours principally accumulate succinate. In situ analyses showed that these tumours also have over-expression of hypoxia-inducible factor 1alpha (HIF1alpha), activation of HIF1alphatargets (such as vascular endothelial growth factor) and high microvessel density. We found no evidence of increased reactive oxygen species in our cells. Our data provide in vivo evidence to support the hypothesis that increased succinate and/or fumarate causes stabilization of HIF1alpha a plausible mechanism, inhibition of HIF prolyl hydroxylases, has previously been suggested by in vitro studies. The basic mechanism of tumorigenesis in HPGL and HLRCC is likely to be pseudo-hypoxic drive, just as it is in von Hippel-Lindau syndrome.

  6. The prediction of malignant risk in the category "atypia of undetermined significance/follicular lesion of undetermined significance" of the Bethesda System for Reporting Thyroid Cytopathology using subcategorization and BRAF mutation results.

    Science.gov (United States)

    Hyeon, Jiyeon; Ahn, Soomin; Shin, Jung Hee; Oh, Young Lyun

    2014-05-01

    The "atypia of undetermined significance/follicular lesion of undetermined significance" (AUS/FLUS) category in the Bethesda System for Reporting Thyroid Cytopathology is a heterogeneous category of cases that are not clearly benign or malignant. We conducted an analysis of cytologic and histologic evaluations of thyroid nodules that had been interpreted as AUS/FLUS on fine-needle aspiration (FNA) at a single institution from April 2011 to April 2012. Those cases were classified into 2 subgroups according to the predominance of nuclear atypia (AUS) or microfollicular architecture (FLUS). In addition, for a number of these cases, BRAF gene mutation analyses were performed. Of 6402 thyroid FNAs performed, 431 cases were diagnosed as AUS and 120 as FLUS. Follow-up cytologic or histologic outcome data were available for 315 AUS cases and 73 FLUS cases. Among AUS cases, 52.7% were malignant on repeat FNA or histologic diagnosis. In contrast, for FLUS, 6.8% were malignant on repeat FNA or histologic diagnosis. Among AUS/FLUS cases, 147 had adequate BRAF mutation analysis, which accompanied the histologic diagnosis. BRAF mutations were found in 87 AUS cases, 86 of which were papillary carcinoma. In contrast, there was only 1 case of BRAF mutation in FLUS. Correlating molecular results with histologic outcome revealed a 98.9% cancer probability for AUS cases with BRAF mutation. The AUS subcategory indicates a higher risk of malignancy than the FLUS subcategory. Furthermore, BRAF molecular testing is helpful in stratifying the malignant risk of AUS cases into high-risk and low-risk groups. © 2014 American Cancer Society.

  7. Factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen - results from a prospective, single center, case control study.

    Science.gov (United States)

    Kovac, Mirjana; Kovac, Zeljko; Tomasevic, Zorica; Vucicevic, Slavko; Djordjevic, Valentina; Pruner, Iva; Radojkovic, Dragica

    2015-01-01

    Estimates of the risk ratio of tamoxifen-associated venous thromboembolism (VTE) in breast cancer patients range from 2.4 to 7.1. The occurrence of thrombosis in patients with breast cancer complicates the clinical condition and causes a change of treatment. Our study was conducted in order to investigate the influence of patient-related risk factors for thrombosis development in breast cancer patients whose treatment included adjuvant tamoxifen. The prospective, single center, case control study included 150 breast cancer women, 50 whom developed venous thrombosis during adjuvant tamoxifen and 100 whom did not have thrombosis, as a control group. Patient-related risk factors such as: age, body mass index, previous VTE, varicose veins, concomitant diseases, the presence of prothrombotic mutations (FV Leiden, FII G20210A) and FVIII activity were evaluated in both groups. In respect of prothrombotic mutations, the FV Leiden mutation was present in a higher number of women from the VTE group (10/50 vs 7/100; P=0.020). Additionally, FVIII activity was significantly higher in the VTE group; median (IQR), of 1.79 (0.69) vs 1.45 (0.55); P1.5IU/ml, who were carriers of prothrombotic mutations, an OR of 3.76 (CI 95% 1.276-11.096; P=0.016) was obtained for VTE. The results of our study showed that the factor V Leiden mutation and high FVIII are associated with an increased risk of VTE in women with breast cancer during adjuvant tamoxifen. Copyright © 2014. Published by Elsevier B.V.

  8. PRRT2 gene mutations

    Science.gov (United States)

    Gardiner, Alice R.; Bhatia, Kailash P.; Stamelou, Maria; Dale, Russell C.; Kurian, Manju A.; Schneider, Susanne A.; Wali, G.M.; Counihan, Tim; Schapira, Anthony H.; Spacey, Sian D.; Valente, Enza-Maria; Silveira-Moriyama, Laura; Teive, Hélio A.G.; Raskin, Salmo; Sander, Josemir W.; Lees, Andrew; Warner, Tom; Kullmann, Dimitri M.; Wood, Nicholas W.; Hanna, Michael

    2012-01-01

    ABSTRACT Objective: The proline-rich transmembrane protein (PRRT2) gene was recently identified using exome sequencing as the cause of autosomal dominant paroxysmal kinesigenic dyskinesia (PKD) with or without infantile convulsions (IC) (PKD/IC syndrome). Episodic neurologic disorders, such as epilepsy, migraine, and paroxysmal movement disorders, often coexist and are thought to have a shared channel-related etiology. To investigate further the frequency, spectrum, and phenotype of PRRT2 mutations, we analyzed this gene in 3 large series of episodic neurologic disorders with PKD/IC, episodic ataxia (EA), and hemiplegic migraine (HM). Methods: The PRRT2 gene was sequenced in 58 family probands/sporadic individuals with PKD/IC, 182 with EA, 128 with HM, and 475 UK and 96 Asian controls. Results: PRRT2 genetic mutations were identified in 28 out of 58 individuals with PKD/IC (48%), 1/182 individuals with EA, and 1/128 individuals with HM. A number of loss-of-function and coding missense mutations were identified; the most common mutation found was the p.R217Pfs*8 insertion. Males were more frequently affected than females (ratio 52:32). There was a high proportion of PRRT2 mutations found in families and sporadic cases with PKD associated with migraine or HM (10 out of 28). One family had EA with HM and another large family had typical HM alone. Conclusions: This work expands the phenotype of mutations in the PRRT2 gene to include the frequent occurrence of migraine and HM with PKD/IC, and the association of mutations with EA and HM and with familial HM alone. We have also extended the PRRT2 mutation type and frequency in PKD and other episodic neurologic disorders. PMID:23077024

  9. Mucopolysaccharidosis IVA mutations in Chinese patients: 16 novel mutations.

    Science.gov (United States)

    Wang, Zheng; Zhang, Weimin; Wang, Yun; Meng, Yan; Su, Liang; Shi, Huiping; Huang, Shangzhi

    2010-08-01

    Mucopolysaccharidosis IVA (MPS IVA; Morquio A syndrome) is a lysosomal storage disease caused by deficiency of N-acetylgalactosamine-6-sulfatase (GALNS) and transmitted as an autosomal recessive trait. This is the first systematic mutation screen in Chinese MPS IVA patients. Mutation detections in 24 unrelated Chinese MPS IVA patients were performed by PCR and direct sequencing of exons or the mRNA of GALNS. A total of 42 mutant alleles were identified, belonging to 27 different mutations. Out of the 27 mutations, 16 were novel, including 2 splicing mutations (c.567-1G>T and c.634-1G>A), 2 nonsense mutations (p.W325X and p.Q422X) and 12 missense mutations (p.T88I, p.H142R, p.P163H, p.G168L, p.H236D, p.N289S, p.T312A, p.G316V, p.A324E, p.L366P, p.Q422K and p.F452L). p.G340D was found to be a common mutation in the Chinese MPS IVA patients, accounting for 16.7% of the total number of mutant alleles. The results show that the mutations in Chinese MPS IVA patients are also family specific but have a different mutation spectrum as compared to those of other populations.

  10. A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.

    Science.gov (United States)

    Vahidnia, Ali; van Empel, Pieter Jan; Costa, Sandra; Oud, Rob T N; van der Straaten, Tahar; Bliekendaal, Harry; Spaargaren, Joke

    2015-07-01

    A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

  11. Mutation of yeast Eug1p CXXS active sites to CXXC results in a dramatic increase in protein disulphide isomerase activity

    DEFF Research Database (Denmark)

    Nørgaard, P; Winther, Jakob R.

    2001-01-01

    Protein disulphide isomerase (PDI) is an essential protein which is localized to the endoplasmic reticulum of eukaryotic cells. It catalyses the formation and isomerization of disulphide bonds during the folding of secretory proteins. PDI is composed of domains with structural homology...... to thioredoxin and with CXXC catalytic motifs. EUG1 encodes a yeast protein, Eug1p, that is highly homologous to PDI. However, Eug1p contains CXXS motifs instead of CXXC. In the current model for PDI function both cysteines in this motif are required for PDI-catalysed oxidase activity. To gain more insight...... into the biochemical properties of this unusual variant of PDI we have purified and characterized the protein. We have furthermore generated a number of mutant forms of Eug1p in which either or both of the active sites have been mutated to a CXXC sequence. To determine the catalytic capacity of the wild...

  12. Mutations induced in plant breeding

    Energy Technology Data Exchange (ETDEWEB)

    Barriga B, P. (Universidad Austral de Chile, Valdivia. Inst. de Produccion y Sanidad Vegetal)

    1984-10-01

    The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented.

  13. Filaggrin mutations and the skin

    Directory of Open Access Journals (Sweden)

    Dipankar De

    2012-01-01

    Full Text Available Filaggrin is very important in the terminal differentiation of the skin and the formation of cornified envelope in the stratum corneum. Several mutations in the filaggrin gene have been identified in the last decade, mostly from the European countries. Loss of function mutations in the filaggrin gene results in reduced production of filaggrin, depending on the type and site of mutation. Such mutations in the filaggrin gene have been shown to be the most significant genetic risk factor for development of atopic dermatitis and undoubtedly has a role in the pathogenesis of ichthyosis vulgaris. Though there is theoretical possibility of association with hand eczema and allergic contact dermatitis; in clinical studies, the strength of these associations was not significantly strong. In this review, we have discussed the structure and function of filaggrin, basic genetics, type of mutations in filaggrin gene, and association of such mutations with different dermatoses.

  14. Filaggrin mutations and the skin.

    Science.gov (United States)

    De, Dipankar; Handa, Sanjeev

    2012-01-01

    Filaggrin is very important in the terminal differentiation of the skin and the formation of cornified envelope in the stratum corneum. Several mutations in the filaggrin gene have been identified in the last decade, mostly from the European countries. Loss of function mutations in the filaggrin gene results in reduced production of filaggrin, depending on the type and site of mutation. Such mutations in the filaggrin gene have been shown to be the most significant genetic risk factor for development of atopic dermatitis and undoubtedly has a role in the pathogenesis of ichthyosis vulgaris. Though there is theoretical possibility of association with hand eczema and allergic contact dermatitis; in clinical studies, the strength of these associations was not significantly strong. In this review, we have discussed the structure and function of filaggrin, basic genetics, type of mutations in filaggrin gene, and association of such mutations with different dermatoses.

  15. D471G Mutation in LCMV-NP Affects Its Ability to Self-associate and Results in a Dominant Negative Effect in Viral RNA Synthesis

    Directory of Open Access Journals (Sweden)

    Luis Martínez-Sobrido

    2012-10-01

    Full Text Available Arenaviruses merit significant interest because several family members are etiological agents of severe hemorrhagic fevers, representing a major burden to public health. Currently, there are no FDA-licensed vaccines against arenaviruses and the only available antiviral therapy is limited to the use of ribavirin that is partially effective. Arenavirus nucleoprotein (NP is found associated with the genomic RNA forming the viral ribonucleoproteins (vRNPs that together with the polymerase (L direct viral replication and transcription. Virion formation requires the recruitment of vRNPs into budding sites, a process in which the arenavirus matrix-like protein (Z plays a major role. Therefore, proper NP-NP and NP-Z interactions are required for the generation of infectious progeny. In this work we demonstrate the role of the amino acid residue D471 in the self-association of lymphocytic choriomeningitis virus nucleoprotein (LCMV-NP. Amino acid substitutions at this position abrogate NP oligomerization, affecting its ability to mediate replication and transcription of a minigenome reporter plasmid. However, its ability to interact with the Z protein, counteract the cellular interferon response and bind to dsRNA analogs was retained. Additionally, we also document the dominant negative effect of D471G mutation on viral infection, suggesting that NP self-association is an excellent target for the development of new antivirals against arenaviruses.

  16. A novel deletion mutation in IL2RG gene results in X-linked severe combined immunodeficiency with an atypical phenotype.

    Science.gov (United States)

    Mou, Wenjun; He, Jianxin; Chen, Xi; Zhang, Hui; Ren, Xiaoya; Wu, Xunyao; Ni, Xin; Xu, Baoping; Gui, Jingang

    2017-01-01

    Severe combined immunodeficiency (SCID) is the most serious disorder among primary immunodeficiency diseases threatening children's life. Atypical SCID variant, presenting with mild reduced T cells subsets, is often associated with infection susceptibility but poor clinical diagnosis. The atypical X-SCID patient in the present study showed a mild clinical presentation with a T(low)NK(+)B(+) immunophenotype. The patient has reduced T- cell subpopulations with a subdued thymic output measured by sjTRECs. Further analysis showed that T cells maintained a normal proliferation and a broad Vβ repertoire. NK cells, however, exhibited a skewed development toward immature CD3(-)CD16(+)CD56(-) cells. Genetic analysis revealed a novel deletion at nucleotide 52 in exon 1 of IL2RG gene. Sequence alignment predicted a truncated IL2RG protein missing signal peptide derived from a possible alternative reading frame. The novel mutation in IL2RG gene identified in our study may help the early diagnosis of atypical X-SCID.

  17. Screening results of deafness gene mutations in 4 679 newborns in Nanning%南宁市4679例新生儿突变耳聋基因筛查结果

    Institute of Scientific and Technical Information of China (English)

    杜娟; 许涓涓; 黄萍丽; 付华钰

    2015-01-01

    Objective To understand the newborns ' carrying situation of the mutation of deafness-related genes in Nanning. Methods Samples of heel blood were collected from 4 679 newborns in Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region who were born in 3-5 days. DNA samples were extracted and detected by Matrix-assis-ted Laser Desorption-Ionization Time of Flight Mass Spectrometry ( MALDI-TOF-MS ) , including 20 mutation sites of 4 deafness-related genes ( GJB2, GJB3, SLC26A4 and 12SrRNA). Results Among 4 679 newborns, 143 cases (3. 056%) were detected with 13 mutation types, which included 76 cases of GJB2 (235delC, 299_300delAT, 176_191del16) gene mutation, 5 cases of GJB3 (538C>T, 547G>A) gene mutation, 48 cases of SLC26A4 ( IVS7-2A>G, 1174A>T, 1229C>T, 1975G>C, 2027T>A, 2168A>G) gene mutation and 14 cases of 12SrRNA (1555A>G) gene mutation. Conclusion The mutation of deafness-related gene screening in neonates may be useful in early detection of de-layed deafness and it helps for the prevention and control of hearing impairment.%目的:了解南宁市新生儿突变耳聋基因携带情况。方法选择在广西壮族自治区妇幼保健院出生3~5 d的新生儿4679例,采集其足跟末稍静脉血,提取 DNA,采用基质辅助激光解吸电离飞行时间质谱技术检测GJB2、GJB3、SLC26A4、12SrRNA四个耳聋基因的20个突变位点。结果4679例新生儿中有143例检出四个耳聋基因的13种突变类型,突变耳聋基因携带率为3.056%。 GJB2基因检出235delC、299_300delAT、176_191del16三种突变共76例,GJB3基因检出538C >T、547G >A 两种突变5例,SLC26A4基因检出 IVS7-2A >G、1174A >T、1229C>T、1975G>C、2027T>A、2168A>G、六种突变48例,12SrRNA基因检出1555A>G突变14例。结论通过突变耳聋基因筛查可早期发现迟发性耳聋患儿,为人群听力障碍防控提供帮助。

  18. Single point mutations result in the miss-sorting of Glut4 to a novel membrane compartment associated with stress granule proteins.

    Directory of Open Access Journals (Sweden)

    XiaoMei Song

    Full Text Available Insulin increases cellular glucose uptake and metabolism in the postprandial state by acutely stimulating the translocation of the Glut4 glucose transporter from intracellular membrane compartments to the cell surface in muscle and fat cells. The intracellular targeting of Glut4 is dictated by specific structural motifs within cytoplasmic domains of the transporter. We demonstrate that two leucine residues at the extreme C-terminus of Glut4 are critical components of a motif (IRM, insulin responsive motif involved in the sorting of the transporter to insulin responsive vesicles in 3T3L1 adipocytes. Light microscopy, immunogold electron microscopy, subcellular fractionation, and sedimentation analysis indicate that mutations in the IRM cause the aberrant targeting of Glut4 to large dispersed membrane vesicles that are not insulin responsive. Proteomic characterization of rapidly and slowly sedimenting membrane vesicles (RSVs and SSVs that were highly enriched by immunoadsorption for either wild-type Glut4 or an IRM mutant revealed that the major vesicle fraction containing the mutant transporter (IRM-RSVs possessed a relatively small and highly distinct protein population that was enriched for proteins associated with stress granules. We suggest that the IRM is critical for an early step in the sorting of Glut4 to insulin-responsive subcellular membrane compartments and that IRM mutants are miss-targeted to relatively large, amorphous membrane vesicles that may be involved in a degradation pathway for miss-targeted or miss-folded proteins or represent a transitional membrane compartment that Glut4 traverses en route to insulin responsive storage compartments.

  19. Single point mutations result in the miss-sorting of Glut4 to a novel membrane compartment associated with stress granule proteins.

    Science.gov (United States)

    Song, XiaoMei; Lichti, Cheryl F; Townsend, R Reid; Mueckler, Mike

    2013-01-01

    Insulin increases cellular glucose uptake and metabolism in the postprandial state by acutely stimulating the translocation of the Glut4 glucose transporter from intracellular membrane compartments to the cell surface in muscle and fat cells. The intracellular targeting of Glut4 is dictated by specific structural motifs within cytoplasmic domains of the transporter. We demonstrate that two leucine residues at the extreme C-terminus of Glut4 are critical components of a motif (IRM, insulin responsive motif) involved in the sorting of the transporter to insulin responsive vesicles in 3T3L1 adipocytes. Light microscopy, immunogold electron microscopy, subcellular fractionation, and sedimentation analysis indicate that mutations in the IRM cause the aberrant targeting of Glut4 to large dispersed membrane vesicles that are not insulin responsive. Proteomic characterization of rapidly and slowly sedimenting membrane vesicles (RSVs and SSVs) that were highly enriched by immunoadsorption for either wild-type Glut4 or an IRM mutant revealed that the major vesicle fraction containing the mutant transporter (IRM-RSVs) possessed a relatively small and highly distinct protein population that was enriched for proteins associated with stress granules. We suggest that the IRM is critical for an early step in the sorting of Glut4 to insulin-responsive subcellular membrane compartments and that IRM mutants are miss-targeted to relatively large, amorphous membrane vesicles that may be involved in a degradation pathway for miss-targeted or miss-folded proteins or represent a transitional membrane compartment that Glut4 traverses en route to insulin responsive storage compartments.

  20. Mutations determining mitomycin resistance in Bacillus subtilis.

    Science.gov (United States)

    Iyer, V N

    1966-12-01

    Iyer, V. N. (Microbiology Research Institute, Canada Department of Agriculture, Ottawa, Canada). Mutations determining mitomycin resistance in Bacillus subtilis. J. Bacteriol. 92:1663-1669. 1966.-The pattern of development of genetic resistance in Bacillus subtilis to mitomycin C was studied, and spontaneous single and multistep mutants were obtained. The transmission and expression of these mutations in sensitive strains proved possible by means of genetic transformation. The mutations were genetically studied in relation to a chromosomal mutation, mac-1, which confers resistance to the macrolide antibiotic erythromycin and which has been previously localized in the early-replicating segment of the B. subtilis chromosome. The results indicate that all of three primary mutations studied in this manner, as well as a secondary and tertiary mutation derived from one of the primary mutations, are clustered in this early-replicating segment. It appears that the secondary and tertiary mutations enhance the resistance conferred by the primary mutation, apparently without themselves conferring any resistance.

  1. Mutations of the multi-drug resistance-associated protein ABC transporter gene 5 result in reduction of phytic acid in rice seeds.

    Science.gov (United States)

    Xu, Xiu-Hong; Zhao, Hai-Jun; Liu, Qing-Long; Frank, Thomas; Engel, Karl-Heinz; An, Gynheung; Shu, Qing-Yao

    2009-06-01

    Phytic acid (PA, myo-inositol 1,2,3,4,5,6-hexakisphosphate) is important to the nutritional quality of cereal and legume seeds. PA and its salts with micronutrient cations, such as iron and zinc, cannot be digested by humans and non-ruminant animals, and hence may affect food/feed nutritional value and cause P pollution of groundwater from animal waste. We previously developed a set of low phytic acid (LPA) rice mutant lines with the aim of increasing the nutritional quality of rice. Two of these lines, Os-lpa-XS110-2 (homozygous non-lethal) Os-lpa-XS110-3 (homozygous lethal), contain two mutant alleles of a LPA gene (hereafter XS-lpa2-1 and XS-lpa2-2, respectively). In this study, we mapped the XS-lpa2-1 gene to a region on chromosome 3 between microsatellite markers RM14360 and RM1332, where the rice orthologue (OsMRP5) of the maize lpa1 gene is located. Sequence analysis of the OsMRP5 gene revealed a single base pair change (C/G-T/A transition) in the sixth exon of XS-lpa2-1 and a 5-bp deletion in the first exon of XS-lpa2-2. OsMRP5 is expressed in both vegetative tissues and developing seeds, and the two mutations do not change the level of RNA transcription. A T-DNA insertion line, 4A-02500, in which OsMRP5 was disrupted, also showed the same high inorganic phosphorus phenotype as Os-lpa-XS110-3 and appeared to be homozygous lethal. PA is significantly reduced in Os-lpa-XS110-2 (~20%) and in 4A-02500 (~90%) seeds compared with their wild type lines, and no PA was detected in Os-lpa-XS110-3 using HPLC analysis. This evidence indicates that the OsMRP5 gene plays an important role in PA metabolism in rice seeds.

  2. Anaerobically Grown Escherichia coli Has an Enhanced Mutation Rate and Distinct Mutational Spectra

    Science.gov (United States)

    Shewaramani, Sonal; Finn, Thomas J.; Kassen, Rees; Rainey, Paul B.

    2017-01-01

    Oxidative stress is a major cause of mutation but little is known about how growth in the absence of oxygen impacts the rate and spectrum of mutations. We employed long-term mutation accumulation experiments to directly measure the rates and spectra of spontaneous mutation events in Escherichia coli populations propagated under aerobic and anaerobic conditions. To detect mutations, whole genome sequencing was coupled with methods of analysis sufficient to identify a broad range of mutational classes, including structural variants (SVs) generated by movement of repetitive elements. The anaerobically grown populations displayed a mutation rate nearly twice that of the aerobic populations, showed distinct asymmetric mutational strand biases, and greater insertion element activity. Consistent with mutation rate and spectra observations, genes for transposition and recombination repair associated with SVs were up-regulated during anaerobic growth. Together, these results define differences in mutational spectra affecting the evolution of facultative anaerobes. PMID:28103245

  3. Mutations in zebrafish leucine-rich repeat-containing six-like affect cilia motility and result in pronephric cysts, but have variable effects on left-right patterning.

    Science.gov (United States)

    Serluca, Fabrizio C; Xu, Bo; Okabe, Noriko; Baker, Kari; Lin, Shin-Yi; Sullivan-Brown, Jessica; Konieczkowski, David J; Jaffe, Kimberly M; Bradner, Joshua M; Fishman, Mark C; Burdine, Rebecca D

    2009-05-01

    Cilia defects have been implicated in a variety of human diseases and genetic disorders, but how cilia motility contributes to these phenotypes is still unknown. To further our understanding of how cilia function in development, we have cloned and characterized two alleles of seahorse, a zebrafish mutation that results in pronephric cysts. seahorse encodes Lrrc6l, a leucine-rich repeat-containing protein that is highly conserved in organisms that have motile cilia. seahorse is expressed in zebrafish tissues known to contain motile cilia. Although mutants do not affect cilia structure and retain the ability to interact with Disheveled, both alleles of seahorse strongly affect cilia motility in the zebrafish pronephros and neural tube. Intriguingly, although seahorse mutations variably affect fluid flow in Kupffer's vesicle, they can have very weak effects on left-right patterning. Combined with recently published results, our alleles suggest that the function of seahorse in cilia motility is separable from its function in other cilia-related phenotypes.

  4. CF Mutation Panel

    Science.gov (United States)

    ... Testing; Cystic Fibrosis Transmembrane Conductance Regulator Mutation Analysis; CFTR Mutation Analysis Formal name: Cystic Fibrosis Gene Mutation ... an elevated immunoreactive trypsinogen (IRT) or positive sweat chloride test , to confirm the diagnosis of cystic fibrosis. ...

  5. Identifying driver mutations in sequenced cancer genomes

    DEFF Research Database (Denmark)

    Raphael, Benjamin J; Dobson, Jason R; Oesper, Layla

    2014-01-01

    High-throughput DNA sequencing is revolutionizing the study of cancer and enabling the measurement of the somatic mutations that drive cancer development. However, the resulting sequencing datasets are large and complex, obscuring the clinically important mutations in a background of errors, noise......, and random mutations. Here, we review computational approaches to identify somatic mutations in cancer genome sequences and to distinguish the driver mutations that are responsible for cancer from random, passenger mutations. First, we describe approaches to detect somatic mutations from high-throughput DNA...... sequencing data, particularly for tumor samples that comprise heterogeneous populations of cells. Next, we review computational approaches that aim to predict driver mutations according to their frequency of occurrence in a cohort of samples, or according to their predicted functional impact on protein...

  6. A novel Wiskott-Aldrich syndrome protein (WASP) complex mutation identified in a WAS patient results in an aberrant product at the C-terminus from two transcripts with unusual polyA signals.

    Science.gov (United States)

    Andreu, Nuria; García-Rodríguez, Maricruz; Volpini, Victor; Frecha, Cecilia; Molina, Ignacio J; Fontan, Gumersindo; Fillat, Cristina

    2006-01-01

    Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disorder characterized by immunodeficiency, thrombocytopenia and eczema. A broad spectrum of mutations in the WASP gene has been identified as causing the disease. In the present paper, we report on a patient affected by WAS with a novel complex mutation, characterized by a small 9 bp deletion followed by an inversion of 151 bp and a gross deletion of 4.3 kb within the Xp11.23 region. The small deletion and the inverted fragment are found in intron 11. The large deletion initiates downstream of exon 11 of the WASP gene, including exon 12, and a genomic region upstream of the promoter of the contiguous SUV39H1 gene. Expression studies of the mRNA of the patient's sample showed the presence of two aberrant transcripts that code for a protein of 519 amino acids. We demonstrate that these two transcripts differ in the 3' UTR region, and result from the use of two alternative polyadenylation signals. The severe phenotype of the patient correlates with the presence of an aberrant protein.

  7. APOBEC3G induces a hypermutation gradient: purifying selection at multiple steps during HIV-1 replication results in levels of G-to-A mutations that are high in DNA, intermediate in cellular viral RNA, and low in virion RNA

    Directory of Open Access Journals (Sweden)

    Pathak Vinay K

    2009-02-01

    Full Text Available Abstract Background Naturally occurring Vif variants that are unable to inhibit the host restriction factor APOBEC3G (A3G have been isolated from infected individuals. A3G can potentially induce G-to-A hypermutation in these viruses, and hypermutation could contribute to genetic variation in HIV-1 populations through recombination between hypermutant and wild-type genomes. Thus, hypermutation could contribute to the generation of immune escape and drug resistant variants, but the genetic contribution of hypermutation to the viral evolutionary potential is poorly understood. In addition, the mechanisms by which these viruses persist in the host despite the presence of A3G remain unknown. Results To address these questions, we generated a replication-competent HIV-1 Vif mutant in which the A3G-binding residues of Vif, Y40RHHY44, were substituted with five alanines. As expected, the mutant was severely defective in an A3G-expressing T cell line and exhibited a significant delay in replication kinetics. Analysis of viral DNA showed the expected high level of G-to-A hypermutation; however, we found substantially reduced levels of G-to-A hypermutation in intracellular viral RNA (cRNA, and the levels of G-to-A mutations in virion RNA (vRNA were even further reduced. The frequencies of hypermutation in DNA, cRNA, and vRNA were 0.73%, 0.12%, and 0.05% of the nucleotides sequenced, indicating a gradient of hypermutation. Additionally, genomes containing start codon mutations and early termination codons within gag were isolated from the vRNA. Conclusion These results suggest that sublethal levels of hypermutation coupled with purifying selection at multiple steps during the early phase of viral replication lead to the packaging of largely unmutated genomes, providing a mechanism by which mutant Vif variants can persist in infected individuals. The persistence of genomes containing mutated gag genes despite this selection pressure indicates that dual

  8. Mutation of Auslander generators

    CERN Document Server

    Lada, Magdalini

    2009-01-01

    Let $\\Lambda$ be an artin algebra with representation dimension equal to three and $M$ an Auslander generator of $\\Lambda$. We show how, under certain assumptions, we can mutate $M$ to get a new Auslander generator whose endomorphism ring is derived equivalent to the endomorphism ring of $M$. We apply our results to selfinjective algebras with radical cube zero of infinite representation type, where we construct an infinite set of Auslander generators.

  9. HNPCC: Six new pathogenic mutations

    Directory of Open Access Journals (Sweden)

    Epplen Joerg T

    2004-06-01

    Full Text Available Abstract Background Hereditary non-polyposis colorectal cancer (HNPCC is an autosomal dominant disease with a high risk for colorectal and endometrial cancer caused by germline mutations in DNA mismatch-repair genes (MMR. HNPCC accounts for approximately 2 to 5% of all colorectal cancers. Here we present 6 novel mutations in the DNA mismatch-repair genes MLH1, MSH2 and MSH6. Methods Patients with clinical diagnosis of HNPCC were counselled. Tumor specimen were analysed for microsatellite instability and immunohistochemistry for MLH1, MSH2 and MSH6 protein was performed. If one of these proteins was not detectable in the tumor mutation analysis of the corresponding gene was carried out. Results We identified 6 frameshift mutations (2 in MLH1, 3 in MSH2, 1 in MSH6 resulting in a premature stop: two mutations in MLH1 (c.2198_2199insAACA [p.N733fsX745], c.2076_2077delTG [p.G693fsX702], three mutations in MSH2 (c.810_811delGT [p.C271fsX282], c.763_766delAGTGinsTT [p.F255fsX282], c.873_876delGACT [p.L292fsX298] and one mutation in MSH6 (c.1421_1422dupTG [p.C475fsX480]. All six tumors tested for microsatellite instability showed high levels of microsatellite instability (MSI-H. Conclusions HNPCC in families with MSH6 germline mutations may show an age of onset that is comparable to this of patients with MLH1 and MSH2 mutations.

  10. Mutation in a D-alanine-D-alanine ligase of Azospirillum brasilense Cd results in an overproduction of exopolysaccharides and a decreased tolerance to saline stress.

    Science.gov (United States)

    Jofré, Edgardo; Fischer, Sonia; Príncipe, Analía; Castro, Marina; Ferrari, Walter; Lagares, Antonio; Mori, Gladys

    2009-01-01

    Bacteria of the genus Azospirillum are free-living nitrogen-fixing, rhizobacteria that are found in close association with plant roots, where they exert beneficial effects on plant growth and yield in many crops of agronomic importance. Unlike other bacteria, little is known about the genetics and biochemistry of exopolysaccharides in Azospirillum brasilense. In an attempt to characterize genes associated with exopolysaccharides production, we generated an A. brasilense Cd Tn5 mutant that showed exopolysaccharides overproduction, decreased tolerance to saline conditions, altered cell morphology, and increased sensitivity to detergents. Genetic characterization showed that the Tn5 was inserted within a ddlB gene encoding for a d-alanine-d-alanine ligase, and located upstream of the ftsQAZ gene cluster responsible for cell division in different bacteria. Heterologous complementation of the ddlB Tn5 mutant restored the exopolysaccharides production to wild-type levels and the ability to grow in the presence of detergents, but not the morphology and growth characteristics of the wild-type bacteria, suggesting a polar effect of Tn5 on the fts genes. This result and the construction of a nonpolar ddlB mutant provide solid evidence of the presence of transcriptional coupling between a gene associated with peptidoglycan biosynthesis and the fts genes required to control cell division.

  11. Minisequencing mitochondrial DNA pathogenic mutations

    Directory of Open Access Journals (Sweden)

    Carracedo Ángel

    2008-04-01

    Full Text Available Abstract Background There are a number of well-known mutations responsible of common mitochondrial DNA (mtDNA diseases. In order to overcome technical problems related to the analysis of complete mtDNA genomes, a variety of different techniques have been proposed that allow the screening of coding region pathogenic mutations. Methods We here propose a minisequencing assay for the analysis of mtDNA mutations. In a single reaction, we interrogate a total of 25 pathogenic mutations distributed all around the whole mtDNA genome in a sample of patients suspected for mtDNA disease. Results We have detected 11 causal homoplasmic mutations in patients suspected for Leber disease, which were further confirmed by standard automatic sequencing. Mutations m.11778G>A and m.14484T>C occur at higher frequency than expected by change in the Galician (northwest Spain patients carrying haplogroup J lineages (Fisher's Exact test, P-value Conclusion We here developed a minisequencing genotyping method for the screening of the most common pathogenic mtDNA mutations which is simple, fast, and low-cost. The technique is robust and reproducible and can easily be implemented in standard clinical laboratories.

  12. Androgen receptor gene mutation, rearrangement, polymorphism.

    Science.gov (United States)

    Eisermann, Kurtis; Wang, Dan; Jing, Yifeng; Pascal, Laura E; Wang, Zhou

    2013-09-01

    Genetic aberrations of the androgen receptor (AR) caused by mutations, rearrangements, and polymorphisms result in a mutant receptor that has varied functions compared to wild type AR. To date, over 1,000 mutations have been reported in the AR with most of these being associated with androgen insensitivity syndrome (AIS). While mutations of AR associated with prostate cancer occur less often in early stage localized disease, mutations in castration-resistant prostate cancer (CRPC) patients treated with anti-androgens occur more frequently with 10-30% of these patients having some form of mutation in the AR. Resistance to anti-androgen therapy usually results from gain-of-function mutations in the LBD such as is seen with bicalutamide and more recently with enzalutamide (MDV3100). Thus, it is crucial to investigate these new AR mutations arising from drug resistance to anti-androgens and other small molecule pharmacological agents.

  13. TCOF1 mutation database: novel mutation in the alternatively spliced exon 6A and update in mutation nomenclature.

    Science.gov (United States)

    Splendore, Alessandra; Fanganiello, Roberto D; Masotti, Cibele; Morganti, Lucas S C; Passos-Bueno, M Rita

    2005-05-01

    Recently, a novel exon was described in TCOF1 that, although alternatively spliced, is included in the major protein isoform. In addition, most published mutations in this gene do not conform to current mutation nomenclature guidelines. Given these observations, we developed an online database of TCOF1 mutations in which all the reported mutations are renamed according to standard recommendations and in reference to the genomic and novel cDNA reference sequences (www.genoma.ib.usp.br/TCOF1_database). We also report in this work: 1) results of the first screening for large deletions in TCOF1 by Southern blot in patients without mutation detected by direct sequencing; 2) the identification of the first pathogenic mutation in the newly described exon 6A; and 3) statistical analysis of pathogenic mutations and polymorphism distribution throughout the gene.

  14. Aberrant expression pattern of a novel mutation in connexin 26 gene resulting in autosomal recessive deafness%连接蛋白基因一个新致聋突变体p.Y155X及功能分析

    Institute of Scientific and Technical Information of China (English)

    杨中纯; 肖自安; 谢鼎华; 夏昆

    2010-01-01

    Objective To report a novel deafness-causing mutation c. 465T→A, p. Y155X in connexin 26 (CX26) (also called gap junction protein β-2, GJB2 ), and perform functional analysis of the mutated protein p. Y155X in Hela cells to explore the underlying mechanism on deafness. Methods Mutations in CX26 gene of the proband in an autosomal recessive inherited deafness family were tested by direct DNA sequencing method. Mutant p. Y155X, which was found in the deafness family, and wild type CX26 (wtCX26), were directionally subcloned into the pEGFP-N1 plasmid to construct the recombinant fusion protein expression vector of CX26 p. Y155X-EGFP and wtCX26-EGFP, followed by transfecting into HeLa cells. The expression of the mutated and wild type proteins was analyzed using Western blot analysis. The intracellular localization of proteins and the formation of gap junction-like plaques at plasma membrane were observed under confocal microscope. Gap junction coupling was tested by calcein-AM dye transfer experiment. Results A novel nonsense mutation c. 465T→A, p. Y155X in the CX26 gene was found in the autosomal recessive deafness family. The molecular weight of protein p. Y155X was smaller than that of wtCX26 in transiently expressed HeLa cells. The mutated protein failed to reach the cell surface to form gap junction plaques, and displayed cytoplasmic accumulation. Also, no calcein-AM dye was transferred from the donor cells to the recipient cells when both were transfected with CX26 p. Y155X. The wtCX26 protein localized at the cell membrane to form gap junction plaques with permeability to fluorescent dye calcein-AM. Conclusion CX26 p. Y155X could not be targeted to the plasma membrane and there was no formation of gap junction channels between the adjacent cells. The mutation c. 465T→A, p. Y155X in CX26 gene was responsible for the autosomal recessive hearing impairment in this family.%目的 观察连接蛋白(connexin 26,CX26)基因的一个新致聋突变c.465T

  15. PAX6 mutations: genotype-phenotype correlations

    Directory of Open Access Journals (Sweden)

    Hanson Isabel M

    2005-05-01

    Full Text Available Abstract Background The PAX6 protein is a highly conserved transcriptional regulator that is important for normal ocular and neural development. In humans, heterozygous mutations of the PAX6 gene cause aniridia (absence of the iris and related developmental eye diseases. PAX6 mutations are archived in the Human PAX6 Allelic Variant Database, which currently contains 309 records, 286 of which are mutations in patients with eye malformations. Results We examined the records in the Human PAX6 Allelic Variant Database and documented the frequency of different mutation types, the phenotypes associated with different mutation types, the contribution of CpG transitions to the PAX6 mutation spectrum, and the distribution of chain-terminating mutations in the open reading frame. Mutations that introduce a premature termination codon into the open reading frame are predominantly associated with aniridia; in contrast, non-aniridia phenotypes are typically associated with missense mutations. Four CpG dinucleotides in exons 8, 9, 10 and 11 are major mutation hotspots, and transitions at these CpG's account for over half of all nonsense mutations in the database. Truncating mutations are distributed throughout the PAX6 coding region, except for the last half of exon 12 and the coding part of exon 13, where they are completely absent. The absence of truncating mutations in the 3' part of the coding region is statistically significant and is consistent with the idea that nonsense-mediated decay acts on PAX6 mutant alleles. Conclusion The PAX6 Allelic Variant Database is a valuable resource for studying genotype-phenotype correlations. The consistent association of truncating mutations with the aniridia phenotype, and the distribution of truncating mutations in the PAX6 open reading frame, suggests that nonsense-mediated decay acts on PAX6 mutant alleles.

  16. Mutational profiling reveals PIK3CA mutations in gallbladder carcinoma

    Directory of Open Access Journals (Sweden)

    Bardeesy Nabeel

    2011-02-01

    Full Text Available Abstract Background The genetics of advanced biliary tract cancers (BTC, which encompass intra- and extra-hepatic cholangiocarcinomas as well as gallbladder carcinomas, are heterogeneous and remain to be fully defined. Methods To better characterize mutations in established known oncogenes and tumor suppressor genes we tested a mass spectrometric based platform to interrogate common cancer associated mutations across a panel of 77 formalin fixed paraffin embedded archived BTC cases. Results Mutations among three genes, KRAS, NRAS and PIK3CA were confirmed in this cohort. Activating mutations in PIK3CA were identified exclusively in GBC (4/32, 12.5%. KRAS mutations were identified in 3 (13% intra-hepatic cholangiocarcinomas and 1 (33% perihillar cholangiocarcinoma but were not identified in gallbladder carcinomas and extra-hepatic cholangiocarcinoma. Conclusions The presence of activating mutations in PIK3CA specifically in GBC has clinical implications in both the diagnosis of this cancer type, as well as the potential utility of targeted therapies such as PI3 kinase inhibitors.

  17. WRN mutations in Werner syndrome patients: genomic rearrangements, unusual intronic mutations and ethnic-specific alterations.

    Science.gov (United States)

    Friedrich, Katrin; Lee, Lin; Leistritz, Dru F; Nürnberg, Gudrun; Saha, Bidisha; Hisama, Fuki M; Eyman, Daniel K; Lessel, Davor; Nürnberg, Peter; Li, Chumei; Garcia-F-Villalta, María J; Kets, Carolien M; Schmidtke, Joerg; Cruz, Vítor Tedim; Van den Akker, Peter C; Boak, Joseph; Peter, Dincy; Compoginis, Goli; Cefle, Kivanc; Ozturk, Sukru; López, Norberto; Wessel, Theda; Poot, Martin; Ippel, P F; Groff-Kellermann, Birgit; Hoehn, Holger; Martin, George M; Kubisch, Christian; Oshima, Junko

    2010-07-01

    Werner syndrome (WS) is an autosomal recessive segmental progeroid syndrome caused by null mutations at the WRN locus, which codes for a member of the RecQ family of DNA helicases. Since 1988, the International Registry of Werner syndrome had enrolled 130 molecularly confirmed WS cases from among 110 worldwide pedigrees. We now report 18 new mutations, including two genomic rearrangements, a deep intronic mutation resulting in a novel exon, a splice consensus mutation leading to utilization of the nearby splice site, and two rare missense mutations. We also review evidence for founder mutations among various ethnic/geographic groups. Founder WRN mutations had been previously reported in Japan and Northern Sardinia. Our Registry now suggests characteristic mutations originated in Morocco, Turkey, The Netherlands and elsewhere.

  18. Oncogene mutational profile in nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang ZC

    2014-03-01

    Full Text Available Zi-Chen Zhang,1,* Sha Fu,1,* Fang Wang,1 Hai-Yun Wang,1 Yi-Xin Zeng,2 Jian-Yong Shao11Department of Molecular Diagnostics, 2Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, People's Republic of China *These authors contributed equally to this work Abstract: Nasopharyngeal carcinoma (NPC is a common tumor in Southern China, but the oncogene mutational status of NPC patients has not been clarified. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined in 123 NPC patients. The relationships between mutational status and clinical data were assessed with a χ2 or Fisher's exact test. Survival analysis was performed using the Kaplan–Meier method with the log-rank test. In 123 patients, 21 (17.1% NPC tumors were positive for mutations in eight oncogenes: six patients had PIK3CA mutations (4.9%, five NRAS mutations (4.1%, four KIT mutations (3.3%, two PDGFRA mutations (1.6%, two ABL mutations (1.6%, and one with simultaneous mutations in HRAS, EGFR, and BRAF (1%. Patients with mutations were more likely to relapse or develop metastasis than those with wild-type alleles (P=0.019. No differences or correlations were found in other clinical characteristics or in patient survival. No mutations were detected in oncogenes AKT1, AKT2, CDK, ERBB2, FGFR1, FGFR3, FLT3, JAK2, KRAS, MET, and RET. These results demonstrate an association between NPC and mutations in NRAS, KIT, PIK3CA, PDGFRA, and ABL, which are associated with patient relapse and metastasis. Keywords: NPC, oncogene, mutation

  19. Mutation of EMG1 causing Bowen-Conradi syndrome results in reduced cell proliferation rates concomitant with G2/M arrest and 18S rRNA processing delay.

