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

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

2016-01-01

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

Absence of a primary role for TTN missense variants in arrhythmogenic cardiomyopathy: From a clinical and pathological perspective.

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Chen, Kai; Song, Jiangping; Wang, Zhen; Rao, Man; Chen, Liang; Hu, Shengshou

2018-05-01

Arrhythmogenic cardiomyopathy (ACM) is an inheritable heart disease characterized by fibro-fatty replacement of the myocardium. TTN missense variants were previously reported as a pathogenic factor for ACM. TTN missense variants are commonly identified in ACM, but have limited effect on the phenotype of ACM. We sequenced 15 ACM-related genes in 35 patients who had a heart transplantation and quantified myocardium, and fibrous and adipose tissue in blocks of the explanted heart. Clinical and pathological characteristics were compared between patients with TTN variants and others. Pedigree analysis was performed in 3 families with TTN variants. TTN variants were detected in 11 patients (all missense, 9 heterozygous and 2 oligogenic form). The TTN truncating variant was absent in the cohort. Patients with TTN variants had late onset age of the disease (31 ±13 years vs 17 ±3 years, P = 0.049) and age of heart transplantation (41 ±14 years vs 24 ±9 years, P = 0.027), larger left ventricle end-diastolic diameter (62 ±10 mm vs 45 ±10 mm, P = 0.019), smaller right ventricular outflow tract (34 ±14 mm vs 50 ±15 mm, P = 0.046), more myocardium (40.8% ±29.4% vs 13.8% ±11.0%, P = 0.017), and less adipose tissue (43.0% ±30.9% vs 66.9% ±18.5%, P = 0.036) in right ventricle than those with desmosomal variants. There was few difference between patients with TTN variants and those without variants. Pedigrees showed none of the family members with TTN missense variants had a disease phenotype, indicating a very low penetrance. TTN missense variants was commonly identified in ACM patients in this cohort, but hardly played a primary role in ACM as causative variants. © 2018 Wiley Periodicals, Inc.

Novel compound heterozygous mutations in MYO7A gene associated with autosomal recessive sensorineural hearing loss in a Chinese family.

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Ma, Yalin; Xiao, Yun; Zhang, Fengguo; Han, Yuechen; Li, Jianfeng; Xu, Lei; Bai, Xiaohui; Wang, Haibo

2016-04-01

Mutations in MYO7A gene have been reported to be associated with Usher Syndrome type 1B (USH1B) and nonsyndromic hearing loss (DFNB2, DFNA11). Most mutations in MYO7A gene caused USH1B, whereas only a few reported mutations led to DFNB2 and DFNA11. The current study was designed to investigate the mutations among a Chinese family with autosomal recessive hearing loss. In this study, we present the clinical, genetic and molecular characteristics of a Chinese family. Targeted capture of 127 known deafness genes and next-generation sequencing were employed to study the genetic causes of two siblings in the Chinese family. Sanger sequencing was employed to examine those variant mutations in the members of this family and other ethnicity-matched controls. We identified the novel compound heterozygous mutant alleles of MYO7A gene: a novel missense mutation c.3671C>A (p.A1224D) and a reported insert mutation c.390_391insC (p.P131PfsX9). Variants were further confirmed by Sanger sequencing. These two compound heterozygous variants were co-segregated with autosomal recessive hearing loss phenotype. The gene mutation analysis and protein sequence alignment further supported that the novel compound heterozygous mutations were pathogenic. The novel compound heterozygous mutations (c.3671C>A and c.390_391insC) in MYO7A gene identified in this study were responsible for the autosomal recessive sensorineural hearing loss of this Chinese family. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

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

2017-09-01

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

Compound-heterozygous Marfan syndrome

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van Dijk, F. S.; Hamel, B. C.; Hilhorst-Hofstee, Y.; Mulder, B. J. M.; Timmermans, J.; Pals, G.; Cobben, J. M.

2009-01-01

We report two families in which the probands have compound-heterozygous Marfan syndrome (MFS). The proband of family I has the R2726W FBN1 mutation associated with isolated skeletal features on one allele and a pathogenic FBN1 mutation on the other allele. The phenotype of the compound-heterozygous

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

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

2016-01-01

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

Waardenburg syndrome type 3 (Klein-Waardenburg syndrome) segregating with a heterozygous deletion in the paired box domain of PAX3: a simple variant or a true syndrome?

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Tekin, M; Bodurtha, J N; Nance, W E; Pandya, A

2001-10-01

Klein-Waardenburg syndrome or Waardenburg syndrome type 3 (WS-III; MIM 148820) is characterized by the presence of musculoskeletal abnormalities in association with clinical features of Waardenburg syndrome type 1 (WS-I). Since the description of the first patient in 1947 (D. Klein, Arch Klaus Stift Vererb Forsch 1947: 22: 336-342), a few cases have been reported. Only occasional families have demonstrated autosomal-dominant inheritance of WS-III. In a previous report, a missense mutation in the paired domain of the PAX3 gene has been described in a family with dominant segregation of WS-III. In this report, we present a second family (mother and son) with typical clinical findings of WS-III segregating with a heterozygous 13-bp deletion in the paired domain of the PAX3 gene. Although homozygosity or compound heterozygosity has also been documented in patients with severe limb involvement, a consistent genotype-phenotype correlation for limb abnormalities associated with heterozygous PAX3 mutations has not previously been apparent. Heterozygous mutations could either reflect a unique dominant-negative effect or possibly the contribution of other unlinked genetic modifiers in determining the phenotype.