    Science.gov (United States)

    Armistead, Joy; Hemming, Richard; Patel, Nehal; Triggs-Raine, Barbara

    2014-06-01

    Bowen-Conradi syndrome (BCS) is a lethal autosomal recessive disorder caused by a D86G substitution in the protein, Essential for Mitotic Growth 1 (EMG1). EMG1 is essential for 18S rRNA maturation and 40S ribosome biogenesis in yeast, but no studies of its role in ribosome biogenesis have been done in mammals. To assess the effect of the EMG1 mutation on cell growth and ribosomal biogenesis in humans, we employed BCS patient cells. The D86G substitution did not interfere with EMG1 nucleolar localization. In BCS patient lymphoblasts, cells accumulated in G2/M, resulting in reduced proliferation rates; however, patient fibroblasts showed normal proliferation. The rate of 18S rRNA processing was consistently delayed in patient cells, although this did not lead to a difference in the levels of 40S ribosomes, or a change in protein synthesis rates. These results demonstrate that as in yeast, EMG1 in mammals has a role in ribosome biogenesis. The obvious phenotype in lymphoblasts compared to fibroblasts suggests a greater need for EMG1 in rapidly dividing cells. Tissue-specific effects have been seen in other ribosomal biogenesis disorders, and it seems likely that the impact of EMG1 deficiency would be larger in the rapidly proliferating cells of the developing embryo.

  20. Mutation of EMG1 causing Bowen–Conradi syndrome results in reduced cell proliferation rates concomitant with G2/M arrest and 18S rRNA processing delay

    Directory of Open Access Journals (Sweden)

    Joy Armistead

    2014-06-01

    Full Text Available Bowen–Conradi syndrome (BCS is a lethal autosomal recessive disorder caused by a D86G substitution in the protein, Essential for Mitotic Growth 1 (EMG1. EMG1 is essential for 18S rRNA maturation and 40S ribosome biogenesis in yeast, but no studies of its role in ribosome biogenesis have been done in mammals. To assess the effect of the EMG1 mutation on cell growth and ribosomal biogenesis in humans, we employed BCS patient cells. The D86G substitution did not interfere with EMG1 nucleolar localization. In BCS patient lymphoblasts, cells accumulated in G2/M, resulting in reduced proliferation rates; however, patient fibroblasts showed normal proliferation. The rate of 18S rRNA processing was consistently delayed in patient cells, although this did not lead to a difference in the levels of 40S ribosomes, or a change in protein synthesis rates. These results demonstrate that as in yeast, EMG1 in mammals has a role in ribosome biogenesis. The obvious phenotype in lymphoblasts compared to fibroblasts suggests a greater need for EMG1 in rapidly dividing cells. Tissue-specific effects have been seen in other ribosomal biogenesis disorders, and it seems likely that the impact of EMG1 deficiency would be larger in the rapidly proliferating cells of the developing embryo.

  1. Transgenic Animal Mutation Assays

    Institute of Scientific and Technical Information of China (English)

    Tao Chen; Ph.D.D.A.B.T.

    2005-01-01

    @@ The novel transgenic mouse and rat mutation assays have provided a tool for analyzing in vivo mutation in any tissue, thus permitting the direct comparison of cancer incidence with mutant frequency.

  2. Mutations in exons 10 and 11 of human glucokinase result in conformational variations in the active site of the structure contributing to poor substrate binding - explains hyperglycemia in type 2 diabetic patients.

    Science.gov (United States)

    Yellapu, Nandakumar; Mahto, Manoj Kumar; Valasani, Koteswara Rao; Sarma, P V G K; Matcha, Bhaskar

    2015-01-01

    Mutations in the glucokinase (GK) gene play a critical role in the establishment of type 2 diabetes. In our earlier study, R308K mutation in GK in a clinically proven type 2 diabetic patient showed, structural and functional variations that contributed immensely to the hyperglycemic condition. In the extension of this work, a cohort of 30 patients with established type 2 diabetic condition were chosen and the exons 10 and 11 of GK were PCR-amplified and sequenced. The sequence alignment showed A379S, D400Y, E300A, E395A, E395G, H380N, I348N, L301M, M298I, M381G, M402R, R308K, R394P, R397S, and S398R mutations in 12 different patients. The structural analysis of these mutated GKs, showed a variable number of β-α-β units, hairpins, β-bulges, strands, helices, helix-helix interactions, β-turns, and γ-turns along with the RMSD variations when compared to wild-type GK. Molecular modeling studies revealed that the substrate showed variable binding orientations and could not fit into the active site of these mutated structures; moreover, it was expelled out of the conformations. Therefore, these structural variations in GK due to mutations could be one of the strongest reasons for the hyperglycemic levels in these type 2 diabetic patients.

  3. Evaluation of CFTR gene mutations in Adana

    Directory of Open Access Journals (Sweden)

    Ozlem Goruroglu Ozturk

    2013-04-01

    Full Text Available ABSTRACT Objective: Cystic fibrosis is the most common autosomal recessive inherited disorder seen in the white populations. It develops in result of mutations of cystic fibrosis transmembrane regulator (CFTR gene. Rate of these mutations vary in different geographical regions. In this study, we aimed to determine the frequency of CFTR gene mutations in Adana. Methods: DNA samples of 63 subjects (21 women, 42 men who were diagnosed as cystic fibrosis at Balcali Hospital of Cukurova University, were studied for 19 different CFTR mutations by the strip assay method which is based on reverse hybridization. Results: In cystic fibrosis diagnosed patients, 19 mutations were observed of which 9 were homozygous and 10 were heterozygous. ∆F508 frequency was found as 11.9%, and rate of homozygous was found as 66.7%. Mutation frequencies of W1282X and N1303K were found as 2.40% and 4.80% respectively and rate of homozygous mutations were 50% for both. I148T mutation frequency was found as 3.20% and all were heterozygous. For the whole 19 mutations, frequency of mutation in 63 subjects was 22.3%. Conclusion: Detection of CFTR gene mutations by the strip assay method by reverse hybridization is an easy, fast and informative method. However, due to improvability of the common mutations in probable cystic fibrosis patients because of heterogenity in this region, it is still a major problem and does not exclude cystic fibrosis diagnosis. But this problematic issue can be overcome by evaluating the whole exons of CFTR mutations by advanced molecular tecniques. Key words: CFTR, cystic fibrosis, molecular diagnosis, reverse hibridisation [Cukurova Med J 2013; 38(2.000: 202-208

  4. Somatic mutations in aging, cancer and neurodegeneration.

    Science.gov (United States)

    Kennedy, Scott R; Loeb, Lawrence A; Herr, Alan J

    2012-04-01

    The somatic mutation theory of aging posits that the accumulation of mutations in the genetic material of somatic cells as a function of time results in a decrease in cellular function. In particular, the accumulation of random mutations may inactivate genes that are important for the functioning of the somatic cells of various organ systems of the adult, result in a decrease in organ function. When the organ function decreases below a critical level, death occurs. A significant amount of research has shown that somatic mutations play an important role in aging and a number of age related pathologies. In this review, we explore evidence for increases in somatic nuclear mutation burden with age and the consequences for aging, cancer, and neurodegeneration. We then review evidence for increases in mitochondrial mutation burden and the consequences for dysfunction in the disease processes.

  5. Computational Analysis of PTEN Gene Mutation

    Directory of Open Access Journals (Sweden)

    Siew-Kien Mah

    2012-01-01

    Full Text Available Post-genomic data can be efficiently analyzed using computational tools. It has the advantage over the biochemical and biophysical methods in term of higher coverage. In this research, we adopted a computational analysis on PTEN gene mutation.  Mutation in PTEN is responsible for many human diseases. The results of this research provide insights into the protein domains of PTEN and the distribution of mutation.

  6. Maize Mutator transposon

    Institute of Scientific and Technical Information of China (English)

    Yijun WANG; Mingliang XU; Dexiang DENG; Yunlong BIAN

    2008-01-01

    Transposable elements are widely distributed in eukaryotes. Due to its high copy numbers, high forward mutation rate and preferential insertion into low-copy DNA sequences, among others, the Mutator system has been widely used as a mutagen in genomic research. The discovery, classification, transposition specificity and epige-netic regulation of Mutator transposons were described. The application of Mutator tagging in plant genomic research was also presented. The role of Mu-like elements in genome evolution was briefly depicted. Moreover, the direction of Mutator transposon research in the future was discussed.

  7. Common Β- Thalassaemia Mutations in

    Directory of Open Access Journals (Sweden)

    P Azarfam

    2005-01-01

    Full Text Available Introduction: β –Thalassaemia was first explained by Thomas Cooly as Cooly’s anaemia in 1925. The β- thalassaemias are hereditary autosomal disorders with decreased or absent β-globin chain synthesis. The most common genetic defects in β-thalassaemias are caused by point mutations, micro deletions or insertions within the β-globin gene. Material and Methods: In this research , 142 blood samples (64 from childrens hospital of Tabriz , 15 samples from Shahid Gazi hospital of Tabriz , 18 from Urumia and 45 samples from Aliasghar hospital of Ardebil were taken from thalassaemic patients (who were previously diagnosed .Then 117 non-familial samples were selected . The DNA of the lymphocytes of blood samples was extracted by boiling and Proteinase K- SDS procedure, and mutations were detected by ARMS-PCR methods. Results: From the results obtained, eleven most common mutations,most of which were Mediterranean mutations were detected as follows; IVS-I-110(G-A, IVS-I-1(G-A ،IVS-I-5(G-C ,Frameshift Codon 44 (-C,( codon5(-CT,IVS-1-6(T-C, IVS-I-25(-25bp del ,Frameshift 8.9 (+G ,IVS-II-1(G-A ,Codon 39(C-T, Codon 30(G-C the mutations of the samples were defined. The results showed that Frameshift 8.9 (+G, IVS-I-110 (G-A ,IVS-II-I(G-A, IVS-I-5(G-C, IVS-I-1(G-A , Frameshift Codon 44(-C , codon5(-CT , IVS-1-6(T-C , IVS-I-25(-25bp del with a frequency of 29.9%, 25.47%,17.83%, 7.00%, 6.36% , 6.63% , 3.8% , 2.5% , 0.63% represented the most common mutations in North - west Iran. No mutations in Codon 39(C-T and Codon 30(G-C were detected. Cunclusion: The frequency of the same mutations in patients from North - West of Iran seems to be different as compared to other regions like Turkey, Pakistan, Lebanon and Fars province of Iran. The pattern of mutations in this region is more or less the same as in the Mediterranean region, but different from South west Asia and East Asia.

  8. THE ANALYSIS OF NF2 GENE MUTATION IN SPORADIC SCHWANNOMAS

    Institute of Scientific and Technical Information of China (English)

    卞留贯; 孙青芳; 沈建康; 赵卫国; 罗其中

    2002-01-01

    Objective To analyze the mutation of NF2 gene (exon 2,4,6 and 13) in schwannomas. Methods The NF2 gene mutation in 36 schwannomas were observed by PCR-SSCP and DNA sequence. The proliferative index of schwannoma was detected by immunohistochemistry. Results We found 13 mutations in 36 schwannomas, including 6 deletion or insertion resulting in a frameshift, 2 nonsense mutations, 2 missense mutations, and 3 alterations affecting acceptor or donor of splicing sites in E4,E6,E13. The proliferative index of schwannomas with mutation were significantly higher than those without mutation (P< 0.05). Conclusion NF2 gene mutation is the frequent event in the tumorigenesis of schwannomas, and there is some correlation between the mutation and clinical behavior(tumor proliferation).

  9. A mutation at IVS1 + 5 of the von Hippel-Lindau gene resulting in intron retention in transcripts is not pathogenic in a patient with a tongue cancer?: case report

    Directory of Open Access Journals (Sweden)

    Asakawa Takeshi

    2012-03-01

    Full Text Available Abstract Background Von Hippel-Lindau disease (VHL is a dominantly inherited familial cancer syndrome predisposing the patient to a variety of malignant and benign neoplasms, most frequently hemangioblastoma, renal cell carcinoma, pheochromocytoma, and pancreatic tumors. VHL is caused by mutations of the VHL tumor suppressor gene on the short arm of chromosome 3, and clinical manifestations develop if both alleles are inactivated according to the two-hit hypothesis. VHL mutations are more frequent in the coding region and occur occasionally in the splicing region of the gene. Previously, we reported that the loss of heterozygosity (LOH of the VHL gene is common in squamous cell carcinoma tissues of the tongue. Case Presentation We describe a case of squamous cell carcinoma in the tongue caused by a point mutation in the splicing region of the VHL gene and discuss its association with VHL disease. Sequence analysis of DNA extracted from the tumor and peripheral blood of the patient with squamous cell carcinoma revealed a heterozygous germline mutation (c. 340 + 5 G > C in the splice donor sequence in intron 1 of the VHL gene. RT-PCR analysis of the exon1/intron1 junction in RNA from tumor tissue detected an unspliced transcript. Analysis of LOH using a marker with a heterozygous mutation of nucleotides (G or C revealed a deletion of the mutant C allele in the carcinoma tissues. Conclusions The fifth nucleotide G of the splice donor site of the VHL gene is important for the efficiency of splicing at that site. The development of tongue cancer in this patient was not associated with VHL disease because the mutation occurred in only a single allele of the VHL gene and that allele was deleted in tumor cells.

  10. Lipopolysaccharide-deficient Brucella variants arise spontaneously during infection

    Directory of Open Access Journals (Sweden)

    Joshua E. Turse

    2011-03-01

    Full Text Available Lipopolysaccharide-deficient mutants of smooth Brucella species (rough mutants have been shown to arise spontaneously in culture. However, in situ analysis of Brucella infected macrophages using antibody directed against O-polysaccharide suggested a loss of reactivity of Brucella consistent with the appearance of rough organisms, and a potential contribution to infection. The experiments reported describe the direct recovery of Brucella from macrophages infected in vitro and from the spleens of infected mice at a frequency similar to that described in vitro, suggesting that Brucella dissociation is not simply an in vitro artifact. The frequency of appearance of spontaneous rough organisms deficient in O-polysaccharide expression measured in vitro is approximately 2-3 logs higher than the appearance of mutation to antibiotic resistance, purine auxotrophy or reversion of erythritol sensitive ∆eryC mutants to tolerance. Genetic trans-complementation using a plasmid-based expression of Brucella manBA successfully restored O-polysaccharide expression in only one third of O-polysaccharide deficient spontaneous mutants. Suggesting that the appearance of rough mutants is caused by mutation at more than one locus. In addition, Sanger sequencing of the manBA structural genes detected multiple sequence changes that may explain the observed phenotypic differences. The presence of O-polysaccharide resulted in macrophage and neutrophil infiltration into the peritoneal cavity and systemic distribution of the organism. In contrast, rough organisms are controlled by resident macrophages or by extracellular killing mechanisms and rapidly cleared from this compartment consistent with the inability to cause disease. Loss of O-polysaccharide expression appears to be stochastic giving rise to organisms with biological properties distinct from the parental smooth organism during the course of infection.

  11. Science Letters: Screen p53 mutations in hepatocellular carcinoma by FASAY: A novel splicing mutation

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-mo; FU Jing-geng; GE Wang-zhong; ZHU Jiang-yan; WANG Jun-yong; ZHANG Wei; QIAN Wei; HUO Ke-ke

    2007-01-01

    Objective: To establish a routine procedure for the detection of p53 mutations in hepatocellular carcinoma (HCC)surgical resections using the FASAY (functional analysis of separated alleles of p53 on yeast) procedure. Methods: p53 status was analyzed by FASAY and cDNA sequencing in 50 cases of HCC. After the extraction of RNA from the frozen tumor and corresponding normal tissues, reverse transcription RT-PCR was carried out using these samples. The assay can detect mutations of p53mRNA between codons 67 and 347 by the DNA-binding activity of the protein and reveal them as red colonies. Results: Of the 50specimens, 29 (58%) were positive (mutant) by FASAY. Sequencing analysis confirmed that all 29 FASAY positive tumors harbored mutations, and that no mutations were detectable in any FASAY negative tumors. In 29 p53 mutations, 22 mutations were point missense mutation, 5 were deletions and 2 were splicing mutations. A novel splice mutation on splice donor of intron 6was reported, which could produce two different mRNAs, respectively using the nearest upstream and downstream recessive splice donor sites. Conclusion: FASAY is a sensitive method for detecting the various types of p53 mutations in HCC, suggesting that the yeast functional assay for the detection of p53 mutations may be essential for elucidating their clinical significance.

  12. The Mutational Robustness of Influenza A Virus

    Science.gov (United States)

    McCrone, John T.; Lauring, Adam S.

    2016-01-01

    A virus’ mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16) than in the other 6 segments (0.78 ± 0.24), and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects. PMID:27571422

  13. The Mutational Robustness of Influenza A Virus.

    Directory of Open Access Journals (Sweden)

    Elisa Visher

    2016-08-01

    Full Text Available A virus' mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16 than in the other 6 segments (0.78 ± 0.24, and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects.

  14. Treatment of leber congenital amaurosis due to RPE65 mutations by ocular subretinal injection of adeno-associated virus gene vector: short-term results of a phase I trial.

    Science.gov (United States)

    Hauswirth, William W; Aleman, Tomas S; Kaushal, Shalesh; Cideciyan, Artur V; Schwartz, Sharon B; Wang, Lili; Conlon, Thomas J; Boye, Sanford L; Flotte, Terence R; Byrne, Barry J; Jacobson, Samuel G

    2008-10-01

    Leber congenital amaurosis (LCA) is a group of autosomal recessive blinding retinal diseases that are incurable. One molecular form is caused by mutations in the RPE65 (retinal pigment epithelium-specific 65-kDa) gene. A recombinant adeno-associated virus serotype 2 (rAAV2) vector, altered to carry the human RPE65 gene (rAAV2-CBSB-hRPE65), restored vision in animal models with RPE65 deficiency. A clinical trial was designed to assess the safety of rAAV2-CBSB-hRPE65 in subjects with RPE65-LCA. Three young adults (ages 21-24 years) with RPE65-LCA received a uniocular subretinal injection of 5.96 x 10(10) vector genomes in 150 microl and were studied with follow-up examinations for 90 days. Ocular safety, the primary outcome, was assessed by clinical eye examination. Visual function was measured by visual acuity and dark-adapted full-field sensitivity testing (FST); central retinal structure was monitored by optical coherence tomography (OCT). Neither vector-related serious adverse events nor systemic toxicities were detected. Visual acuity was not significantly different from baseline; one patient showed retinal thinning at the fovea by OCT. All patients self-reported increased visual sensitivity in the study eye compared with their control eye, especially noticeable under reduced ambient light conditions. The dark-adapted FST results were compared between baseline and 30-90 days after treatment. For study eyes, sensitivity increases from mean baseline were highly significant (p gene therapy for RPE65-LCA that were carried out contemporaneously and reported.

  15. Finite mutation classes of coloured quivers

    CERN Document Server

    Torkildsen, Hermund André

    2010-01-01

    We consider the general notion of coloured quiver mutation and show that the mutation class of a coloured quiver $Q$, arising from an $m$-cluster tilting object associated with $H$, is finite if and only if $H$ is of finite or tame representation type, or it has at most 2 simples. This generalizes a result known for 1-cluster categories.

  16. Mutation update for the PORCN gene

    DEFF Research Database (Denmark)

    Lombardi, Maria Paola; Bulk, Saskia; Celli, Jacopo

    2011-01-01

    Mutations in the PORCN gene were first identified in Goltz-Gorlin syndrome patients in 2007. Since then, several reports have been published describing a large variety of genetic defects resulting in the Goltz-Gorlin syndrome, and mutations or deletions were also reported in angioma serpiginosum,...

  17. Mutations in ANKH cause chondrocalcinosis.

    Science.gov (United States)

    Pendleton, Adrian; Johnson, Michelle D; Hughes, Anne; Gurley, Kyle A; Ho, Andrew M; Doherty, Michael; Dixey, Josh; Gillet, Pierre; Loeuille, Damien; McGrath, Rodney; Reginato, Antonio; Shiang, Rita; Wright, Gary; Netter, Patrick; Williams, Charlene; Kingsley, David M

    2002-10-01

    Chondrocalcinosis (CC) is a common cause of joint pain and arthritis that is caused by the deposition of calcium-containing crystals within articular cartilage. Although most cases are sporadic, rare familial forms have been linked to human chromosomes 8 (CCAL1) or 5p (CCAL2) (Baldwin et al. 1995; Hughes et al. 1995; Andrew et al. 1999). Here, we show that two previously described families with CCAL2 have mutations in the human homolog of the mouse progressive ankylosis gene (ANKH). One of the human mutations results in the substitution of a highly conserved amino acid residue within a predicted transmembrane segment. The other creates a new ATG start site that adds four additional residues to the ANKH protein. Both mutations segregate completely with disease status and are not found in control subjects. In addition, 1 of 95 U.K. patients with sporadic CC showed a deletion of a single codon in the ANKH gene. The same change was found in a sister who had bilateral knee replacement for osteoarthritis. Each of the three human mutations was reconstructed in a full-length ANK expression construct previously shown to regulate pyrophosphate levels in cultured cells in vitro. All three of the human mutations showed significantly more activity than a previously described nonsense mutation that causes severe hydroxyapatite mineral deposition and widespread joint ankylosis in mice. These results suggest that small sequence changes in ANKH are one cause of CC and joint disease in humans. Increased ANK activity may explain the different types of crystals commonly deposited in human CCAL2 families and mutant mice and may provide a useful pharmacological target for treating some forms of human CC.

  18. Fitness cost of chromosomal drug resistance-conferring mutations.

    Science.gov (United States)

    Sander, Peter; Springer, Burkhard; Prammananan, Therdsak; Sturmfels, Antje; Kappler, Martin; Pletschette, Michel; Böttger, Erik C

    2002-05-01

    To study the cost of chromosomal drug resistance mutations to bacteria, we investigated the fitness cost of mutations that confer resistance to different classes of antibiotics affecting bacterial protein synthesis (aminocyclitols, 2-deoxystreptamines, macrolides). We used a model system based on an in vitro competition assay with defined Mycobacterium smegmatis laboratory mutants; selected mutations were introduced by genetic techniques to address the possibility that compensatory mutations ameliorate the resistance cost. We found that the chromosomal drug resistance mutations studied often had only a small fitness cost; compensatory mutations were not involved in low-cost or no-cost resistance mutations. When drug resistance mutations found in clinical isolates were considered, selection of those mutations that have little or no fitness cost in the in vitro competition assay seems to occur. These results argue against expectations that link decreased levels of antibiotic consumption with the decline in the level of resistance.

  19. Splice Site Mutations in the ATP7A Gene

    DEFF Research Database (Denmark)

    Skjørringe, Tina; Tümer, Zeynep; Møller, Lisbeth Birk

    2011-01-01

    Menkes disease (MD) is caused by mutations in the ATP7A gene. We describe 33 novel splice site mutations detected in patients with MD or the milder phenotypic form, Occipital Horn Syndrome. We review these 33 mutations together with 28 previously published splice site mutations. We investigate 12...... mutations for their effect on the mRNA transcript in vivo. Transcriptional data from another 16 mutations were collected from the literature. The theoretical consequences of splice site mutations, predicted with the bioinformatics tool Human Splice Finder, were investigated and evaluated in relation...... to in vivo results. Ninety-six percent of the mutations identified in 45 patients with classical MD were predicted to have a significant effect on splicing, which concurs with the absence of any detectable wild-type transcript in all 19 patients investigated in vivo. Sixty-seven percent of the mutations...

  20. Common breast cancer susceptibility alleles are associated with tumour subtypes in BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2

    NARCIS (Netherlands)

    A.M. Mulligan (Anna Marie); F.J. Couch (Fergus); D. Barrowdale (Daniel); S.M. Domchek (Susan); D. Eccles (Diana); H. Nevanlinna (Heli); S.J. Ramus (Susan); M. Robson (Mark); M.E. Sherman (Mark); A.B. Spurdle (Amanda); B. Wapenschmidt (Barbara); A. Lee (Andrew); L. McGuffog (Lesley); S. Healey (Sue); O. Sinilnikova (Olga); R. Janavicius (Ramunas); T.V.O. Hansen (Thomas); F.C. Nielsen (Finn); B. Ejlertsen (Bent); A. Osorio (Ana); I. Muñoz-Repeto (Iván); M. Durán (Mercedes); J. Godino (Javier); M. Pertesi (Maroulio); J. Benítez (Javier); P. Peterlongo (Paolo); S. Manoukian (Siranoush); B. Peissel (Bernard); D. Zaffaroni (D.); E. Cattaneo (Elisa); B. Bonnani (Bernardo); A. Viel (Alessandra); B. Pasini (Barbara); L. Papi (Laura); L. Ottini (Laura); A. Savarese (Antonella); L. Bernard (Loris); P. Radice (Paolo); U. Hamann (Ute); M. Verheus (Martijn); E.J. Meijers-Heijboer (Hanne); J.T. Wijnen (Juul); E.B. Gómez García (Encarna); M.R. Nelen (Marcel); C.M. Kets; C.M. Seynaeve (Caroline); M.M.A. Tilanus-Linthorst (Madeleine); R.B. van der Luijt (Rob); T.V. Os (Theo); M.A. Rookus (Matti); D. Frost (Debra); J.L. Jones (J Louise); D.G. Evans (Gareth); F. Lalloo (Fiona); R. Eeles (Rosalind); L. Izatt (Louise); J.W. Adlard (Julian); R. Davidson (Rosemarie); J. Cook (Jackie); A. Donaldson (Alan); H. Dorkins (Huw); H. Gregory (Helen); J. Eason (Jacqueline); C. Houghton (Catherine); J. Barwell (Julian); L. Side (Lucy); E. McCann (Emma); A. Murray (Alexandra); S. Peock (Susan); A.K. Godwin (Andrew); R.K. Schmutzler (Rita); K. Rhiem (Kerstin); C. Engel (Christoph); A. Meindl (Alfons); I. Ruehl (Ina); N. Arnold (Norbert); D. Niederacher (Dieter); C. Sutter (Christian); H. Deissler (Helmut); D. Gadzicki (Dorothea); K. Kast (Karin); S. Preisler-Adams (Sabine); R. Varon-Mateeva (Raymonda); I. Schoenbuchner (Ines); B. Fiebig (Britta); W. Heinritz (Wolfram); D. Schäfer; H. Gevensleben (Heidrun); V. Caux-Moncoutier (Virginie); M. Fassy-Colcombet (Marion); F. Cornelis (Franco̧is); S. Mazoyer (Sylvie); M. Léone (Mélanie); N. Boutry-Kryza (N.); A. Hardouin (Agnès); P. Berthet (Pascaline); D.W. Muller (Danièle); J.P. Fricker (Jean Pierre); I. Mortemousque (Isabelle); P. Pujol (Pascal); I. Coupier (Isabelle); M. Lebrun (Marine); C. Kientz (Caroline); M. Longy (Michel); N. Sevenet (Nicolas); D. Stoppa-Lyonnet (Dominique); C. Isaacs (Claudine); T. Caldes (Trinidad); M. de La Hoya (Miguel); T. Heikinen (Tuomas); K. Aittomäki (Kristiina); I. Blanco (Ignacio); C. Lazaro (Conxi); R.B. Barkardottir (Rosa); P. Soucy (Penny); M. Dumont (Martine); J. Simard (Jacques); M. Montagna (Marco); S. Tognazzo (Silvia); E. D'Andrea (Emma); S.B. Fox (Stephen); M. Yan (Max); R. Rebbeck (Timothy); O.I. Olopade (Olofunmilayo); J.N. Weitzel (Jeffrey); H. Lynch (Henry); P.A. Ganz (Patricia); G. Tomlinson (Gail); X. Wang (Xing); Z. Fredericksen (Zachary); V.S. Pankratz (Shane); N.M. Lindor (Noralane); C. Szabo (Csilla); K. Offit (Kenneth); R. Sakr (Rita); M.M. Gaudet (Mia); K.P. Bhatia (Kailash); N. Kauff (Noah); C.F. Singer (Christian); M.-K. Tea; D. Gschwantler-Kaulich (Daphne); A. Fink-Retter (Anneliese); P.L. Mai (Phuong); M.H. Greene (Mark); E.N. Imyanitov (Evgeny); F.P. O'Malley (Frances); H. Ozcelik (Hilmi); G. Glendon (Gord); A.E. Toland (Amanda); A-M. Gerdes (Anne-Marie); M. Thomassen (Mads); T.A. Kruse (Torben); U.B. Jensen; A.-B. Skytte (Anne-Bine); M.A. Caligo (Maria); M. Soller (Maria); K. Henriksson (Karin); A. von Wachenfeldt (Anna); B. Arver (Brita Wasteson); M. Stenmark-Askmalm (M.); P. Karlsson (Per); Y.C. Ding (Yuan); S.L. Neuhausen (Susan); M.S. Beattie (Mary); P.D.P. Pharoah (Paul); K.B. Moysich (Kirsten); K.L. Nathanson (Katherine); B. Karlan; J. Gross (Jenny); E.M. John (Esther); M.B. Daly (Mary); S.S. Buys (Saundra); M.C. Southey (Melissa); J.L. Hopper (John); M.-B. Terry (Mary-Beth); W. Chung (Wendy); A. Miron (Alexander); D. Goldgar (David); G. Chenevix-Trench (Georgia); D.F. Easton (Douglas); I.L. Andrulis (Irene); A.C. Antoniou (Antonis)

    2011-01-01

    textabstractIntroduction: Previous studies have demonstrated that common breast cancer susceptibility alleles are differentially associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers. It is currently unknown how these alleles are associated with different breast cancer subtypes

  1. Common breast cancer susceptibility alleles are associated with tumour subtypes in BRCA1 and BRCA2 mutation carriers : results from the Consortium of Investigators of Modifiers of BRCA1/2

    NARCIS (Netherlands)

    Mulligan, Anna Marie; Couch, Fergus J.; Barrowdale, Daniel; Domchek, Susan M.; Eccles, Diana; Nevanlinna, Heli; Ramus, Susan J.; Robson, Mark; Sherman, Mark; Spurdle, Amanda B.; Wappenschmidt, Barbara; Lee, Andrew; McGuffog, Lesley; Healey, Sue; Sinilnikova, Olga M.; Janavicius, Ramunas; Hansen, Thomas V. O.; Nielsen, Finn C.; Ejlertsen, Bent; Osorio, Ana; Munoz-Repeto, Ivan; Duran, Mercedes; Godino, Javier; Pertesi, Maroulio; Benitez, Javier; Peterlongo, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Cattaneo, Elisa; Bonanni, Bernardo; Viel, Alessandra; Pasini, Barbara; Papi, Laura; Ottini, Laura; Savarese, Antonella; Bernard, Loris; Radice, Paolo; Hamann, Ute; Verheus, Martijn; Meijers-Heijboer, Hanne E. J.; Wijnen, Juul; Garcia, Encarna B. Gomez; Nelen, Marcel R.; Kets, C. Marleen; Seynaeve, Caroline; Tilanus-Linthorst, Madeleine M. A.; van der Luijt, Rob B.; van Os, Theo; Rookus, Matti; Frost, Debra; Jones, J. Louise; Evans, D. Gareth; Lalloo, Fiona; Eeles, Ros; Izatt, Louise; Adlard, Julian; Davidson, Rosemarie; Cook, Jackie; Donaldson, Alan; Dorkins, Huw; Gregory, Helen; Eason, Jacqueline; Houghton, Catherine; Barwell, Julian; Side, Lucy E.; McCann, Emma; Murray, Alex; Peock, Susan; Godwin, Andrew K.; Schmutzler, Rita K.; Rhiem, Kerstin; Engel, Christoph; Meindl, Alfons; Ruehl, Ina; Arnold, Norbert; Niederacher, Dieter; Sutter, Christian; Deissler, Helmut; Gadzicki, Dorothea; Kast, Karin; Preisler-Adams, Sabine; Varon-Mateeva, Raymonda; Schoenbuchner, Ines; Fiebig, Britta; Heinritz, Wolfram; Schaefer, Dieter; Gevensleben, Heidrun; Caux-Moncoutier, Virginie; Fassy-Colcombet, Marion; Cornelis, Francois; Mazoyer, Sylvie; Leone, Melanie; Boutry-Kryza, Nadia; Hardouin, Agnes; Berthet, Pascaline; Muller, Daniele; Fricker, Jean-Pierre; Mortemousque, Isabelle; Pujol, Pascal; Coupier, Isabelle; Lebrun, Marine; Kientz, Caroline; Longy, Michel; Sevenet, Nicolas; Stoppa-Lyonnet, Dominique; Isaacs, Claudine; Caldes, Trinidad; de la Hoya, Miguel; Heikkinen, Tuomas; Aittomaki, Kristiina; Blanco, Ignacio; Lazaro, Conxi; Barkardottir, Rosa B.; Soucy, Penny; Dumont, Martine; Simard, Jacques; Montagna, Marco; Tognazzo, Silvia; D'Andrea, Emma; Fox, Stephen; Yan, Max; Rebbeck, Tim; Olopade, Olufunmilayo I.; Weitzel, Jeffrey N.; Lynch, Henry T.; Ganz, Patricia A.; Tomlinson, Gail E.; Wang, Xianshu; Fredericksen, Zachary; Pankratz, Vernon S.; Lindor, Noralane M.; Szabo, Csilla; Offit, Kenneth; Sakr, Rita; Gaudet, Mia; Bhatia, Jasmine; Kauff, Noah; Singer, Christian F.; Tea, Muy-Kheng; Gschwantler-Kaulich, Daphne; Fink-Retter, Anneliese; Mai, Phuong L.; Greene, Mark H.; Imyanitov, Evgeny; O'Malley, Frances P.; Ozcelik, Hilmi; Glendon, Gordon; Toland, Amanda E.; Gerdes, Anne-Marie; Thomassen, Mads; Kruse, Torben A.; Jensen, Uffe Birk; Skytte, Anne-Bine; Caligo, Maria A.; Soller, Maria; Henriksson, Karin; Wachenfeldt, von Anna; Arver, Brita; Stenmark-Askmalm, Marie; Karlsson, Per; Ding, Yuan Chun; Neuhausen, Susan L.; Beattie, Mary; Pharoah, Paul D. P.; Moysich, Kirsten B.; Nathanson, Katherine L.; Karlan, Beth Y.; Gross, Jenny; John, Esther M.; Daly, Mary B.; Buys, Saundra M.; Southey, Melissa C.; Hopper, John L.; Terry, Mary Beth; Chung, Wendy; Miron, Alexander F.; Goldgar, David; Chenevix-Trench, Georgia; Easton, Douglas F.; Andrulis, Irene L.; Antoniou, Antonis C.

    2011-01-01

    Introduction: Previous studies have demonstrated that common breast cancer susceptibility alleles are differentially associated with breast cancer risk for BRCA1 and/or BRCA2 mutation carriers. It is currently unknown how these alleles are associated with different breast cancer subtypes in BRCA1 an

  2. Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the consortium of investigators of modifiers of BRCA1/BRCA2 (CIMBA)

    NARCIS (Netherlands)

    A. Osorio (Ana); R.L. Milne (Roger); G. Pita (G.); P. Peterlongo (Paolo); T. Heikinen (Tuomas); J. Simard (Jacques); G. Chenevix-Trench (Georgia); A.B. Spurdle (Amanda); J. Beesley (Jonathan); X.C. Chen (X. C.); S. Healey (Sue); S.L. Neuhausen (Susan); Y.C. Ding (Yuan); F.J. Couch (Fergus); X. Wang (Xing); N.M. Lindor (Noralane); S. Manoukian (Siranoush); M. Barile (Monica); A. Viel (Alessandra); L. Tizzoni (Laura); C. Szabo (Csilla); L. Foretova (Lenka); M. Zikan (Michal); K. Claes (Kathleen); M.H. Greene (Mark); P.L. Mai (Phuong); G. Rennert (Gad); F. Lejbkowicz (Flavio); O. Barnett-Griness (Ofra); I.L. Andrulis (Irene); H. Ozcelik (Hilmi); N. Weerasooriya (Nayana); A-M. Gerdes (Anne-Marie); M. Thomassen (Mads); D. Cruger (Dorthe); M.A. Caligo (Maria); E. Friedman (Eitan); B. Kaufman (Bella); Y. Laitman (Yael); S. Cohen (Shimrit); T. Kontorovich (Tair); R. Gershoni-Baruch; E. Dagan (Efrat); H. Jernström (H.); M.S. Askmalm (Marie); B. Arver (Brita Wasteson); B. Malmer (Beatrice); S.M. Domchek (Susan); K.L. Nathanson (Katherine); J. Brunet (Joan); T. Ramon Y Cajal; D. Yannoukakos (Drakoulis); U. Hamann (Ute); F.B.L. Hogervorst (Frans); S. Verhoef; E.B.G. Garcíla (E.B. Gómez); J.T. Wijnen (Juul); A.M.W. van den Ouweland (Ans); D.F. Easton (Douglas); S. Peock (Susan); M. Cook (Margaret); C.T. Oliver (Clare); D. Frost (Debra); C. Luccarini (Craig); D.G. Evans (Gareth); F. Lalloo (Fiona); R. Eeles (Rosalind); G. Pichert (Gabriella); J. Cook (Jackie); S.V. Hodgson (Shirley); P.J. Morrison (Patrick); F. Douglas (Fiona); A.K. Godwin (Andrew); O. Sinilnikova (Olga); L. Barjhoux (Laure); D. Stoppa-Lyonnet (Dominique); V. Moncoutier (Virginie); S. Giraud (Sophie); C. Cassini (C.); L. Faivre (Laurence); F. Révillion (Françoise); J.-P. Peyrat; D.W. Muller (Danièle); J.P. Fricker (Jean Pierre); H. Lynch (Henry); E.M. John (Esther); S.S. Buys (Saundra); M.B. Daly (Mary); J.L. Hopper (John); M.-B. Terry (Mary-Beth); A. Miron (Alexander); Y. Yassin (Yosuf); D. Goldgar (David); C.F. Singer (Christian); D. Gschwantler-Kaulich (Daphne); G. Pfeiler (Georg); E. Spiess (Eberhard); T.V.O. Hansen (Thomas); O.T. Johannson (Oskar); T. Kircchoff (Tomas); K. Offit (Kenneth); K. Kosarin (Kristi); M. Piedmonte (Marion); G.C. Rodriguez (Gustavo); K. Wakeley (Katie); J.F. Boggess (John); J. Basil (Jack); P.E. Schwartz (Peter); S.V. Blank (Stephanie); A.E. Toland (Amanda); M. Montagna (Marco); C. Casella (Cinzia); E.N. Imyanitov (Evgeny); A. Allavena (Anna); R.K. Schmutzler (Rita); B. Versmold (Beatrix); C. Engel (Christoph); A. Meindl (Alfons); N. Ditsch (Nina); N. Arnold (Norbert); D. Niederacher (Dieter); H. Deiler (H.); B. Fiebig (Britta); R. Varon-Mateeva (Raymonda); D. Schaefer (D.); U.G. Froster (U.); T. Caldes (Trinidad); M. de La Hoya (Miguel); L. McGuffog (Lesley); A.C. Antoniou (Antonis); H. Nevanlinna (Heli); P. Radice (Paolo); J. Benítez (Javier)

    2009-01-01

    textabstractBackground: In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers. Methods:

  3. Association of PHB 1630 C>T and MTHFR 677 C>T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers: results from a multicenter study.

    NARCIS (Netherlands)

    Jakubowska, A.; Rozkrut, D.; Antoniou, A.; Hamann, U.; Scott, R.J.; McGuffog, L.; Healy, S.; Sinilnikova, O.M.; Rennert, G.; Lejbkowicz, F.; Flugelman, A.; Andrulis, I.L.; Glendon, G.; Ozcelik, H.; Thomassen, M.; Paligo, M.; Aretini, P.; Kantala, J.; Aroer, B.; Wachenfeldt, A. von; Liljegren, A.; Loman, N.; Herbst, K.; Kristoffersson, U.; Rosenquist, R.; Karlsson, P.; Stenmark-Askmalm, M.; Melin, B.; Nathanson, K.L.; Domchek, S.M.; Byrski, T.; Huzarski, T.; Gronwald, J.; Menkiszak, J.; Cybulski, C.; Serrano, P.; Osorio, A.; Cajal, T.R.; Tsitlaidou, M.; Benitez, J.; Gilbert, M.; Rookus, M.; Aalfs, C.M.; Kluijt, I.; Boessenkool-Pape, J.L.; Meijers-Heijboer, H.E.; Oosterwijk, J.C.; Asperen, C.J. van; Blok, M.J.; Nelen, M.R.; Ouweland, A.M. van den; Seynaeve, C.; Luijt, R.B. van der; Devilee, P.; Easton, D.F.; Peock, S.; Frost, D.; Platte, R.; Ellis, S.D.; Fineberg, E.; Evans, D.G.; Lalloo, F.; Eeles, R.; Jacobs, C.; Adlard, J.; Davidson, R.; Eccles, D.; Cole, T.; Cook, J.; Godwin, A.; Bove, B.; Stoppa-Lyonnet, D.; Caux-Moncoutier, V.; Belotti, M.; Tirapo, C.; Mazoyer, S.; Barjhoux, L.; Boutry-Kryza, N.; Pujol, P.; Coupier, I.; Peyrat, J.P.; Vennin, P.; Muller, D.; Fricker, J.P.; Venat-Bouvet, L.; Johannsson, O.T.; Isaacs, C.; Schmutzler, R.; Wappenschmidt, B.; Meindl, A.; Arnold, N.; Varon-Mateeva, R.; Niederacher, D.; Sutter, C.; Deissler, H.; Preisler-Adams, S.; Simard, J.; Soucy, P.; Durocher, F.; Chenevix-Trench, G.; Beesley, J.; Chen, X.; Rebbeck, T.; Couch, F.; Wang, X.; Lindor, N.; Fredericksen, Z.; Pankratz, V.S.; Peterlongo, P.; Bonanni, B.; Fortuzzi, S.; Peissel, B.; Szabo, C.; Mai, P.L.; Loud, J.T.; Lubinski, J.; Ligtenberg, M.J.L.; Hoogerbrugge, N.

    2012-01-01

    BACKGROUND: The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either di

  4. Association of PHB 1630 C > T and MTHFR 677 C > T polymorphisms with breast and ovarian cancer risk in BRCA1/2 mutation carriers : results from a multicenter study

    NARCIS (Netherlands)

    Jakubowska, A.; Rozkrut, D.; Antoniou, A.; Hamann, U.; Scott, R. J.; McGuffog, L.; Healy, S.; Sinilnikova, O. M.; Rennert, G.; Lejbkowicz, F.; Flugelman, A.; Andrulis, I. L.; Glendon, G.; Ozcelik, H.; Thomassen, M.; Paligo, M.; Aretini, P.; Kantala, J.; Aroer, B.; Von Wachenfeldt, A.; Liljegren, A.; Loman, N.; Herbst, K.; Kristoffersson, U.; Rosenquist, R.; Karlsson, P.; Stenmark-Askmalm, M.; Melin, B.; Nathanson, K. L.; Domchek, S. M.; Byrski, T.; Huzarski, T.; Gronwald, J.; Menkiszak, J.; Cybulski, C.; Serrano, P.; Osorio, A.; Cajal, T. R.; Tsitlaidou, M.; Benitez, J.; Gilbert, M.; Rookus, M.; Aalfs, C. M.; Kluijt, I.; Boessenkool-Pape, J. L.; Meijers-Heijboer, H. E. J.; Oosterwijk, J. C.; van Asperen, C. J.; Blok, M. J.; Nelen, M. R.; van den Ouweland, A. M. W.; Seynaeve, C.; van der Luijt, R. B.; Devilee, P.; Easton, D. F.; Peock, S.; Frost, D.; Platte, R.; Ellis, S. D.; Fineberg, E.; Evans, D. G.; Lalloo, F.; Eeles, R.; Jacobs, C.; Adlard, J.; Davidson, R.; Eccles, D.; Cole, T.; Cook, J.; Godwin, A.; Bove, B.; Stoppa-Lyonnet, D.; Caux-Moncoutier, V.; Belotti, M.; Tirapo, C.; Mazoyer, S.; Barjhoux, L.; Boutry-Kryza, N.; Pujol, P.; Coupier, I.; Peyrat, J-P; Vennin, P.; Muller, D.; Fricker, J-P; Venat-Bouvet, L.; Johannsson, OTh; Isaacs, C.; Schmutzler, R.; Wappenschmidt, B.; Meindl, A.; Arnold, N.; Varon-Mateeva, R.; Niederacher, D.; Sutter, C.; Deissler, H.; Preisler-Adams, S.; Simard, J.; Soucy, P.; Durocher, F.; Chenevix-Trench, G.; Beesley, J.; Chen, X.; Rebbeck, T.; Couch, F.; Wang, X.; Lindor, N.; Fredericksen, Z.; Pankratz, V. S.; Peterlongo, P.; Bonanni, B.; Fortuzzi, S.; Peissel, B.; Szabo, C.; Mai, P. L.; Loud, J. T.; Lubinski, J.

    2012-01-01

    BACKGROUND: The variable penetrance of breast cancer in BRCA1/2 mutation carriers suggests that other genetic or environmental factors modify breast cancer risk. Two genes of special interest are prohibitin (PHB) and methylene-tetrahydrofolate reductase (MTHFR), both of which are important either di

  5. Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the consortium of investigators of modifiers of BRCA1/BRCA2 (CIMBA)

    NARCIS (Netherlands)

    A. Osorio (Ana); R.L. Milne (Roger); G. Pita (G.); P. Peterlongo (Paolo); T. Heikinen (Tuomas); J. Simard (Jacques); G. Chenevix-Trench (Georgia); A.B. Spurdle (Amanda); J. Beesley (Jonathan); X.C. Chen (X. C.); S. Healey (Sue); S.L. Neuhausen (Susan); Y.C. Ding (Yuan); F.J. Couch (Fergus); X. Wang (Xing); N.M. Lindor (Noralane); S. Manoukian (Siranoush); M. Barile (Monica); A. Viel (Alessandra); L. Tizzoni (Laura); C. Szabo (Csilla); L. Foretova (Lenka); M. Zikan (Michal); K. Claes (Kathleen); M.H. Greene (Mark); P.L. Mai (Phuong); G. Rennert (Gad); F. Lejbkowicz (Flavio); O. Barnett-Griness (Ofra); I.L. Andrulis (Irene); H. Ozcelik (Hilmi); N. Weerasooriya (Nayana); A-M. Gerdes (Anne-Marie); M. Thomassen (Mads); D. Cruger (Dorthe); M.A. Caligo (Maria); E. Friedman (Eitan); B. Kaufman (Bella); Y. Laitman (Yael); S. Cohen (Shimrit); T. Kontorovich (Tair); R. Gershoni-Baruch; E. Dagan (Efrat); H. Jernström (H.); M.S. Askmalm (Marie); B. Arver (Brita Wasteson); B. Malmer (Beatrice); S.M. Domchek (Susan); K.L. Nathanson (Katherine); J. Brunet (Joan); T. Ramon Y Cajal; D. Yannoukakos (Drakoulis); U. Hamann (Ute); F.B.L. Hogervorst (Frans); S. Verhoef; E.B.G. Garcíla (E.B. Gómez); J.T. Wijnen (Juul); A.M.W. van den Ouweland (Ans); D.F. Easton (Douglas); S. Peock (Susan); M. Cook (Margaret); C.T. Oliver (Clare); D. Frost (Debra); C. Luccarini (Craig); D.G. Evans (Gareth); F. Lalloo (Fiona); R. Eeles (Rosalind); G. Pichert (Gabriella); J. Cook (Jackie); S.V. Hodgson (Shirley); P.J. Morrison (Patrick); F. Douglas (Fiona); A.K. Godwin (Andrew); O. Sinilnikova (Olga); L. Barjhoux (Laure); D. Stoppa-Lyonnet (Dominique); V. Moncoutier (Virginie); S. Giraud (Sophie); C. Cassini (C.); L. Faivre (Laurence); F. Révillion (Françoise); J.-P. Peyrat; D.W. Muller (Danièle); J.P. Fricker (Jean Pierre); H. Lynch (Henry); E.M. John (Esther); S.S. Buys (Saundra); M.B. Daly (Mary); J.L. Hopper (John); M.-B. Terry (Mary-Beth); A. Miron (Alexander); Y. Yassin (Yosuf); D. Goldgar (David); C.F. Singer (Christian); D. Gschwantler-Kaulich (Daphne); G. Pfeiler (Georg); E. Spiess (Eberhard); T.V.O. Hansen (Thomas); O.T. Johannson (Oskar); T. Kircchoff (Tomas); K. Offit (Kenneth); K. Kosarin (Kristi); M. Piedmonte (Marion); G.C. Rodriguez (Gustavo); K. Wakeley (Katie); J.F. Boggess (John); J. Basil (Jack); P.E. Schwartz (Peter); S.V. Blank (Stephanie); A.E. Toland (Amanda); M. Montagna (Marco); C. Casella (Cinzia); E.N. Imyanitov (Evgeny); A. Allavena (Anna); R.K. Schmutzler (Rita); B. Versmold (Beatrix); C. Engel (Christoph); A. Meindl (Alfons); N. Ditsch (Nina); N. Arnold (Norbert); D. Niederacher (Dieter); H. Deiler (H.); B. Fiebig (Britta); R. Varon-Mateeva (Raymonda); D. Schaefer (D.); U.G. Froster (U.); T. Caldes (Trinidad); M. de La Hoya (Miguel); L. McGuffog (Lesley); A.C. Antoniou (Antonis); H. Nevanlinna (Heli); P. Radice (Paolo); J. Benítez (Javier)

    2009-01-01

    textabstractBackground: In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers. Methods:

  6. Three kinds of mutation

    CERN Document Server

    Buan, Aslak Bakke; Thomas, Hugh

    2010-01-01

    For a finite dimensional hereditary algebra, we consider: exceptional sequences in the category of finite dimensional modules, silting objects in the bounded derived category, and m-cluster tilting objects in the m-cluster category. There are mutation operations on both the set of m-cluster tilting objects and the set of exceptional sequences. It is also possible to define a mutation operation for silting objects. We compare these three different notions of mutation.

  7. Multiple oncogenic mutations related to targeted therapy in nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jian-Wei Zhang; Hong-Yuan Zhao; Yu-Xiang Ma; Zhi-Huang Hu; Pei-Yu Huang; Li Zhang; Tao Qin; Shao-Dong Hong; Jing Zhang; Wen-Feng Fang; Yuan-Yuan Zhao; Yun-Peng Yang; Cong Xue; Yan Huang

    2015-01-01

    Introduction:An increasing number of targeted drugs have been tested for the treatment of nasopharyngeal carcinoma (NPC). However, targeted therapy-related oncogenic mutations have not been fully evaluated. This study aimed to detect targeted therapy-related oncogenic mutations in NPC and to determine which targeted therapy might be potentially effective in treating NPC. Methods:By using the SNaPshot assay, a rapid detection method, 19 mutation hotspots in 6 targeted therapy-related oncogenes were examined in 70 NPC patients. The associations between oncogenic mutations and clinicopathologic factors were analyzed. Results:Among 70 patients, 12 (17.1%) had mutations in 5 oncogenes:7 (10.0%) had v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) mutation, 2 (2.8%) had epidermal growth factor receptor (EGFR) mutation, 1 (1.4%) had phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutation, 1 (1.4%) had Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation, and 1 (1.4%) had simultaneous EGFR and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations. No significant differences were observed between oncogenic mutations and clinicopathologic characteristics. Additionally, these oncogenic mutations were not associated with tumor recurrence and metastasis. Conclusions:Oncogenic mutations are present in NPC patients. The efficacy of targeted drugs on patients with the related oncogenic mutations requires further validation.

  8. Gestational mutations in radiation carcinogenesis

    Science.gov (United States)

    Meza, R.; Luebeck, G.; Moolgavkar, S.

    Mutations in critical genes during gestation could increase substantially the risk of cancer. We examine the consequences of such mutations using the Luebeck-Moolgavkar model for colorectal cancer and the Lea-Coulson modification of the Luria-Delbruck model for the accumulation of mutations during gestation. When gestational mutation rates are high, such mutations make a significant contribution to cancer risk even for adult tumors. Furthermore, gestational mutations ocurring at distinct times during emryonic developmemt lead to substantially different numbers of mutated cells at birth, with early mutations leading to a large number (jackpots) of mutated cells at birth and mutation occurring late leading to only a few mutated cells. Thus gestational mutations could confer considerable heterogeneity of the risk of cancer. If the fetus is exposed to an environmental mutagen, such as ionizing radiation, the gestational mutation rate would be expected to increase. We examine the consequences of such exposures during gestation on the subsequent development of cancer.

  9. A DSPP mutation causing dentinogenesis imperfecta and characterization of the mutational effect.

    Science.gov (United States)

    Lee, Sook-Kyung; Lee, Kyung-Eun; Song, Su Jeong; Hyun, Hong-Keun; Lee, Sang-Hoon; Kim, Jung-Wook

    2013-01-01

    Mutations in the DSPP gene have been identified in nonsyndromic hereditary dentin defects, but the genotype-phenotype correlations are not fully understood. Recently, it has been demonstrated that the mutations of DSPP affecting the IPV leader sequence result in mutant DSPP retention in rough endoplasmic reticulum (ER). In this study, we identified a Korean family with dentinogenesis imperfecta type III. To identify the disease causing mutation in this family, we performed mutational analysis based on candidate gene sequencing. Exons and exon-intron boundaries of DSPP gene were sequenced, and the effects of the identified mutation on the pre-mRNA splicing and protein secretion were investigated. Candidate gene sequencing revealed a mutation (c.50C > T, p.P17L) in exon 2 of the DSPP gene. The splicing assay showed that the mutation did not influence pre-mRNA splicing. However, the mutation interfered with protein secretion and resulted in the mutant protein remaining largely in the ER. These results suggest that the mutation affects ER-to-Golgi apparatus export and results in the reduction of secreted DSPP and ER overload. This may induce cell stress and damage processing and/or transport of dentin matrix proteins or other critical proteins.

  10. A DSPP Mutation Causing Dentinogenesis Imperfecta and Characterization of the Mutational Effect

    Directory of Open Access Journals (Sweden)

    Sook-Kyung Lee

    2013-01-01

    Full Text Available Mutations in the DSPP gene have been identified in nonsyndromic hereditary dentin defects, but the genotype-phenotype correlations are not fully understood. Recently, it has been demonstrated that the mutations of DSPP affecting the IPV leader sequence result in mutant DSPP retention in rough endoplasmic reticulum (ER. In this study, we identified a Korean family with dentinogenesis imperfecta type III. To identify the disease causing mutation in this family, we performed mutational analysis based on candidate gene sequencing. Exons and exon-intron boundaries of DSPP gene were sequenced, and the effects of the identified mutation on the pre-mRNA splicing and protein secretion were investigated. Candidate gene sequencing revealed a mutation (c.50C > T, p.P17L in exon 2 of the DSPP gene. The splicing assay showed that the mutation did not influence pre-mRNA splicing. However, the mutation interfered with protein secretion and resulted in the mutant protein remaining largely in the ER. These results suggest that the mutation affects ER-to-Golgi apparatus export and results in the reduction of secreted DSPP and ER overload. This may induce cell stress and damage processing and/or transport of dentin matrix proteins or other critical proteins.

  11. FLG mutations in ichthyosis vulgaris and atopic eczema: spectrum of mutations and population genetics.

    Science.gov (United States)

    Akiyama, M

    2010-03-01

    Filaggrin is a key protein involved in skin barrier function. Mutations in the gene encoding filaggrin (FLG) have been identified as the cause of ichthyosis vulgaris and have been shown to be major predisposing factors for atopic eczema (AE), initially in European populations. Subsequently, FLG mutations were identified in Japanese, Chinese, Taiwanese and Korean populations. It was demonstrated that FLG mutations are closely associated with AE in the Japanese population. Notably, the same FLG mutations identified in the European population were rarely found in Asians. These results exemplify differences in filaggrin population genetics between Europe and Asia. For mutation screening, background information needs to be obtained on prevalent FLG mutations for each geographical population. It is therefore important to establish the global population genetics maps for FLG mutations. Mutations at any site within FLG, even mutations in C-terminal imperfect filaggrin repeats, cause significant reductions in amounts of profilaggrin/filaggrin peptide in patient epidermis as the C-terminal region is essential for proper processing of profilaggrin into filaggrin. Thus, no genotype-phenotype correlation has been observed in patients with FLG mutations. A restoration of the barrier function seems a feasible and promising strategy for treatment and prevention in individuals with filaggrin deficiency.

  12. LMNA mutations in progeroid syndromes.

    Science.gov (United States)

    Huang, Shurong; Kennedy, Brian K; Oshima, Junko

    2005-01-01

    Segmental progeroid syndromes are disorders in which affected individuals. present various features that suggest accelerated ageing. The two best-known examples are Hutchinson-Gilford progeria syndrome (HGPS, 'Progeria of childhood') and Werner syndrome (WS, 'Progeria of the adult'). A novel, recurrent de novo mutation in the LMNA gene, responsible for the majority of HGPS cases, results in an in-frame deletion of 50 amino acids, including endoproteolytic sites required for processing of prelamin A to mature lamin A protein. Another mutation results in a 35 amino acid in-frame deletion with a milder HGPS phenotype. WRN, the gene responsible for the majority of WS cases, encodes a multifunctional nuclear protein with exonuclease and helicase activities and may participate in optimizing DNA repair/recombination. A subset of WS patients do not show mutations at the WRN locus (atypical WS), but show heterozygous amino acid substitutions in the heptad repeat region of lamin A. Structural analysis suggests that mutations in atypical WS may interfere with protein-protein interactions. When compared to WRN-mutant WS, LMNA-mutant atypical WS patients appear to show earlier onset and possibly more severe ageing-related symptoms.

  13. HIV-1 Drug Resistance Mutations Among Antiretroviral-Naïve HIV-1–Infected Patients in Asia: Results From the TREAT Asia Studies to Evaluate Resistance-Monitoring Study

    Science.gov (United States)

    Oyomopito, Rebecca; Sirivichayakul, Sunee; Sirisanthana, Thira; Kantipong, Pacharee; Lee, Christopher K. C.; Kamarulzaman, Adeeba; Messerschmidt, Liesl; Law, Matthew G.; Phanuphak, Praphan

    2011-01-01

    (See editorial commentary by Jordan on pages 1058–1060.) Of 682 antiretroviral-naïve patients initiating antiretroviral therapy in a prospective, multicenter human immunodeficiency virus type 1 (HIV-1) drug resistance monitoring study involving 8 sites in Hong Kong, Malaysia, and Thailand, the prevalence of patients with ≥1 drug resistance mutation was 13.8%. Primary HIV drug resistance is emerging after rapid scaling-up of antiretroviral therapy use in Asia. PMID:21460324

  14. Mutation and premating isolation.

    Science.gov (United States)

    Woodruff, R C; Thompson, J N

    2002-11-01

    While premating isolation might be traceable to different genetic mechanisms in different species, evidence supports the idea that as few as one or two genes may often be sufficient to initiate isolation. Thus, new mutation can theoretically play a key role in the process. But it has long been thought that a new isolation mutation would fail, because there would be no other individuals for the isolation-mutation-carrier to mate with. We now realize that premeiotic mutations are very common and will yield a cluster of progeny carrying the same new mutant allele. In this paper, we discuss the evidence for genetically simple premating isolation barriers and the role that clusters of an isolation mutation may play in initiating allopatric, and even sympatric, species divisions.

  15. Mutation studies in ascidians: a review.

    Science.gov (United States)

    Crocetta, Fabio; Marino, Rita; Cirino, Paola; Macina, Alberto; Staiano, Leopoldo; Esposito, Rosaria; Pezzotti, Maria Rosa; Racioppi, Claudia; Toscano, Francesco; De Felice, Elena; Locascio, Annamaria; Ristoratore, Filomena; Spagnuolo, Antonietta; Zanetti, Laura; Branno, Margherita; Sordino, Paolo

    2015-01-01

    Historically, mutations have had a significant impact on the study of developmental processes and phenotypic evolution. Lesions in DNA are created by artificial methods or detected by natural genetic variation. Random mutations are then ascribed to genetic change by direct sequencing or positional cloning. Tunicate species of the ascidian genus Ciona represent nearly fully realized model systems in which gene function can be investigated in depth. Additionally, tunicates are valuable organisms for the study of naturally occurring mutations due to the capability to exploit genetic variation down to the molecular level. Here, we summarize the available information about how mutations are studied in ascidians with examples of insights that have resulted from these applications. We also describe notions and methodologies that might be useful for the implementation of easy and tight procedures for mutations studies in Ciona.

  16. Inverse PCR for Point Mutation Introduction.

    Science.gov (United States)

    Silva, Diogo; Santos, Gustavo; Barroca, Mário; Collins, Tony

    2017-01-01

    Inverse PCR is a powerful tool for the rapid introduction of desired mutations at desired positions in a circular double-stranded DNA sequence. Here, custom-designed mutant primers oriented in the inverse direction are used to amplify the entire circular template with incorporation of the required mutation(s). By careful primer design it can be used to perform such diverse modifications as the introduction of point mutations and multiple mutations, the insertion of new sequences, and even sequence deletions. Three primer formats are commonly used; nonoverlapping, partially overlapping and fully overlapping primers, and here we describe the use of nonoverlapping primers for introduction of a point mutation. Use of such a primer setup in the PCR reaction, with one of the primers containing the desired mismatch mutation, results in the amplification of a linear, double-stranded, mutated product. Methylated template DNA is removed from the nonmethylated PCR product by DpnI digestion and the PCR product is then phosphorylated by polynucleotide kinase treatment before being recircularized by ligation, and transformed to E. coli. This relatively simple site-directed mutagenesis procedure is of major importance in biology and biotechnology today where it is commonly employed for the study and engineering of DNA, RNA, and proteins.

  17. Analyzing effects of naturally occurring missense mutations.

    Science.gov (United States)

    Zhang, Zhe; Miteva, Maria A; Wang, Lin; Alexov, Emil

    2012-01-01

    Single-point mutation in genome, for example, single-nucleotide polymorphism (SNP) or rare genetic mutation, is the change of a single nucleotide for another in the genome sequence. Some of them will produce an amino acid substitution in the corresponding protein sequence (missense mutations); others will not. This paper focuses on genetic mutations resulting in a change in the amino acid sequence of the corresponding protein and how to assess their effects on protein wild-type characteristics. The existing methods and approaches for predicting the effects of mutation on protein stability, structure, and dynamics are outlined and discussed with respect to their underlying principles. Available resources, either as stand-alone applications or webservers, are pointed out as well. It is emphasized that understanding the molecular mechanisms behind these effects due to these missense mutations is of critical importance for detecting disease-causing mutations. The paper provides several examples of the application of 3D structure-based methods to model the effects of protein stability and protein-protein interactions caused by missense mutations as well.

  18. Molecular methods for the detection of mutations.

    Science.gov (United States)

    Monteiro, C; Marcelino, L A; Conde, A R; Saraiva, C; Giphart-Gassler, M; De Nooij-van Dalen, A G; Van Buuren-van Seggelen, V; Van der Keur, M; May, C A; Cole, J; Lehmann, A R; Steinsgrimsdottir, H; Beare, D; Capulas, E; Armour, J A

    2000-01-01

    We report the results of a collaborative study aimed at developing reliable, direct assays for mutation in human cells. The project used common lymphoblastoid cell lines, both with and without mutagen treatment, as a shared resource to validate the development of new molecular methods for the detection of low-level mutations in the presence of a large excess of normal alleles. As the "gold standard, " hprt mutation frequencies were also measured on the same samples. The methods under development included i) the restriction site mutation (RSM) assay, in which mutations lead to the destruction of a restriction site; ii) minisatellite length-change mutation, in which mutations lead to alleles containing new numbers of tandem repeat units; iii) loss of heterozygosity for HLA epitopes, in which antibodies can be used to direct selection for mutant cells; iv) multiple fluorescence-based long linker arm nucleotides assay (mf-LLA) technology, for the detection of substitutional mutations; v) detection of alterations in the TP53 locus using a (CA) array as the target for the screening; and vi) PCR analysis of lymphocytes for the presence of the BCL2 t(14:18) translocation. The relative merits of these molecular methods are discussed, and a comparison made with more "traditional" methods.

  19. Markov chain for estimating human mitochondrial DNA mutation pattern

    Science.gov (United States)

    Vantika, Sandy; Pasaribu, Udjianna S.

    2015-12-01

    The Markov chain was proposed to estimate the human mitochondrial DNA mutation pattern. One DNA sequence was taken randomly from 100 sequences in Genbank. The nucleotide transition matrix and mutation transition matrix were estimated from this sequence. We determined whether the states (mutation/normal) are recurrent or transient. The results showed that both of them are recurrent.

  20. Adaptive synonymous mutations in an experimentally evolved Pseudomonas fluorescens population

    DEFF Research Database (Denmark)

    Bailey, Susan; Hinz, Aaron; Kassen, Rees

    2014-01-01

    in an experimentally evolved population of Pseudomonas fluorescens. We show experimentally that these mutations increase fitness by an amount comparable to non-synonymous mutations and that the fitness increases stem from increased gene expression. These results provide unequivocal evidence that synonymous mutations...

  1. Germline fumarate hydratase mutations in patients with ovarian mucinous cystadenoma

    DEFF Research Database (Denmark)

    Ylisaukko-oja, Sanna K.; Cybulski, Cezary; Lehtonen, Rainer;

    2006-01-01

    analyzed for somatic FH mutations. Two patients diagnosed with ovarian mucinous cystadenoma (two out of 33, 6%) were found to be FH germline mutation carriers. One of the changes was a novel mutation (Ala231Thr) and the other one (435insAAA) was previously described in FH deficiency families. These results...

  2. Mutation rates among RNA viruses

    OpenAIRE

    Drake, John W.; Holland, John J.

    1999-01-01

    The rate of spontaneous mutation is a key parameter in modeling the genetic structure and evolution of populations. The impact of the accumulated load of mutations and the consequences of increasing the mutation rate are important in assessing the genetic health of populations. Mutation frequencies are among the more directly measurable population parameters, although the information needed to convert them into mutation rates is often lacking. A previous analysis of mutation rates in RNA viru...

  3. Spectrum of small mutations in the dystrophin coding region.

    Science.gov (United States)

    Prior, T W; Bartolo, C; Pearl, D K; Papp, A C; Snyder, P J; Sedra, M S; Burghes, A H; Mendell, J R

    1995-07-01

    Duchenne and Becker muscular dystrophies (DMD and BMD) are caused by defects in the dystrophin gene. About two-thirds of the affected patients have large deletions or duplications, which occur in the 5' and central portion of the gene. The nondeletion/duplication cases are most likely the result of smaller mutations that cannot be identified by current diagnostic screening strategies. We screened approximately 80% of the dystrophin coding sequence for small mutations in 158 patients without deletions or duplications and identified 29 mutations. The study indicates that many of the DMD and the majority of the BMD small mutations lie in noncoding regions of the gene. All of the mutations identified were unique to single patients, and most of the mutations resulted in protein truncation. We did not find a clustering of small mutations similar to the deletion distribution but found > 40% of the small mutations 3' of exon 55. The extent of protein truncation caused by the 3' mutations did not determine the phenotype, since even the exon 76 nonsense mutation resulted in the severe DMD phenotype. Our study confirms that the dystrophin gene is subject to a high rate of mutation in CpG sequences. As a consequence of not finding any hotspots or prevalent small mutations, we conclude that it is presently not possible to perform direct carrier and prenatal diagnostics for many families without deletions or duplications.

  4. MANBA, CXCR5, SOX8, RPS6KB1 and ZBTB46 are genetic risk loci for multiple sclerosis

    NARCIS (Netherlands)

    Lill, Christina M.; Schjeide, Brit-Maren M.; Graetz, Christiane; Ban, Maria; Alcina, Antonio; Ortiz, Miguel A.; Perez, Jennifer; Damotte, Vincent; Booth, David; Lopez de lapuente, Aitzkoa; Broer, Linda; Schilling, Marcel; Akkad, Denis A.; Aktas, Orhan; Alloza, Iraide; Antigueedad, Alfredo; Arroyo, Rafa; Blaschke, Paul; Buttmann, Mathias; Chan, Andrew; Compston, Alastair; Cournu-Rebeix, Isabelle; Doerner, Thomas; Epplen, Joerg T.; Fernandez, Oscar; Gerdes, Lisa-Ann; Guillot-Noel, Lena; Hartung, Hans-Peter; Hoffjan, Sabine; Izquierdo, Guillermo; Kemppinen, Anu; Kroner, Antje; Kubisch, Christian; Kuempfel, Tania; Li, Shu-Chen; Lindenberger, Ulman; Lohse, Peter; Lubetzki, Catherine; Luessi, Felix; Malhotra, Sunny; Mescheriakova, Julia; Montalban, Xavier; Papeix, Caroline; Paredes, Lidia F.; Rieckmann, Peter; Steinhagen-Thiessen, Elisabeth; Winkelmann, Alexander; Zettl, Uwe K.; Hintzen, Rogier; Vandenbroeck, Koen; Stewart, Graeme; Fontaine, Bertrand; Comabella, Manuel; Urcelay, Elena; Matesanz, Fuencisla; Sawcer, Stephen; Bertram, Lars; Zipp, Frauke

    2013-01-01

    A recent genome-wide association study reported five loci for which there was strong, but sub-genome-wide significant evidence for association with multiple sclerosis risk. The aim of this study was to evaluate the role of these potential risk loci in a large and independent data set of similar to 2

  5. Exonuclease mutations in DNA polymerase epsilon reveal replication strand specific mutation patterns and human origins of replication.

    Science.gov (United States)

    Shinbrot, Eve; Henninger, Erin E; Weinhold, Nils; Covington, Kyle R; Göksenin, A Yasemin; Schultz, Nikolaus; Chao, Hsu; Doddapaneni, HarshaVardhan; Muzny, Donna M; Gibbs, Richard A; Sander, Chris; Pursell, Zachary F; Wheeler, David A

    2014-11-01

    Tumors with somatic mutations in the proofreading exonuclease domain of DNA polymerase epsilon (POLE-exo*) exhibit a novel mutator phenotype, with markedly elevated TCT→TAT and TCG→TTG mutations and overall mutation frequencies often exceeding 100 mutations/Mb. Here, we identify POLE-exo* tumors in numerous cancers and classify them into two groups, A and B, according to their mutational properties. Group A mutants are found only in POLE, whereas Group B mutants are found in POLE and POLD1 and appear to be nonfunctional. In Group A, cell-free polymerase assays confirm that mutations in the exonuclease domain result in high mutation frequencies with a preference for C→A mutation. We describe the patterns of amino acid substitutions caused by POLE-exo* and compare them to other tumor types. The nucleotide preference of POLE-exo* leads to increased frequencies of recurrent nonsense mutations in key tumor suppressors such as TP53, ATM, and PIK3R1. We further demonstrate that strand-specific mutation patterns arise from some of these POLE-exo* mutants during genome duplication. This is the first direct proof of leading strand-specific replication by human POLE, which has only been demonstrated in yeast so far. Taken together, the extremely high mutation frequency and strand specificity of mutations provide a unique identifier of eukaryotic origins of replication.

  6. Mutations affecting gyrase in Haemophilus influenzae

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, J.K.; Cabrera-Juarez, E.; Albritton, W.L.; Spikes, D.; Mutschler, A.

    1985-11-01

    Mutants separately resistant to novobiocin, coumermycin, nalidixic acid, and oxolinic acid contained gyrase activity as measured in vitro that was resistant to the antibiotics, indicating that the mutations represented structural alterations of the enzyme. One Novr mutant contained an altered B subunit of the enzyme, as judged by the ability of a plasmid, pNov1, containing the mutation to complement a temperature-sensitive gyrase B mutation in Escherichia coli and to cause novobiocin resistance in that strain. Three other Novr mutations did not confer antibiotic resistance to the gyrase but appeared to increase the amount of active enzyme in the cell. One of these, novB1, could only act in cis, whereas a new mutation, novC, could act in trans. An RNA polymerase mutation partially substituted for the novB1 mutation, suggesting that novB1 may be a mutation in a promoter region for the B subunit gene. Growth responses of strains containing various combinations of mutations on plasmids or on the chromosome indicated that low-level resistance to novobiocin or coumermycin may have resulted from multiple copies of wild-type genes coding for the gyrase B subunit, whereas high-level resistance required a structural change in the gyrase B gene and was also dependent on alteration in a regulatory region. When there was mismatch at the novB locus, with the novB1 mutation either on a plasmid or the chromosome, and the corresponding wild-type gene present in trans, chromosome to plasmid recombination during transformation was much higher than when the genes matched, probably because plasmid to chromosome recombination, eliminating the plasmid, was inhibited by the mismatch.

  7. Frameshift mutations in dentin phosphoprotein and dependence of dentin disease phenotype on mutation location

    NARCIS (Netherlands)

    P. Nieminen; L. Papagiannoulis-Lascarides; J. Waltimo-Siren; P. Ollila; S. Karjalainen; S. Arte; J. Veerkamp; V. Tallon Walton; E. Chimenos Küstner; T. Siltanen; H. Holappa; P.L. Lukinmaa; S. Alaluusua

    2011-01-01

    We describe results from a mutational analysis of the region of the dentin sialophosphoprotein (DSPP) gene encoding dentin phosphoprotein (DPP) in 12 families with dominantly inherited dentin diseases. In eight families (five mutations in the N-terminal third of DPP), the clinical and radiologic fea

  8. Benchmarking infrastructure for mutation text mining

    Science.gov (United States)

    2014-01-01

    Background Experimental research on the automatic extraction of information about mutations from texts is greatly hindered by the lack of consensus evaluation infrastructure for the testing and benchmarking of mutation text mining systems. Results We propose a community-oriented annotation and benchmarking infrastructure to support development, testing, benchmarking, and comparison of mutation text mining systems. The design is based on semantic standards, where RDF is used to represent annotations, an OWL ontology provides an extensible schema for the data and SPARQL is used to compute various performance metrics, so that in many cases no programming is needed to analyze results from a text mining system. While large benchmark corpora for biological entity and relation extraction are focused mostly on genes, proteins, diseases, and species, our benchmarking infrastructure fills the gap for mutation information. The core infrastructure comprises (1) an ontology for modelling annotations, (2) SPARQL queries for computing performance metrics, and (3) a sizeable collection of manually curated documents, that can support mutation grounding and mutation impact extraction experiments. Conclusion We have developed the principal infrastructure for the benchmarking of mutation text mining tasks. The use of RDF and OWL as the representation for corpora ensures extensibility. The infrastructure is suitable for out-of-the-box use in several important scenarios and is ready, in its current state, for initial community adoption. PMID:24568600

  9. AIP mutations and gigantism.

    Science.gov (United States)

    Rostomyan, Liliya; Potorac, Iulia; Beckers, Pablo; Daly, Adrian F; Beckers, Albert

    2017-06-01

    AIP mutations are rare in sporadic acromegaly but they are seen at a higher frequency among certain specific populations of pituitary adenoma patients (pituitary gigantism cases, familial isolated pituitary adenoma (FIPA) kindreds, and patients with macroadenomas who are diagnosed ≤30 years). AIP mutations are most prevalent in patients with pituitary gigantism (29% of this group were found to have mutations in AIP gene). These data support targeted genetic screening for AIP mutations/deletions in these groups of pituitary adenoma patients. Earlier diagnosis of AIP-related acromegaly-gigantism cases enables timely clinical evaluation and treatment, thereby improving outcomes in terms of excessive linear growth and acromegaly comorbidities. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Mapping Mutations on Phylogenies

    DEFF Research Database (Denmark)

    Nielsen, Rasmus

    2005-01-01

    This chapter provides a short review of recent methodologies developed for mapping mutations on phylogenies. Mapping of mutations, or character changes in general, using the maximum parsimony principle has been one of the most powerful tools in phylogenetics, and it has been used in a variety...... of different applications, for example, in the detection of correlated evolution and to identify selection acting on DNA sequences. However, many uses of parsimony mappings have been criticized because they focus on only one of many possible mappings and/or because they do not incorporate statistical...... uncertainty in the mapping. Recently developed probabilistic methods can incorporate statistical uncertainty in the character mappings. In these methods, focus is on a probability distribution of mutational mappings instead of a single estimate of the mutational mapping....

  11. Impact of HBsAg Mutation to Detection Result by Immunodiagnostic Kit%乙型肝炎病毒表面抗原变异对免疫诊断试剂检测结果的影响

    Institute of Scientific and Technical Information of China (English)

    姚昕; 周诚; 祁自柏

    2009-01-01

    乙型肝炎疫苗和抗病毒药物在全球的广泛应用有效地防止了乙肝病毒(HBV)的感染.但随之而来的问题是在疫苗免疫后的人群、进行抗病毒治疗的患者以及慢性HBV感染的人群中,出现了HBV表面抗原的变异,而大量文献报道了免疫诊断试剂对变异表面抗原的漏检.本文对乙肝病毒表面抗原变异对免疫诊断试剂检测结果的影响作一综述.%Hepatitis B (HB) vaccination and antiviral therapies are widely used for the successful prevention of hepatitis B virus (HBV ) infection throughout the world. However, ample evidences indicated that HBsAg mutants occurred in vaccinated subjects, patients receiving antiviral therapy and chronic carriers. Lots of studies reported that the current immunoassays were challenged by these mutations which failed to be detected by some commercial diagnostic kits. This review attempts to give an overview of the impact of HBsAg mutation to immunodiagnostic kits.

  12. Characterization of Staphylococcus aureus Strains Isolated from Czech Cystic Fibrosis Patients: High Rate of Ribosomal Mutation Conferring Resistance to MLS(B) Antibiotics as a Result of Long-Term and Low-Dose Azithromycin Treatment.

    Science.gov (United States)

    Tkadlec, Jan; Vařeková, Eva; Pantůček, Roman; Doškař, Jiří; Růžičková, Vladislava; Botka, Tibor; Fila, Libor; Melter, Oto

    2015-08-01

    Staphylococcus aureus is one of the most frequent pathogens infecting the respiratory tract of patients with cystic fibrosis (CF). This study was the first to examine S. aureus isolates from CF patients in the Czech Republic. Among 100 S. aureus isolates from 92 of 107 observed patients, we found a high prevalence of resistance to macrolide-lincosamide-streptogramin B (MLS(B)) antibiotics (56%). More than half of the resistant strains (29 of 56) carried a mutation in the MLS(B) target site. The emergence of MLS(B) resistance and mutations conferring resistance to MLS(B) antibiotics was associated with azithromycin treatment (p=0.000000184 and p=0.000681, respectively). Methicillin resistance was only detected in 3% of isolates and the rate of resistance to other antibiotics did not exceed 12%. The prevalence of small-colony variant (SCV) strains was relatively low (9%) and eight of nine isolates with the SCV phenotype were thymidine dependent. The study population of S. aureus was heterogeneous in structure and both the most prevalent community-associated and hospital-acquired clonal lineages were represented. Of the virulence genes, enterotoxin genes seg (n=52), sei (n=49), and sec (n=16) were the most frequently detected among the isolates. The PVL genes (lukS-PV and lukF-PV) have not been revealed in any of the isolates.

  13. Particle Swarm Optimization with Adaptive Mutation

    Institute of Scientific and Technical Information of China (English)

    LU Zhen-su; HOU Zhi-rong; DU Juan

    2006-01-01

    A new adaptive mutation particle swarm optimizer,which is based on the variance of the population's fitness,is presented in this paper.During the rtmning time,the mutation probability for the current best particle is determined by two factors:the variance of the population's fitness and the current optimal solution.The ability of particle swarm optimization (PSO) algorithm to break away from the local optimum is greatly improved by the mutation.The experimental results show that the new algorithm not only has great advantage of convergence property over genetic algorithm and PSO,but can also avoid the premature convergence problem effectively.

  14. Subquivers of mutation-acyclic quivers are mutation-acyclic

    CERN Document Server

    Warkentin, Matthias

    2011-01-01

    Quiver mutation plays a crucial role in the definition of cluster algebras by Fomin and Zelevinsky. It induces an equivalence relation on the set of all quivers without loops and two-cycles. A quiver is called mutation-acyclic if it is mutation-equivalent to an acyclic quiver. The aim of this note is to show that full subquivers of mutation-acyclic quivers are mutation-acyclic.

  15. NRAS and BRAF mutation frequency in primary oral mucosal melanoma.

    Science.gov (United States)

    Buery, Rosario Rivera; Siar, Chong Huat; Katase, Naoki; Gunduz, Mehmet; Lefeuvre, Mathieu; Fujii, Masae; Inoue, Masahisa; Setsu, Kojun; Nagatsuka, Hitoshi

    2011-10-01

    Oral mucosal melanoma (OMM) is a fatal sarcoma of unknown etiology. Histological morphology and genetic events are distinct from those of its cutaneous counterpart. Mutation and up-regulation of c-kit has been identified in OMM which may activate downstream molecules such as RAS and RAF. These molecules are involved in the mitogen-activated protein kinase (MAPK) pathway leading to tremendous cell proliferation and survival. NRAS and BRAF mutation and protein expression have been studied in other melanoma subtypes. The purpose of this study was to determine RAS protein expression and NRAS and BRAF mutation in 18 primary OMM cases using immunohistochemistry and mutation analysis. Results showed that RAS is intensely expressed in both in situ and invasive OMMs. However, NRAS mutation was only observed in 2/15 polymerase chain reaction (PCR) amplified cases both of which were silent mutations. On the other hand, BRAF missense mutations were observed only in 1/15 cases with PCR amplification. NRAS and BRAF mutations were independent from previously reported c-kit mutations. The classical V600E BRAF mutation was not found; instead a novel V600L was observed suggesting that the oncogenic event in OMM is different from that in skin melanoma. The low frequency of NRAS and BRAF mutations indicate that these genes are not common, but probable events in OMM pathogenesis, most likely independent of c-kit mutation.

  16. Mutational robustness of gene regulatory networks.

    Directory of Open Access Journals (Sweden)

    Aalt D J van Dijk

    Full Text Available Mutational robustness of gene regulatory networks refers to their ability to generate constant biological output upon mutations that change network structure. Such networks contain regulatory interactions (transcription factor-target gene interactions but often also protein-protein interactions between transcription factors. Using computational modeling, we study factors that influence robustness and we infer several network properties governing it. These include the type of mutation, i.e. whether a regulatory interaction or a protein-protein interaction is mutated, and in the case of mutation of a regulatory interaction, the sign of the interaction (activating vs. repressive. In addition, we analyze the effect of combinations of mutations and we compare networks containing monomeric with those containing dimeric transcription factors. Our results are consistent with available data on biological networks, for example based on evolutionary conservation of network features. As a novel and remarkable property, we predict that networks are more robust against mutations in monomer than in dimer transcription factors, a prediction for which analysis of conservation of DNA binding residues in monomeric vs. dimeric transcription factors provides indirect evidence.

  17. Predicting Resistance Mutations Using Protein Design Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Frey, K.; Georgiev, I; Donald, B; Anderson, A

    2010-01-01

    Drug resistance resulting from mutations to the target is an unfortunate common phenomenon that limits the lifetime of many of the most successful drugs. In contrast to the investigation of mutations after clinical exposure, it would be powerful to be able to incorporate strategies early in the development process to predict and overcome the effects of possible resistance mutations. Here we present a unique prospective application of an ensemble-based protein design algorithm, K*, to predict potential resistance mutations in dihydrofolate reductase from Staphylococcus aureus using positive design to maintain catalytic function and negative design to interfere with binding of a lead inhibitor. Enzyme inhibition assays show that three of the four highly-ranked predicted mutants are active yet display lower affinity (18-, 9-, and 13-fold) for the inhibitor. A crystal structure of the top-ranked mutant enzyme validates the predicted conformations of the mutated residues and the structural basis of the loss of potency. The use of protein design algorithms to predict resistance mutations could be incorporated in a lead design strategy against any target that is susceptible to mutational resistance.

  18. Mutation Clusters from Cancer Exome.

    Science.gov (United States)

    Kakushadze, Zura; Yu, Willie

    2017-08-15

    We apply our statistically deterministic machine learning/clustering algorithm *K-means (recently developed in https://ssrn.com/abstract=2908286) to 10,656 published exome samples for 32 cancer types. A majority of cancer types exhibit a mutation clustering structure. Our results are in-sample stable. They are also out-of-sample stable when applied to 1389 published genome samples across 14 cancer types. In contrast, we find in- and out-of-sample instabilities in cancer signatures extracted from exome samples via nonnegative matrix factorization (NMF), a computationally-costly and non-deterministic method. Extracting stable mutation structures from exome data could have important implications for speed and cost, which are critical for early-stage cancer diagnostics, such as novel blood-test methods currently in development.

  19. The three faces of riboviral spontaneous mutation: spectrum, mode of genome replication, and mutation rate.

    Directory of Open Access Journals (Sweden)

    Libertad García-Villada

    Full Text Available Riboviruses (RNA viruses without DNA replication intermediates are the most abundant pathogens infecting animals and plants. Only a few riboviral infections can be controlled with antiviral drugs, mainly because of the rapid appearance of resistance mutations. Little reliable information is available concerning i kinds and relative frequencies of mutations (the mutational spectrum, ii mode of genome replication and mutation accumulation, and iii rates of spontaneous mutation. To illuminate these issues, we developed a model in vivo system based on phage Qß infecting its natural host, Escherichia coli. The Qß RT gene encoding the Read-Through protein was used as a mutation reporter. To reduce uncertainties in mutation frequencies due to selection, the experimental Qß populations were established after a single cycle of infection and selection against RT(- mutants during phage growth was ameliorated by plasmid-based RT complementation in trans. The dynamics of Qß genome replication were confirmed to reflect the linear process of iterative copying (the stamping-machine mode. A total of 32 RT mutants were detected among 7,517 Qß isolates. Sequencing analysis of 45 RT mutations revealed a spectrum dominated by 39 transitions, plus 4 transversions and 2 indels. A clear template•primer mismatch bias was observed: A•C>C•A>U•G>G•U> transversion mismatches. The average mutation rate per base replication was ≈9.1×10(-6 for base substitutions and ≈2.3×10(-7 for indels. The estimated mutation rate per genome replication, μ(g, was ≈0.04 (or, per phage generation, ≈0.08, although secondary RT mutations arose during the growth of some RT mutants at a rate about 7-fold higher, signaling the possible impact of transitory bouts of hypermutation. These results are contrasted with those previously reported for other riboviruses to depict the current state of the art in riboviral mutagenesis.

  20. Novel recurrently mutated genes and a prognostic mutation signature in colorectal cancer

    Science.gov (United States)

    Yu, Jun; Wu, William K K; Li, Xiangchun; He, Jun; Li, Xiao-Xing; Ng, Simon S M; Yu, Chang; Gao, Zhibo; Yang, Jie; Li, Miao; Wang, Qiaoxiu; Liang, Qiaoyi; Pan, Yi; Tong, Joanna H; To, Ka F; Wong, Nathalie; Zhang, Ning; Chen, Jie; Lu, Youyong; Lai, Paul B S; Chan, Francis K L; Li, Yingrui; Kung, Hsiang-Fu; Yang, Huanming; Wang, Jun; Sung, Joseph J Y

    2015-01-01

    Background Characterisation of colorectal cancer (CRC) genomes by next-generation sequencing has led to the discovery of novel recurrently mutated genes. Nevertheless, genomic data has not yet been used for CRC prognostication. Objective To identify recurrent somatic mutations with prognostic significance in patients with CRC. Method Exome sequencing was performed to identify somatic mutations in tumour tissues of 22 patients with CRC, followed by validation of 187 recurrent and pathway-related genes using targeted capture sequencing in additional 160 cases. Results Seven significantly mutated genes, including four reported (APC, TP53, KRAS and SMAD4) and three novel recurrently mutated genes (CDH10, FAT4 and DOCK2), exhibited high mutation prevalence (6–14% for novel cancer genes) and higher-than-expected number of non-silent mutations in our CRC cohort. For prognostication, a five-gene-signature (CDH10, COL6A3, SMAD4, TMEM132D, VCAN) was devised, in which mutation(s) in one or more of these genes was significantly associated with better overall survival independent of tumor-node-metastasis (TNM) staging. The median survival time was 80.4 months in the mutant group versus 42.4 months in the wild type group (p=0.0051). The prognostic significance of this signature was successfully verified using the data set from the Cancer Genome Atlas study. Conclusions The application of next-generation sequencing has led to the identification of three novel significantly mutated genes in CRC and a mutation signature that predicts survival outcomes for stratifying patients with CRC independent of TNM staging. PMID:24951259

  1. EGFR Mutation Status in Uighur Lung Adenocarcinoma Patients

    Directory of Open Access Journals (Sweden)

    Li SHAN

    2013-02-01

    Full Text Available Background and objective Epidermal growth factor receptor (EGFR, a transmembrane protein, is a member of the tyrosine kinase family. Gefitinib, an EGFR tyrosine-kinase inhibitors, has shown a high response rate in the treatment of lung cancer in patients with EGFR mutation. However, significant differences in EGFR mutations exist among different ethnic groups. The aim of this study is to investigate the prevalence of EGFR mutations in Uighur lung adenocarcinoma patients by using a rapid and sensitive detection method and to analyze EGFR mutation differences compared with Han lung adenocarcinoma patients. Methods We examined lung adenocarcinoma tissues from 138 patients, including 68 Uighur lung adenocarcinoma patients and 70 Han lung adenocarcinoma patients, for EGFR mutations in exons 18, 19, 20, and 21 by using the amplification refractory mutation system (ARMS PCR method. The mutation differences between Uighur and Han lung adenocarcinoma were compared by using the chi-square test method. Results EGFR mutations were detected in 43 (31.2% of the 138 lung adenocarcinoma patients. EGFR mutations were detected in 11 (16.2% of the 68 Uighur lung adenocarcinoma patients and in 32 (45.7% of the 70 Han lung adenocarcinoma patients. Significant differences were observed in the EGFR mutations between Uighur lung adenocarcinoma patients and Han lung adenocarcinoma patients (P<0.001. Conclusion Our results indicate that the EGFR mutation in Uighur lung adenocarcinoma patients (16.2% is significantly lower than that in Han lung adenocarcinoma patients (45.7%.

  2. Tumor Mutation Burden Forecasts Outcome in Ovarian Cancer with BRCA1 or BRCA2 Mutations

    DEFF Research Database (Denmark)

    Birkbak, Nicolai Juul; Kochupurakkal, Bose; Gonzalez-Izarzugaza, Jose Maria;

    2013-01-01

    Background: Increased number of single nucleotide substitutions is seen in breast and ovarian cancer genomes carrying disease-associated mutations in BRCA1 or BRCA2. The significance of these genome-wide mutations is unknown. We hypothesize genome-wide mutation burden mirrors deficiencies in DNA...... repair and is associated with treatment outcome in ovarian cancer. Methods and Results: The total number of synonymous and non-synonymous exome mutations (Nmut), and the presence of germline or somatic mutation in BRCA1 or BRCA2 (mBRCA) were extracted from whole-exome sequences of high-grade serous...... ovarian cancers from The Cancer Genome Atlas (TCGA). Cox regression and Kaplan-Meier methods were used to correlate Nmut with chemotherapy response and outcome. Higher Nmut correlated with a better response to chemotherapy after surgery. In patients with mBRCA-associated cancer, low Nmut was associated...

  3. Sexual selection, germline mutation rate and sperm competition

    Directory of Open Access Journals (Sweden)

    Møller AP

    2003-04-01

    Full Text Available Abstract Background An important component of sexual selection arises because females obtain viability benefits for their offspring from their mate choice. Females choosing extra-pair fertilization generally favor males with exaggerated secondary sexual characters, and extra-pair paternity increases the variance in male reproductive success. Furthermore, females are assumed to benefit from 'good genes' from extra-pair sires. How additive genetic variance in such viability genes is maintained despite strong directional selection remains an evolutionary enigma. We propose that sexual selection is associated with elevated mutation rates, changing the balance between mutation and selection, thereby increasing variance in fitness and hence the benefits to be obtained from good genes sexual selection. Two hypotheses may account for such elevated mutation: (1 Increased sperm production associated with sperm competition may increase mutation rate. (2 Mutator alleles increase mutation rates that are revealed by the expression of condition-dependent secondary sexual characters used by choosy females during their mate choice. M Petrie has independently developed the idea that mutator alleles may account for the maintenance of genetic variation in viability despite strong directional selection. Results A comparative study of birds revealed a positive correlation between mutation rate at minisatellite loci and extra-pair paternity, but not between mutation rate and relative testes mass which is a measure of relative sperm production. Minisatellite mutation rates were not related to longevity, suggesting a meiotic rather than a mitotic origin of mutations. Conclusion We found evidence of increased mutation rate in species with more intense sexual selection. Increased mutation was not associated with increased sperm production, and we suggest that species with intense sexual selection may maintain elevated mutation rates because sexual selection continuously

  4. Mutations in ARSB in MPS VI patients in India.

    Science.gov (United States)

    Mathew, Juby; Jagadeesh, Sujatha M; Bhat, Meenakshi; Udhaya Kumar, S; Thiyagarajan, Saravanamuthu; Srinivasan, Sudha

    2015-09-01

    Mucopolysaccharidosis VI (MPS VI) is an autosomal recessive inborn error of metabolism caused by mutations in the arylsulfatase B gene (ARSB) and consequent deficient activity of ARSB, a lysosomal enzyme. We present here the results of a study undertaken to identify the mutations in ARSB in MPS VI patients in India. Around 160 ARSB mutations, of which just 4 are from India, have been reported in the literature. Our study covered nine MPS VI patients from eight families. Both familial mutations were found in seven families, and only one mutation was found in one family. Seven mutations were found - four novel (p.G38_G40del3, p.C91R, p.L98R and p.R315P), two previously reported from India (p.D53N and p.W450C), and one reported from outside India (p.R160Q). One mutation, p.W450C, was present in two families, and the other six mutations were present in one family each. Analysis of the molecular structure of the enzyme revealed that most of these mutations either cause loss of an active site residue or destabilize the structure of the enzyme. The only previous study on mutations in ARSB in Indian MPS VI patients, by Kantaputra et al. 2014 [1], reported four novel mutations of which two (p.D53N and p.W450C) were found in our study as well. Till date, nine mutations have been reported from India, through our study and the Kantaputra study. Eight out of these nine mutations have been found only in India. This suggests that the population studied by us might have its own typical set of mutations, with other populations equally likely to have their own set of mutations.

  5. 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.

  6. Mutation analysis and prenatal diagnosis of EXT1 gene mutations in Chinese patients with multiple osteochondromas

    Institute of Scientific and Technical Information of China (English)

    ZHU Hai-yan; HU Ya-li; YANG Ying; WU Xing; ZHU Rui-fang; ZHU Xiang-yu; DUAN Hong-lei; ZHANG Ying; ZHOU Jin-yong

    2011-01-01

    Background Multiple osteochondromas (MO), an inherited autosomal dominant disorder, is characterized by the presence of multiple exostoses on the long bones. MO is caused by mutations in the EXT1 or EXT2 genes which encode glycosyltransferases implicated in heparin sulfate biosynthesis.Methods In this study, efforts were made to identify the underlying disease-causing mutations in patients from two MO families in China.Results Two novel EXT1 gene mutations were identified and no mutation was found in EXT2 gene. The mutation c.497T>A in exon 1 of the EXT1 gene was cosegregated with the disease phenotype in family 1 and formed a stop codon at amino acid site 166. The fetus of the proband was diagnosed negative. In family 2, the mutation c. 1430-1431delCC in exon 6 of the EXT1 gene would cause frameshift and introduce a premature stop codon after the reading frame being open for 42 amino acids. The fetus of this family inherited this mutation from the father.Conclusions Mutation analysis of two MO families in this study demonstrates its further application in MO genetic counseling and prenatal diagnosis.

  7. Germline mutations of STR-alleles include multi-step mutations as defined by sequencing of repeat and flanking regions.

    Science.gov (United States)

    Dauber, Eva-Maria; Kratzer, Adelgunde; Neuhuber, Franz; Parson, Walther; Klintschar, Michael; Bär, Walter; Mayr, Wolfgang R

    2012-05-01

    Well defined estimates of mutation rates are a prerequisite for the use of short tandem repeat (STR-) loci in relationship testing. We investigated 65 isolated genetic inconsistencies, which were observed within 50,796 allelic transfers at 23 STR-loci (ACTBP2 (SE33), CD4, CSF1PO, F13A1, F13B, FES, FGA, vWA, TH01, TPOX, D2S1338, D3S1358, D5S818, D7S820, D8S1132, D8S1179, D12S391, D13S317, D16S539, D17S976, D18S51, D19S433, D21S11) in Caucasoid families residing in Austria and Switzerland. Sequencing data of repeat and flanking regions and the median of all theoretically possible mutational steps showed valuable information to characterise the mutational events with regard to parental origin, change of repeat number (mutational step size) and direction of mutation (losses and gains of repeats). Apart from predominant single-step mutations including one case with a double genetic inconsistency, two double-step and two apparent four-step mutations could be identified. More losses than gains of repeats and more mutations originating from the paternal than the maternal lineage were observed (31 losses, 22 gains, 12 losses or gains and 47 paternal, 11 maternal mutations and 7 unclear of parental origin). The mutation in the paternal germline was 3.3 times higher than in the maternal germline. The results of our study show, that apart from the vast majority of single-step mutations rare multi-step mutations can be observed. Therefore, the interpretation of mutational events should not rigidly be restricted to the shortest possible mutational step, because rare but true multi-step mutations can easily be overlooked, if haplotype analysis is not possible.

  8. Silting mutation in triangulated categories

    CERN Document Server

    Aihara, Takuma

    2010-01-01

    In representation theory of algebras the notion of `mutation' often plays important roles, and two cases are well known, i.e. `cluster tilting mutation' and `exceptional mutation'. In this paper we focus on `tilting mutation', which has a disadvantage that it is often impossible, i.e. some of summands of a tilting object can not be replaced to get a new tilting object. The aim of this paper is to take away this disadvantage by introducing `silting mutation' for silting objects as a generalization of `tilting mutation'. We shall develope a basic theory of silting mutation. In particular, we introduce a partial order on the set of silting objects and establish the relationship with `silting mutation' by generalizing the theory of Riedmann-Schofield and Happel-Unger. We show that iterated silting mutation act transitively on the set of silting objects for local, hereditary or canonical algebras. Finally we give a bijection between silting subcategories and certain t-structures.

  9. MUTATIONS IN CALMODULIN GENES

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder. The ...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  10. MUTATIONS IN CALMODULIN GENES

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  11. Are There Mutator Polymerases?

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    Miguel Garcia-Diaz

    2003-01-01

    Full Text Available DNA polymerases are involved in different cellular events, including genome replication and DNA repair. In the last few years, a large number of novel DNA polymerases have been discovered, and the biochemical analysis of their properties has revealed a long list of intriguing features. Some of these polymerases have a very low fidelity and have been suggested to play mutator roles in different processes, like translesion synthesis or somatic hypermutation. The current view of these processes is reviewed, and the current understanding of DNA polymerases and their role as mutator enzymes is discussed.

  12. Mutation analysis of 28 gaucher disease patients: The Australasian experience

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.D.; Nelson, P.V.; Robertson, E.F.; Morris, C.P. [Women`s and Children`s Hospital, North Adelaide, South Australia (Australia)

    1994-01-15

    Gaucher disease is the most common lysomal storage disease. It is an autosomal recessive disorder that results from a deficiency of {beta}-glucocerrebrosidase. Three clinical phenotypes have been described: non-neuronopathic, acute neuronopathic, and subacuteneuronopathic. Genomic DNA from 28 Australasian patients of diverse ethnic origin with Gaucher disease was screened for 3 common mutations (1226G, 1448C and 84GG) using the amplification refractory mutation system (ARMS), and one uncommon mutation (1504T) by restriction enzyme digestion. Thirty-eight of the 56 independent alleles in these patients were characterized, with 1448C present in 42% and 1226G in 28% of the alleles. The 1226G mutation was associated only with the nonneuronopathic phenotype and 7 of the 15 patients who carried the 1448C mutation developed neuronopathic disease. Three infants who died in the neonatal period following a rapidly progressive neurodegenerative course carried no identifiable mutations. The 84GG mutation was carried by 2 Jewish patients and 1504T was present in one patient. It is now possible to rapidly identify the common Gaucher mutations using ARMS and restriction enzyme digestion, and our findings confirm the heterogeneity of mutations in Gaucher disease. It is also possible to predict in part the phenotypic outcome when screening patients for these mutations. The authors consider mutation analysis to be of most use in prenatal diagnosis and for carrier detection within affected families. 27 refs., 2 figs., 2 tabs.

  13. Filaggrin Mutation in Korean Patients with Atopic Dermatitis

    Science.gov (United States)

    On, Hye Rang; Lee, Sang Eun; Kim, Song-Ee; Hong, Won Jin; Kim, Hyun Jung; Nomura, Toshifumi; Suzuki, Shotaro; Shimizu, Hiroshi

    2017-01-01

    Purpose Atopic dermatitis (AD) is a chronic, relapsing eczematous inflammatory skin disease. Mutations in the filaggrin gene (FLG) are major predisposing factors for AD. Ethnic differences exist between Asian and European populations in the frequency and spectrum of FLG mutations. Moreover, a distinct set of FLG mutations has been reported in Asian populations. The aim of this study was to examine the spectrum of FLG mutations in Koreans with AD. We also investigated the association of FLG mutations and clinical features of AD and compared the Korean FLG landscape with that of other East Asian countries. Materials and Methods Seventy Korean patients with AD were enrolled in this study. Fourteen FLG mutations previously detected in Korean, Japanese, and Chinese patients were screened by genotyping. Results Four FLG null mutations (3321delA, K4022X, S3296X, and S2889X) were identified in eleven patients (15.7%). The most commonly detected mutations in Korean patients with AD were 3321delA (n=6, 9.1%) and K4022X (n=3, 4.5%). FLG mutations were significantly associated with elevated IgE (≥200 KIU/L and/or MAST-CLA >3+, p=0.005), palmar hyperlinearity (p<0.001), and a family history of allergic disease (p=0.021). Conclusion This study expanded our understanding of the landscape of FLG mutations in Koreans and revealed an association between FLG mutations and AD phenotype. PMID:28120571

  14. Prognostic value of KTT mutation in gastrointestinal stromal tumors

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hong Liu; Chen-Guang Bai; Qiang Xie; Fei Feng; Zhi-Yun Xu; Da-Lie Ma

    2005-01-01

    AIM: To examine the prevalence and prognostic significance of C-kit gene mutation and analysis the correlation of Ckit gene mutation and the clinicalpathologic parameters of GISTs.METHODS: Eighty-two GISTs were studied for the mutation of C-kit gene by PCR-SSCP, DNA sequence.Statistical comparison were used to analysis the correlation of C-kit gene mutation and clinicalpathology,clinical behavior, recurrence.RESULTS: (1) Mutation-positive and mutation-negative GISTs were 34 and 48,respectively; (2) Among these patients with C-kit mutation remained a significantly poor prognosis associated with 59% 3-year survival compared to those whose tumors did not; (3) Tunor size, PCNA index, mitotic cell number, presence of necrosis, microscopic invasion to adjacent tissues, recurrence and distant metastasis among mutation-positive and mutation-negative GISTs were significantly different.CONCLUSION: C-kit mutation is a undoubtedly pivotal event in GIST and may be associated with poor prognosis.Evaluation of C-kit gene mutation may have both prognosis and therapeutic significances.

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

    Directory of Open Access Journals (Sweden)

    Filip Janku

    Full Text Available BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

  16. Noise-mean relationship in mutated promoters.

    Science.gov (United States)

    Hornung, Gil; Bar-Ziv, Raz; Rosin, Dalia; Tokuriki, Nobuhiko; Tawfik, Dan S; Oren, Moshe; Barkai, Naama

    2012-12-01

    Gene expression depends on the frequency of transcription events (burst frequency) and on the number of mRNA molecules made per event (burst size). Both processes are encoded in promoter sequence, yet their dependence on mutations is poorly understood. Theory suggests that burst size and frequency can be distinguished by monitoring the stochastic variation (noise) in gene expression: Increasing burst size will increase mean expression without changing noise, while increasing burst frequency will increase mean expression and decrease noise. To reveal principles by which promoter sequence regulates burst size and frequency, we randomly mutated 22 yeast promoters chosen to span a range of expression and noise levels, generating libraries of hundreds of sequence variants. In each library, mean expression (m) and noise (coefficient of variation, η) varied together, defining a scaling curve: η(2) = b/m + η(ext)(2). This relation is expected if sequence mutations modulate burst frequency primarily. The estimated burst size (b) differed between promoters, being higher in promoter containing a TATA box and lacking a nucleosome-free region. The rare variants that significantly decreased b were explained by mutations in TATA, or by an insertion of an out-of-frame translation start site. The decrease in burst size due to mutations in TATA was promoter-dependent, but independent of other mutations. These TATA box mutations also modulated the responsiveness of gene expression to changing conditions. Our results suggest that burst size is a promoter-specific property that is relatively robust to sequence mutations but is strongly dependent on the interaction between the TATA box and promoter nucleosomes.

  17. Mutation spectra of complex environmental mixtures

    Energy Technology Data Exchange (ETDEWEB)

    DeMarini, D.M. [EPA, Research Triangle Park, NC (United States)

    1997-10-01

    Bioassay-directed chemical analysis of complex environmental mixtures has indicated that much of the genotoxic activity of mixtures is due to the presence of one or a few classes or chemicals within the mixture. We have extended this observation to the molecular level by using colony probe hybridization and PCR/DNA sequence analysis to determine the mutation spectra of {approximately}8,000 revertants induced by a variety of complex mixtures and their chemical fractions in TA100 and TA98 of Salmonella. For urban air, >80% of mutagenic activity was due to a base/neutral fraction that contained primarily PAHs. The mutation spectrum induced by unfractionated urban air was not significantly different from that produced by a model PAH, B(a)P. The mutation spectrum induced by organic extracts of chlorinated drinking water were similar to those produced by the chlorinated furanone MX, which accounted for {approximately}20% of the mutagenic activity of the samples. The base/neutral fraction of municipal waste incinerator emissions accounted for the primary class of mutations induced by the emissions, and a polar neutral fraction accounted for the secondary class of mutations induced by the emissions. The primary class of mutations induced by cigarette smoke condensate in TA100 (GC {yields} TA) is also the primary class of mutations in the p53 gene of lung tumors of cigarette smokers. These results confirm at the molecular level that the mutations induced by a complex mixture reflect the dominance of one or a few classes of chemicals within the mixture.

  18. Msx1 Mutations

    Science.gov (United States)

    Wang, Y.; Kong, H.; Mues, G.; D’Souza, R.

    2011-01-01

    Mutations in the transcription factors PAX9 and MSX1 cause selective tooth agenesis in humans. In tooth bud mesenchyme of mice, both proteins are required for the expression of Bmp4, which is the key signaling factor for progression to the next step of tooth development. We have previously shown that Pax9 can transactivate a 2.4-kb Bmp4 promoter construct, and that most tooth-agenesis-causing PAX9 mutations impair DNA binding and Bmp4 promoter activation. We also found that Msx1 by itself represses transcription from this proximal Bmp4 promoter, and that, in combination with Pax9, it acts as a potentiator of Pax9-induced Bmp4 transactivation. This synergism of Msx1 with Pax9 is significant, because it is currently the only documented mechanism for Msx1-mediated activation of Bmp4. In this study, we investigated whether the 5 known tooth-agenesis-causing MSX1 missense mutations disrupt this Pax9-potentiation effect, or if they lead to deficiencies in protein stability, protein-protein interactions, nuclear translocation, and DNA-binding. We found that none of the studied molecular mechanisms yielded a satisfactory explanation for the pathogenic effects of the Msx1 mutations, calling for an entirely different approach to the investigation of this step of odontogenesis on the molecular level. PMID:21297014

  19. 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.

  20. Frequent MAGE mutations in human melanoma.

    Directory of Open Access Journals (Sweden)

    Otavia L Caballero

    Full Text Available BACKGROUND: Cancer/testis (CT genes are expressed only in the germ line and certain tumors and are most frequently located on the X-chromosome (the CT-X genes. Amongst the best studied CT-X genes are those encoding several MAGE protein families. The function of MAGE proteins is not well understood, but several have been shown to potentially influence the tumorigenic phenotype. METHODOLOGY/PRINCIPAL FINDINGS: We undertook a mutational analysis of coding regions of four CT-X MAGE genes, MAGEA1, MAGEA4, MAGEC1, MAGEC2 and the ubiquitously expressed MAGEE1 in human melanoma samples. We first examined cell lines established from tumors and matching blood samples from 27 melanoma patients. We found that melanoma cell lines from 37% of patients contained at least one mutated MAGE gene. The frequency of mutations in the coding regions of individual MAGE genes varied from 3.7% for MAGEA1 and MAGEA4 to 14.8% for MAGEC2. We also examined 111 fresh melanoma samples collected from 86 patients. In this case, samples from 32% of the patients exhibited mutations in one or more MAGE genes with the frequency of mutations in individual MAGE genes ranging from 6% in MAGEA1 to 16% in MAGEC1. SIGNIFICANCE: These results demonstrate for the first time that the MAGE gene family is frequently mutated in melanoma.

  1. Differential Persistence of Transmitted HIV-1 Drug Resistance Mutation Classes

    Science.gov (United States)

    Jain, Vivek; Sucupira, Maria C.; Bacchetti, Peter; Hartogensis, Wendy; Diaz, Ricardo S.; Kallas, Esper G.; Janini, Luiz M.; Liegler, Teri; Pilcher, Christopher D.; Grant, Robert M.; Cortes, Rodrigo; Deeks, Steven G.

    2011-01-01

    Background. Transmitted human immunodeficiency virus type 1 (HIV-1) drug resistance (TDR) mutations can become replaced over time by emerging wild-type viral variants with improved fitness. The impact of class-specific mutations on this rate of mutation replacement is uncertain. Methods. We studied participants with acute and/or early HIV infection and TDR in 2 cohorts (San Francisco, California, and São Paulo, Brazil). We followed baseline mutations longitudinally and compared replacement rates between mutation classes with use of a parametric proportional hazards model. Results. Among 75 individuals with 195 TDR mutations, M184V/I became undetectable markedly faster than did nonnucleoside reverse-transcriptase inhibitor (NNRTI) mutations (hazard ratio, 77.5; 95% confidence interval [CI], 14.7–408.2; P < .0001), while protease inhibitor and NNRTI replacement rates were similar. Higher plasma HIV-1 RNA level predicted faster mutation replacement, but this was not statistically significant (hazard ratio, 1.71 log10 copies/mL; 95% CI, .90–3.25 log10 copies/mL; P = .11). We found substantial person-to-person variability in mutation replacement rates not accounted for by viral load or mutation class (P < .0001). Conclusions. The rapid replacement of M184V/I mutations is consistent with known fitness costs. The long-term persistence of NNRTI and protease inhibitor mutations suggests a risk for person-to-person propagation. Host and/or viral factors not accounted for by viral load or mutation class are likely influencing mutation replacement and warrant further study. PMID:21451005

  2. Differential Expression of GNAS and KRAS Mutations in Pancreatic Cysts

    Directory of Open Access Journals (Sweden)

    Linda S Lee

    2014-11-01

    Full Text Available Context KRAS mutations play an important role in pancreatic cancer. GNAS mutations were discovered in intraductal papillary mucinous neoplasms (IPMN. Objectives Our aim was to identify the frequency of KRAS and GNAS mutations in pancreatic cystic neoplasms and pancreatic ductal adenocarcinoma (PDAC. Methods Sixty-eight surgically resected formalin fixed, paraffin embedded pancreatic specimens were analyzed, including: 1 benign [20 serous cystadenoma (SCA], 2 pre-malignant [10 mucinous cystic neoplasm (MCN, 10 branch duct intraductal papillary mucinous neoplasm (BD-IPMN, 9 main duct IPMN (MD-IPMN], 3 malignant [19 PDAC]. Total nucleic acid extraction was performed. KRAS codon 12/13 and GNAS codon 201 mutations were interrogated via targeted sequencing using the Ion Torrent's Personal Genome Machine (PGM. Results Mean age of 68 patients was 61.9± 8.4 with 72% female. KRAS and GNAS mutations were more common in PDAC and IPMN. KRAS mutations predominated in PDAC compared to pancreatic cysts (16/19, 84%versus 10/49, 20%; p0.001. GNAS mutatins were more common in IPMN compared to non-IPMN lesions (8/19, 42% versus 2/49, 4%;p=0.0003. No GNAS mutations were detected in PDAC and MCN while 2 SCA carried GNAS mutations. Double mutations with KRAS and GNAS were only present in IPMN (5/19 versus 0/30 SCA and MCN, p=0.006. Conclusions KRAS and GNAS mutations were more common in PDAC and IPMN with KRAS mutations primarily in PDAC and GNAS mutations more frequent in IPMN. No GNAS mutations occurred in MCN and double mutations were only present in IPMN.

  3. 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.

  4. Mutations in galactosemia

    Energy Technology Data Exchange (ETDEWEB)

    Reichardt, J.K.V. [Univ. of Southern California School of Medicine, Los Angeles, CA (United States)

    1995-10-01

    This Letter raises four issues concerning two papers on galactosemia published in the March 1995 of the Journal. First, table 2 in the paper by Elsas et al. incorrectly attributes seven galactose-l-phosphate uridyl transferase (GALT) mutations (S135L, L195P, K285N, N314D, R333W, R333G, and K334R). The table also fails to mention that others have reported the same two findings attributed to {open_quotes}Leslie et al.; Elsas et al. and in press{close_quotes} and {open_quotes}Leslie et al.; Elsas et al.{close_quotes} The first finding on the prevalence of the Q188R galactosemia mutation in the G/G Caucasian population has also been described by Ng et al., and the second finding on the correlation of the N314D GALT mutation with the Duarte variant was reported by Lin et al. Second, Elsas et al. suggest that the E203K and N314D mutations may {open_quotes}produce intra-allelic complementation when in cis{close_quotes}. This speculation is supported by the activity data of individual III-2 but is inconsistent with the activities of three other individuals I-1, II-1, and III-1 of the same pedigree. The GALT activity measured in these three individuals suggests a dominant negative effect of E203K in E203K-N314D chromosomes, since they all have less than normal activity. Thus, the preponderance of the data in this paper is at odds with the authors speculation. It is worth recalling that Lin et al. also identified four N314D GALT mutations on 95 galactosemic chromosomes examined. A similar situation also appears to be the case in proband III-1 (with genotype E203K-N314D/IVSC) in the Elsas et al. paper. 9 refs.

  5. Evolutionary Stability Against Multiple Mutations

    CERN Document Server

    Ghatak, Anirban; Shaiju, A J

    2012-01-01

    It is known (see e.g. Weibull (1995)) that ESS is not robust against multiple mutations. In this article, we introduce robustness against multiple mutations and study some equivalent formulations and consequences.

  6. BRAF mutations in conjunctival melanoma

    DEFF Research Database (Denmark)

    Larsen, Ann-Cathrine; Dahl, Christina; Dahmcke, Christina M.

    2016-01-01

    Purpose: To investigate incidence, clinicopathological features and prognosis of BRAF-mutated conjunctival melanoma in Denmark. Furthermore, to determine BRAF mutations in paired premalignant lesions and evaluate immunohistochemical BRAF V600E oncoprotein detection. Methods: Data from 139 patients...

  7. Positive mutations and mutation-dependent Verhulst factor in Penna ageing model

    Science.gov (United States)

    Moss de Oliveira, S.; Stauffer, D.; de Oliveira, P. M. C.; Sá Martins, J. S.

    2004-02-01

    We modify twice the Penna model for biological ageing. First, we introduce back (good) mutations and a memory for them into the model. It allows us to observe an improvement of the species fitness over long-time scales as well as punctuated equilibrium. Second, we adopt a food/space competition factor that depends on the number of accumulated mutations in the individuals genomes, and get rid of the fixed limiting number of allowed mutations. Besides reproducing the main results of the standard model, we also observe a mortality maximum for the oldest old.

  8. A germ-line-selective advantage rather than an increased mutation rate can explain some unexpectedly common human disease mutations.

    Science.gov (United States)

    Choi, Soo-Kyung; Yoon, Song-Ro; Calabrese, Peter; Arnheim, Norman

    2008-07-22

    Two nucleotide substitutions in the human FGFR2 gene (C755G or C758G) are responsible for virtually all sporadic cases of Apert syndrome. This condition is 100-1,000 times more common than genomic mutation frequency data predict. Here, we report on the C758G de novo Apert syndrome mutation. Using data on older donors, we show that spontaneous mutations are not uniformly distributed throughout normal testes. Instead, we find foci where C758G mutation frequencies are 3-4 orders of magnitude greater than the remaining tissue. We conclude this nucleotide site is not a mutation hot spot even after accounting for possible Luria-Delbruck "mutation jackpots." An alternative explanation for such foci involving positive selection acting on adult self-renewing Ap spermatogonia experiencing the rare mutation could not be rejected. Further, the two youngest individuals studied (19 and 23 years old) had lower mutation frequencies and smaller foci at both mutation sites compared with the older individuals. This implies that the mutation frequency of foci increases as adults age, and thus selection could explain the paternal age effect for Apert syndrome and other genetic conditions. Our results, now including the analysis of two mutations in the same set of testes, suggest that positive selection can increase the relative frequency of premeiotic germ cells carrying such mutations, although individuals who inherit them have reduced fitness. In addition, we compared the anatomical distribution of C758G mutation foci with both new and old data on the C755G mutation in the same testis and found their positions were not correlated with one another.

  9. Isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma.

    Science.gov (United States)

    Kipp, Benjamin R; Voss, Jesse S; Kerr, Sarah E; Barr Fritcher, Emily G; Graham, Rondell P; Zhang, Lizhi; Highsmith, W Edward; Zhang, Jun; Roberts, Lewis R; Gores, Gregory J; Halling, Kevin C

    2012-10-01

    Somatic mutations in isocitrate dehydrogenase 1 and 2 genes are common in gliomas and help stratify patients with brain cancer into histologic and molecular subtypes. However, these mutations are considered rare in other solid tumors. The aims of this study were to determine the frequency of isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma and to assess histopathologic differences between specimens with and without an isocitrate dehydrogenase mutation. We sequenced 94 formalin-fixed, paraffin-embedded cholangiocarcinoma (67 intrahepatic and 27 extrahepatic) assessing for isocitrate dehydrogenase 1 (codon 132) and isocitrate dehydrogenase 2 (codons 140 and 172) mutations. Multiple histopathologic characteristics were also evaluated and compared with isocitrate dehydrogenase 1/2 mutation status. Of the 94 evaluated specimens, 21 (22%) had a mutation including 14 isocitrate dehydrogenase 1 and 7 isocitrate dehydrogenase 2 mutations. Isocitrate dehydrogenase mutations were more frequently observed in intrahepatic cholangiocarcinoma than in extrahepatic cholangiocarcinoma (28% versus 7%, respectively; P = .030). The 14 isocitrate dehydrogenase 1 mutations were R132C (n = 9), R132S (n = 2), R132G (n = 2), and R132L (n = 1). The 7 isocitrate dehydrogenase 2 mutations were R172K (n = 5), R172M (n = 1), and R172G (n = 1). Isocitrate dehydrogenase mutations were more frequently observed in tumors with clear cell change (P < .001) and poorly differentiated histology (P = .012). The results of this study show for the first time that isocitrate dehydrogenase 1 and 2 genes are mutated in cholangiocarcinoma. The results of this study are encouraging because it identifies a new potential target for genotype-directed therapeutic trials and may represent a potential biomarker for earlier detection of cholangiocarcinoma in a subset of cases.

  10. Somatic CALR Mutations in Myeloproliferative Neoplasms with Nonmutated JAK2

    Science.gov (United States)

    Baxter, E.J.; Nice, F.L.; Gundem, G.; Wedge, D.C.; Avezov, E.; Li, J.; Kollmann, K.; Kent, D.G.; Aziz, A.; Godfrey, A.L.; Hinton, J.; Martincorena, I.; Van Loo, P.; Jones, A.V.; Guglielmelli, P.; Tarpey, P.; Harding, H.P.; Fitzpatrick, J.D.; Goudie, C.T.; Ortmann, C.A.; Loughran, S.J.; Raine, K.; Jones, D.R.; Butler, A.P.; Teague, J.W.; O’Meara, S.; McLaren, S.; Bianchi, M.; Silber, Y.; Dimitropoulou, D.; Bloxham, D.; Mudie, L.; Maddison, M.; Robinson, B.; Keohane, C.; Maclean, C.; Hill, K.; Orchard, K.; Tauro, S.; Du, M.-Q.; Greaves, M.; Bowen, D.; Huntly, B.J.P.; Harrison, C.N.; Cross, N.C.P.; Ron, D.; Vannucchi, A.M.; Papaemmanuil, E.; Campbell, P.J.; Green, A.R.

    2014-01-01

    BACKGROUND Somatic mutations in the Janus kinase 2 gene (JAK2) occur in many myeloproliferative neoplasms, but the molecular pathogenesis of myeloproliferative neoplasms with nonmutated JAK2 is obscure, and the diagnosis of these neoplasms remains a challenge. METHODS We performed exome sequencing of samples obtained from 151 patients with myeloproliferative neoplasms. The mutation status of the gene encoding calreticulin (CALR) was assessed in an additional 1345 hematologic cancers, 1517 other cancers, and 550 controls. We established phylogenetic trees using hematopoietic colonies. We assessed calreticulin subcellular localization using immunofluorescence and flow cytometry. RESULTS Exome sequencing identified 1498 mutations in 151 patients, with medians of 6.5, 6.5, and 13.0 mutations per patient in samples of polycythemia vera, essential thrombocythemia, and myelofibrosis, respectively. Somatic CALR mutations were found in 70 to 84% of samples of myeloproliferative neoplasms with nonmutated JAK2, in 8% of myelodysplasia samples, in occasional samples of other myeloid cancers, and in none of the other cancers. A total of 148 CALR mutations were identified with 19 distinct variants. Mutations were located in exon 9 and generated a +1 base-pair frameshift, which would result in a mutant protein with a novel C-terminal. Mutant calreticulin was observed in the endoplasmic reticulum without increased cell-surface or Golgi accumulation. Patients with myeloproliferative neoplasms carrying CALR mutations presented with higher platelet counts and lower hemoglobin levels than patients with mutated JAK2. Mutation of CALR was detected in hematopoietic stem and progenitor cells. Clonal analyses showed CALR mutations in the earliest phylogenetic node, a finding consistent with its role as an initiating mutation in some patients. CONCLUSIONS Somatic mutations in the endoplasmic reticulum chaperone CALR were found in a majority of patients with myeloproliferative neoplasms with

  11. Artificial Bee Colony with Different Mutation Schemes: A comparative study

    Directory of Open Access Journals (Sweden)

    Iyad Abu Doush

    2014-03-01

    Full Text Available Artificial Bee Colony (ABC is a swarm-based metaheuristic for continuous optimization. Recent work hybridized this algorithm with other metaheuristics in order to improve performance. The work in this paper, experimentally evaluates the use of different mutation operators with the ABC algorithm. The introduced operator is activated according to a determined probability called mutation rate (MR. The results on standard benchmark function suggest that the use of this operator improves performance in terms of convergence speed and quality of final obtained solution. It shows that Power and Polynomial mutations give best results. The fastest convergence was for the mutation rate value (MR=0.2.

  12. Somatic mutations of APC gene in carcinomas from hereditary non-polyposis colorectal cancer patients

    Institute of Scientific and Technical Information of China (English)

    Jian Huang; Shu Zheng; Shen-Hang Jin; Su-Zhan Zhang

    2004-01-01

    AIM: To investigate the mutational features of adenomatous polyposis coii (APC) gene and its possible arising mechanism in hereditary non-polyposis colorectal cancers (HNPCC).METHODS: PCR-based In Vitro Synthesized Protein Test (IVSP) assay and sequencing analysis were used to confirm somatic mutations of whole APC gene in 19 HNPCC cases. RESULTS: Eleven cases with 13 mutations were determined to harbor APC mutations. The prevalence of APC mutation was 58%(11/19). The mutations consisted of 9 frameshift and 4 nonsense ones, indicating that there were more frameshift mutations (69%). The frameshift mutations allexhibited deletion or insertion of 1-2 bp and most of them (7/9) happened at simple nucleotide repeat sequences, particularly within (A)n tracts (5/9). All point mutations presented C-to-T transitions at CpG sites. CONCLUSION: Mutations of APC gene were detected in more than half of HNPCC, indicating that its mutation was a common molecular event and might play an important role in the tumorigenesis of HNPCC. Locations of frameshift mutations at simple nucleotide repeat sequences and point mutations at CpG sites suggested that many mutations probably derived from endogenous processes including mismatch repair (MMR) deficiency. Defective MMR might affect the nature of APC mutations in HNPCC and likely occur earlier than APC mutational inactivation in some patients.

  13. Founder mutations characterise the mutation panorama in 200 Swedish index cases referred for Long QT syndrome genetic testing

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    Stattin Eva-Lena

    2012-10-01

    Full Text Available Abstract Background Long QT syndrome (LQTS is an inherited arrhythmic disorder characterised by prolongation of the QT interval on ECG, presence of syncope and sudden death. The symptoms in LQTS patients are highly variable, and genotype influences the clinical course. This study aims to report the spectrum of LQTS mutations in a Swedish cohort. Methods Between March 2006 and October 2009, two hundred, unrelated index cases were referred to the Department of Clinical Genetics, Umeå University Hospital, Sweden, for LQTS genetic testing. We scanned five of the LQTS-susceptibility genes (KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 for mutations by DHPLC and/or sequencing. We applied MLPA to detect large deletions or duplications in the KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 genes. Furthermore, the gene RYR2 was screened in 36 selected LQTS genotype-negative patients to detect cases with the clinically overlapping disease catecholaminergic polymorphic ventricular tachycardia (CPVT. Results In total, a disease-causing mutation was identified in 103 of the 200 (52% index cases. Of these, altered exon copy numbers in the KCNH2 gene accounted for 2% of the mutations, whereas a RYR2 mutation accounted for 3% of the mutations. The genotype-positive cases stemmed from 64 distinct mutations, of which 28% were novel to this cohort. The majority of the distinct mutations were found in a single case (80%, whereas 20% of the mutations were observed more than once. Two founder mutations, KCNQ1 p.Y111C and KCNQ1 p.R518*, accounted for 25% of the genotype-positive index cases. Genetic cascade screening of 481 relatives to the 103 index cases with an identified mutation revealed 41% mutation carriers who were at risk of cardiac events such as syncope or sudden unexpected death. Conclusion In this cohort of Swedish index cases with suspected LQTS, a disease-causing mutation was identified in 52% of the referred patients. Copy number variations explained 2% of the

  14. The entropy characters of point mutation

    Institute of Scientific and Technical Information of China (English)

    MA GuoJi; LIANG LiJing; FAN YanHui; WANG WenJuan; DAI JiaQing; YUAN ZhiFa

    2008-01-01

    The biological diversity, which depends on the genetic material DNA, is the foundation for a species to survive and evolve. The entropy is the best measurement of biological diversity. Based on the sin-gle-parameter and the two-parameter models, here we established some differential equations about the point mutation of a DNA sequence with finite length, as well as some functions describing the processes of the variation in quantities of 4 kinds of bases (A, T, G and C) in the DNA sequence. At the molecular level, we discussed the entropy characteristics of point mutation. The results proved that a species maintained its entropy and evolved in the direction of the increasing biological diversity. In order to testify the theoretical results, we did a series of computer simulations of random point muta-tion in Matlab environment. The results were well consistent with the theoretical researches.

  15. The structure of mutations and the evolution of cooperation.

    Directory of Open Access Journals (Sweden)

    Julián García

    Full Text Available Evolutionary game dynamics in finite populations assumes that all mutations are equally likely, i.e., if there are n strategies a single mutation can result in any strategy with probability 1/n. However, in biological systems it seems natural that not all mutations can arise from a given state. Certain mutations may be far away, or even be unreachable given the current composition of an evolving population. These distances between strategies (or genotypes define a topology of mutations that so far has been neglected in evolutionary game theory. In this paper we re-evaluate classic results in the evolution of cooperation departing from the assumption of uniform mutations. We examine two cases: the evolution of reciprocal strategies in a repeated prisoner's dilemma, and the evolution of altruistic punishment in a public goods game. In both cases, alternative but reasonable mutation kernels shift known results in the direction of less cooperation. We therefore show that assuming uniform mutations has a substantial impact on the fate of an evolving population. Our results call for a reassessment of the "model-less" approach to mutations in evolutionary dynamics.

  16. Immunohistochemical correlates of TP53 somatic mutations in cancer.

    Science.gov (United States)

    Murnyák, Balázs; Hortobágyi, Tibor

    2016-10-04

    Despite controversy on the correlation between p53 accumulation and TP53 mutational status, immunohistochemical (IHC) detection of overexpressed protein has long been used as a surrogate method for mutation analysis. The aim of our study was to characterise the IHC expression features of TP53 somatic mutations and define their occurrence in human cancers. A large-scale database analysis was conducted in the IARC TP53 Database (R17); 7878 mutations with IHC features were retrieved representing 60 distinct tumour sites. The majority of the alterations were immunopositive (p TP53 mutations were divided into three IHC groups according to mutation frequency and IHC positivity. Each group had female dominance. Among the IHC groups, significant correlations were observed with age at diagnosis in breast, bladder, liver, haematopoietic system and head & neck cancers. An increased likelihood of false negative IHC associated with rare nonsense mutations was observed in certain tumour sites. Our study demonstrates that p53 immunopositivity largely correlates with TP53 mutational status but expression is absent in certain mutation types.Besides, describing the complex IHC expression of TP53 somatic mutations, our results reveal some caveats for the diagnostic practice.

  17. 5'UTR mutations of ENG cause hereditary hemorrhagic telangiectasia.

    Science.gov (United States)

    Damjanovich, Kristy; Langa, Carmen; Blanco, Francisco J; McDonald, Jamie; Botella, Luisa M; Bernabeu, Carmelo; Wooderchak-Donahue, Whitney; Stevenson, David A; Bayrak-Toydemir, Pinar

    2011-12-22

    Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder characterized by epistaxis, arteriovenous malformations, and telangiectases. The majority of the patients have a mutation in the coding region of the activin A receptor type II-like 1 (ACVRL1) or Endoglin (ENG) gene. However, in approximately 15% of cases, sequencing analysis and deletion/duplication testing fail to identify mutations in the coding regions of these genes. Knowing its vital role in transcription and translation control, we were prompted to investigate the 5'untranslated region (UTR) of ENG. We sequenced the 5'UTR of ENG for 154 HHT patients without mutations in ENG or ACVRL1 coding regions. We found a mutation (c.-127C > T), which is predicted to affect translation initiation and alter the reading frame of endoglin. This mutation was found in a family with linkage to the ENG, as well as in three other patients, one of which had an affected sibling with the same mutation. In vitro expression studies showed that a construct with the c.-127C > T mutation alters the translation and decreases the level of the endoglin protein. In addition, a c.-9G > A mutation was found in three patients, one of whom was homozygous for this mutation. Expression studies showed decreased protein levels suggesting that the c.-9G > A is a hypomorphic mutation. Our results emphasize the need for the inclusion of the 5'UTR region of ENG in clinical testing for HHT.

  18. HUMAN MITOCHONDRIAL tRNA MUTATIONS IN MATERNALLY INHERITED DEAFNESS

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jing; GONG Sha-sha; TANG Xiao-wen; ZHU Yi; GUAN Min-xin

    2013-01-01

    Mutations in mitochondrial tRNA genes have been shown to be associated with maternally inherited syn-dromic and non-syndromic deafness. Among those, mutations such as tRNALeu(UUR) 3243A>G associated with syndromic deafness are often present in heteroplasmy, and the non-syndromic deafness-associated tRNA mu-tations including tRNASer(UCN) 7445A>G are often in homoplasmy or in high levels of heteroplasmy. These tRNA mutations are the primary factors underlying the development of hearing loss. However, other tRNA mutations such as tRNAThr 15927G>A and tRNASer(UCN) 7444G>A are insufficient to produce a deafness phe-notype, but always act in synergy with the primary mitochondrial DNA mutations, and can modulate their phenotypic manifestation. These tRNA mutations may alter the structure and function of the corresponding mitochondrial tRNAs and cause failures in tRNAs metabolism. Thereby, the impairment of mitochondrial protein synthesis and subsequent defects in respiration caused by these tRNA mutations, results in mitochon-drial dysfunctions and eventually leads to the development of hearing loss. Here, we summarized the deaf-ness-associated mitochondrial tRNA mutations and discussed the pathophysiology of these mitochondrial tRNA mutations, and we hope these data will provide a foundation for the early diagnosis, management, and treatment of maternally inherited deafness.

  19. The mutational spectrum in Treacher Collins syndrome reveals a predominance of mutations that create a premature-termination codon

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, S.J.; Gladwin, A.J.; Dixon, M.J. [Univ. of Manchester (United Kingdom)

    1997-03-01

    Treacher Collins syndrome (TCS) is an autosomal dominant disorder of craniofacial development, the features of which include conductive hearing loss and cleft palate. The TCS locus has been mapped to human chromosome 5q31.3-32 and the mutated gene identified. In the current investigation, 25 previously undescribed mutations, which are spread throughout the gene, are presented. This brings the total reported to date to 35, which represents a detection rate of 60%. Of the mutations that have been reported to date, all but one result in the introduction of a premature-termination codon into the predicted protein, treacle. Moreover, the mutations are largely family specific, although a common 5-bp deletion in exon 24 (seven different families) and a recurrent splicing mutation in intron 3 (two different families) have been identified. This mutational spectrum supports the hypothesis that TCS results from haploin-sufficiency. 49 refs., 4 figs., 3 tabs.

  20. Kin Selection - Mutation Balance

    DEFF Research Database (Denmark)

    Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.

    2011-01-01

    Abstract Social conflict, in the form of intraspecific selfish "cheating" has been observed in a number of natural systems. However, a formal, evolutionary genetic theory of social cheating that provides an explanatory, predictive framework for these observations is lacking. Here we derive the kin...... selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...... lineages are transient and do not invade. Instead, cheating lineages are eliminated by kin selection but are constantly reintroduced by mutation, maintaining a stable equilibrium frequency of cheaters. The presence of cheaters at equilibrium creates a "cheater load" that selects for mechanisms of cheater...

  1. Novel chloride channel gene mutations in two unrelated Chinese families with myotonia congenita

    Directory of Open Access Journals (Sweden)

    Gao Feng

    2010-12-01

    Full Text Available Myotonia congenita (MC is a genetic disease characterized by mutations in the muscle chloride channel gene (CLCN1. To date, approximately 130 different mutations on the CLCN1 gene have been identified. However, most of the studies have focused on Caucasians, and reports on CLCN1 mutations in Chinese population are rare. This study investigated the mutation of CLCN1 in two Chinese families with MC. Direct sequencing of the CLCN1 gene revealed a heterozygous mutation (892G>A, resulting in A298T in one family and a compound heterozygous mutations (782A>G, resulting in Y261C; 1679T>C, resulting in M560T in the other family, None of the 100 normal controls had these mutations. Our findings add more to the available information on the CLCN1 mutation spectrum, and provide a valuable reference for studying the mutation types and inheritance pattern of CLCN1 in the Chinese population.

  2. High-throughput oncogene mutation profiling shows demographic differences in BRAF mutation rates among melanoma patients.

    Science.gov (United States)

    van den Hurk, Karin; Balint, Balazs; Toomey, Sinead; O'Leary, Patrick C; Unwin, Louise; Sheahan, Kieran; McDermott, Enda W; Murphy, Ian; van den Oord, Joost J; Rafferty, Mairin; FitzGerald, Dara M; Moran, Julie; Cummins, Robert; MacEneaney, Owen; Kay, Elaine W; O'Brien, Cathal P; Finn, Stephen P; Heffron, Cynthia C B B; Murphy, Michelle; Yela, Ruben; Power, Derek G; Regan, Padraic J; McDermott, Clodagh M; O'Keeffe, Allan; Orosz, Zsolt; Donnellan, Paul P; Crown, John P; Hennessy, Bryan T; Gallagher, William M

    2015-06-01

    Because of advances in targeted therapies, the clinical evaluation of cutaneous melanoma is increasingly based on a combination of traditional histopathology and molecular pathology. Therefore, it is necessary to expand our knowledge of the molecular events that accompany the development and progression of melanoma to optimize clinical management. The central objective of this study was to increase our knowledge of the mutational events that complement melanoma progression. High-throughput genotyping was adapted to query 159 known single nucleotide mutations in 33 cancer-related genes across two melanoma cohorts from Ireland (n=94) and Belgium (n=60). Results were correlated with various clinicopathological characteristics. A total of 23 mutations in 12 genes were identified, that is--BRAF, NRAS, MET, PHLPP2, PIK3R1, IDH1, KIT, STK11, CTNNB1, JAK2, ALK, and GNAS. Unexpectedly, we discovered significant differences in BRAF, MET, and PIK3R1 mutations between the cohorts. That is, cases from Ireland showed significantly lower (PBRAF(V600E) mutation rates (19%) compared with the mutation frequency observed in Belgian patients (43%). Moreover, MET mutations were detected in 12% of Irish cases, whereas none of the Belgian patients harbored these mutations, and Irish patients significantly more often (P=0.027) had PIK3R1-mutant (33%) melanoma versus 17% of Belgian cases. The low incidence of BRAF(V600E)(-) mutant melanoma among Irish patients was confirmed in five independent Irish cohorts, and in total, only 165 of 689 (24%) Irish cases carried mutant BRAF(V600E). Together, our data show that melanoma-driving mutations vary by demographic area, which has important implications for the clinical management of this disease.

  3. Benchmarking mutation effect prediction algorithms using functionally validated cancer-related missense mutations.

    Science.gov (United States)

    Martelotto, Luciano G; Ng, Charlotte Ky; De Filippo, Maria R; Zhang, Yan; Piscuoglio, Salvatore; Lim, Raymond S; Shen, Ronglai; Norton, Larry; Reis-Filho, Jorge S; Weigelt, Britta

    2014-10-28

    Massively parallel sequencing studies have led to the identification of a large number of mutations present in a minority of cancers of a given site. Hence, methods to identify the likely pathogenic mutations that are worth exploring experimentally and clinically are required. We sought to compare the performance of 15 mutation effect prediction algorithms and their agreement. As a hypothesis-generating aim, we sought to define whether combinations of prediction algorithms would improve the functional effect predictions of specific mutations. Literature and database mining of single nucleotide variants (SNVs) affecting 15 cancer genes was performed to identify mutations supported by functional evidence or hereditary disease association to be classified either as non-neutral (n = 849) or neutral (n = 140) with respect to their impact on protein function. These SNVs were employed to test the performance of 15 mutation effect prediction algorithms. The accuracy of the prediction algorithms varies considerably. Although all algorithms perform consistently well in terms of positive predictive value, their negative predictive value varies substantially. Cancer-specific mutation effect predictors display no-to-almost perfect agreement in their predictions of these SNVs, whereas the non-cancer-specific predictors showed no-to-moderate agreement. Combinations of predictors modestly improve accuracy and significantly improve negative predictive values. The information provided by mutation effect predictors is not equivalent. No algorithm is able to predict sufficiently accurately SNVs that should be taken forward for experimental or clinical testing. Combining algorithms aggregates orthogonal information and may result in improvements in the negative predictive value of mutation effect predictions.

  4. Clinical disease presentation and ECG characteristics of LMNA mutation carriers

    Science.gov (United States)

    Ollila, Laura; Nikus, Kjell; Holmström, Miia; Jalanko, Mikko; Jurkko, Raija; Kaartinen, Maija; Koskenvuo, Juha; Kuusisto, Johanna; Kärkkäinen, Satu; Palojoki, Eeva; Reissell, Eeva; Piirilä, Päivi; Heliö, Tiina

    2017-01-01

    Objective Mutations in the LMNA gene encoding lamins A and C of the nuclear lamina are a frequent cause of cardiomyopathy accounting for 5–8% of familial dilated cardiomyopathy (DCM). Our aim was to study disease onset, presentation and progression among LMNA mutation carriers. Methods Clinical follow-up data from 27 LMNA mutation carriers and 78 patients with idiopathic DCM without an LMNA mutation were collected. In addition, ECG data were collected and analysed systematically from 20 healthy controls. Results Kaplan-Meier analysis revealed no difference in event-free survival (death, heart transplant, resuscitation and appropriate implantable cardioverter-defibrillator therapy included as events) between LMNA mutation carriers and DCM controls (p=0.5). LMNA mutation carriers presented with atrial fibrillation at a younger age than the DCM controls (47 vs 57 years, p=0.003). Male LMNA mutation carriers presented with clinical manifestations roughly a decade earlier than females. In close follow-up non-sustained ventricular tachycardia was detected in 78% of LMNA mutation carriers. ECG signs of septal remodelling were present in 81% of the LMNA mutation carriers, 21% of the DCM controls and none of the healthy controls giving a high sensitivity and specificity for the standard ECG in distinguishing LMNA mutation carriers from patients with DCM and healthy controls. Conclusions Male LMNA mutation carriers present clinical manifestations at a younger age than females. ECG septal remodelling appears to distinguish LMNA mutation carriers from healthy controls and patients with DCM without LMNA mutations. PMID:28123761

  5. Sex and deleterious mutations.

    Science.gov (United States)

    Gordo, Isabel; Campos, Paulo R A

    2008-05-01

    The evolutionary advantage of sexual reproduction has been considered as one of the most pressing questions in evolutionary biology. While a pluralistic view of the evolution of sex and recombination has been suggested by some, here we take a simpler view and try to quantify the conditions under which sex can evolve given a set of minimal assumptions. Since real populations are finite and also subject to recurrent deleterious mutations, this minimal model should apply generally to all populations. We show that the maximum advantage of recombination occurs for an intermediate value of the deleterious effect of mutations. Furthermore we show that the conditions under which the biggest advantage of sex is achieved are those that produce the fastest fitness decline in the corresponding asexual population and are therefore the conditions for which Muller's ratchet has the strongest effect. We also show that the selective advantage of a modifier of the recombination rate depends on its strength. The quantification of the range of selective effects that favors recombination then leads us to suggest that, if in stressful environments the effect of deleterious mutations is enhanced, a connection between sex and stress could be expected, as it is found in several species.

  6. The impact of point mutations in the human androgen receptor: classification of mutations on the basis of transcriptional activity.

    Directory of Open Access Journals (Sweden)

    Colin W Hay

    Full Text Available Androgen receptor mediated signaling drives prostate cancer cell growth and survival. Mutations within the receptor occur infrequently in prostate cancer prior to hormonal therapy but become prevalent in incurable androgen independent and metastatic tumors. Despite the determining role played by the androgen receptor in all stages of prostate cancer progression, there is a conspicuous dearth of comparable data on the consequences of mutations. In order to remedy this omission, we have combined an expansive study of forty five mutations which are predominantly associated with high Gleason scores and metastatic tumors, and span the entire length of the receptor, with a literature review of the mutations under investigation. We report the discovery of a novel prevalent class of androgen receptor mutation that possesses loss of function at low levels of androgen yet transforms to a gain of function at physiological levels. Importantly, mutations introducing constitutive gain of function are uncommon, with the majority of mutations leading to either loss of function or no significant change from wild-type activity. Therefore, the widely accepted supposition that androgen receptor mutations in prostate cancer result in gain of function is appealing, but mistaken. In addition, the transcriptional outcome of some mutations is dependent upon the androgen receptor responsive element. We discuss the consequences of these findings and the role of androgen receptor mutations for prostate cancer progression and current treatment options.

  7. BRCA1 mutations in Brazilian patients

    Directory of Open Access Journals (Sweden)

    Juliano Javert Lourenço

    2004-01-01

    Full Text Available BRCA1 mutations are known to be responsible for the majority of hereditary breast and ovarian cancers in women with early onset and a family history of the disease. In this paper we present a mutational survey conducted in 47 Brazilian patients with breast/ovarian cancer, selected based on age at diagnosis, family history, tumor laterality, and presence of breast cancer in male patients. All 22 coding exons and intron-exon junctions were sequenced. Constitutional mutations were found in seven families, consisting of one insertion (insC5382 in exon 20 (four patients, one four base-pair deletion (3450-3453delCAAG in exon 11 resulting in a premature stop codon (one patient, one transition (IVS17+2T> C in intron 17 affecting a mRNA splicing site (one patient, and a C> T transition resulting in a stop-codon (Q1135X in exon 11 (one patient. The identification of these mutations which are associated to hereditary breast and ovarian cancers will contribute to the characterization of the mutational spectrum of BRCA1 and to the improvement of genetic counseling for familial breast/ovarian cancer patients in Brazil.

  8. Septin mutations in human cancers

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    Elias T Spiliotis

    2016-11-01

    Full Text Available Septins are GTP-binding proteins that are evolutionarily and structurally related to the RAS oncogenes. Septin expression levels are altered in many cancers and new advances point to how abnormal septin expression may contribute to the progression of cancer. In contrast to the RAS GTPases, which are frequently mutated and actively promote tumorigenesis, little is known about the occurrence and role of septin mutations in human cancers. Here, we review septin missense mutations that are currently in the Catalog of Somatic Mutations in Cancer (COSMIC database. The majority of septin mutations occur in tumors of the large intestine, skin, endometrium and stomach. Over 25% of the annotated mutations in SEPT2, SEPT4 and SEPT9 belong to large intestine tumors. From all septins, SEPT9 and SEPT14 exhibit the highest mutation frequencies in skin, stomach and large intestine cancers. While septin mutations occur with frequencies lower than 3%, recurring mutations in several invariant and highly conserved amino acids are found across different septin paralogs and tumor types. Interestingly, a significant number of these mutations occur in the GTP-binding pocket and septin dimerization interfaces. Future studies may determine how these somatic mutations affect septin structure and function, whether they contribute to the progression of specific cancers and if they could serve as tumor-specific biomarkers.

  9. Applications of homemade kit in mutation detection of genes

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chunxia; XU Guowang; SHI Xianzhe; MA Jianmei; ZHANG Yan; L(U) Shen; YANG Qing

    2004-01-01

    Several methods of mutation detection, such as single-strand conformation polymorphism (SSCP), tandem SSCP/heteroduplex analysis and SNaPshot analysis were developed using homemade kit on ABI 310 genetic analyzer, and were successfully applied to mutation detection of 31 colorectal tumor samples. The sieving capability of homemade kit and commercial kit were compared, results demonstrate that homemade kit has higher resolution and shorter analysis time. In clinical tumor samples, 26% K-ras (exon 1) and 24% p53 (exons 7-8) were found to have mutations, and all mutations were single point variations. A majority of mutations occurred in one gene, only 1 tumor contained alterations in the two genes, which indicates that development of colorectal cancer lies on alternate pathways, and may correlate with different gene mutations.

  10. Mutations affecting the chemosensory neurons of Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Starich, T.A.; Herman, R.K.; Kari, C.K. [Univ. of Minnesota, St. Paul, MN (United States)] [and others

    1995-01-01

    We have identified and characterized 95 mutations that reduce or abolish dye filling of amphid and phasmid neurons and that have little effect on viability, fertility or movement. Twenty-seven mutations occurred spontaneously in strains with a high frequency of transposon insertion. Sixty-eight were isolated after treatment with EMS. All of the mutations result in defects in one or more chemosensory responses, such as chemotaxis to ammonium chloride or formation of dauer larvae under conditions of starvation and overcrowding. Seventy-five of the mutations are alleles of 12 previously defined genes, mutations which were previously shown to lead to defects in amphid ultrastructure. We have assigned 20 mutations to 13 new genes, called dyf-1 through dyf-13. We expect that the genes represented by dye-filling defective mutants are important for the differentiation of amphid and phasmid chemosensilla. 58 refs., 3 figs., 6 tabs.

  11. Frequency of TERT promoter mutations in human cancers.

    Science.gov (United States)

    Vinagre, João; Almeida, Ana; Pópulo, Helena; Batista, Rui; Lyra, Joana; Pinto, Vasco; Coelho, Ricardo; Celestino, Ricardo; Prazeres, Hugo; Lima, Luis; Melo, Miguel; da Rocha, Adriana Gaspar; Preto, Ana; Castro, Patrícia; Castro, Ligia; Pardal, Fernando; Lopes, José Manuel; Santos, Lúcio Lara; Reis, Rui Manuel; Cameselle-Teijeiro, José; Sobrinho-Simões, Manuel; Lima, Jorge; Máximo, Valdemar; Soares, Paula

    2013-01-01

    Reactivation of telomerase has been implicated in human tumorigenesis, but the underlying mechanisms remain poorly understood. Here we report the presence of recurrent somatic mutations in the TERT promoter in cancers of the central nervous system (43%), bladder (59%), thyroid (follicular cell-derived, 10%) and skin (melanoma, 29%). In thyroid cancers, the presence of TERT promoter mutations (when occurring together with BRAF mutations) is significantly associated with higher TERT mRNA expression, and in glioblastoma we find a trend for increased telomerase expression in cases harbouring TERT promoter mutations. Both in thyroid cancers and glioblastoma, TERT promoter mutations are significantly associated with older age of the patients. Our results show that TERT promoter mutations are relatively frequent in specific types of human cancers, where they lead to enhanced expression of telomerase.

  12. Immune clonal selection optimization method with combining mutation strategies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In artificial immune optimization algorithm, the mutation of immune cells has been considered as the key operator that determines the algorithm performance. Traditional immune optimization algorithms have used a single mutation operator, typically a Gaussian. Using a variety of mutation operators that can be combined during evolution to generate different probability density function could hold the potential for producing better solutions with less computational effort. In view of this, a linear combination mutation operator of Gaussian and Cauchy mutation is presented in this paper, and a novel clonal selection optimization method based on clonal selection principle is proposed also. The simulation results show the combining mutation strategy can obtain the same performance as the best of pure strategies or even better in some cases.

  13. Calreticulin Mutations in Myeloproliferative Neoplasms

    Directory of Open Access Journals (Sweden)

    Noa Lavi

    2014-10-01

    Full Text Available With the discovery of the JAK2V617F mutation in patients with Philadelphia chromosome-negative (Ph− myeloproliferative neoplasms (MPNs in 2005, major advances have been made in the diagnosis of MPNs, in understanding of their pathogenesis involving the JAK/STAT pathway, and finally in the development of novel therapies targeting this pathway. Nevertheless, it remains unknown which mutations exist in approximately one-third of patients with non-mutated JAK2 or MPL essential thrombocythemia (ET and primary myelofibrosis (PMF. At the end of 2013, two studies identified recurrent mutations in the gene encoding calreticulin (CALR using whole-exome sequencing. These mutations were revealed in the majority of ET and PMF patients with non-mutated JAK2 or MPL but not in polycythemia vera patients. Somatic 52-bp deletions (type 1 mutations and recurrent 5-bp insertions (type 2 mutations in exon 9 of the CALR gene (the last exon encoding the C-terminal amino acids of the protein calreticulin were detected and found always to generate frameshift mutations. All detected mutant calreticulin proteins shared a novel amino acid sequence at the C-terminal. Mutations in CALR are acquired early in the clonal history of the disease, and they cause activation of JAK/STAT signaling. The CALR mutations are the second most frequent mutations in Ph− MPN patients after the JAK2V617F mutation, and their detection has significantly improved the diagnostic approach for ET and PMF. The characteristics of the CALR mutations as well as their diagnostic, clinical, and pathogenesis implications are discussed in this review.

  14. Implications of mitochondrial DNA mutations and mitochondrial dysfunction in tumorigenesis

    Institute of Scientific and Technical Information of China (English)

    Jianxin Lu; Lokendra Kumar Sharma; Yidong Bai

    2009-01-01

    Alterations in oxidative phosphorylation resulting from mitochondrial dysfunction have long been hypothesized to be involved in tumorigenesis. Mitochondria have recently been shown to play an important role in regulating both programmed cell death and cell proliferation. Furthermore, mitochondrial DNA (mtDNA) mutations have been found in various cancer cells. However, the role of these mtDNA mutations in tumorigenesis remains largely unknown. This review focuses on basic mitochondrial genetics, mtDNA mutations and consequential mitochondrial dysfunction associated with cancer. The potential molecular mechanisms, mediating the pathogenesis from mtDNA mutations and mitochondrial dysfunction to tumorigenesis are also discussed.

  15. GJB2 (Cx26) gene mutations in Chinese patients with congenital sensorineural deafness and a report of one novel mutation

    Institute of Scientific and Technical Information of China (English)

    肖自安; 谢鼎华

    2004-01-01

    Background Mutations in GJB2 gene are a major cause of autosomal recessive congenital hearing loss and the cause in some rare cases of the autosomal dominant form. The purpose of This study was to investigate the frequency and the features of GJB2 mutations in the Chinese patients with congenital sensorineural deafness. Methods Using PCR amplifying the entire coding region of GJB2 gene and direct DNA sequencing to analyze mutations in this gene among unrelated 69 cases with autosomal recessive congenital nonsyndromic deafness and 27 cases of dominant congenital deafness and 35 sporadic cases. We also detected mutations in GJB2 in 100 control subjects with normal hearing.Results 17.4% (12/69) of the probands in the autosomal recessive, 7.4% (2/27) of dominant families and 5.7% (2/35) of the sporadic congenital deafness patients had deafness-causing mutations in GJB2, respectively. Nine types of the mutations in GJB2 were detected in the recessive and sporadic group. They consisted of five types of polymorphism, and four types of deafness-causing mutation with homozygous 35delG in 1 sporadic (1/35), and 235delC frameshift mutation in 1 sporadic (homozygotes) and 10 recessive patients (2 heterozygotes and 8 homozygotes), and homozygous 442G→A missense mutation and homozygous 465T→A nonsense mutation in 1 different recessive proband, respectively. The 465T→A that related to recessive deafness was a novel mutation found by this study. The homozygous (10/69, 14.5%) and the heterozygous (2/69, 2.9%) GJB2 mutation in the recessive patients (12/69, 17.4%) and the homozygotes in the sporadic patient (2/35, 5.7%) all had congenital severe to profound sensorineural hearing loss. 511G→A missense mutation and 299-300delAT frameshift mutation were found in two autosomal dominant congenital deafness families (2/27, 7.4%). The total mutation frequency of GJB2 was 12.2% (16/131) in the Chinese patients with congenital sensorineural deafness and 235delC was the most common

  16. [ Spectrum of oncogene mutations is different in melanoma subtypes].

    Science.gov (United States)

    Mazurenko, N N; Tsyganova, I V; Lushnikova, A A; Ponkratova, D A; Anurova, O A; Cheremushkin, E A; Mikhailova, I N; Demidov, L V

    2015-01-01

    Melanoma is the most lethal malignancy of skin, which is comprised of clinically relevant molecular subsets defined by specific "driver" mutations in BRAF, NRAS, and KIT genes. Recently, the better results in melanoma treatment were obtained with the mutation-specific inhibitors that have been developed for clinical use and target only patients with particular tumor genotypes. The aim of the study was to characterize the spectrum of "driver" mutations in melanoma subtypes from 137 patients with skin melanoma and 14 patients with mucosal melanoma. In total 151 melanoma cases, the frequency of BRAF, NRAS, KIT, PDGFRA, and KRAS mutations was 55.0, 10.6, 4.0, 0.7, and 0.7%, respectively. BRAF mutations were found in 69% of cutaneous melanoma without UV exposure and in 43% of cutaneous melanoma with chronic UV exposure (p=0.045), rarely in acral and mucosal melanomas. Most of melanomas containing BRAF mutations, V600E (92%) and V600K (6.0%) were potentially sensitive to inhibitors vemurafenib and dabrafenib. NRAS mutations were more common in cutaneous melanoma with chronic UV exposure (26.0%), in acral and mucosal melanomas; the dominant mutations being Q61R/K/L (87.5%). KIT mutations were found in cutaneous melanoma with chronic UV exposure (8.7%) and mucosal one (28.6%), but not in acral melanoma. Most of KIT mutations were identified in exon 11; these tumors being sensitive to tyrosine kinase inhibitors. This is the first monitoring of BRAF, NRAS, KIT, PDGFRA, and KRAS hotspot mutations in different subtypes of melanoma for Russian population. On the base of data obtained, one can suppose that at the molecular level melanomas are heterogeneous tumors that should be tested for "driver" mutations in the each case for evaluation of the potential sensitivity to target therapy. The obtained results were used for treatment of melanoma patients.

  17. TP53 Mutational Spectrum in Endometrioid and Serous Endometrial Cancers.

    Science.gov (United States)

    Schultheis, Anne M; Martelotto, Luciano G; De Filippo, Maria R; Piscuglio, Salvatore; Ng, Charlotte K Y; Hussein, Yaser R; Reis-Filho, Jorge S; Soslow, Robert A; Weigelt, Britta

    2016-07-01

    Endometrial carcinomas (ECs) are heterogeneous at the genetic level. Although TP53 mutations are highly recurrent in serous endometrial carcinomas (SECs), these are also present in a subset of endometrioid endometrial carcinomas (EECs). Here, we sought to define the frequency, pattern, distribution, and type of TP53 somatic mutations in ECs by performing a reanalysis of the publicly available data from The Cancer Genome Atlas (TCGA). A total of 228 EECs (n=186) and SECs (n=42) from the TCGA data set, for which an integrated genomic characterization was performed, were interrogated for the presence and type of TP53 mutations, and for mutations in genes frequently mutated in ECs. TP53 mutations were found in 15% of EECs and 88% of SECs, and in 91% of copy-number-high and 35% of polymerase (DNA directed), epsilon, catalytic subunit (POLE) integrative genomic subtypes. In addition to differences in prevalence, variations in the type and pattern of TP53 mutations were observed between histologic types and between integrative genomic subtypes. TP53 hotspot mutations were significantly more frequently found in SECs (46%) than in EECs (15%). TP53-mutant EECs significantly more frequently harbored a co-occurring PTEN mutation than TP53-mutant SECs. Finally, a subset of TP53-mutant ECs (22%) was found to harbor frameshift or nonsense mutations. Given that nonsense and frameshift TP53 mutations result in distinct p53 immunohistochemical results that require careful interpretation, and that EECs and SECs display different patterns, types, and distributions of TP53 mutations, the use of the TP53/p53 status alone for the differential diagnosis of EECs and SECs may not be sufficient.

  18. Splice site mutations in the ATP7A gene.

    Directory of Open Access Journals (Sweden)

    Tina Skjørringe

    Full Text Available Menkes disease (MD is caused by mutations in the ATP7A gene. We describe 33 novel splice site mutations detected in patients with MD or the milder phenotypic form, Occipital Horn Syndrome. We review these 33 mutations together with 28 previously published splice site mutations. We investigate 12 mutations for their effect on the mRNA transcript in vivo. Transcriptional data from another 16 mutations were collected from the literature. The theoretical consequences of splice site mutations, predicted with the bioinformatics tool Human Splice Finder, were investigated and evaluated in relation to in vivo results. Ninety-six percent of the mutations identified in 45 patients with classical MD were predicted to have a significant effect on splicing, which concurs with the absence of any detectable wild-type transcript in all 19 patients investigated in vivo. Sixty-seven percent of the mutations identified in 12 patients with milder phenotypes were predicted to have no significant effect on splicing, which concurs with the presence of wild-type transcript in 7 out of 9 patients investigated in vivo. Both the in silico predictions and the in vivo results support the hypothesis previously suggested by us and others, that the presence of some wild-type transcript is correlated to a milder phenotype.

  19. 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.

  20. The functional importance of disease-associated mutation

    Directory of Open Access Journals (Sweden)

    Klein Teri E

    2002-09-01

    Full Text Available Abstract Background For many years, scientists believed that point mutations in genes are the genetic switches for somatic and inherited diseases such as cystic fibrosis, phenylketonuria and cancer. Some of these mutations likely alter a protein's function in a manner that is deleterious, and they should occur in functionally important regions of the protein products of genes. Here we show that disease-associated mutations occur in regions of genes that are conserved, and can identify likely disease-causing mutations. Results To show this, we have determined conservation patterns for 6185 non-synonymous and heritable disease-associated mutations in 231 genes. We define a parameter, the conservation ratio, as the ratio of average negative entropy of analyzable positions with reported mutations to that of every analyzable position in the gene sequence. We found that 84.0% of the 231 genes have conservation ratios less than one. 139 genes had eleven or more analyzable mutations and 88.0% of those had conservation ratios less than one. Conclusions These results indicate that phylogenetic information is a powerful tool for the study of disease-associated mutations. Our alignments and analysis has been made available as part of the database at http://cancer.stanford.edu/mut-paper/. Within this dataset, each position is annotated with the analysis, so the most likely disease-causing mutations can be identified.

  1. Mutational analysis of Bloom helicase.

    Science.gov (United States)

    Xi, Xu Guang

    2010-01-01

    DNA helicases are biomolecular motors that convert the chemical energy derived from the hydrolysis of nucleotide triphosphate (usually ATP) into mechanical energy to unwind double-stranded DNA. The unwinding of double-stranded DNA is an essential process for DNA replication, repair, recombination, and transcription. Mutations in human RecQ helicases result in inherent human disease including Bloom's syndrome, Werner's syndrome, and Rothmund-Thomson syndrome. Bloom's syndrome (BS) is a rare human autosomal recessive disorder characterized by a strong predisposition to a wide range of cancers commonly affecting the general population. In order to understand the molecular basis of BS pathology and the mechanism underlying the function of Bloom helicase, we have analyzed BS-causing missense mutations by a combination of structural modeling, site-directed mutagenesis, and biochemical and biophysical approaches. Here, we describe the methods and protocols for measuring ATPase, ATP and DNA binding, DNA strand annealing, and DNA unwinding activities of Bloom protein and its mutant variants. These approaches should be applicable and useful for studying other helicases.

  2. Mitochondrial DNA mutations in mutator mice confer respiration defects and B-cell lymphoma development.

    Directory of Open Access Journals (Sweden)

    Takayuki Mito

    Full Text Available Mitochondrial DNA (mtDNA mutator mice are proposed to express premature aging phenotypes including kyphosis and hair loss (alopecia due to their carrying a nuclear-encoded mtDNA polymerase with a defective proofreading function, which causes accelerated accumulation of random mutations in mtDNA, resulting in expression of respiration defects. On the contrary, transmitochondrial mito-miceΔ carrying mtDNA with a large-scale deletion mutation (ΔmtDNA also express respiration defects, but not express premature aging phenotypes. Here, we resolved this discrepancy by generating mtDNA mutator mice sharing the same C57BL/6J (B6J nuclear background with that of mito-miceΔ. Expression patterns of premature aging phenotypes are very close, when we compared between homozygous mtDNA mutator mice carrying a B6J nuclear background and selected mito-miceΔ only carrying predominant amounts of ΔmtDNA, in their expression of significant respiration defects, kyphosis, and a short lifespan, but not the alopecia. Therefore, the apparent discrepancy in the presence and absence of premature aging phenotypes in mtDNA mutator mice and mito-miceΔ, respectively, is partly the result of differences in the nuclear background of mtDNA mutator mice and of the broad range of ΔmtDNA proportions of mito-miceΔ used in previous studies. We also provided direct evidence that mtDNA abnormalities in homozygous mtDNA mutator mice are responsible for respiration defects by demonstrating the co-transfer of mtDNA and respiration defects from mtDNA mutator mice into mtDNA-less (ρ(0 mouse cells. Moreover, heterozygous mtDNA mutator mice had a normal lifespan, but frequently developed B-cell lymphoma, suggesting that the mtDNA abnormalities in heterozygous mutator mice are not sufficient to induce a short lifespan and aging phenotypes, but are able to contribute to the B-cell lymphoma development during their prolonged lifespan.

  3. Reverse mutations in the fragile X syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.T.; Houck, G.E. Jr.; Ding, Xiaohua [New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY (United States)

    1996-08-09

    Three females were identified who have apparent reversal of fragile X premutations. Based on haplotype analysis of nearby markers, they were found to have inherited a fragile X chromosome from their premutation carrier mothers, and yet had normal size FMR1 repeat alleles. The changes in repeat sizes from mother to daughter was 95 to 35 in the first, 145 to 43 in the second, and 82 to 33 in the third. In the first family, mutations of the nearby microsatellites FRAXAC2 and DXS548 were also observed. In the other two, only mutations involving the FMR1 repeats were found. We suggest differing mutational mechanisms such as gene conversion versus DNA replication slippage may underlie such reversions. We estimate that such revertants may occur among 1% or less of premutation carrier offspring. Our results indicate that women identified to be carriers by linkage should be retested by direct DNA analysis. 35 refs., 5 figs.

  4. Radiation-induced mutations and plant breeding

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, S.H.M.

    1985-01-01

    Ionizing radiation could cause genetic changes in an organism and could modify gene linkages. The induction of mutation through radiation is random and the probability of getting the desired genetic change is low but can be increased by manipulating different parameters such as dose rate, physical conditions under which the material has been irradiated, etc. Induced mutations have been used as a supplement to conventional plant breeding, particularly for creating genetic variability for specific characters such as improved plant structure, pest and disease resistance, and desired changes in maturity period; more than 200 varieties of crop plants have been developed by this technique. The Pakistan Atomic Energy Commission has used this technique fruitfully to evolve better germplasm in cotton, rice, chickpea, wheat and mungbean; some of the mutants have become popular commercial varieties. This paper describes some uses of radiation induced mutations and the results achieved in Pakistan so far.

  5. Selection-Mutation Dynamics of Signaling Games

    Directory of Open Access Journals (Sweden)

    Josef Hofbauer

    2015-01-01

    Full Text Available We study the structure of the rest points of signaling games and their dynamic behavior under selection-mutation dynamics by taking the case of three signals as our canonical example. Many rest points of the replicator dynamics of signaling games are not isolated and, therefore, not robust under perturbations. However, some of them attract open sets of initial conditions. We prove the existence of certain rest points of the selection-mutation dynamics close to Nash equilibria of the signaling game and show that all but the perturbed rest points close to strict Nash equilibria are dynamically unstable. This is an important result for the evolution of signaling behavior, since it shows that the second-order forces that are governed by mutation can increase the chances of successful signaling.

  6. Hereditary Angioedema Resulting from C1 Inhibitor Gene Mutation Leading to Premature Stop Codons%C1抑制物基因突变提前形成终止密码子导致遗传性血管水肿

    Institute of Scientific and Technical Information of China (English)

    徐迎阳; 支玉香

    2013-01-01

    目的 检测7例来自不同遗传性血管水肿家系患者进行C1抑制物(C1 inhibitor,C1 INH)基因突变.方法 2011 至2012年北京协和医院变态反应科诊断为Ⅰ型HAE的7例来自不同HAE家系的先证者及53名健康成人为研究对象,采集外周静脉血,提取基因组DNA,聚合酶链反应扩增C1 INH基因的8个外显子及其相邻序列并进行序列检测.将检测结果与GenBank公布的C1 INH 基因序列相比较,确定突变及基因多态性.结果 7例患者C1 INH基因序列中均鉴定到致病突变,分别为c.289 CA,g.3248T>C,g.3493T>C,g.5755 G>A,g.9498 T>C,g.15193 A>G,g.18012 G>A.结论 本研究鉴定的7种不同C1 INH基因突变中有5种为国内外首次报道,丰富了中国C1 INH基因突变数据库.%Objective To detect C1 inhibitor gene mutations in 7 HAE patients from different families. Methods Seven HAE patients with from different families and 53 healthy controls were recruited in this study. Peripheral blood was collected for genome DNA extraction. All the eight exons and intron-exon boundaries of Cl inhibitor gene were amplified by PCR and sequenced. Mutations and SNPs were detected by alignment with the reference sequences from GenBank. Results Mutations were identified in all the 7 patients: c. 289 C A, g. 3248T>C, g. 3493T > C, g. 5755 G > A, g. 9498 T > C, g. 15193 A > G, g. 18012 G > A) . Conclusions Totally 7 different mutations of Cl-INH gene (3 nonsense and 4 frame shift) were detected in 7 HAE patients, 5 of them were reported for the first time. 7 SNPs were also identified in this patient group.

  7. 白介素7受体α基因缺陷导致严重联合免疫缺陷病一例%A compound heterozygosity mutation in the interleukin-7 recoptor-α gene resulted in severe combined immunodeficiency in a Chinese patient

    Institute of Scientific and Technical Information of China (English)

    张志勇; 赵晓东; 王墨; 于洁; 安云飞; 杨锡强

    2009-01-01

    Objective Mutation in the interleukin-7 receptor-α (IL-TR α) chain causes a rare type of severe combined immunodeficiency (SCID) with presence of NK cells in the peripheral blood. Here we report the molecular and clinical characterization of a compound heterozygosity mutation in the interleukin-7 receptor-α gene that resulted in SCID in a patient firstly from China. Method A 5 month-old male patient and his parents were enrolled in this study. Since 15 days of age, the patient had had recurrent fever, persistent cough and diarrhea. He was in poor general condition with pyorrhea and ulceration of the BCG scar. His brother died of severe infection at 4 months of age. He was initially diagnosed as SCID according to clinical manifestation and immunological analysis. A panel of SCID candidate genes including IL-2RG, RAG1/RAG2 and IL-7R α of patient and his parents were amplified by polymerase chain reaction (PCR) from genomic DNA. Reverse transcription polymerase chain reaction(RT-PCR) was used to amplify the IL-7R α transcripts. Sequencing was performed directly on the PCR products forward and reversely. Result The serum immunoglobulin (Ig) profile was IgG 6867 mg/L (normal range, 3050-8870 mg/L); IgM 206 mg/L and IgA 249 mg/L,IgE 2.3 IU/ml (normal range < 150 IU/ml). The patient was treated with IVIG previously. There were no T-cells but increased percentage of B-cells (58%) and NK cells (42%) in the peripheral blood was found. Needle biopsies from enlarged axillary lymph node was identified positive for Mycobacterium boris under microscope and by culture. The patient had a compound heterozygosity mutation in the IL-7R α gene: on one allele, there was a splice-junction mutation in intrun 4 (intron 4 (+1)GA), for which his father was a carrier; whereas on the other allele, a nonsense mutation at position 638 in exon 5 with a premature stop codon (638 C T, R206X) was identified, for which his mother was a carrier. The splice-junction mutation in intron 4 of IL-7R

  8. Absence of R140Q mutation of isocitrate dehydrogenase 2 in gliomas and breast cancers.

    Science.gov (United States)

    Raynaud, Stéphane; Carbuccia, Nadine; Colin, Carole; Adélaïde, José; Mozziconacci, Marie-Joelle; Metellus, Philippe; Chinot, Olivier; Birnbaum, Daniel; Chaffanet, Max; Figarella-Branger, Dominique

    2010-09-01

    Somatic mutations of isocitrate dehydrogenase (IDH)-1 and IDH2 proteins have been described in gliomas. The mutations target the R132 amino acid residue and the R172 residue in IDH1 and IDH2, respectively. The same mutations were observed in acute myeloid leukemias with normal karyotype, but a new mutation in IDH2 (R140Q substitution) was detected in malignant myeloid diseases and appears to be the most frequent IDH mutation in these pathologies. To the best of our knowledge, no study thus far has reported the presence of this R140Q mutation in IDH2 in tumors of the nervous system and breast cancers. We evaluated IDH1 and IDH2 exon 4 in 48 low-grade gliomas, 58 primary glioblastomas and 94 breast cancers to evaluate the frequency of mutation and investigated the R140Q substitution in IDH2. The results were compared to our recently obtained results in hematopoietic diseases. The frequency of IDH1 and IDH2 mutations in our panel of gliomas was similar to previously reported mutations. No IDH2 R140 mutation was observed. Compared to hematopoietic diseases, the IDH2 R172 mutation was also more rare and IDH1 mutations more prominent in tumors of the nervous system. No IDH1 or IDH2 mutation was detected in the 94 breast cancer samples. Thus, the IDH2 R140 mutation appears to be restricted to hematopoietic diseases.

  9. Beyond BRAFV600: clinical mutation panel testing by next-generation sequencing in advanced melanoma

    Science.gov (United States)

    Siroy, Alan E.; Boland, Genevieve M.; Milton, Denái R.; Roszik, Jason; Frankian, Silva; Malke, Jared; Haydu, Lauren; Prieto, Victor G.; Tetzlaff, Michael; Ivan, Doina; Wang, Wei-Lien; Torres-Cabala, Carlos; Curry, Jonathan; Roy-Chowdhuri, Sinchita; Broaddus, Russell; Rashid, Asif; Stewart, John; Gershenwald, Jeffrey E.; Amaria, Rodabe N.; Patel, Sapna P.; Papadopoulos, Nicholas E.; Bedikian, Agop; Hwu, Wen-Jen; Hwu, Patrick; Diab, Adi; Woodman, Scott E.; Aldape, Kenneth D.; Luthra, Rajyalakshmi; Patel, Keyur P.; Shaw, Kenna R.; Mills, Gordon B.; Mendelsohn, John; Meric-Bernstam, Funda; Kim, Kevin B.; Routbort, Mark J.; Lazar, Alexander J.; Davies, Michael A.

    2014-01-01

    The management of melanoma has evolved due to improved understanding of its molecular drivers. To augment the current understanding of the prevalence, patterns, and associations of mutations in this disease, the results of clinical testing of 699 advanced melanoma patients using a pan-cancer next generation sequencing (NGS) panel of hotspot regions in 46 genes were reviewed. Mutations were identified in 43 of the 46 genes on the panel. The most common mutations were BRAFV600 (36%), NRAS (21%), TP53 (16%), BRAFNon-V600 (6%), and KIT (4%). Approximately one-third of melanomas had >1 mutation detected, and the number of mutations per tumor was associated with melanoma subtype. Concurrent TP53 mutations were the most frequent event in tumors with BRAFV600 and NRAS mutations. Melanomas with BRAFNon-V600 mutations frequently harbored concurrent NRAS mutations (18%), which were rare in tumors with BRAFV600 mutations (1.6%). The prevalence of BRAFV600 and KIT mutations were significantly associated with melanoma subtypes, and BRAFV600 and TP53 mutations were significantly associated with cutaneous primary tumor location. Multiple potential therapeutic targets were identified in metastatic unknown primary and cutaneous melanomas that lacked BRAFV600 and NRAS mutations. These results enrich our understanding of the patterns and clinical associations of oncogenic mutations in melanoma. PMID:25148578

  10. Twelve novel Atm mutations identified in Chinese ataxia telangiectasia patients.

    Science.gov (United States)

    Huang, Yu; Yang, Lu; Wang, Jianchun; Yang, Fan; Xiao, Ying; Xia, Rongjun; Yuan, Xianhou; Yan, Mingshan

    2013-09-01

    Ataxia telangiectasia (A-T) is an autosomal recessive disease characterized mainly by progressive cerebellar ataxia, oculocutaneous telangiectasia, and immunodeficiency. This disease is caused by mutations of the ataxia telangiectasia mutated (Atm) gene. More than 500 Atm mutations that are responsible for A-T have been identified so far. However, there have been very few A-T cases reported in China, and only two Chinese A-T patients have undergone Atm gene analysis. In order to systemically investigate A-T in China and map their Atm mutation spectrum, we recruited eight Chinese A-T patients from six unrelated families nationwide. Using direct sequencing of genomic DNA and the multiplex ligation-dependent probe amplification, we identified twelve pathogenic Atm mutations, including one missense, four nonsense, five frameshift, one splicing, and one large genomic deletion. All the Atm mutations we identified were novel, and no homozygous mutation and founder-effect mutation were found. These results suggest that Atm mutations in Chinese populations are diverse and distinct largely from those in other ethnic areas.

  11. Identification of trunk mutations in gastric carcinoma: a case study.

    Science.gov (United States)

    Zhou, Zhan; Wu, Shanshan; Lai, Jun; Shi, Yuan; Qiu, Chixiao; Chen, Zhe; Wang, Yufeng; Gu, Xun; Zhou, Jie; Chen, Shuqing

    2017-07-17

    Intratumor heterogeneity (ITH) poses an urgent challenge for cancer precision medicine because it can cause drug resistance against cancer target therapy and immunotherapy. The search for trunk mutations that are present in all cancer cells is therefore critical for each patient. In this study, we aimed to evaluate the efficiency of multiregional sequencing for the identification of trunk mutations present in all regions of a tumor as a case study. We applied multiregional whole-exome sequencing (WES) to investigate the genetic heterogeneity and homogeneity of a case of gastric carcinoma. Approximately 83% of common missense mutations present in two samples and approximately 89% of common missense mutations present in three samples were trunk mutations. Notably, trunk mutations appeared to have higher variant allele frequencies (VAFs) than non-trunk mutations. Our results indicate that small-scale multiregional sampling and subsequent screening of low VAF somatic mutations might be a cost-effective strategy for identifying the majority of trunk mutations in gastric carcinoma.

  12. Chlorambucil effectively induces deletion mutations in mouse germ cells.

    Science.gov (United States)

    Russell, L B; Hunsicker, P R; Cacheiro, N L; Bangham, J W; Russell, W L; Shelby, M D

    1989-01-01

    The chemotherapeutic agent chlorambucil was found to be more effective than x-rays or any chemical investigated to date in inducing high yields of mouse germ-line mutations that appear to be deletions or other structural changes. Induction of mutations involving seven specific loci was studied after exposures of various male germ-cell stages to chlorambucil at 10-25 mg/kg. A total of 60,750 offspring was scored. Mutation rates in spermatogonial stem cells were not significantly increased over control values; this negative result is not attributable to selective elimination of mutant cells. Mutations were, however, clearly induced in treated post-stem-cell stages, among which marked variations in mutational response were found. Maximum yield occurred after exposure of early spermatids, with approximately 1% of all offspring carrying a specific-locus mutation in the 10 mg/kg group. The stage-response pattern for chlorambucil differs from that of all other chemicals investigated to date in the specific-locus test. Thus far, all but one of the tested mutations induced by chlorambucil in post-stem-cell stages have been proved deletions or other structural changes by genetic, cytogenetic, and/or molecular criteria. Deletion mutations have recently been useful for molecular mapping and for structure-function correlations of genomic regions. For generating presumed large-lesion germ-line mutations at highest frequencies, chlorambucil may be the mutagen of choice. Images PMID:2726748

  13. Chlorambucil effectively induces deletion mutations in mouse germ cells

    Energy Technology Data Exchange (ETDEWEB)

    Russell, L.B.; Hunsicker, P.R.; Cacheiro, N.L.A.; Bangham, J.W.; Russell, W.L.; Shelby, M.D. (Oak Ridge National Laboratory, TN (USA))

    1989-05-01

    The chemotherapeutic agent chlorambucil was found to be more effective than x-rays or any chemical investigated to data in inducing high yields of mouse germ-line mutations that appear to be deletions or other structural changes. Induction of mutations involving seven specific loci was studied after exposures of various male germ-cell stages to chlorambucil at 10-25 mg/kg. A total of 60,750 offspring was scored. Mutation rates in spermatogonial stem cells were not significantly increased over control values; this negative result is not attributable to selective elimination of mutant cells. Mutations were, however, clearly induced in treated post-stem-cell stages, among which marked variations in mutational response were found. Maximum yield occurred after exposure of early spermatids, with {approx} 1% of all offspring carrying a specific-locus mutation in the 10 mg/kg group. The stage-response pattern for chlorambucil differs from that of all other chemicals investigated to date in the specific-locus test. Thus far, all but one of the tested mutations induced by chlorambucil in post-stem-cell stages have been proved deletions or other structural changes by genetic, cytogenetic, and/or molecular criteria. Deletion mutations have recently been useful for molecular mapping and for structure-function correlations of genomic regions. For generating presumed large-lesion germline mutations at highest frequencies, chlorambucil may be the mutagen of choice.

  14. Acute myeloid leukemia with DNMT3A mutations.

    Science.gov (United States)

    Li, Yunlong; Zhu, Baosheng

    2014-09-01

    Acute myeloid leukemia (AML), a type of blood cancer, is characterized by an increase in the number of abnormal white blood cells in the bone marrow, frequently causing hematopoietic insufficiency. It is a heterogeneous disease featuring cytogenetic aberrations, recurrent somatic mutations and alterations in gene expression. DNA (cytosine-5-)-methyltransferase 3 alpha (DNMT3A) is closely associated with epigenetic modifications in mammalian development and disease. More recent studies have identified recurrent somatic mutations in DNMT3A in AML, most of which are heterozygous. The DNMT3A R882 codon is a mutational hotspot. The frequency of DNMT3A mutations varies among different countries, but mutations have been found to be associated with cytogenetics, age, white blood cell (WBC) count, prognosis and response of patients to chemotherapy. The normal function of DNMT3A can be disrupted by these mutations, which subsequently results in an abnormality of epigenetic modification. These data suggest that mutations in the DNMT3A gene represent a novel class of mutations in AML with distinct biological and clinical features. Further studies are needed to elucidate the exact molecular mechanism and function of DNMT3A mutations in leukemogenesis.

  15. Mutation study of Spanish patients with Hereditary Hemorrhagic Telangiectasia

    Directory of Open Access Journals (Sweden)

    Blanco Francisco J

    2008-08-01

    Full Text Available Abstract Background Hereditary Hemorrhagic Telangiectasia (HHT is an autosomal dominant and age-dependent vascular disorder characterised mainly by mutations in the Endoglin (ENG or activin receptor-like kinase-1 (ALK1, ACVRL1 genes. Methods Here, we have identified 22 ALK1 mutations and 15 ENG mutations, many of which had not previously been reported, in independent Spanish families afflicted with HHT. Results We identified mutations in thirty-seven unrelated families. A detailed analysis of clinical symptoms was recorded for each patient analyzed, with a higher significant presence of pulmonary arteriovenous malformations (PAVM in HHT1 patients over HHT2. Twenty-two mutations in ALK1 and fifteen in ENG genes were identified. Many of them, almost half, represented new mutations in ALK1 and in ENG. Missense mutations in ENG and ALK1 were localized in a tridimensional protein structure model. Conclusion Overall, ALK1 mutations (HHT2 were predominant over ENG mutations (HHT1 in our Spanish population, in agreement with previous data from our country and other Mediterranean countries (France, Italy, but different to Northern Europe or North America. There was a significant increase of PAVM associated with HHT1 over HHT2 in these families.

  16. IDH Mutation Analysis in Ewing Sarcoma Family Tumors

    Directory of Open Access Journals (Sweden)

    Ki Yong Na

    2015-05-01

    Full Text Available Background: Isocitrate dehydrogenase (IDH catalyzes the oxidative decarboxylation of isocitrate to yield α-ketoglutarate (α-KG with production of reduced nicotinamide adenine dinucleotide (NADH. Dysfunctional IDH leads to reduced production of α-KG and NADH and increased production of 2-hydroxyglutarate, an oncometabolite. This results in increased oxidative damage and stabilization of hypoxia-inducible factor α, causing cells to be prone to tumorigenesis. Methods: This study investigated IDH mutations in 61 Ewing sarcoma family tumors (ESFTs, using a pentose nucleic acid clamping method and direct sequencing. Results: We identified four cases of ESFTs harboring IDH mutations. The number of IDH1 and IDH2 mutations was equal and the subtype of IDH mutations was variable. Clinicopathologic analysis according to IDH mutation status did not reveal significant results. Conclusions: This study is the first to report IDH mutations in ESFTs. The results indicate that ESFTs can harbor IDH mutations in previously known hot-spot regions, although their incidence is rare. Further validation with a larger case-based study would establish more reliable and significant data on prevalence rate and the biological significance of IDH mutations in ESFTs.

  17. A new experimental system for study on adaptive mutations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A super-repressed mutant of purR (purRS), which encodes arepressor protein controlling expression of purine biosynthetic genes in Salmonella typhimurium, grew very slowly on NCE medium with 10 mg / mL Ade and lactose as sole carbon source (cannot form colonies). However, a phenomenon of late-arising mutations was observed when purRS mutants were spread on NCE+lactose plates and subjected to a prolonged non-lethal selection. The reconstruction experiments of revertants showed that the late-arising "lac+" mutants are not slow growing mutants. Statistical analysis indicated that the distribution of late-arising mutants is Poisson distribution, showing that reversion occurred after plating. The result of co-transductional analysis preliminarily showed that late-arising mutation occurred at selected gene purR or 16 bp PUR box, cis element of structural gene purD. The above results suggest that the phenomenon of late-arising mutation observed by our system is a result of adaptive mutations which are different from random mutations. This is the first time to extend target genes at which adaptive mutations could occur from structural genes involved in carbon metabolism and amino acid biosynthesis to trans regulatory gene coding repressor protein. Our results have provided not only a new proof for generality of adaptive mutations but also a new system for study on adaptive mutations.

  18. Mutation classes of skew-symmetrizable 3x3 matrices

    CERN Document Server

    Seven, Ahmet

    2010-01-01

    In this paper, we determine representatives for the mutation classes of skew-symmetrizable 3x3 matrices and associated graphs using a natural minimality condition, generalizing and strengthening results of Beineke-Brustle-Hille and Felikson-Shapiro-Tumarkin. Furthermore, we obtain a new numerical invariant for the mutation operation on skew-symmetrizable matrices of arbitrary size.

  19. Oxidative Stress in Dilated Cardiomyopathy Caused by MYBPC3 Mutation

    NARCIS (Netherlands)

    T.L. Lynch (Thomas L.); M. Sivaguru (Mayandi); M. Velayutham (Murugesan); A.J. Cardounel (Arturo J.); M. Michels (Michelle); D. Barefield (David); S. Govindan (Suresh); C.D. Remedios (Cristobal Dos); J. van der Velden (Jolanda); S. Sadayappan (Sakthivel)

    2015-01-01

    textabstractCardiomyopathies can result from mutations in genes encoding sarcomere proteins including MYBPC3, which encodes cardiac myosin binding protein-C (cMyBP-C). However, whether oxidative stress is augmented due to contractile dysfunction and cardiomyocyte damage in MYBPC3-mutated cardiomyopa

  20. Mutations in TBL1X are associated with central hypothyroidism

    NARCIS (Netherlands)

    Heinen, C.A. (Charlotte A.); M. Losekoot (Monique); Sun, Y. (Yu); Watson, P.J. (Peter J.); Fairall, L. (Louise); S.D. Joustra (Sjoerd); N. Zwaveling-Soonawala (Nitash); W. Oostdijk (Wilma); E.L.T. van den Akker (Erica); M. Alders (Mariëlle); G.W.E. Santen (Gijs); R.R. van Rijn (Rick); W.A. Dreschler (Wouter); Surovtseva, O.V. (Olga V.); N.R. Biermasz; R.C.M. Hennekam (Raoul); J.M. Wit (Jan); Schwabe, J.W.R. (John W.R.); A. Boelen (Anita); E. Fliers (Eric); A.S.P. van Trotsenburg (Paul)

    2016-01-01

    textabstractContext: Isolated congenital central hypothyroidism (CeH) can result from mutations in TRHR, TSHB, and IGSF1, but its etiology often remains unexplained. We identified a missense mutation in the transducin X-like protein 1, X-linked (TBL1X) gene in three relatives diagnosed with isolated

  1. CNGA3 mutations in hereditary cone photoreceptor disorders

    NARCIS (Netherlands)

    Wissinger, B; Gamer, D; Jagle, H; Giorda, R; Marx, T; Mayer, S; Tippmann, S; Broghammer, M; Jurklies, B; Rosenberg, T; Jacobson, SG; Sener, EC; Tatlipinar, S; Hoyng, CB; Castellan, C; Bitoun, P; Andreasson, S; Rudolph, G; Kellner, U; Lorenz, B; Wolff, G; Verellen-Dumoulin, C; Schwartz, M; Cremers, FPM; Apfelstedt-ylla, E; Zrenner, E; Salati, R; Sharpe, LT; Kohl, S

    2001-01-01

    We recently showed that mutations in the CNGA3 gene encoding the alpha -subunit of the cone photoreceptor cGMP-gated channel cause autosomal recessive complete achromatopsia linked to chromosome 2q11. We now report the results of a first comprehensive screening for CNGA3 mutations in a cohort of 258

  2. CNGA3 mutations in hereditary cone photoreceptor disorders

    NARCIS (Netherlands)

    Wissinger, B; Gamer, D; Jagle, H; Giorda, R; Marx, T; Mayer, S; Tippmann, S; Broghammer, M; Jurklies, B; Rosenberg, T; Jacobson, SG; Sener, EC; Tatlipinar, S; Hoyng, CB; Castellan, C; Bitoun, P; Andreasson, S; Rudolph, G; Kellner, U; Lorenz, B; Wolff, G; Verellen-Dumoulin, C; Schwartz, M; Cremers, FPM; Apfelstedt-ylla, E; Zrenner, E; Salati, R; Sharpe, LT; Kohl, S

    2001-01-01

    We recently showed that mutations in the CNGA3 gene encoding the alpha -subunit of the cone photoreceptor cGMP-gated channel cause autosomal recessive complete achromatopsia linked to chromosome 2q11. We now report the results of a first comprehensive screening for CNGA3 mutations in a cohort of 258

  3. Cancer-Associated IDH1 Mutations Produce 2-hydroxyglutarate

    Energy Technology Data Exchange (ETDEWEB)

    Dang, L.; White, D; Gross, S; Bennett, B; Bittinger, M; Driggers, E; Fantin, V; Jang, H; Jin, S; et al.

    2009-01-01

    Mutations in the enzyme cytosolic isocitrate dehydrogenase 1 (IDH1) are a common feature of a major subset of primary human brain cancers. These mutations occur at a single amino acid residue of the IDH1 active site, resulting in loss of the enzyme's ability to catalyse conversion of isocitrate to {alpha}-ketoglutarate. However, only a single copy of the gene is mutated in tumours, raising the possibility that the mutations do not result in a simple loss of function. Here we show that cancer-associated IDH1 mutations result in a new ability of the enzyme to catalyse the NADPH-dependent reduction of {alpha}-ketoglutarate to R(-)-2-hydroxyglutarate (2HG). Structural studies demonstrate that when arginine 132 is mutated to histidine, residues in the active site are shifted to produce structural changes consistent with reduced oxidative decarboxylation of isocitrate and acquisition of the ability to convert {alpha}-ketoglutarate to 2HG. Excess accumulation of 2HG has been shown to lead to an elevated risk of malignant brain tumours in patients with inborn errors of 2HG metabolism. Similarly, in human malignant gliomas harbouring IDH1 mutations, we find markedly elevated levels of 2HG. These data demonstrate that the IDH1 mutations result in production of the onco-metabolite 2HG, and indicate that the excess 2HG which accumulates in vivo contributes to the formation and malignant progression of gliomas.

  4. Structural Effects of Oncogenic PI3K alpha Mutations

    Energy Technology Data Exchange (ETDEWEB)

    S Gabelli; C Huang; D Mandelker; O Schmidt-Kittler; B Vogelstein; L Amzel

    2011-12-31

    Physiological activation of PI3K{alpha} is brought about by the release of the inhibition by p85 when the nSH2 binds the phosphorylated tyrosine of activated receptors or their substrates. Oncogenic mutations of PI3K{alpha} result in a constitutively activated enzyme that triggers downstream pathways that increase tumor aggressiveness and survival. Structural information suggests that some mutations also activate the enzyme by releasing p85 inhibition. Other mutations work by different mechanisms. For example, the most common mutation, His1047Arg, causes a conformational change that increases membrane association resulting in greater accessibility to the substrate, an integral membrane component. These effects are examples of the subtle structural changes that result in increased activity. The structures of these and other mutants are providing the basis for the design of isozyme-specific, mutation-specific inhibitors for individualized cancer therapies.

  5. Limit Cycles Sparked by Mutation in the Repeated Prisoner's Dilemma

    CERN Document Server

    Toupo, Danielle F P; Strogatz, Steven H

    2015-01-01

    We explore a replicator-mutator model of the repeated Prisoner's Dilemma involving three strategies: always cooperate (ALLC), always defect (ALLD), and tit-for-tat (TFT). The dynamics resulting from single unidirectional mutations are considered, with detailed results presented for the mutations TFT $\\rightarrow$ ALLC and ALLD $\\rightarrow$ ALLC. For certain combinations of parameters, given by the mutation rate $\\mu$ and the complexity cost $c$ of playing tit-for-tat, we find that the population settles into limit cycle oscillations, with the relative abundance of ALLC, ALLD, and TFT cycling periodically. Surprisingly, these oscillations can occur for unidirectional mutations between any two strategies. In each case, the limit cycles are created and destroyed by supercritical Hopf and homoclinic bifurcations, organized by a Bogdanov-Takens bifurcation. Our results suggest that stable oscillations are a robust aspect of a world of ALLC, ALLD, and costly TFT; the existence of cycles does not depend on the deta...

  6. Structural effects of oncogenic PI3Kα mutations.

    Science.gov (United States)

    Gabelli, Sandra B; Huang, Chuan-Hsiang; Mandelker, Diana; Schmidt-Kittler, Oleg; Vogelstein, Bert; Amzel, L Mario

    2010-01-01

    Physiological activation of PI3Kα is brought about by the release of the inhibition by p85 when the nSH2 binds the phosphorylated tyrosine of activated receptors or their substrates. Oncogenic mutations of PI3Kα result in a constitutively activated enzyme that triggers downstream pathways that increase tumor aggressiveness and survival. Structural information suggests that some mutations also activate the enzyme by releasing p85 inhibition. Other mutations work by different mechanisms. For example, the most common mutation, His1047Arg, causes a conformational change that increases membrane association resulting in greater accessibility to the substrate, an integral membrane component. These effects are examples of the subtle structural changes that result in increased activity. The structures of these and other mutants are providing the basis for the design of isozyme-specific, mutation-specific inhibitors for individualized cancer therapies.

  7. Mutations of short tandem repeat loci in cases of paternity testing in Chinese.

    Science.gov (United States)

    Sun, Mao; Zhang, XiaoNan; Wu, Dan; Shen, Qi; Wu, YuanMing; Fu, ShanMin

    2016-09-01

    In order to find out the characteristics of genetic mutations in 15 short tandem repeat (STR) loci, 3734 parentage cases were analyzed using AmpFlSTR Sinofiler kit. The allele source, mutation rate, and mutation rule of the STR loci were determined. Seventy mutations were observed in all cases for paternity testing. Among 15 STR loci, the highest mutation rate was observed in D12S391 (0.21 %), but the D5S818 gene mutation rate was relatively low (0.02 %). One-step mutation cases accounted for 95.7 % of all of the cases monitored. And the mutations in this study mainly showed paternal mutation (64/70). The research results are of great significance for identification and paternity tests and for the improvement of genetic studies on Chinese population in the future.

  8. Mutation Rate at Commonly Used Forensic STR Loci: Paternity Testing Experience

    Directory of Open Access Journals (Sweden)

    Faruk Aşıcıoğlua

    2004-01-01

    Full Text Available Paternity tests are carried out by the analysis of hypervariable short tandem repeat DNA loci. These microsatellite sequences mutate at a higher rate than that of bulk DNA. The occurrence of germline mutations at STR loci posses problems in interpretation of resulting genetic profiles. We recently analyzed 59–159 parent/child allele transfers at 13 microsatellite loci. We identified 12 mutations in 7 microsatellite loci. No mutations were occurred in other 6 loci. The highest mutation rate was observed with 5 mutations at D8S1179 locus at different alleles. The event was always single repeat related. The mutation rate was between 0 and 1.5 x 10-2 per locus per gamete per generation. The mutation event is very crucial for forensic DNA testing and accumulation of STR mutation data is extremely important for genetic profile interpretation.

  9. Frameshift mutations in dentin phosphoprotein and dependence of dentin disease phenotype on mutation location.

    Science.gov (United States)

    Nieminen, Pekka; Papagiannoulis-Lascarides, Lisa; Waltimo-Siren, Janna; Ollila, Päivi; Karjalainen, Sara; Arte, Sirpa; Veerkamp, Jaap; Tallon Walton, Victoria; Chimenos Küstner, Eduard; Siltanen, Tarja; Holappa, Heidi; Lukinmaa, Pirjo-Liisa; Alaluusua, Satu

    2011-04-01

    We describe results from a mutational analysis of the region of the dentin sialophosphoprotein (DSPP) gene encoding dentin phosphoprotein (DPP) in 12 families with dominantly inherited dentin diseases. In eight families (five mutations in the N-terminal third of DPP), the clinical and radiologic features were uniform and compatible with dentin dysplasia type II (DD-II) with major clinical signs in the deciduous dentition. In the other families (four mutations in the more C-terminal part), the permanent teeth also were affected, and the diseases could be classified as variants of dentinogenesis imperfecta. Attrition was not prominent, but periapical infections were common. Discoloring with varying intensity was evident, and pulps and root canals were obliterated in the permanent dentition. All mutations caused a frameshift that replaced the Ser-Ser-Asx repeat by a code for a hydrophobic downstream sequence of approximately original length. We conclude that frameshift mutations in DSPP explain a significant part of dentin diseases. Furthermore, we propose that the location of the mutation is reflected in the phenotypic features as a gradient from DD-II to more severe disease that does not conform to the classic definitions of DI-II. Copyright © 2011 American Society for Bone and Mineral Research.

  10. Fitness of Arabidopsis thaliana mutation accumulation lines whose spontaneous mutations are known.

    Science.gov (United States)

    Rutter, Matthew T; Roles, Angela; Conner, Jeffrey K; Shaw, Ruth G; Shaw, Frank H; Schneeberger, Korbinian; Ossowski, Stephan; Weigel, Detlef; Fenster, Charles B

    2012-07-01

    Despite the fundamental importance of mutation to the evolutionary process, we have little knowledge of the direct consequences of specific spontaneous mutations to the fitness of the organism. Combining results of whole-genome sequencing with repeated field assays of survival and reproduction, we quantify the combined effects on fitness of spontaneous mutations identified in Arabidopsis thaliana. We demonstrate that the effects are beneficial, deleterious, or neutral depending on the environmental context. Some lines, bearing mutations disrupting known loci, differ strongly in fitness from the founder or premutation genotype. Those effects vary across environments, for example, a line with a major deletion spanning a transcription factor gene expressed lower fitness than the founder under most conditions but exceeded the founder's fitness in one environment. The large contribution of genotype by environment interaction (G × E) to mutation effects on fitness implies spatial and/or temporal variation in selection on new mutations and could contribute to the maintenance of standing genetic variation. © 2012 The Author(s).

  11. Muller's ratchet with compensatory mutations

    CERN Document Server

    Pfaffelhuber, Peter; Wakolbinger, Anton

    2011-01-01

    We consider an infinite dimensional system of stochastic differential equations which describes the evolution of type frequencies in a large population. Random reproduction is modeled by a Wright-Fisher noise whose inverse diffusion coefficient $N$ corresponds to the total population size. The type of an individual is the number $k$ of deleterious mutations it carries. We assume that fitness of individuals carrying $k$ mutations is decreased by $\\alpha k$ for some $\\alpha >0$. Along the individual lines of descent, (new) mutations accumulate at rate $\\lambda$ per generation, and each of these mutations has a small probability $\\gamma$ per generation to disappear. While the case $\\gamma =0 $ is known as (the Fleming-Viot version of) {\\em Muller's ratchet}, the case $\\gamma > 0$ is referred to as that of {\\em compensatory mutations} in the biological literature. In the former case ($\\gamma=0$), an ever increasing number of mutations is accumulated over time, while in the latter ($\\gamma > 0$) this is prevented ...

  12. JAK2-V617F mutation in patients with myeloproliferative neoplasms: Association with FLT3-ITD mutation

    Directory of Open Access Journals (Sweden)

    Čolović Milica

    2010-01-01

    Full Text Available Introduction. An acquired somatic mutation V617F in Janus kinase 2 gene (JAK2 is the cause of uncontrolled proliferation in patients with myeloproliferative neoplasms. It is known that uncontrolled myeloid cell proliferation is also provoked by alteration in other genes, e.g. mutations in receptor tyrosine kinase FLT3 gene. FLT3 represents the most frequently mutated gene in acute myeloid leukaemia. Interestingly, mutated FLT3- ITD (internal tandem duplication protein is a member of the same signalling pathway as JAK2 protein, the STAT5 signalling pathway. STAT5 activation is recognized as important for selfrenewal of haematopoetic stem cells. Objective. The aim of this study was the detection of JAK2- V617F mutation in patients with myeloproliferative neoplasms. Additionally, we investigated the presence of FLT3-ITD mutation in JAK2-V617F-positive patients in order to shed the light on the hypothesis of a similar role of these two molecular markers in haematological malignancies. Methods. Using allele-specific PCR, 61 patients with known or suspected diagnosis of myeloproliferative neoplasms were tested for the presence of JAK2-V617F mutation. Samples that were positive for JAK2 mutation were subsequently tested for the presence of FLT3-ITD mutation by PCR. Results. Eighteen of 61 analysed patients were positive for JAK2-V617F mutation. Among them, 8/18 samples were diagnosed as polycythaemia vera, and 10/18 as essential thrombocythaemia. None of JAK2-V617F-positive patient was positive for FLT3-ITD mutation. Conclusion. This study suggests that one activating mutation is sufficient for aberrant cell proliferation leading to malignant transformation of haematopoetic stem cell.

  13. Germ-line origins of mutation in families with hemophilia B: The sex ratio varies with the type of mutation

    Energy Technology Data Exchange (ETDEWEB)

    Ketterling, R.P.; Vielhaber, E.; Bottema, C.D.K.; Schaid, D.J.; Sommer, S.S. (Mayo Clinic/Foundation, Rochester, MN (United States)); Cohen, M.P. (Vanderbilt Univ., Nashville, TN (United States)); Sexauer, C.L. (Children' s Hospital, Oklahoma City, OK (United States))

    1993-01-01

    Previous epidemiological and biochemical studies have generated conflicting estimates of the sex ratio of mutation. Direct genomic sequencing in combination with haplotype analysis extends previous analyses by allowing the precise mutation to be determined in a given family. From analysis of the factor IX gene of 260 consecutive families with hemophilia B, the authors report the germ-line origin of mutation in 25 families. When combined with 14 origins of mutation reported by others and with 4 origins previously reported by them, a total of 25 occur in the female germ line, and 18 occur in the male germ line. The excess of germ-line origins in females does not imply an overall excess mutation rate per base pair in the female germ line. Bayesian analysis of the data indicates that the sex ratio varies with the type of mutation. The aggregate of single-base substitutions shows a male predominance of germ-line mutations (P < .002). The maximum-likelihood estimate of the male predominance is 3.5-fold. Of the single-base substitutions, deletions display a sex ratio of unity. Analysis of the parental age at transmission of a new mutation suggests that germ-line mutations are associated with a small increase in parental age in females but little, if any, increase in males. Although direct genomic sequencing offers a general method for defining the origin of mutation in specific families, accurate estimates of the sex ratios of different mutational classes require large sample sizes and careful correction for multiple biases of ascertainment. The biases in the present data result in an underestimate of the enhancement of mutation in males. 62 refs., 1 fig., 5 tabs.

  14. The phenotypic features of osteogenesis imperfecta resulting from a mutation of the carboxyl-terminal pro alpha 1(I) propeptide that impairs the assembly of type I procollagen and formation of the extracellular matrix

    NARCIS (Netherlands)

    Cole, WG; Chow, CW; Bateman, JF; Sillence, DO

    1996-01-01

    The features of a baby with lethal perinatal osteogenesis imperfecta (OI-II), resulting from the substitution of tryptophan 94 by cysteine in the carboxyl-terminal propeptide of pro alpha 1(I) chains of type I procollagen, were studied. The limbs and torso were of normal length, shape, and proportio

  15. The phenotypic features of osteogenesis imperfecta resulting from a mutation of the carboxyl-terminal pro alpha 1(I) propeptide that impairs the assembly of type I procollagen and formation of the extracellular matrix

    NARCIS (Netherlands)

    Cole, WG; Chow, CW; Bateman, JF; Sillence, DO

    1996-01-01

    The features of a baby with lethal perinatal osteogenesis imperfecta (OI-II), resulting from the substitution of tryptophan 94 by cysteine in the carboxyl-terminal propeptide of pro alpha 1(I) chains of type I procollagen, were studied. The limbs and torso were of normal length, shape, and proportio

  16. The phenotypic features of osteogenesis imperfecta resulting from a mutation of the carboxyl-terminal pro alpha 1(I) propeptide that impairs the assembly of type I procollagen and formation of the extracellular matrix

    NARCIS (Netherlands)

    Cole, WG; Chow, CW; Bateman, JF; Sillence, DO

    1996-01-01

    The features of a baby with lethal perinatal osteogenesis imperfecta (OI-II), resulting from the substitution of tryptophan 94 by cysteine in the carboxyl-terminal propeptide of pro alpha 1(I) chains of type I procollagen, were studied. The limbs and torso were of normal length, shape, and

  17. Analysis of FUS gene mutation in familial amyotrophic lateral sclerosis within an Italian cohort.

    Science.gov (United States)

    Ticozzi, N; Silani, V; LeClerc, A L; Keagle, P; Gellera, C; Ratti, A; Taroni, F; Kwiatkowski, T J; McKenna-Yasek, D M; Sapp, P C; Brown, R H; Landers, J E

    2009-10-13

    Mutations in the FUS gene on chromosome 16 have been recently discovered as a cause of familial amyotrophic lateral sclerosis (FALS). This study determined the frequency and identities of FUS gene mutations in a cohort of Italian patients with FALS. We screened all 15 coding exons of FUS for mutations in 94 Italian patients with FALS. We identified 4 distinct missense mutations in 5 patients; 2 were novel. The mutations were not present in 376 healthy Italian controls and thus are likely to be pathogenic. Our results demonstrate that FUS mutations cause approximately 4% of familial amyotrophic lateral sclerosis cases in the Italian population.

  18. MUTATIONAL SCREEN AT THE OEYTS-JEGHERS (LKB1) LOCUS IN SPORDIC COLON AND OVARIAN TUMORS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To screen LKB1 mutation in sporadic colon and ovarian tumors. Methods: Using PCR-SSCP analysis, 72 colon cancer, 45 ovarian cancer, 14 granulosa cell tumor were screened for LKB1 mutation. Results: no mutation was in sporadic colon and ovarian adenocarcinomas. Two mutations were detected in one of the granulosa cell tumors: a mis-sense mutation affecting the putative start codon (ATG?ACG, MIT); and a silent change in erxon 7 (CTT?CTA, leucine). Conclusion: LKB1 mutations in sporadic colon and ovarian cancers are rare event and LKB1 is not the target gene lost on chromosome 19p13.3 in ovarian cancers.

  19. IL7R and RAG1/2 genes mutations/polymorphisms in patients with SCID.

    Science.gov (United States)

    Safaei, Sepideh; Pourpak, Zahra; Moin, Mostafa; Houshmand, Massoud

    2011-06-01

    SCID disorder is major failure of the immune system, usually genetic. The aim of this study was on mutations detection of RAG1, RAG2, and IL7RG genes in SCID cases. Mutation detection was performed by PCR sequencing. Our results indicated that 13 mutations were found through cases which include 4 mutations in IL7R gene (T661I, I138V, T56A, C57W), 7 mutations in RAG1 (W896X, W204R, M324V, T731I, M1006V, K820R, and R249H), and 2 mutations in RAG2 gene (R229W, ΔT251).

  20. Common breast cancer susceptibility alleles are associated with tumor subtypes in BRCA1 and BRCA2 mutation carriers: results from the Consortium of Investigators of Modifiers of BRCA1/2

    DEFF Research Database (Denmark)

    Mulligan, Anna Marie; Couch, Fergus J; Barrowdale, Daniel

    2011-01-01

    -negative breast cancer risk for both BRCA1 and BRCA2 carriers. In BRCA2 carriers, SNPs in FGFR2, TOX3, LSP1, SLC4A7/NEK10, 5p12, 2q35, and1p11.2 were significantly associated with ER-positive but not ER-negative disease. Similar results were observed when differentiating breast cancer cases by PR status...

  1. The Mutational Landscape of Circulating Tumor Cells in Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Yuji Mishima

    2017-04-01

    Full Text Available The development of sensitive and non-invasive “liquid biopsies” presents new opportunities for longitudinal monitoring of tumor dissemination and clonal evolution. The number of circulating tumor cells (CTCs is prognostic in multiple myeloma (MM, but there is little information on their genetic features. Here, we have analyzed the genomic landscape of CTCs from 29 MM patients, including eight cases with matched/paired bone marrow (BM tumor cells. Our results show that 100% of clonal mutations in patient BM were detected in CTCs and that 99% of clonal mutations in CTCs were present in BM MM. These include typical driver mutations in MM such as in KRAS, NRAS, or BRAF. These data suggest that BM and CTC samples have similar clonal structures, as discordances between the two were restricted to subclonal mutations. Accordingly, our results pave the way for potentially less invasive mutation screening of MM patients through characterization of CTCs.

  2. Stem cell divisions, somatic mutations, cancer etiology, and cancer prevention.

    Science.gov (United States)

    Tomasetti, Cristian; Li, Lu; Vogelstein, Bert

    2017-03-24

    Cancers are caused by mutations that may be inherited, induced by environmental factors, or result from DNA replication errors (R). We studied the relationship between the number of normal stem cell divisions and the risk of 17 cancer types in 69 countries throughout the world. The data revealed a strong correlation (median = 0.80) between cancer incidence and normal stem cell divisions in all countries, regardless of their environment. The major role of R mutations in cancer etiology was supported by an independent approach, based solely on cancer genome sequencing and epidemiological data, which suggested that R mutations are responsible for two-thirds of the mutations in human cancers. All of these results are consistent with epidemiological estimates of the fraction of cancers that can be prevented by changes in the environment. Moreover, they accentuate the importance of early detection and intervention to reduce deaths from the many cancers arising from unavoidable R mutations.

  3. TP53 mutations, expression and interaction networks in human cancers.

    Science.gov (United States)

    Wang, Xiaosheng; Sun, Qingrong

    2017-01-03

    Although the associations of p53 dysfunction, p53 interaction networks and oncogenesis have been widely explored, a systematic analysis of TP53 mutations and its related interaction networks in various types of human cancers is lacking. Our study explored the associations of TP53 mutations, gene expression, clinical outcomes, and TP53 interaction networks across 33 cancer types using data from The Cancer Genome Atlas (TCGA). We show that TP53 is the most frequently mutated gene in a number of cancers, and its mutations appear to be early events in cancer initiation. We identified genes potentially repressed by p53, and genes whose expression correlates significantly with TP53 expression. These gene products may be especially important nodes in p53 interaction networks in human cancers. This study shows that while TP53-truncating mutations often result in decreased TP53 expression, other non-truncating TP53 mutations result in increased TP53 expression in some cancers. Survival analyses in a number of cancers show that patients with TP53 mutations are more likely to have worse prognoses than TP53-wildtype patients, and that elevated TP53 expression often leads to poor clinical outcomes. We identified a set of candidate synthetic lethal (SL) genes for TP53, and validated some of these SL interactions using data from the Cancer Cell Line Project. These predicted SL genes are promising candidates for experimental validation and the development of personalized therapeutics for patients with TP53-mutated cancers.

  4. Knock-out of SO1377 gene, which encodes the member of a conserved hypothetical bacterial protein family COG2268, results in alteration of iron metabolism, increased spontaneous mutation and hydrogen peroxide sensitivity in Shewanella oneidensis MR-1

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    Klingeman Dawn M

    2006-04-01

    Full Text Available Abstract Background Shewanella oneidensis MR-1 is a facultative, gram-negative bacterium capable of coupling the oxidation of organic carbon to a wide range of electron acceptors such as oxygen, nitrate and metals, and has potential for bioremediation of heavy metal contaminated sites. The complete 5-Mb genome of S. oneidensis MR-1 was sequenced and standard sequence-comparison methods revealed approximately 42% of the MR-1 genome encodes proteins of unknown function. Defining the functions of hypothetical proteins is a great challenge and may need a systems approach. In this study, by using integrated approaches including whole genomic microarray and proteomics, we examined knockout effects of the gene encoding SO1377 (gi24372955, a member of the conserved, hypothetical, bacterial protein family COG2268 (Clusters of Orthologous Group in bacterium Shewanella oneidensis MR-1, under various physiological conditions. Results Compared with the wild-type strain, growth assays showed that the deletion mutant had a decreased growth rate when cultured aerobically, but not affected under anaerobic conditions. Whole-genome expression (RNA and protein profiles revealed numerous gene and protein expression changes relative to the wild-type control, including some involved in iron metabolism, oxidative damage protection and respiratory electron transfer, e. g. complex IV of the respiration chain. Although total intracellular iron levels remained unchanged, whole-cell electron paramagnetic resonance (EPR demonstrated that the level of free iron in mutant cells was 3 times less than that of the wild-type strain. Siderophore excretion in the mutant also decreased in iron-depleted medium. The mutant was more sensitive to hydrogen peroxide and gave rise to 100 times more colonies resistant to gentamicin or kanamycin. Conclusion Our results showed that the knock-out of SO1377 gene had pleiotropic effects and suggested that SO1377 may play a role in iron

  5. Diverse growth hormone receptor gene mutations in Laron syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Berg, M.A.; Francke, U. (Stanford Univ. School of Medicine, CA (United States)); Gracia, R.; Rosenbloom, A.; Toledo, S.P.A. (Univ. Autonoma, Madrid (Spain)); Chernausek, S. (Children' s Hospital Medical Center, Cincinnati, OH (United States)); Guevara-Aguirre, J. (Institute of Endocrinology, Metabolism, and Reproduction, Quito (Ecuador)); Hopp, M. (Univ. of Witwatersrand, Johannesburg (South Africa)); Rosenbloom, A.; Argente, J. (Univ. of Florida, Gainesville (United States)); Toledo, S.P.A. (Univ. of Sao Paulo (Brazil))

    1993-05-01

    To better understand the molecular genetic basis and genetic epidemiology of Laron syndrome (growth-hormone insensitivity syndrome), the authors analysed the growth-hormone receptor (GHR) genes of seven unrelated affected individuals from the United States, South America, Europe, and Africa. They 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). They 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, they 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 identified are unique to patients from particular geographic regions. Ten GHR gene mutations have now been described in this disorder. The authors 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. 35 refs., 3 figs., 1 tab.

  6. C-kit gene mutation in human gastrointestinal stromal tumors

    Institute of Scientific and Technical Information of China (English)

    Ying-Yong Hou; Ai-Hua Zheng; Tai-Ming Zhang; Wen-Zhong Hou; Jian Wang; Xiang Du; Xiong-Zeng Zhu; Yun-Shan Tan; Meng-Hong Sun; Yong-Kun Wei; Jian-Fang Xu; Shao-Hua Lu; Su-Jie A-Ke-Su; Yan-Nan Zhou; Feng Gao

    2004-01-01

    AIM: To investigate the significance of c-kit gene mutation in gastrointestinal stromal tumors (GIST).METHODS: Fifty two cases of GIST and 28 cases of other tumors were examined. DNA samples were extracted from paraffin sections and fresh blocks. Exons 11, 9 and 13 of the c-kit gene were amplified by PCR and sequenced.RESULTS: Mutations of exon 11 were found in 14 of 25 malignant GISTs (56%), mutations of exon 11 of the c-kit gene were revealed in 2 of 19 borderline GISTs (10.5%),and no mutation was found in benign tumors. The mutation rate showed significant difference (X2=14.39, P<0.01)between malignant and benign GISTs. Most of mutations consisted of the in-frame deletion or replication from 3 to 48 bp in heterozygous and homozygous fashions, None of the mutations disrupted the downstream reading frame of the gene. Point mutations and frame deletions were most frequently observed at codons 550-560, but duplications were most concentrated at codons 570-585. No mutations of exons 9 and 13 were revealed in GISTs, Neither c-kit gene expression nor gene mutations were found in 3 leiomyomas, 8 leiomyosarcomas, 2 schwannomas, 2malignant peripheral nerve sheath tumors, 2 intraabdominal fibromatoses, 2 malignant fibrous histiocytomas and 9 adenocarcinomas.CONCLUSION: C-kit gene mutations occur preferentially in malignant GISTs and might be a clinically useful adjunct marker in the evaluation of GISTs and can help to differentiate GISTs from other mesenchymal tumors of gastrointestinal tract, such as smooth muscle tumors,schwannomas, etc.

  7. Hemochromatosis (HFE gene mutations in Brazilian chronic hemodialysis patients

    Directory of Open Access Journals (Sweden)

    F.V. Perícole

    2005-09-01

    Full Text Available Patients with chronic renal insufficiency (CRI have reduced hemoglobin levels, mostly as a result of decreased kidney production of erythropoietin, but the relation between renal insufficiency and the magnitude of hemoglobin reduction has not been well defined. Hereditary hemochromatosis is an inherited disorder of iron metabolism. The importance of the association of hemochromatosis with treatment for anemia among patients with CRI has not been well described. We analyzed the frequency of the C282Y and H63D mutations in the HFE gene in 201 Brazilian individuals with CRI undergoing hemodialysis. The analysis of the effects of HFE mutations on iron metabolism and anemia with biochemical parameters was possible in 118 patients of this study (hemoglobin, hematocrit, ferritin levels, transferrin saturation, and serum iron. A C282Y heterozygous mutation was found in 7/201 (3.4% and H63D homozygous and heterozygous mutation were found in 2/201 (1.0% and 46/201 (22.9%, respectively. The allelic frequencies of the HFE mutations (0.017 for C282Y mutation and 0.124 for H63D mutation did not differ between patients with CRI and healthy controls. Regarding the biochemical parameters, no differences were observed between HFE heterozygous and mutation-negative patients, although ferritin levels were not higher among patients with the H63D mutation (P = 0.08. From what we observed in our study, C282Y/H63D HFE gene mutations are not related to degrees of anemia or iron stores in CRI patients receiving intravenous iron supplementation (P > 0.10. Nevertheless, the present data suggest that the H63D mutation may have an important function as a modulating factor of iron overload in these patients.

  8. Application of DNA microarray in the identification of Candida spp. and mutations of ERG11 gene resulting in fluconazole resistance%DNA芯片鉴定念珠菌种和氟康唑耐药基因ERG11突变

    Institute of Scientific and Technical Information of China (English)

    徐永豪; 王克玉; 李颖; 陈腊梅; 苏英; 孙青; 李春阳

    2009-01-01

    目的 建立DNA芯片技术鉴定念珠菌种和氟康唑耐药基因ERG11突变.方法 根据6种常见念珠菌内转录间隔(ITS2)区种特异性序列和白念珠菌ERG11基因中已证实可导致对氟康唑耐药的6种突变序列设计探针,制备DNA芯片,鉴定12条50 bp的念珠菌种特异性序列和ERG11突变序列及34株念珠菌(其中白念珠菌29株,热带念珠菌、光滑念珠菌、都柏林念珠菌、近平滑念珠菌和克柔念珠菌各1株).结果 ①芯片玤确鉴定12条人工合成序列;②正确鉴定34株试验菌株的菌种;③正确鉴定29株白念珠菌ERG11基因中可致耐药的已知突变.敏感性和特异性均为100%.结论 用DNA芯片进行念珠菌菌种鉴定和自念珠菌ERG11突变筛查,结果可靠.%Objective To investigate the performance of DNA microarray in identifying 6 common Candida spp. and validating ERG11 mutations resulting in fluconazolc-resistance in Candida albicans. Methods Oligonucleotide probes were designed and synthesized targeting the species-specific sequence in the internal transcribed spacer 2 (ITS2) region of rDNA of Candida albicans, Candida tropicalis, Candida glabrata, Candida dubliniensis, Candida parapsilosis and Candida krusei, as well as 6 sequences embracing the following mutations respectively in ERG11 gene leading to fluconazole-resistance, i.c., T541C, A 1090G, C1361T, G1537A, G1547A, and T1559C, then arranged onto a chip. Twelve 50-base-pair oligonucleotides were artificially synthesized based on the above specific sequences, and utilized to hybridize with the DNA microarray. Thirty-lbur Candida strains, including 29 C. albicans, 1 Candida tropicalis, 1 Candida glabrata,1 Candida dubliniensis, 1 Candida parapsilosis and 1 Candida krusei, were detected with microarray. Genomic DNA was extracted from these tested strains and underwent multiple PCR for the amplification of ITS2 region and ERGI 1 gene. Sequencing was performed to analyze the sequence of ERG11 in 29 strains

  9. The frequency of NPM1 mutations in childhood acute myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Karamolegou Kalliopi

    2010-10-01

    Full Text Available Abstract Background Mutations in the nucleophosmin (NPM1 gene have been solely associated with childhood acute myeloid leukemia (AML. We evaluated the frequency of NPM1 mutations in childhood AML, their relation to clinical and cytogenetic features and the presence of common FLT3 and RAS mutations. Results NPM1 mutations were found in 8% of cases. They involved the typical type 'A' mutation and one novel mutation characterized by two individual base pair substitutions, which resulted in 2 amino acid changes (W290 and (S293 in the NPM protein. FLT3/ITD mutations were observed in 12% of the cases and in one NPM1-mutated case bearing also t(8;21 (q22;q22. No common RAS mutations were identified. Conclusions A relatively consistent NPM1 mutation rate was observed, but with variations in types of mutations. The role of different types of NPM1 mutations, either individually or in the presence of other common gene mutations may be essential for childhood AML prognosis.

  10. Low prevalence of germline hMSH6 mutations in colorectal cancer families from Spain

    Institute of Scientific and Technical Information of China (English)

    Ana Sánchez de Abajo; Trinidad Caldes; Miguel de la Hoya; Alicia Tosar; Javier Godino; Juan Manuel Fernández; Jose Lopez Asenjo; Beatriz Perez Villamil; Pedro Perez Segura; Eduardo Diaz-Rubio

    2005-01-01

    AIM: To investigate the prevalence and penetrance of hMSH6 mutations in Spanish HNPCC families that was negative for mutation in hMLH1 or hMSH2.METHODS: We used PCR-based DGGE assay and direct Sequencing to screen for hMSH6 gene in 91 HNPCC families.RESULTS: we have identified 10 families with germ-line mutations in the DNA sequence. These mutations included two intronic variation, three missense mutation, one nonsense mutation, and four silent mutations. Among the 10 germ-line mutations identified in the Spanish cohort,8 were novel, perhaps, suggesting different mutational spectra in the Spanish population. Detailed pedigrees were constructed for the three families with a possible pathogenic hMSH6 mutation. The two silent mutations H388H and L758L, detected in a person affected of colorectal cancer at age 29, produce loss of the wild-type allele in the tumor sample. Immunohistochemical analysis showed that expression of MSH6 protein was lost only in the tumors from the carriers of V878A and Q263X mutations.CONCLUSION: Altogether, our results indicate that disease-causing germ-line mutations of hMSH6 are very less frequent in Spanish HNPCC families.

  11. MPL mutations in myeloproliferative disorders

    DEFF Research Database (Denmark)

    Beer, Philip A.; Campbell, Peter J.; Scott, Linda M.

    2008-01-01

    Activating mutations of MPL exon 10 have been described in a minority of patients with idiopathic myelofibrosis (IMF) or essential thrombocythemia (ET), but their prevalence and clinical significance are unclear. Here we demonstrate that MPL mutations outside exon 10 are uncommon in platelet cDNA...

  12. Mitochondrial mutations in subjects with psychiatric disorders.

    Directory of Open Access Journals (Sweden)

    Adolfo Sequeira

    Full Text Available A considerable body of evidence supports the role of mitochondrial dysfunction in psychiatric disorders and mitochondrial DNA (mtDNA mutations are known to alter brain energy metabolism, neurotransmission, and cause neurodegenerative disorders. Genetic studies focusing on common nuclear genome variants associated with these disorders have produced genome wide significant results but those studies have not directly studied mtDNA variants. The purpose of this study is to investigate, using next generation sequencing, the involvement of mtDNA variation in bipolar disorder, schizophrenia, major depressive disorder, and methamphetamine use. MtDNA extracted from multiple brain regions and blood were sequenced (121 mtDNA samples with an average of 8,800x coverage and compared to an electronic database containing 26,850 mtDNA genomes. We confirmed novel and rare variants, and confirmed next generation sequencing error hotspots by traditional sequencing and genotyping methods. We observed a significant increase of non-synonymous mutations found in individuals with schizophrenia. Novel and rare non-synonymous mutations were found in psychiatric cases in mtDNA genes: ND6, ATP6, CYTB, and ND2. We also observed mtDNA heteroplasmy in brain at a locus previously associated with schizophrenia (T16519C. Large differences in heteroplasmy levels across brain regions within subjects suggest that somatic mutations accumulate differentially in brain regions. Finally, multiplasmy, a heteroplasmic measure of repeat length, was observed in brain from selective cases at a higher frequency than controls. These results offer support for increased rates of mtDNA substitutions in schizophrenia shown in our prior results. The variable levels of heteroplasmic/multiplasmic somatic mutations that occur in brain may be indicators of genetic instability in mtDNA.

  13. Genetic mutations associated with status epilepticus.

    Science.gov (United States)

    Bhatnagar, M; Shorvon, S

    2015-08-01

    This paper reports the results of a preliminary search of the literature aimed at identifying the genetic mutations reported to be strongly associated with status epilepticus. Genetic mutations were selected for inclusion if status epilepticus was specifically mentioned as a consequence of the mutation in standard genetic databases or in a case report or review article. Mutations in 122 genes were identified. The genetic mutations identified were found in only rare conditions (sometimes vanishingly rare) and mostly in infants and young children with multiple other handicaps. Most of the genetic mutations can be subdivided into those associated with cortical dysplasias, inborn errors of metabolism, mitochondrial disease, or epileptic encephalopathies and childhood syndromes. There are no identified 'pure status epilepticus genes'. The range of genes underpinning status epilepticus differs in many ways from the range of genes underpinning epilepsy, which suggests that the processes underpinning status epilepticus differ from those underpinning epilepsy. It has been frequently postulated that status epilepticus is the result of a failure of 'seizure termination mechanisms', but the wide variety of genes affecting very diverse biochemical pathways identified in this survey makes any unitary cause unlikely. The genetic influences in status epilepticus are likely to involve a wide range of mechanisms, some related to development, some to cerebral energy production, some to diverse altered biochemical pathways, some to transmitter and membrane function, and some to defects in networks or systems. The fact that many of the identified genes are involved with cerebral development suggests that status epilepticus might often be a system or network phenomenon. To date, there are very few genes identified which are associated with adult-onset status epilepticus (except in those with preexisting neurological damage), and this is disappointing as the cause of many adult

  14. Impact of TP53 Mutations on Outcome in EGFR-Mutated Patients Treated with First-Line Tyrosine Kinase Inhibitors.

    Science.gov (United States)

    Canale, Matteo; Petracci, Elisabetta; Delmonte, Angelo; Chiadini, Elisa; Dazzi, Claudio; Papi, Maximilian; Capelli, Laura; Casanova, Claudia; De Luigi, Nicoletta; Mariotti, Marita; Gamboni, Alessandro; Chiari, Rita; Bennati, Chiara; Calistri, Daniele; Ludovini, Vienna; Crinò, Lucio; Amadori, Dino; Ulivi, Paola

    2016-10-25

    Purpose: To analyze the impact of TP53 mutations on response to first-line tyrosine kinase inhibitors (TKI) in patients with EGFR-mutated non-small cell lung cancer (NSCLC).Experimental Design: 136 EGFR-mutated NSCLC patients receiving first-line TKIs were analyzed. TP53 mutations were evaluated in 123 patients in relation to disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).Results:TP53 mutations were observed in 37 (30.1%), 10 (27.0%), 6 (16.2%), 9 (24.3%), and 12 (32.4%) patients in exons 5, 6, 7, and 8, respectively. DCR was 70% in TP53-mutated patients compared with 88% in TP53-wild type (wt) patients [relative risk, RR, of disease progression: 3.17 (95% CI, 1.21-8.48), P = 0.019]. In particular, a 42% DCR was observed in patients with TP53 exon 8 mutation versus 87% in exon 8 wt patients [RR of disease progression 9.6 (2.71-36.63), P TP53 exon 8 mutations compared with others (4.2 vs. 12.5, P = 0.058, and 16.2 vs. 32.3, P = 0.114, respectively); these differences became significant in the subgroup with EGFR exon 19 deletion (4.2 vs. 16.8, P TP53 mutations, especially exon 8 mutations, reduce responsiveness to TKIs and worsen prognosis in EGFR-mutated NSCLC patients, mainly those carrying exon 19 deletions. Clin Cancer Res; 1-8. ©2016 AACR.

  15. Whole genome sequencing of mutation accumulation lines reveals a low mutation rate in the social amoeba Dictyostelium discoideum.

    Directory of Open Access Journals (Sweden)

    Gerda Saxer

    Full Text Available Spontaneous mutations play a central role in evolution. Despite their importance, mutation rates are some of the most elusive parameters to measure in evolutionary biology. The combination of mutation accumulation (MA experiments and whole-genome sequencing now makes it possible to estimate mutation rates by directly observing new mutations at the molecular level across the whole genome. We performed an MA experiment with the social amoeba Dictyostelium discoideum and sequenced the genomes of three randomly chosen lines using high-throughput sequencing to estimate the spontaneous mutation rate in this model organism. The mitochondrial mutation rate of 6.76×10(-9, with a Poisson confidence interval of 4.1×10(-9 - 9.5×10(-9, per nucleotide per generation is slightly lower than estimates for other taxa. The mutation rate estimate for the nuclear DNA of 2.9×10(-11, with a Poisson confidence interval ranging from 7.4×10(-13 to 1.6×10(-10, is the lowest reported for any eukaryote. These results are consistent with low microsatellite mutation rates previously observed in D. discoideum and low levels of genetic variation observed in wild D. discoideum populations. In addition, D. discoideum has been shown to be quite resistant to DNA damage, which suggests an efficient DNA-repair mechanism that could be an adaptation to life in soil and frequent exposure to intracellular and extracellular mutagenic compounds. The social aspect of the life cycle of D. discoideum and a large portion of the genome under relaxed selection during vegetative growth could also select for a low mutation rate. This hypothesis is supported by a significantly lower mutation rate per cell division in multicellular eukaryotes compared with unicellular eukaryotes.

  16. Identification of CYP4V2 mutation in 21 families and overview of mutation spectrum in Bietti crystalline corneoretinal dystrophy.

    Science.gov (United States)

    Xiao, Xueshan; Mai, Guiying; Li, Shiqiang; Guo, Xiangming; Zhang, Qingjiong

    2011-06-03

    Bietti crystalline corneoretinal dystrophy (BCD, MIM 210370) is a common form of hereditary retinal degeneration in the Chinese population. BCD is caused by CYP4V2 mutations. Understanding the CYP4V2 mutational spectrum and associated phenotypes is of value for clinical practice. In this study, nine CYP4V2 mutations, including four novel ones (c.215-2A>G, c.761A>G, c.958C>T, and c.1169G>A), were detected in all 21 families with BCD. All patients with CYP4V2 mutations had phenotypes typical for BCD. As of now, 34 CYP4V2 mutations have been identified in 104 of 109 families (95.4%), affecting 204 of the 218 alleles (93.6%). Of the 34 mutations, c.802-8_810del17insGC, c.992A>C, and c.1091-2A>G are the most common mutations, accounting for 62.7%, 7.4%, and 6.4% of the 204 mutant alleles, respectively. The remaining 31 mutations were only detected in 1-6 alleles. Mutations in exons 7, 8, and 9 account for 83.3% of mutant alleles (64.7%, 9.3%, and 10.3%, respectively). Our results expand the mutation spectrum of CYP4V2 and demonstrate an overview of the CYP4V2 mutation spectrum and its frequency in families with BCD. BCD is a clinically and genetically homogenous disease.

  17. Lynch Syndrome Caused by Germline PMS2 Mutations

    DEFF Research Database (Denmark)

    Ten Broeke, Sanne W; Brohet, Richard M; Tops, Carli M

    2015-01-01

    . Standardized incidence ratios (SIRs) were calculated to estimate risks for other Lynch syndrome-associated cancers. RESULTS: The cumulative risk (CR) of CRC for male mutation carriers by age 70 years was 19%. The CR among female carriers was 11% for CRC and 12% for EC. The mean age of CRC development was 52......PURPOSE: The clinical consequences of PMS2 germline mutations are poorly understood compared with other Lynch-associated mismatch repair gene (MMR) mutations. The aim of this European cohort study was to define the cancer risk faced by PMS2 mutation carriers. METHODS: Data were collected from 98...... years, and there was a significant difference in mean age of CRC between the probands (mean, 47 years; range, 26 to 68 years) and other family members with a PMS2 mutation (mean, 58 years; range, 31 to 86 years; P

  18. Exhaustive Database Searching for Amino Acid Mutations in Proteomes

    Energy Technology Data Exchange (ETDEWEB)

    Hyatt, Philip Douglas [ORNL; Pan, Chongle [ORNL

    2012-01-01

    Amino acid mutations in proteins can be found by searching tandem mass spectra acquired in shotgun proteomics experiments against protein sequences predicted from genomes. Traditionally, unconstrained searches for amino acid mutations have been accomplished by using a sequence tagging approach that combines de novo sequencing with database searching. However, this approach is limited by the performance of de novo sequencing. The Sipros algorithm v2.0 was developed to perform unconstrained database searching using high-resolution tandem mass spectra by exhaustively enumerating all single non-isobaric mutations for every residue in a protein database. The performance of Sipros for amino acid mutation identification exceeded that of an established sequence tagging algorithm, Inspect, based on benchmarking results from a Rhodopseudomonas palustris proteomics dataset. To demonstrate the viability of the algorithm for meta-proteomics, Sipros was used to identify amino acid mutations in a natural microbial community in acid mine drainage.

  19. Simple method for detection of mutations causing hereditary fructose intolerance.

    Science.gov (United States)

    Kullberg-Lindh, C; Hannoun, C; Lindh, M

    2002-11-01

    Aldolase B is critical for sugar metabolism, and a catalytic deficiency due to mutations in its gene may result in hereditary fructose intolerance (HFI) syndrome, with hypoglycaemia and severe abdominal symptoms. This report describes two cases of HFI, which were identified by intravenous fructose tolerance test and a new RFLP (restriction fragment length polymorphism) test that detects the two most common mutations, A149P and A174D. The method includes PCR of a 224-base-pair segment of exon 5, a subsequent 3 h incubation with Cac8I and agarose electrophoresis, which reveals either or both of the mutations in one single reaction. The method might be useful for screening of these mutations, which may account for more than 70% of the mutations causing HFI.

  20. Somatic mutation patterns and compound response in cancers

    Directory of Open Access Journals (Sweden)

    Ningning He

    2013-02-01

    Full Text Available The use of various cancer cell lines can recapitulate knowntumor-associated mutations and genetically define cancersubsets. This approach also enables comparative surveys ofassociations between cancer mutations and drug responses.Here, we analyzed the effects of ∼40,000 compounds oncancer cell lines that showed diverse mutation-dependentsensitivity profiles. Over 1,000 compounds exhibited uniquesensitivity on cell lines with specific mutational genotypes,and these compounds were clustered into six different classesof mutation-oriented sensitivity. The present analysis providesnew insights into the relationship between somatic mutationsand selectivity response of chemicals, and these results shouldhave applications related to predicting and optimizing therapeuticwindows for anti-cancer agents. [BMB Reports 2013;46(2: 97-102

  1. Skin pH, Atopic Dermatitis, and Filaggrin Mutations

    DEFF Research Database (Denmark)

    Bandier, Josefine; Johansen, Jeanne Duus; Petersen, Lars Jelstrup

    2014-01-01

    BACKGROUND: The acidic pH of the skin plays a role in antimicrobial defense by regulating the bacterial skin flora and aspects of barrier. Filaggrin is a co-factor in maintaining a low skin pH because of its degradation into acidic amino acids. Accordingly, lack of filaggrin due to filaggrin...... mutations may influence skin pH. OBJECTIVE: We aimed to determine the epidermal pH in different groups stratified by filaggrin mutations and atopic dermatitis. Further, we investigated the changes in pH according to severity of mutational status among patients with dermatitis, irrespective of skin condition....... METHODS: pH was measured with a multiprobe system pH probe (PH 905), and the study population was composed of 67 individuals, who had all been genotyped for 3 filaggrin mutations (R501X, 2282del4, R2447X). RESULTS: We found no clear pattern in relation to filaggrin mutation carrier status. Individuals...

  2. Rapid screen for truncating ATM mutations by PTT-ELISA

    Energy Technology Data Exchange (ETDEWEB)

    Du Liutao; Lai, C.-H. [Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, CA 90095 (United States); Concannon, Patrick [Department of Biochemistry and Molecular Genetics, University of Virginia, VA 22908 (United States); Gatti, Richard A. [Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, CA 90095 (United States); Department of Human Genetics, David Geffen School of Medicine at UCLA, CA 90095 (United States)], E-mail: rgatti@mednet.ucla.edu

    2008-04-02

    Mutations in the ataxia-telangiectasia mutated (ATM) gene are responsible for the autosomal recessive genetic disorder, ataxia-telangiectasia (A-T). Approximately 80% of ATM mutations found in A-T patients results in truncations, which can be detected by Protein Truncation Test (PTT). Conventional PTT uses SDS-PAGE electrophoresis to detect mobility of radiolabeled truncated protein fragments. In this study, we developed a non-radioactive Protein Truncation Test which utilizes an enzyme-linked immunosorbent assay (PTT-ELISA) to detect ATM mutations in eight overlapping fragments. N- and C-terminal epitopes (c-myc and V5, respectively) were introduced into transcription/translation products, which could then be detected by Sandwich ELISA. Using this assay, we screened 9 newly diagnosed A-T patients consecutively. Of the 18 expected mutations, 14 truncating mutations were independently identified by cDNA direct sequencing and/or DNA dHPLC analysis. PTT-ELISA detected all of these 14. Four mutations were novel. The PTT-ELISA provides a rapid method for detecting truncating mutations in large genes and should be considered prior to using more laborious or costly methods, such as direct sequencing.

  3. TP53 mutations in older adults with acute myeloid leukemia.

    Science.gov (United States)

    Yanada, Masamitsu; Yamamoto, Yukiya; Iba, Sachiko; Okamoto, Akinao; Inaguma, Yoko; Tokuda, Masutaka; Morishima, Satoko; Kanie, Tadaharu; Mizuta, Shuichi; Akatsuka, Yoshiki; Okamoto, Masataka; Emi, Nobuhiko

    2016-04-01

    The net benefits of induction therapy for older adults with acute myeloid leukemia (AML) remain controversial. Because AML in older adults is a heterogeneous disease, it is important to identify those who are unlikely to benefit from induction therapy based on information available at the initial assessment. We used next-generation sequencing to analyze TP53 mutation status in AML patients aged 60 years or older, and evaluated its effects on outcomes. TP53 mutations were detected in 12 of 77 patients (16 %), and there was a significant association between TP53 mutations and monosomal karyotype. Patients with TP53 mutations had significantly worse survival than those without (P = 0.009), and multivariate analysis identified TP53 mutation status as the most significant prognostic factor for survival. Neverthelsess, TP53-mutated patients had a 42 % chance of complete remission and a median survival of 8.0 months, which compares favorably with those who did not undergo induction therapy, even in the short term. These results suggest that screening for TP53 mutations at diagnosis is useful for identifying older adults with AML who are least likely to respond to chemotherapy, although the presence of this mutation alone does not seem to justify rejecting induction therapy.

  4. From minisatellites and genes: When do germinal mutations occur

    Energy Technology Data Exchange (ETDEWEB)

    Mohrenweiser, H. [Lawrence Livermore National Lab., CA (United States)

    1997-10-01

    Utilization of molecular techniques has provided insight into the molecular techniques has provided insight into the molecular techniques has provided insight into the molecular character and origins of spontaneous and induced germinal mutations. Review of the variants and disease loci suggests differences among loci in the frequency of nucleotide substitutions and more complex events. Mechanistic features associated with the alterations in DNA structure are observed in each variant class. The spectrum of mutations identified reflects the gene structure and the selective pressure generating disease phenotypes, and the techniques employed to screen for variation. Locus specificity in spectra has the potential to compromise estimates of increases in germinal gene mutation rates. Recent studies have identified mosaicism, rather than de novo mutation, as the explanation for the non-traditional pattern of inheritance of disease in some families. Mosaicism is a concern for studies of induced mutation rates as it reflects embryonic exposure of the parent of the proband. This is in contrast to the {open_quotes}normal expectation{close_quotes} that induced mutations result from parental exposure to genotoxins in the environment. Observations suggest that the germ cell stage sensitivity may reflect interaction of the mutagen and the loci screened. The mosaicism and germ cell stage issues, in conjunction with incomplete ascertainment of mutational events, increase the complexity of efforts to estimate induced germinal mutation rates and associated health consequences in populations exposed to genotoxic agents.

  5. AKT1 and BRAF mutations in pediatric aggressive fibromatosis.

    Science.gov (United States)

    Meazza, Cristina; Belfiore, Antonino; Busico, Adele; Settanni, Giulio; Paielli, Nicholas; Cesana, Luca; Ferrari, Andrea; Chiaravalli, Stefano; Massimino, Maura; Gronchi, Alessandro; Colombo, Chiara; Pilotti, Silvana; Perrone, Federica

    2016-06-01

    Aside from the CTNNB1 and adenomatous polyposis coli (APC) mutations, the genetic profile of pediatric aggressive fibromatosis (AF) has remained poorly characterized. The aim of this study was to shed more light on the mutational spectrum of pediatric AF, comparing it with its adult counterpart, with a view to identifying biomarkers for use as prognostic factors or new potential therapeutic targets. CTNNB1, APC, AKT1, BRAF TP53, and RET Sanger sequencing and next-generation sequencing (NGS) with the 50-gene Ion AmpliSeq Cancer Hotspot Panel v2 were performed on formalin-fixed samples from 28 pediatric and 33 adult AFs. The prognostic value of CTNNB1, AKT1, and BRAF mutations in pediatric AF patients was investigated. Recurrence-free survival (RFS) curves were estimated with the Kaplan-Meier method and statistical comparisons were drawn using the log-rank test. In addition to the CTNNB1 mutation (64%), pediatric AF showed AKT1 (31%), BRAF (19%), and TP53 (9%) mutations, whereas only the CTNNB1 mutation was found in adult AF. The polymorphism Q472H VEGFR was identified in both pediatric (56%) and adult (40%) AF. Our results indicate that the mutational spectrum of pediatric AF is more complex than that of adult AF, with multiple gene mutations involving not only CTNNB1 but also AKT1 and BRAF. This intriguing finding may have clinical implications and warrants further investigations. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  6. Leiden Mutation and the Course of Severe Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    A. V. Ershov

    2013-01-01

    Full Text Available Objective: to evaluate the impact of Leiden mutation on the course of severe acute pancreatitis. Subjects and methods. One hundred and twelve people were examined. Group 1 comprised 50 patients diagnosed with severe acute pancreatitis without coagulation factor V (Leiden mutation. Group 2 included 42 patients with severe acute pancreatitis who were found to have Leiden mutation. Acute pancreatitis was first diagnosed in both groups. Group 3 consisted of 20 apparently healthy individuals (a control group. The severity of the underlying disease was determined in accordance with the clinical and laboratory parameters recommended by the I. I. Dzhanelidze Saint Petersburg Research Institute of Emergence Care. Results. This investigation revealed an association of Leiden mutation with trends in the development of acute pancreatitis. Group 2 exhibited a more severe disease: large focal pancreatic necrosis was twice more common and infectious complications developed more frequently; more aggressive and radical treatments were more often used. The patients with Leiden mutation had higher mortality rates (33% in the Leiden mutation group and 24% in the non-mutation group. Conclusion. The findings should be kept in mind in elaborating new diagnostic methods and principles in the treatment of the underlying disease and in the prevention of its complications in patients with severe acute pancreatitis. Key words: acute pancreatitis, Leiden mutation.

  7. Prevention of avoidable mutational disease: memorandum from a WHO meeting.

    Science.gov (United States)

    1986-01-01

    About 1% of children are born with a serious disorder which is the direct result of a mutational event in a parent or a more distant ancestor. These disorders, of which several thousand are known, mainly afflict the blood, bone, brain, ear, eye or muscle and the changes are usually irrevocable by the time of diagnosis. Another 1% of individuals will develop a serious genetic disease some time after birth. In addition to these direct consequences of a mutant event, far higher proportions will suffer from the indirect effects of one or several mutations.In view of their chronic and severe nature most of these disorders impose a burden disproportionate to their frequency, and it is sound public health policy to avoid the birth of babies known to have the established mutations and prevent further cases in the immediate or distant future by minimizing the exposure of people at risk to known mutagens. The advantages in permitting certain mutagenic exposures must be assessed against the later costs.Owing to the natural mutation rate and the vast backlog of previous mutations, the prospects of prevention are limited to preventing an increase, rather than to achieving any substantial decrease. This Memorandum describes progress in the ability to dissect and interpret the mutational process, to identify populations at risk, and to evaluate the consequences of the various types of mutational event and emphasizes that the current approach to prevention of mutational disease must involve improving our ability to study populations that appear to be at increased risk.

  8. Differential evolution with ranking-based mutation operators.

    Science.gov (United States)

    Gong, Wenyin; Cai, Zhihua

    2013-12-01

    Differential evolution (DE) has been proven to be one of the most powerful global numerical optimization algorithms in the evolutionary algorithm family. The core operator of DE is the differential mutation operator. Generally, the parents in the mutation operator are randomly chosen from the current population. In nature, good species always contain good information, and hence, they have more chance to be utilized to guide other species. Inspired by this phenomenon, in this paper, we propose the ranking-based mutation operators for the DE algorithm, where some of the parents in the mutation operators are proportionally selected according to their rankings in the current population. The higher ranking a parent obtains, the more opportunity it will be selected. In order to evaluate the influence of our proposed ranking-based mutation operators on DE, our approach is compared with the jDE algorithm, which is a highly competitive DE variant with self-adaptive parameters, with different mutation operators. In addition, the proposed ranking-based mutation operators are also integrated into other advanced DE variants to verify the effect on them. Experimental results indicate that our proposed ranking-based mutation operators are able to enhance the performance of the original DE algorithm and the advanced DE algorithms.

  9. Somatic mutation of immunoglobulin VH6 genes in human infants

    Science.gov (United States)

    Ridings, J; Dinan, L; Williams, R; Roberton, D; Zola, H

    1998-01-01

    Infants respond to antigen by making antibody that is generally of low affinity for antigen. Somatic hypermutation of immunoglobulin genes, and selection of cells expressing mutations with improved affinity for antigen, are the molecular and cellular processes underlying the maturation of antibody affinity. We have reported previously that neonates and infants up to 2 months of age, including individuals undergoing strong immunological challenge, show very few mutated VH6 sequences, with low mutation frequencies in mutated sequences, and little evidence of selection. We have now examined immunoglobulin genes from healthy infants between 2 and 10 months old for mutation and evidence of selection. In this age group, the proportion of VH6 sequences which are mutated and the mutation frequency in mutated sequences increase with age. There is evidence of selection from 6 months old. These results indicate that the process of affinity maturation, which depends on cognate T–B cell interaction and functional germinal centres, is approaching maturity from 6 months old. PMID:9764600

  10. Polymorphic Mutation Frequencies of Clinical and Environmental Stenotrophomonas maltophilia Populations▿

    Science.gov (United States)

    Turrientes, María Carmen; Baquero, María Rosario; Sánchez, María Blanca; Valdezate, Sylvia; Escudero, Esther; Berg, Gabrielle; Cantón, Rafael; Baquero, Fernando; Galán, Juan Carlos; Martínez, José Luis

    2010-01-01

    Mutation frequencies were studied in 174 Stenotrophomonas maltophilia isolates from clinical and nonclinical environments by detecting spontaneous rifampin-resistant mutants in otherwise-susceptible populations. The distribution of mutation frequencies followed a pattern similar to that found for other bacterial species, with a modal value of 1 × 10−8. Nevertheless, the proportion of isolates showing mutation frequencies below the modal value (hypomutators) was significantly higher for S. maltophilia than those so far reported in other organisms. Low mutation frequencies were particularly frequent among environmental S. maltophilia strains (58.3%), whereas strong mutators were found only among isolates with a clinical origin. These results indicate that clinical environments might select bacterial populations with high mutation frequencies, likely by second-order selection processes. In several of the strong-mutator isolates, functional-complementation assays with a wild-type allele of the mutS gene demonstrated that the mutator phenotype was due to the impairment of MutS activity. In silico analysis of the amino acid changes present in the MutS proteins of these hypermutator strains in comparison with the normomutator isolates suggests that the cause of the defect in MutS might be a H683P amino acid change. PMID:20097818

  11. HRAS mutation analysis in Costello syndrome: genotype and phenotype correlation.

    Science.gov (United States)

    Gripp, Karen W; Lin, Angela E; Stabley, Deborah L; Nicholson, Linda; Scott, Charles I; Doyle, Daniel; Aoki, Yoko; Matsubara, Yoichi; Zackai, Elaine H; Lapunzina, Pablo; Gonzalez-Meneses, Antonio; Holbrook, Jennifer; Agresta, Cynthia A; Gonzalez, Iris L; Sol-Church, Katia

    2006-01-01

    Costello syndrome is a rare condition comprising mental retardation, distinctive facial appearance, cardiovascular abnormalities (typically pulmonic stenosis, hypertrophic cardiomyopathy, and/or atrial tachycardia), tumor predisposition, and skin and musculoskeletal abnormalities. Recently mutations in HRAS were identified in 12 Japanese and Italian patients with clinical information available on 7 of the Japanese patients. To expand the molecular delineation of Costello syndrome, we performed mutation analysis in 34 North American and 6 European (total 40) patients with Costello syndrome, and detected missense mutations in HRAS in 33 (82.5%) patients. All mutations affected either codon 12 or 13 of the protein product, with G12S occurring in 30 (90.9%) patients of the mutation-positive cases. In two patients, we found a mutation resulting in an alanine substitution in position 12 (G12A), and in one patient, we detected a novel mutation (G13C). Five different HRAS mutations have now been reported in Costello syndrome, however genotype-phenotype correlation remains incomplete.

  12. Imatinib resistance mutation analysis: experience from a tertiary oncology center

    Directory of Open Access Journals (Sweden)

    Mallekavu Suresh Babu

    2015-01-01

    Full Text Available Purpose: BCR-ABL kinase domain (KD mutations account for 50-90% of the imatinib resistance observed in patients of CML-chronic phase. In CML-CP patients receiving imatinib first-line, mutation analysis is recommended in case of failure or suboptimal response using European LeukemiaNet (ELN criteria. The present study was carried out at a tertiary oncology centre in south India to assess which mutations accounted for resistance to imatinib among patients of chronic phase CML being treated with imatinib.Methods: This was a retrospective observational study. We analyzed patients who were tested for imatinib resistance mutation in view of suboptimal responses while on imatinib or imatinib failure. Direct sequencing of the BCR-ABL transcript by the Sanger method was used for IRMA testing.Results: Out of 120 tested for IRMA, 36 (30% had detectable mutations. We observed a higher frequency of mutations at amino acids T315, F359 and M351T.Conclusions: Among the patients who were tested for imatinib resistance mutation in view of suboptimal responses while on imatinib or imatinib failure, 30% had IRMA +ve mutations. The high incidence of imatinib resistance in present study may be attributed to the fact that our patients were given higher dose of imatinib (600 mg, if they failed to achieve CCyR at 12 months or CHR at 3 months as they could not afford second generation TKIs.

  13. Mitochondrial gene mutations and type 2 diabetes in Chinese families

    Institute of Scientific and Technical Information of China (English)

    LI Ming-zhen; YU De-min; YU Pei; LIU De-min; WANG Kun; TANG Xin-zhi

    2008-01-01

    Background Numerous mitochondrial DNA mutations are significantly correlated with development of diabetes. This study investigated mitochondrial gene, point mutations in patients with type 2 diabetes and their families. Methods Unrelated patients with type 2 diabetes(n=826)were randomly recruited; unrelated and nondiabetic subjects (n=637)served as controls. The clinical and biochemical data of the participants were collected. Total genome was extracted from peripheral leucocytes. Polymerase chain reaction, restriction fragment length polymorphism (PCR-RFLP)and clonig techniques were used to screen mitochondrial genes including np3316,np3394 and np3426 in the ND1 region and np3243 in the tRNALeu (UUR). Results In 39 diabetics with one or more mitochondrial gene point mutations, the prevalence(4.7%,39/826)of mtDNA mutations was higher than that(0.7%,5/637)in the controls. The identical mutation was found in 23 of 43 tested members from three pedigrees. Affected family members presented with variable clinical features ranging from normal glucose tolerance to impaired glucose tolerance (IGT)(n=2),impaired fasting glucose(IFG)(n=1)to type 2 diabetes (n=13)with 3 family members suffering from hearing loss. Conclusions Type 2 diabetes in China is associated with several mitochondrial gene mutations. Aged patients with diabetic family history had a higher prevalence of mutation and various clinical pictures. Mitochondrial gene mutation might be one of the genetic factors contributing to diabetic familial clustering.

  14. Exempting homologous pseudogene sequences from polymerase chain reaction amplification allows genomic keratin 14 hotspot mutation analysis

    NARCIS (Netherlands)

    Hut, PHL; van der Vlies, P; Jonkman, MF; Verlind, E; Shimizu, H; Buys, CHCM; Scheffer, H

    In patients with the major forms of epidermolysis bullosa simplex, either of the keratin genes KRT5 or KRT14 is mutated. This causes a disturbance of the filament network resulting in skin fragility and blistering. For KRT5, a genomic mutation detection system has been described previously. Mutation

  15. Analysis of AGXT gene mutation in primary hyperoxaluria type I family

    Institute of Scientific and Technical Information of China (English)

    高延霞

    2014-01-01

    Objective To describe the clinical characteristics,and to analyze the AGXT gene mutation in three siblings with primary hyperoxaluria typeⅠ(PHI).Methods AGXT gene mutation was analyzed by direct sequencing analysis in this family,and the minor allele status was also tested.One hundred unrelated healthy subjects were also analyzed as controls.Results Three mutations in

  16. Mutational meltdown in laboratory yeast populations

    NARCIS (Netherlands)

    Zeyl, C.; Mizesko, M.; Visser, de J.A.G.M.

    2001-01-01

    In small or repeatedly bottlenecked populations, mutations are expected to accumulate by genetic drift, causing fitness declines. In mutational meltdown models, such fitness declines further reduce population size, thus accelerating additional mutation accumulation and leading to extinction. Because

  17. Exome mutation burden predicts clinical outcome in ovarian cancer carrying mutated BRCA1 and BRCA2 genes

    DEFF Research Database (Denmark)

    Birkbak, Nicolai Juul; Kochupurakkal, Bose; Gonzalez-Izarzugaza, Jose Maria;

    2013-01-01

    Reliable biomarkers predicting resistance or sensitivity to anti-cancer therapy are critical for oncologists to select proper therapeutic drugs in individual cancer patients. Ovarian and breast cancer patients carrying germline mutations in BRCA1 or BRCA2 genes are often sensitive to DNA damaging...... drugs and relative to non-mutation carriers present a favorable clinical outcome following therapy. Genome sequencing studies have shown a high number of mutations in the tumor genome in patients carrying BRCA1 or BRCA2 mutations (mBRCA). The present study used exome-sequencing and SNP 6 array data...... had either germlines or somatic mutations of BRCA1 or BRCA2 genes. The results revealed that the Nmut was significantly lower in the chemotherapy-resistant mBRCA HGSOC defined by progression within 6 months after completion of first line platinum-based chemotherapy. We found a significant association...

  18. Tissue-specific mutation accumulation in human adult stem cells during life

    Science.gov (United States)

    Blokzijl, Francis; de Ligt, Joep; Jager, Myrthe; Sasselli, Valentina; Roerink, Sophie; Sasaki, Nobuo; Huch, Meritxell; Boymans, Sander; Kuijk, Ewart; Prins, Pjotr; Nijman, Isaac J.; Martincorena, Inigo; Mokry, Michal; Wiegerinck, Caroline L.; Middendorp, Sabine; Sato, Toshiro; Schwank, Gerald; Nieuwenhuis, Edward E. S.; Verstegen, Monique M. A.; van der Laan, Luc J. W.; de Jonge, Jeroen; Ijzermans, Jan N. M.; Vries, Robert G.; van de Wetering, Marc; Stratton, Michael R.; Clevers, Hans; Cuppen, Edwin; van Boxtel, Ruben

    2016-10-01

    The gradual accumulation of genetic mutations in human adult stem cells (ASCs) during life is associated with various age-related diseases, including cancer. Extreme variation in cancer risk across tissues was recently proposed to depend on the lifetime number of ASC divisions, owing to unavoidable random mutations that arise during DNA replication. However, the rates and patterns of mutations in normal ASCs remain unknown. Here we determine genome-wide mutation patterns in ASCs of the small intestine, colon and liver of human donors with ages ranging from 3 to 87 years by sequencing clonal organoid cultures derived from primary multipotent cells. Our results show that mutations accumulate steadily over time in all of the assessed tissue types, at a rate of approximately 40 novel mutations per year, despite the large variation in cancer incidence among these tissues. Liver ASCs, however, have different mutation spectra compared to those of the colon and small intestine. Mutational signature analysis reveals that this difference can be attributed to spontaneous deamination of methylated cytosine residues in the colon and small intestine, probably reflecting their high ASC division rate. In liver, a signature with an as-yet-unknown underlying mechanism is predominant. Mutation spectra of driver genes in cancer show high similarity to the tissue-specific ASC mutation spectra, suggesting that intrinsic mutational processes in ASCs can initiate tumorigenesis. Notably, the inter-individual variation in mutation rate and spectra are low, suggesting tissue-specific activity of common mutational processes throughout life.

  19. The effect of population bottlenecks on mutation rate evolution in asexual populations.

    Science.gov (United States)

    Raynes, Y; Halstead, A L; Sniegowski, P D

    2014-01-01

    In the absence of recombination, a mutator allele can spread through a population by hitchhiking with beneficial mutations that appear in its genetic background. Theoretical studies over the past decade have shown that the survival and fixation probability of beneficial mutations can be severely reduced by population size bottlenecks. Here, we use computational modelling and evolution experiments with the yeast S. cerevisiae to examine whether population bottlenecks can affect mutator dynamics in adapting asexual populations. In simulation, we show that population bottlenecks can inhibit mutator hitchhiking with beneficial mutations and are most effective at lower beneficial mutation supply rates. We then subjected experimental populations of yeast propagated at the same effective population size to three different bottleneck regimes and observed that the speed of mutator hitchhiking was significantly slower at smaller bottlenecks, consistent with our theoretical expectations. Our results, thus, suggest that bottlenecks can be an important factor in mutation rate evolution and can in certain circumstances act to stabilize or, at least, delay the progressive elevation of mutation rates in asexual populations. Additionally, our findings provide the first experimental support for the theoretically postulated effect of population bottlenecks on beneficial mutations and demonstrate the usefulness of studying mutator frequency dynamics for understanding the underlying dynamics of fitness-affecting mutations.

  20. Suppression of Beneficial Mutations in Dynamic Microbial Populations

    Science.gov (United States)

    Bittihn, Philip; Hasty, Jeff; Tsimring, Lev S.

    2017-01-01

    Quantitative predictions for the spread of mutations in bacterial populations are essential to interpret evolution experiments and to improve the stability of synthetic gene circuits. We derive analytical expressions for the suppression factor for beneficial mutations in populations that undergo periodic dilutions, covering arbitrary population sizes, dilution factors, and growth advantages in a single stochastic model. We find that the suppression factor grows with the dilution factor and depends nontrivially on the growth advantage, resulting in the preferential elimination of mutations with certain growth advantages. We confirm our results by extensive numerical simulations.

  1. Escherichia coli frameshift mutation rate depends on the chromosomal context but not on the GATC content near the mutation site.

    Directory of Open Access Journals (Sweden)

    Mariana A Martina

    Full Text Available Different studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent manner, being almost nonfunctional when GATC sequences are located at 1 kb or more from the mutation site. Interestingly, we found that in E. coli genomic DNA the mismatch repair system can efficiently function even if the nearest GATC sequence is located more than 2 kb away from the mutation site. The results presented in this work show that even though frameshift mutations can be efficiently generated and/or repaired anywhere in the genome, these processes can be modulated by the chromosomal context that surrounds the mutation site.

  2. Escherichia coli frameshift mutation rate depends on the chromosomal context but not on the GATC content near the mutation site.

    Science.gov (United States)

    Martina, Mariana A; Correa, Elisa M E; Argaraña, Carlos E; Barra, José L

    2012-01-01

    Different studies have suggested that mutation rate varies at different positions in the genome. In this work we analyzed if the chromosomal context and/or the presence of GATC sites can affect the frameshift mutation rate in the Escherichia coli genome. We show that in a mismatch repair deficient background, a condition where the mutation rate reflects the fidelity of the DNA polymerization process, the frameshift mutation rate could vary up to four times among different chromosomal contexts. Furthermore, the mismatch repair efficiency could vary up to eight times when compared at different chromosomal locations, indicating that detection and/or repair of frameshift events also depends on the chromosomal context. Also, GATC sequences have been proved to be essential for the correct functioning of the E. coli mismatch repair system. Using bacteriophage heteroduplexes molecules it has been shown that GATC influence the mismatch repair efficiency in a distance- and number-dependent manner, being almost nonfunctional when GATC sequences are located at 1 kb or more from the mutation site. Interestingly, we found that in E. coli genomic DNA the mismatch repair system can efficiently function even if the nearest GATC sequence is located more than 2 kb away from the mutation site. The results presented in this work show that even though frameshift mutations can be efficiently generated and/or repaired anywhere in the genome, these processes can be modulated by the chromosomal context that surrounds the mutation site.

  3. Evolution of mutation rates in hypermutable populations of Escherichia coli propagated at very small effective population size.

    Science.gov (United States)

    Singh, Tanya; Hyun, Meredith; Sniegowski, Paul

    2017-03-01

    Mutation is the ultimate source of the genetic variation-including variation for mutation rate itself-that fuels evolution. Natural selection can raise or lower the genomic mutation rate of a population by changing the frequencies of mutation rate modifier alleles associated with beneficial and deleterious mutations. Existing theory and observations suggest that where selection is minimized, rapid systematic evolution of mutation rate either up or down is unlikely. Here, we report systematic evolution of higher and lower mutation rates in replicate hypermutable Escherichia coli populations experimentally propagated at very small effective size-a circumstance under which selection is greatly reduced. Several populations went extinct during this experiment, and these populations tended to evolve elevated mutation rates. In contrast, populations that survived to the end of the experiment tended to evolve decreased mutation rates. We discuss the relevance of our results to current ideas about the evolution, maintenance and consequences of high mutation rates.

  4. Solar-UV-signature mutation prefers TCG to CCG: extrapolative consideration from UVA1-induced mutation spectra in mouse skin.

    Science.gov (United States)

    Ikehata, Hironobu; Kumagai, Jun; Ono, Tetsuya; Morita, Akimichi

    2013-08-01

    UVA1 exerts its genotoxicity on mammalian skin by producing cyclobutane pyrimidine dimers (CPDs) in DNA and preferentially inducing solar-UV-signature mutations, C → T base substitution mutations at methylated CpG-associated dipyrimidine (Py-mCpG) sites, as demonstrated previously using a 364 nm laser as a UVA1 source and lacZ-transgenic mice that utilize the transgene as a mutational reporter. In the present study, we confirmed that a broadband UVA1 source induced the same mutation profiles in mouse epidermis as the UVA1 laser, generalizing the previous result from a single 364 nm to a wider wavelength range of UVA1 (340-400 nm). Combined with our previous data on the mutation spectra induced in mouse epidermis by UVB, UVA2 and solar UVR, we proved that the solar-UV-signature mutation is commonly observed in the wavelength range from UVB to UVA, and found that UVA1 induces this mutation more preferentially than the other shorter wavelength ranges. This finding indicates that the solar-UV-signature mutation-causing CPDs, which are known to prefer Py-mCpG sites, could be produced with the energy provided by the longer wavelength region of UVR, suggesting a photochemical reaction through the excitation of pyrimidine bases to energy states that can be accomplished by absorption of even low-energy UVR. On the other hand, the lower proportions of solar-UV-signature mutations observed in the mutation spectra for UVB and solar UVR indicate that the direct photochemical reaction through excited singlet state of pyrimidine bases, which can be accomplished only by high-energy UVR, is also involved in the mutation induction at those shorter wavelengths of UVR. We also found that the solar-UV signature prefers 5'-TCG-3' to 5'-CCG-3' as mutational target sites, consistent with the fact that UVA induces CPDs selectively at thymine-containing dipyrimidine sites and that solar UVR induces them preferably at Py-mCpG sites. However, the mutation spectrum in human p53 gene from non

  5. Analysis of Mitochondrial Gene Mutations in Chinese Pedigrees of Leber's Hereditary Optic Neuropathy

    Institute of Scientific and Technical Information of China (English)

    Ling Lin; Yikai Chen; Yi Tong; Zhihong Zheng; Jianyin Lin

    2002-01-01

    Purpose: To investigate the frequency of common pathogenic primary mitochondrial DNA mutations in Leber's hereditary optic neuropathy (LHON) families.Methods: Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing were used to detect mitochondrial DNA mutations.Sixty-six Chinese examiners from 15 families, including 22 visual affected and their 44 unaffected maternal relatives, underwent molecular genetic evaluation. Eleven normal individuals underwent evaluation as contrl.Results: Of the 15 families with suspicion of LHON, 13 had nucleotide position (nt) Gl1778A mutations, 2 had nt T14484C mutations. All examiners had nt G11719A mutations.Conclusions: The mutations at nucleotides 11778 and 14484 are primary LHON mutations. Molecular genetic findings suggest that the silent mutation at nt G11719A may be a common genetic polymorphism in Chinese.

  6. High-resolution melting facilitates mutation screening of PYGM in patients with McArdle disease

    DEFF Research Database (Denmark)

    Duno, M.; Quinlivan, R.; Vissing, J.

    2009-01-01

    variations. Thirteen of these are pathogenic, and three were classified as polymorphisms. Nine variations had not previously been described. One of the novel mutations, c.2430C > T, was initially predicted to result in a silent G810G change, but cDNA analysis demonstrated that the mutation led to abnormal m......Mutations in PYGM, encoding the muscle-specific glycogen phosphorylase (myophosphorylase), are responsible for McArdle disease. Among Caucasians, a large proportion of patients are homozygous for the R50X mutation, but other mutations can affect all the 20 exons of PYGM, making mutation detection...... laborious. We have developed a high-resolution melting (HRM) assay for mutation detection in PYGM. Twelve McArdle patients were investigated, in whom pre-screening had ruled out homozygosity or compound heterozygosity for the two common G205S and R50X mutations. In total, we identified 16 different...

  7. Missense mutations of the fibrillin-1 gene in two Chinese patients with severe Marfan syndrome

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To describe two Chinese patients with severe forms of Marfan syndrome and to report findings of mutational analysis of the fibrillin-1 (FBN1) gene.Methods Two Chinese patients were studied, one suffering from Marfan syndrome of infantile onset and the other of neonatal onset. Their clinical features were described. Mutational analysis of the FBN1 gene was performed using polymerase chain reaction (PCR) technique and direct sequencing of exons 23 - 32,where the mutational hotspots for severe forms of Marfan syndrome are located.Results Two missense mutations were successfully identified, a G3037A transition and an A3083T transversion, the latter being an unreported mutation.Conclusion Taking advantage of the clustering phenomenon of mutations in severe forms of Marfan syndrome, one can identify FBN1 mutations in these patients by first screening the mutational hotspots,thus reducing the effort that would otherwise be much greater because of the size of the gene.

  8. Hepatitis C virus induces a mutator phenotype: enhanced mutations of immunoglobulin and protooncogenes.

    Science.gov (United States)

    Machida, Keigo; Cheng, Kevin T-N; Sung, Vicky M-H; Shimodaira, Shigetaka; Lindsay, Karen L; Levine, Alexandra M; Lai, Ming-Yang; Lai, Michael M C

    2004-03-23

    Hepatitis C virus (HCV) is a nonretroviral oncogenic RNA virus, which is frequently associated with hepatocellular carcinoma (HCC) and B cell lymphoma. We demonstrated here that acute and chronic HCV infection caused a 5- to 10-fold increase in mutation frequency in Ig heavy chain, BCL-6, p53, and beta-catenin genes of in vitro HCV-infected B cell lines and HCV-associated peripheral blood mononuclear cells, lymphomas, and HCCs. The nucleotide-substitution pattern of p53 and beta-catenin was different from that of Ig heavy chain in HCV-infected cells, suggesting two different mechanisms of mutation. In addition, the mutated protooncogenes were amplified in HCV-associated lymphomas and HCCs, but not in lymphomas of nonviral origin or HBV-associated HCC. HCV induced error-prone DNA polymerase zeta, polymerase iota, and activation-induced cytidine deaminase, which together, contributed to the enhancement of mutation frequency, as demonstrated by the RNA interference experiments. These results indicate that HCV induces a mutator phenotype and may transform cells by a hit-and-run mechanism. This finding provides a mechanism of oncogenesis for an RNA virus.

  9. A missense mutation (Q279R in the Fumarylacetoacetate Hydrolase gene, responsible for hereditary tyrosinemia, acts as a splicing mutation

    Directory of Open Access Journals (Sweden)

    Baklouti Faouzi

    2001-06-01

    Full Text Available Abstract Background Tyrosinemia type I, the most severe disease of the tyrosine catabolic pathway is caused by a deficiency in fumarylacetoacetate hydrolase (FAH. A patient showing few of the symptoms associated with the disease, was found to be a compound heterozygote for a splice mutation, IVS6-1g->t, and a putative missense mutation, Q279R. Analysis of FAH expression in liver sections obtained after resection for hepatocellular carcinoma revealed a mosaic pattern of expression. No FAH was found in tumor regions while a healthy region contained enzyme-expressing nodules. Results Analysis of DNA from a FAH expressing region showed that the expression of the protein was due to correction of the Q279R mutation. RT-PCR was used to assess if Q279R RNA was produced in the liver cells and in fibroblasts from the patient. Normal mRNA was found in the liver region where the mutation had reverted while splicing intermediates were found in non-expressing regions suggesting that the Q279R mutation acted as a splicing mutation in vivo. Sequence of transcripts showed skipping of exon 8 alone or together with exon 9. Using minigenes in transfection assays, the Q279R mutation was shown to induce skipping of exon 9 when placed in a constitutive splicing environment. Conclusion These data suggest that the putative missense mutation Q279R in the FAH gene acts as a splicing mutation in vivo. Moreover FAH expression can be partially restored in certain liver cells as a result of a reversion of the Q279R mutation and expansion of the corrected cells.

  10. Diagnostic and prognostic value of IDH1 mutation in gliomas

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    YANG Yan-wu

    2012-12-01

    Full Text Available Objective To discuss the significance of IDH1 mutation for diagnosis and prognosis of gliomas through detecting of IDH1 mutation in supratentorial glioma cells. Methods IDH1 genes of postoperative pathological samples obtained from 315 patients with supratentorial gliomas (3 cases of WHO Ⅰ, 95 cases of WHO Ⅱ, 37 cases of WHO Ⅲ and 180 cases of WHO Ⅳ were collected for DNA extraction, on which PCR amplification and direct sequencing were done. At the same time, multiple-factor analysis was used on those patients' age, sex, tumor location, excision extension, Karnofsky Performance Status (KPS and progression-free survival time or median survival time, to investigate the influence of IDH1 mutation on the prognosis of patients. Results A total of 112 gene mutations among 315 cases (35.56% were found and they were all R132H type of mutations. Mutation rates in WHOⅡ, Ⅲ and Ⅳ gliomas were 72.63% (69/95, 24.32% (9/37 and 18.89% (34/180 respectively, which were significantly different (P = 0.000, for all. Among patients with IDH1 mutations in WHOⅣ gliomas, there were 18 cases of primary glioblastoma and 16 cases of secondary glioblastoma, the mutation rates of which were 11.39% (18/158 and 72.73% (16/22, respectively. The latter was much higher than the former and the difference was statistically significant ( χ 2 = 23.654,P = 0.001. Survival analysis revealed that IDH1 mutation presented notable effect on the prognosis of patients with gliomas. Conclusion IDH1 mutation can happen in WHO Ⅱ, Ⅲ and Ⅳ gliomas, and the mutation rates of WHOⅡ gliomas and secondary glioblastomas of WHO Ⅳ are higher than others. The survival time of patients are remarkably influenced by IDH1 mutation, and the prognosis of patient with IDH1 mutation is good, which may suggest that IDH1 mutation is an important diagnostic and prognostic biomarker in different grades of gliomas.

  11. Radiation mutation breeding

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

    1998-04-01

    In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected.

  12. Mutations induced by ultraviolet light

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Gerd P. [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States)]. E-mail: gpfeifer@coh.org; You, Young-Hyun [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States); Besaratinia, Ahmad [Department of Biology, Beckman Research Institute, City of Hope, Duarte, CA 91010 (United States)

    2005-04-01

    The different ultraviolet (UV) wavelength components, UVA (320-400 nm), UVB (280-320 nm), and UVC (200-280 nm), have distinct mutagenic properties. A hallmark of UVC and UVB mutagenesis is the high frequency of transition mutations at dipyrimidine sequences containing cytosine. In human skin cancers, about 35% of all mutations in the p53 gene are transitions at dipyrimidines within the sequence 5'-TCG and 5'-CCG, and these are localized at several mutational hotspots. Since 5'-CG sequences are methylated along the p53 coding sequence in human cells, these mutations may be derived from sunlight-induced pyrimidine dimers forming at sequences that contain 5-methylcytosine. Cyclobutane pyrimidine dimers (CPDs) form preferentially at dipyrimidines containing 5-methylcytosine when cells are irradiated with UVB or sunlight. In order to define the contribution of 5-methylcytosine to sunlight-induced mutations, the lacI and cII transgenes in mouse fibroblasts were used as mutational targets. After 254 nm UVC irradiation, only 6-9% of the base substitutions were at dipyrimidines containing 5-methylcytosine. However, 24-32% of the solar light-induced mutations were at dipyrimidines that contain 5-methylcytosine and most of these mutations were transitions. Thus, CPDs forming preferentially at dipyrimidines with 5-methylcytosine are responsible for a considerable fraction of the mutations induced by sunlight in mammalian cells. Using mouse cell lines harboring photoproduct-specific photolyases and mutational reporter genes, we showed that CPDs (rather than 6-4 photoproducts or other lesions) are responsible for the great majority of UVB-induced mutations. An important component of UVB mutagenesis is the deamination of cytosine and 5-methylcytosine within CPDs. The mutational specificity of long-wave UVA (340-400 nm) is distinct from that of the shorter wavelength UV and is characterized mainly by G to T transversions presumably arising through mechanisms

  13. Profiling critical cancer gene mutations in clinical tumor samples.

    Directory of Open Access Journals (Sweden)

    Laura E MacConaill

    Full Text Available BACKGROUND: Detection of critical cancer gene mutations in clinical tumor specimens may predict patient outcomes and inform treatment options; however, high-throughput mutation profiling remains underdeveloped as a diagnostic approach. We report the implementation of a genotyping and validation algorithm that enables robust tumor mutation profiling in the clinical setting. METHODOLOGY: We developed and implemented an optimized mutation profiling platform ("OncoMap" to interrogate approximately 400 mutations in 33 known oncogenes and tumor suppressors, many of which are known to predict response or resistance to targeted therapies. The performance of OncoMap was analyzed using DNA derived from both frozen and FFPE clinical material in a diverse set of cancer types. A subsequent in-depth analysis was conducted on histologically and clinically annotated pediatric gliomas. The sensitivity and specificity of OncoMap were 93.8% and 100% in fresh frozen tissue; and 89.3% and 99.4% in FFPE-derived DNA. We detected known mutations at the expected frequencies in common cancers, as well as novel mutations in adult and pediatric cancers that are likely to predict heightened response or resistance to existing or developmental cancer therapies. OncoMap profiles also support a new molecular stratification of pediatric low-grade gliomas based on BRAF mutations that may have immediate clinical impact. CONCLUSIONS: Our results demonstrate the clinical feasibility of high-throughput mutation profiling to query a large panel of "actionable" cancer gene mutations. In the future, this type of approach may be incorporated into both cancer epidemiologic studies and clinical decision making to specify the use of many targeted anticancer agents.

  14. Mutations of FUS gene in sporadic amyotrophic lateral sclerosis.

    Science.gov (United States)

    Corrado, Lucia; Del Bo, Roberto; Castellotti, Barbara; Ratti, Antonia; Cereda, Cristina; Penco, Silvana; Sorarù, Gianni; Carlomagno, Yari; Ghezzi, Serena; Pensato, Viviana; Colombrita, Claudia; Gagliardi, Stella; Cozzi, Lorena; Orsetti, Valeria; Mancuso, Michelangelo; Siciliano, Gabriele; Mazzini, Letizia; Comi, Giacomo Pietro; Gellera, Cinzia; Ceroni, Mauro; D'Alfonso, Sandra; Silani, Vincenzo

    2010-03-01

    Mutations in the FUS gene have recently been discovered to be a major cause of familial amyotrophic lateral sclerosis (FALS). To determine the identity and frequency of FUS gene mutations in a large cohort of Italian patients enriched in sporadic cases (SALS). Exons 5, 6, 14 and 15 of the FUS gene were screened for mutations in 1009 patients (45 FALS and 964 SALS). The genetic analysis was extended to the entire coding sequence of FUS in all the FALS and 293 of the SALS patients. Seven missense mutations (p.G191S, p.R216C, p.G225V, p.G230C, p.R234C, p.G507D and p.R521C) were identified in nine patients (seven SALS and two FALS), and none in 500 healthy Italian controls. All mutations are novel except for the p.R521C mutation identified in one SALS and one FALS case. Both patients showed a similar unusual presentation, with proximal, mostly symmetrical, upper limb weakness, with neck and axial involvement. With the exception of p.G507D and p.R521C, the mutations identified in SALS patients are all localised in the glycine-rich region encoded by exon 6. In addition, eight different in-frame deletions in two polyglycine motifs were detected, the frequency of which was not significantly different in patients and controls. The results show that FUS missense mutations are present in 0.7% of Italian SALS cases, and confirm the previous mutational frequency reported in FALS (4.4%). An unusual proximal and axial clinical presentation seems to be associated with the presence of the p.R521C mutation.

  15. Algorithms and semantic infrastructure for mutation impact extraction and grounding

    Directory of Open Access Journals (Sweden)

    Kouznetsov Alexandre

    2010-12-01

    Full Text Available Abstract Background Mutation impact extraction is a hitherto unaccomplished task in state of the art mutation extraction systems. Protein mutations and their impacts on protein properties are hidden in scientific literature, making them poorly accessible for protein engineers and inaccessible for phenotype-prediction systems that currently depend on manually curated genomic variation databases. Results We present the first rule-based approach for the extraction of mutation impacts on protein properties, categorizing their directionality as positive, negative or neutral. Furthermore protein and mutation mentions are grounded to their respective UniProtKB IDs and selected protein properties, namely protein functions to concepts found in the Gene Ontology. The extracted entities are populated to an OWL-DL Mutation Impact ontology facilitating complex querying for mutation impacts using SPARQL. We illustrate retrieval of proteins and mutant sequences for a given direction of impact on specific protein properties. Moreover we provide programmatic access to the data through semantic web services using the SADI (Semantic Automated Discovery and Integration framework. Conclusion We address the problem of access to legacy mutation data in unstructured form through the creation of novel mutation impact extraction methods which are evaluated on a corpus of full-text articles on haloalkane dehalogenases, tagged by domain experts. Our approaches show state of the art levels of precision and recall for Mutation Grounding and respectable level of precision but lower recall for the task of Mutant-Impact relation extraction. The system is deployed using text mining and semantic web technologies with the goal of publishing to a broad spectrum of consumers.

  16. Comprehensive analysis of cooperative gene mutations between class I and class II in de novo acute myeloid leukemia.

    Science.gov (United States)

    Ishikawa, Yuichi; Kiyoi, Hitoshi; Tsujimura, Akane; Miyawaki, Shuichi; Miyazaki, Yasushi; Kuriyama, Kazutaka; Tomonaga, Masao; Naoe, Tomoki

    2009-08-01

    Acute myeloid leukemia (AML) has been thought to be the consequence of two broad complementation classes of mutations: class I and class II. However, overlap-mutations between them or within the same class and the position of TP53 mutation are not fully analyzed. We comprehensively analyzed the FLT3, cKIT, N-RAS, C/EBPA, AML1, MLL, NPM1, and TP53 mutations in 144 newly diagnosed de novo AML. We found 103 of 165 identified mutations were overlapped with other mutations, and most overlap-mutations consisted of class I and class II mutations. Although overlap-mutations within the same class were found in seven patients, five of them additionally had the other class mutation. These results suggest that most overlap-mutations within the same class might be the consequence of acquiring an additional mutation after the completion both of class I and class II mutations. However, mutated genes overlapped with the same class were limited in N-RAS, TP53, MLL-PTD, and NPM1, suggesting the possibility that these irregular overlap-mutations might cooperatively participate in the development of AML. Notably, TP53 mutation was overlapped with both class I and class II mutations, and associated with morphologic multilineage dysplasia and complex karyotype. The genotype consisting of complex karyotype and TP53 mutation was an unfavorable prognostic factor in entire AML patients, indicating this genotype generates a disease entity in de novo AML. These results collectively suggest that TP53 mutation might be a functionally distinguishable class of mutation.

  17. TERT promoter mutations in skin cancer: the effects of sun exposure and X-irradiation.

    Science.gov (United States)

    Pópulo, Helena; Boaventura, Paula; Vinagre, João; Batista, Rui; Mendes, Adélia; Caldas, Regina; Pardal, Joana; Azevedo, Filomena; Honavar, Mrinalini; Guimarães, Isabel; Manuel Lopes, José; Sobrinho-Simões, Manuel; Soares, Paula

    2014-08-01

    The reactivation or reexpression of telomerase (TERT) is a widespread feature of neoplasms. TERT promoter mutations were recently reported that were hypothesized to result from UV radiation. In this retrospective study, we assessed TERT promoter mutations in 196 cutaneous basal cell carcinomas (BCCs), including 102 tumors from X-irradiated patients, 94 tumors from patients never exposed to ionizing radiation treatment, and 116 melanomas. We sought to evaluate the effects of UV and X-ray irradiation on TERT mutation frequency. TERT mutations were detected in 27% of BCCs from X-irradiated patients, 51% of BCCs from nonirradiated patients, and 22% of melanoma patients. TERT mutations were significantly increased in non-X-irradiated BCC patients compared with X-irradiated BCC patients; the mutations also presented a different mutation signature. In nonirradiated patients, TERT mutations were more frequent in BCCs of sun-exposed skin, supporting a possible causative role of UV radiation. In melanoma, TERT promoter mutations were generally restricted to intermittent sun-exposed areas and were associated with nodular and superficial spreading subtypes, increased thickness, ulceration, increased mitotic rate, and BRAFV600E mutations. Our results suggest that various carcinogenic factors may cause distinct TERT promoter mutations in BCC and that TERT promoter mutations might be associated with a poorer prognosis in melanoma.

  18. [Mutation analysis of the pathogenic gene in a Chinese family with hereditary hemochromatosis].

    Science.gov (United States)

    Yuanfeng, Li; Hongxing, Zhang; Haitao, Zhang; Xiaobo, Peng; Lili, Bai; Fuchu, He; Zewu, Qiu; Gangqiao, Zhou

    2014-11-01

    Hereditary hemochromatosis (HHC) is a rare autosomal recessive disorder. We recruited a consanguineous Chinese family including the proband with HHC and other four members without HHC. Using whole-exome sequencing, we identified two homozygous mutations (c.G18C [p.Q6H] and c.GC962_963AA [p.C321X]) in the hemojuvelin gene (HJV) in the proband with HHC. No mutation was found in other four previously identified HHC related genes, HAMP, TFR2, FPN and HFE. The functional impact of p.Q6H mutation is weak whereas p.C321X, a premature termination mutation, results in a truncated HJV protein, which lacks the glycosylphosphatidylinositol (GPI) anchor domain. In addition to the mutations in HJV, other 12 homozygous mutations were identified in this patient. However, none of these mutations showed strong damaging impact and the mutated genes are not related to iron metabolism. Our in-house data further demonstrated that p.C321X is absent in the general Chinese population, suggesting that the homozygous mutation p.C321X in HJV is causative in the patient with HHC. Accordingly, all of the four members without HHC from the same family carried wild-type alleles or heterozygous mutations, but not the homozygous mutation in this site. Thus, we found for the first time that the homozygous mutation p.C321X in HJV can result in HHC, which will help genetic diagnosis and prenatal counseling for HHC.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Simultaneous mutation detection of three homoeologous genes in wheat by High Resolution Melting analysis and Mutation Surveyor®

    Directory of Open Access Journals (Sweden)

    Vincent Kate

    2009-12-01

    Full Text Available Abstract Background TILLING (Targeting Induced Local Lesions IN Genomes is a powerful tool for reverse genetics, combining traditional chemical mutagenesis with high-throughput PCR-based mutation detection to discover induced mutations that alter protein function. The most popular mutation detection method for TILLING is a mismatch cleavage assay using the endonuclease CelI. For this method, locus-specific PCR is essential. Most wheat genes are present as three similar sequences with high homology in exons and low homology in introns. Locus-specific primers can usually be designed in introns. However, it is sometimes difficult to design locus-specific PCR primers in a conserved region with high homology among the three homoeologous genes, or in a gene lacking introns, or if information on introns is not available. Here we describe a mutation detection method which combines High Resolution Melting (HRM analysis of mixed PCR amplicons containing three homoeologous gene fragments and sequence analysis using Mutation Surveyor® software, aimed at simultaneous detection of mutations in three homoeologous genes. Results We demonstrate that High Resolution Melting (HRM analysis can be used in mutation scans in mixed PCR amplicons containing three homoeologous gene fragments. Combining HRM scanning with sequence analysis using Mutation Surveyor® is sensitive enough to detect a single nucleotide mutation in the heterozygous state in a mixed PCR amplicon containing three homoeoloci. The method was tested and validated in an EMS (ethylmethane sulfonate-treated wheat TILLING population, screening mutations in the carboxyl terminal domain of the Starch Synthase II (SSII gene. Selected identified mutations of interest can be further analysed by cloning to confirm the mutation and determine the genomic origin of the mutation. Conclusion Polyploidy is common in plants. Conserved regions of a gene often represent functional domains and have high sequence

  1. Human Papillomavirus 16E6 Oncogene Mutation in Cervical Cancer

    Institute of Scientific and Technical Information of China (English)

    Feng Sun; Xiao-qin Ha; Tong-de Lv; Chuan-ping Xing; Bin Liu; Xiao-zhe Cao

    2009-01-01

    Objective: Cervical cancer (CC) is the second most common type of cancer in women worldwide, after breast cancer. High-risk human papillomaviruses (HR-HPVs) are considered to be the major causes of cervical cancer. HPV16 is the most common type of HR-HPVs and HPV16 E6 gene is one of the major oncogenes. Specific mutations are considered as dangerous factors causing CC. This study was designed to find mutations of HPV16 E6 and the relationship between the mutations and the happening of CC.Methods: The tissue DNA was extracted from 15 biopsies of CC. Part of HPV16 E6 gene (nucleotide 201-523) was amplified by polymerase chain reaction (PCR) from the CC tissue DNA. The PCR fragments were sequenced and analyzed.Results: The result of PCR showed that the positive rate of HPV16 E6 was 93.33% (14/15). After sequencing and analyzing, in the 13 out of 14 PCR fragments, 4 maintained prototype (30.77%), 8 had a same 350G mutation (61.54%), and 1 had a 249G mutation (7.69%).Conclusion: This study suggest that there is a high infection rate of HPV in cervical cancer and most of the HPV16 E6 gene has mutations. Those mutations may have an association with the development of cervical cancer.

  2. Mutation-selection balance and mixed mating with asexual reproduction.

    Science.gov (United States)

    Marriage, Tara N; Orive, Maria E

    2012-09-07

    The effects of asexual reproduction on both the number of deleterious mutations per gamete and the mean fitness under mutation-selection balance are investigated. We use two simulation models, considering both finite and infinite populations. The two models incorporate asexual reproduction with varying levels of outcrossing and selfing, degrees of dominance and selection coefficients. The values for mean fitness and number of deleterious mutations per gamete are compared within and among finite and infinite populations to identify the effect of asexual reproduction on levels of load, and how asexual reproduction may interact with genetic drift (population size). Increasing asexual reproduction resulted in an increase in mean fitness and a decrease in the average number of deleterious mutations per gamete for both nearly recessive and additive alleles in both the infinite and finite simulations. Increased mean fitness with increasing asexuality is possibly due to two interacting forces: a greater opportunity for selection to act on heterozygous versus homozygous mutations and the shielding of a proportion of the population from meiotic mutations due to asexual reproduction. The results found here highlight the need to consider asexual reproduction along with mixed mating in models of genetic load and mutation-selection balance.

  3. Deleterious mutation accumulation in asexual Timema stick insects.

    Science.gov (United States)

    Henry, Lee; Schwander, Tanja; Crespi, Bernard J

    2012-01-01

    Sexual reproduction is extremely widespread in spite of its presumed costs relative to asexual reproduction, indicating that it must provide significant advantages. One postulated benefit of sex and recombination is that they facilitate the purging of mildly deleterious mutations, which would accumulate in asexual lineages and contribute to their short evolutionary life span. To test this prediction, we estimated the accumulation rate of coding (nonsynonymous) mutations, which are expected to be deleterious, in parts of one mitochondrial (COI) and two nuclear (Actin and Hsp70) genes in six independently derived asexual lineages and related sexual species of Timema stick insects. We found signatures of increased coding mutation accumulation in all six asexual Timema and for each of the three analyzed genes, with 3.6- to 13.4-fold higher rates in the asexuals as compared with the sexuals. In addition, because coding mutations in the asexuals often resulted in considerable hydrophobicity changes at the concerned amino acid positions, coding mutations in the asexuals are likely associated with more strongly deleterious effects than in the sexuals. Our results demonstrate that deleterious mutation accumulation can differentially affect sexual and asexual lineages and support the idea that deleterious mutation accumulation plays an important role in limiting the long-term persistence of all-female lineages.

  4. Markov models for accumulating mutations

    CERN Document Server

    Beerenwinkel, Niko

    2007-01-01

    We introduce and analyze a waiting time model for the accumulation of genetic changes. The continuous time conjunctive Bayesian network is defined by a partially ordered set of mutations and by the rate of fixation of each mutation. The partial order encodes constraints on the order in which mutations can fixate in the population, shedding light on the mutational pathways underlying the evolutionary process. We study a censored version of the model and derive equations for an EM algorithm to perform maximum likelihood estimation of the model parameters. We also show how to select the maximum likelihood poset. The model is applied to genetic data from different cancers and from drug resistant HIV samples, indicating implications for diagnosis and treatment.

  5. Dynamical Mutation of Dark Energy

    CERN Document Server

    Abramo, L R; Liberato, L; Rosenfeld, R

    2007-01-01

    We discuss the intriguing possibility that dark energy may change its equation of state in situations where large dark energy fluctuations are present. We show indications of this dynamical mutation in some generic models of dark energy.

  6. Mutation Analysis in the BRCA1 Gene in Chinese Breast Cancer Families

    Institute of Scientific and Technical Information of China (English)

    WUZhengyan; ZHENLinlin; FANPing

    2003-01-01

    Objective: To study the mutation of BRCA1 gene in Chinese breast cancer families. Methods:Fifteen families were selected, involving 41 members, consisting of 23 breast cancer patients. Using poly-merase chain reaction and single stranded conformation polymorphism (PCR-SSCP), and subsequent DNA sequencing, the mutation of BRCA1 genes were analyzed. Results: Four mutations were found in all fam-ilies, and the proportion of mutation was 26.7% (4/15) in breast cancer families. One of the 4 mutations was 2228 insC, resulting in chain termination at codon 711. The remaining 3 mutations were 1884A→T and 3232A→G, resulting in single amino acid change respectively. Conclusion: BRCA1 is a breast cancer susceptibility gene. The relatively low proportion and frequency of BRCA1 mutations in our study hints additional BRCA genes existed.

  7. Energy parasites trigger oncogene mutation.

    Science.gov (United States)

    Pokorný, Jiří; Pokorný, Jan; Jandová, Anna; Kobilková, Jitka; Vrba, Jan; Vrba, Jan

    2016-10-01

    Cancer initialization can be explained as a result of parasitic virus energy consumption leading to randomized genome chemical bonding. Analysis of experimental data on cell-mediated immunity (CMI) containing about 12,000 cases of healthy humans, cancer patients and patients with precancerous cervical lesions disclosed that the specific cancer and the non-specific lactate dehydrogenase-elevating (LDH) virus antigen elicit similar responses. The specific antigen is effective only in cancer type of its origin but the non-specific antigen in all examined cancers. CMI results of CIN patients display both healthy and cancer state. The ribonucleic acid (RNA) of the LDH virus parasitizing on energy reduces the ratio of coherent/random oscillations. Decreased effect of coherent cellular electromagnetic field on bonding electrons in biological macromolecules leads to elevating probability of random genome reactions. Overlapping of wave functions in biological macromolecules depends on energy of the cellular electromagnetic field which supplies energy to bonding electrons for selective chemical bonds. CMI responses of cancer and LDH virus antigens in all examined healthy, precancerous and cancer cases point to energy mechanism in cancer initiation. Dependence of the rate of biochemical reactions on biological electromagnetic field explains yet unknown mechanism of genome mutation.

  8. PPARγ mutations, lipodystrophy and diabetes.

    Science.gov (United States)

    Astapova, Olga; Leff, Todd

    2014-11-01

    The focus of this review is the lipodystrophy syndrome caused by mutation in the PPARγ nuclear receptor - partial familial lipodystrophy FPLD3. To provide a broader context for how these mutations act to generate the clinical features of partial lipodystrophy we will review the basic biology of PPARγ and also survey the set PPARγ genetic variants that do not cause lipodystrophy, but are nonetheless associated with clinically related syndromes, specifically type 2 diabetes.

  9. Gene mutations in hepatocellular adenomas

    DEFF Research Database (Denmark)

    Raft, Marie B; Jørgensen, Ernö N; Vainer, Ben

    2015-01-01

    is associated with bi-allelic mutations in the TCF1 gene and morphologically has marked steatosis. β-catenin activating HCA has increased activity of the Wnt/β-catenin pathway and is associated with possible malignant transformation. Inflammatory HCA is characterized by an oncogene-induced inflammation due....... This review offers an overview of the reported gene mutations associated with hepatocellular adenomas together with a discussion of the diagnostic and prognostic value....

  10. β-Thalassemia major resulting from compound heterozygosity for HBB: c.92+2T>C [formerly known as IVS-I-2 (T>C)] and a novel β(0)-thalassemia frameshift mutation: HBB: c.209delG; p.Gly70Valfs*20.

    Science.gov (United States)

    Kluge, Michelle L; Hoyer, James D; Swanson, Kenneth C; Oliveira, Jennifer L

    2014-01-01

    A novel β(0)-thalassemia (β-thal) frameshift mutation, HBB: c.209delG; p.Gly70Valfs*20, is described in a 21-year-old African American female with β-thalassemia major (β-TM) due to compound heterozygosity for the β(0)-thal mutation HBB: c.92+2T>C [formerly known as IVS-I-2 (T>C)] and HBB: c.209delG. The combination of these mutations demonstrates a complete lack of β-globin chain synthesis, evidenced by the proband having no Hb A present.

  11. Mutation studies in Cymbopogon nardus var. Confertiflorus

    Energy Technology Data Exchange (ETDEWEB)

    Choudhary, D.K.; Kak, S.N.; Kaul, B.L. (Regional Research Lab., Jammu (India))

    1981-09-01

    Vegetative slips of Cymbopogon nardus var, confertiflorus after irradiation with various doses of X-rays left a clone among the surviving plants that showed mutation resulting in a higher content of geranyl acetate. From its progeny, raised after selfing a fresh clone, possessing about 60% geranyl acetate in the oil without any effect on the herb yield, has been isolated. This mutant has a significant commercial importance as a new source of geranyl acetate, an important aroma chemical.

  12. Molecular analysis of WT1 and KIT mutations in patients from an Indian population with de novo acute myeloid leukemia: determination of incidence, distribution patterns, and report of a novel KIT mutation.

    Science.gov (United States)

    Ahmad, Firoz; D'Souza, Wilma; Mandava, Swarna; Das, Bibhu Ranjan

    2011-05-01

    Mutations of the WT1 gene have been reported as the most common abnormality after NPM1 and FLT3 gene mutations in acute myeloid leukemia (AML), while KIT mutations are predominantly found in core-binding factor (CBF) AMLs. We report for the first time the prevalence and distribution patterns of WT1 and KIT mutations in an Indian population of 150. Overall, 10 (6.7%) and four (2.7%) of the cases had WT1 and KIT mutations, respectively. Of the six mutations observed in exon 7, five were frameshift while the remaining one case showed a substitution mutation. In contrast to exon 7, no frameshift mutation was detected in exon 9, where all mutations were substitution mutations. Interestingly, we observed a novel mutation in exon 8 of the KIT gene resulting from the deletion of nine nucleotides and insertion of three nucleotides affecting the extracellular domain of the KIT receptor, while Asp816Tyr and Asp816His were commonly found in exon 17 of the KIT gene. The WT1 mutation was more prevalent in normal karyotype AML while KIT was associated with t(8;21). With respect to FLT3 and NPM1 mutations, WT1 was more predominant in FLT3 positive cases and less in NPM1 mutation cases, while no KIT mutation was found in FLT3/NPM1 positive cases.

  13. Pyridoxine responsiveness in novel mutations of the PNPO gene

    OpenAIRE

    2014-01-01

    OBJECTIVE: To determine whether patients with pyridoxine-responsive seizures but normal biomarkers for antiquitin deficiency and normal sequencing of the ALDH7A1 gene may have PNPO mutations. METHODS: We sequenced the PNPO gene in 31 patients who fulfilled the above-mentioned criteria. RESULTS: We were able to identify 11 patients carrying 3 novel mutations of the PNPO gene. In 6 families, a homozygous missense mutation p.Arg225His in exon 7 was identified, while 1 family was compound h...

  14. Mutations causative of familial hypercholesterolaemia

    DEFF Research Database (Denmark)

    Benn, Marianne; Watts, Gerald F; Tybjærg-Hansen, Anne

    2016-01-01

    AIMS: Ideally, familial hypercholesterolaemia (FH) is diagnosed by testing for mutations that decrease the catabolism of low-density lipoprotein (LDL) cholesterol; however, genetic testing is not universally available. The aim of the present study was to assess the frequency and predictors of FH....... The prevalence of the four FH mutations was 0.18% (1:565), suggesting a total prevalence of FH mutations of 0.46% (1:217). Using the Dutch Lipid Clinic Network (DLCN) criteria, odds ratios for an FH mutation were 439 (95% CI: 170-1 138) for definite FH, 90 (53-152) for probable FH, and 18 (13-25) for possible FH......-cholesterol concentration to discriminate between mutation carriers and non-carriers was 4.4 mmol/L. CONCLUSION: Familial hypercholesterolaemia-causing mutations are estimated to occur in 1:217 in the general population and are best identified by a definite or probable phenotypic diagnosis of FH based on the DLCN criteria...

  15. The Frequency and clinical significance of IDH1 mutations in Chinese acute myeloid leukemia patients.

    Directory of Open Access Journals (Sweden)

    Lixun Guan

    Full Text Available OBJECTIVE: Mutations in the gene encoding isocitrate dehydrogenease 1 (IDH1 occur in various hematopoietic tumors including acute myeloid leukemia (AML, myeloproliferative neoplasms and myelodysplastic syndromes. IDH1 mutations are significant in both diagnosis and prognosis of these conditions. In the present study we determined the prevalence and clinical significance of IDH1 mutations in 349 samples from newly diagnosed AML patients. RESULTS: Of the 349 AML patient specimens analyzed, 35 (10.03% were found to have IDH1 mutations including 4 IDH1 R132 mutations and 31 non-R132 mutations. IDH1 non-R132 mutations were largely concentrated within AML-M1 (35.72%, pA, p.R100Q; (2 c.311G>T, p.G104V; (3 c.322T>C, p.F108L; (4 c.356G>A, p.R119Q; and (5 c.388A>G, p.I130V. In addition, we identified three IDH1 mutations that were previously described in AML. The frequency of IDH1 mutations in AML patients with normal karyotype was 9.9%. IDH1 non-R132 mutations were concurrent with mutations in FLT3-ITD (p<0.01, CEBPA (p<0.01, and NRAS (p<0.01, as well as the overexpression of MN1 (p<0.01 and WT1(p<0.01. The overall survival (OS in the patients with IDH1 non-R132 mutations compared to patients without IDH1 mutations don't reach statistically significance (median 521 days vs median: not reached; n.s.. CONCLUSION: IDH1 non-R132 mutations occurred frequently in newly diagnosed adult Chinese AML patients, and these mutations were associated with genetic alterations. The OS was not influenced by IDH1 non-R132 mutations in the present study.

  16. Dysferlin Gene Mutation Spectrum in a Large Cohort of Chinese Patients with Dysferlinopathy

    Science.gov (United States)

    Jin, Su-Qin; Yu, Meng; Zhang, Wei; Lyu, He; Yuan, Yun; Wang, Zhao-Xia

    2016-01-01

    Background: Dysferlinopathy is caused by mutations in the dysferlin (DYSF) gene. Here, we described the genetic features of a large cohort of Chinese patients with this disease. Methods: Eighty-nine index patients were included in the study. DYSF gene analysis was performed by Sanger sequencing in 41 patients and targeted next generation sequencing (NGS) in 48 patients. Multiplex ligation-dependent probe amplification (MLPA) was performed to detect exon duplication/deletion in patients with only one pathogenic mutation. Results: Among the 89 index patients, 79 patients were demonstrated to carry two disease-causing (73 cases) or possibly disease-causing mutations (6 cases), including 26 patients with homozygous mutations. We identified 105 different mutations, including 59 novel ones. Notably, in 13 patients in whom only one pathogenic mutation was initially found by Sanger sequencing or NGS, 3 were further identified to carry exon deletions by MLPA. The mutations identified in this study appeared to cluster in the N-terminal region. Mutation types included missense mutations (30.06%), nonsense mutations (17.18%), frameshift mutations (30.67%), in-frame deletions (2.45%), intronic mutations (17.79%), and exonic rearrangement (1.84%). No genotype-phenotype correlation was identified. Conclusions: DYSF mutations in Chinese patients clustered in the N-terminal region of the gene. Exonic rearrangements were found in 23% of patients with only one pathogenic mutation identified by Sanger sequencing or NGS. The novel mutations found in this study greatly expanded the mutational spectrum of dysferlinopathy. PMID:27647186

  17. Dysferlin Gene Mutation Spectrum in a Large Cohort of Chinese Patients with Dysferlinopathy

    Institute of Scientific and Technical Information of China (English)

    Su-Qin Jin; Meng Yu; Wei Zhang; He Lyu; Yun Yuan; Zhao-Xia Wang

    2016-01-01

    Background:Dysferlinopathy is caused by mutations in the dysferlin (DYSF) gene.Here,we described the genetic features of a large cohort of Chinese patients with this disease.Methods:Eighty-nine index patients were included in the study.DYSF gene analysis was performed by Sanger sequencing in 41 patients and targeted next generation sequencing (NGS) in 48 patients.Multiplex ligation-dependent probe amplification (MLPA) was performed to detect exon duplication/deletion in patients with only one pathogenic mutation.Results:Among the 89 index patients,79 patients were demonstrated to carry two disease-causing (73 cases) or possibly disease-causing mutations (6 cases),including 26 patients with homozygous mutations.We identified 105 different mutations,including 59 novel ones.Notably,in 13 patients in whom only one pathogenic mutation was initially found by Sanger sequencing or NGS,3 were further identified to carry exon deletions by MLPA.The mutations identified in this study appeared to cluster in the N-terminal region.Mutation types included missense mutations (30.06%),nonsense mutations (1 7.18%),frameshift mutations (30.67%),in-frame deletions (2.45%),intronic mutations (17.79%),and exonic rearrangement (1.84%).No genotype-phenotype correlation was identified.Conclusions:DYSF mutations in Chinese patients clustered in the N-terminal region of the gene.Exonic rearrangements were found in 23% of patients with only one pathogenic mutation identified by Sanger sequencing or NGS.The novel mutations found in this study greatly expanded the mutational spectrum of dysferlinopathy.

  18. Timing constraints of in vivo gag mutations during primary HIV-1 subtype C infection.

    Directory of Open Access Journals (Sweden)

    Vladimir Novitsky

    Full Text Available BACKGROUND: Aiming to answer the broad question "When does mutation occur?" this study examined the time of appearance, dominance, and completeness of in vivo Gag mutations in primary HIV-1 subtype C infection. METHODS: A primary HIV-1C infection cohort comprised of 8 acutely and 34 recently infected subjects were followed frequently up to 500 days post-seroconversion (p/s. Gag mutations were analyzed by employing single-genome amplification and direct sequencing. Gag mutations were determined in relation to the estimated time of seroconversion. Time of appearance, dominance, and completeness was compared for different types of in vivo Gag mutations. RESULTS: Reverse mutations to the wild type appeared at a median (IQR of 62 (44;139 days p/s, while escape mutations from the wild type appeared at 234 (169;326 days p/s (p<0.001. Within the subset of mutations that became dominant, reverse and escape mutations appeared at 54 (30;78 days p/s and 104 (47;198 days p/s, respectively (p<0.001. Among the mutations that reached completeness, reverse and escape mutations appeared at 54 (30;78 days p/s and 90 (44;196 days p/s, respectively (p=0.006. Time of dominance for reverse mutations to and escape mutations from the wild type was 58 (44;105 days p/s and 219 (90;326 days p/s, respectively (p<0.001. Time of completeness for reverse and escape mutations was 152 (100;176 days p/s and 243 (101;370 days p/s, respectively (p=0.001. Fitting a Cox proportional hazards model with frailties confirmed a significantly earlier time of appearance (hazard ratio (HR: 2.6; 95% CI: 2.3-3.0, dominance (4.8 (3.4-6.8, and completeness (3.6 (2.3-5.5 of reverse mutations to the wild type Gag than escape mutations from the wild type. Some complex mutational pathways in Gag included sequential series of reversions and escapes. CONCLUSIONS: The study identified the timing of different types of in vivo Gag mutations in primary HIV-1 subtype C infection in relation to the

  19. Identification of a Danish breast/ovarian cancer family double heterozygote for BRCA1 and BRCA2 mutations

    DEFF Research Database (Denmark)

    Steffensen, Ane Y; Jønson, Lars; Ejlertsen, Bent;

    2010-01-01