Pyogranulomatous pneumonia in goats caused by an undescribed Porphyromonas species, "Porphyromonas katsikii".

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Filioussis, George; Petridou, Evanthia; Karavanis, Emmanouel; Frey, Joachim

2015-03-01

A yet-undescribed bacterial species, tentatively named "Porphyromonas katsikii," was isolated from individuals of a small goat herd with pyogranulomatous pneumonia during an outbreak of acute respiratory disease. The isolated bacteria grew in the form of black-pigmented colonies after 14 days of incubation under anaerobic conditions at 37°C on a tryptic soy blood agar medium. The bacteria were identified as a yet-undescribed Porphyromonas species by determination of the nucleotide sequence of the rrs 16S rRNA gene, and this species was tentatively named Porphyromonas katsikii. PCR amplification with specific primers for this yet-undescribed species revealed the presence of P. katsikii in the lung tissue of all affected animals, while no PCR signals were evidenced from the lungs of healthy goats or from goats with pasteurellosis caused by Mannheimia haemolytica. These data indicate P. katsikii as the causative agent of acute respiratory distress. P. katsikii is phylogenetically related to Porphyromonas somerae and Porphyromonas levii, which cause pathologies in humans and animals, respectively. P. katsikii was not detected by PCR from samples of the gingival pockets or of the faces of healthy goats. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

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

2011-12-01

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

Missense mutations in ITPR1 cause autosomal dominant congenital nonprogressive spinocerebellar ataxia

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Huang Lijia

2012-09-01

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

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

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

2017-10-12

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

Pyogranulomatous Pneumonia in Goats Caused by an Undescribed Porphyromonas Species, “Porphyromonas katsikii”

Science.gov (United States)

Filioussis, George; Petridou, Evanthia; Karavanis, Emmanouel

2014-01-01

A yet-undescribed bacterial species, tentatively named “Porphyromonas katsikii,” was isolated from individuals of a small goat herd with pyogranulomatous pneumonia during an outbreak of acute respiratory disease. The isolated bacteria grew in the form of black-pigmented colonies after 14 days of incubation under anaerobic conditions at 37°C on a tryptic soy blood agar medium. The bacteria were identified as a yet-undescribed Porphyromonas species by determination of the nucleotide sequence of the rrs 16S rRNA gene, and this species was tentatively named Porphyromonas katsikii. PCR amplification with specific primers for this yet-undescribed species revealed the presence of P. katsikii in the lung tissue of all affected animals, while no PCR signals were evidenced from the lungs of healthy goats or from goats with pasteurellosis caused by Mannheimia haemolytica. These data indicate P. katsikii as the causative agent of acute respiratory distress. P. katsikii is phylogenetically related to Porphyromonas somerae and Porphyromonas levii, which cause pathologies in humans and animals, respectively. P. katsikii was not detected by PCR from samples of the gingival pockets or of the faces of healthy goats. PMID:25540395

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

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

2011-01-01

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

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

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

2013-01-01

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

Severe hypertriglyceridemia in a patient heterozygous for a lipoprotein lipase gene allele with two novel missense variants.

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Kassner, Ursula; Salewsky, Bastian; Wühle-Demuth, Marion; Szijarto, Istvan Andras; Grenkowitz, Thomas; Binner, Priska; März, Winfried; Steinhagen-Thiessen, Elisabeth; Demuth, Ilja

2015-09-01

Rare monogenic hyperchylomicronemia is caused by loss-of-function mutations in genes involved in the catabolism of triglyceride-rich lipoproteins, including the lipoprotein lipase gene, LPL. Clinical hallmarks of this condition are eruptive xanthomas, recurrent pancreatitis and abdominal pain. Patients with LPL deficiency and severe or recurrent pancreatitis are eligible for the first gene therapy treatment approved by the European Union. Therefore the precise molecular diagnosis of familial hyperchylomicronemia may affect treatment decisions. We present a 57-year-old male patient with excessive hypertriglyceridemia despite intensive lipid-lowering therapy. Abdominal sonography showed signs of chronic pancreatitis. Direct DNA sequencing and cloning revealed two novel missense variants, c.1302A>T and c.1306G>A, in exon 8 of the LPL gene coexisting on the same allele. The variants result in the amino-acid exchanges p.(Lys434Asn) and p.(Gly436Arg). They are located in the carboxy-terminal domain of lipoprotein lipase that interacts with the glycosylphosphatidylinositol-anchored HDL-binding protein (GPIHBP1) and are likely of functional relevance. No further relevant mutations were found by direct sequencing of the genes for APOA5, APOC2, LMF1 and GPIHBP1. We conclude that heterozygosity for damaging mutations of LPL may be sufficient to produce severe hypertriglyceridemia and that chylomicronemia may be transmitted in a dominant manner, at least in some families.

In Silico Analysis of FMR1 Gene Missense SNPs.

Science.gov (United States)

Tekcan, Akin

2016-06-01

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

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

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

2010-01-01

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

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

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

2010-01-15

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

Personalized Stem Cell Therapy to Correct Corneal Defects Due to a Unique Homozygous-Heterozygous Mosaicism of Ectrodactyly-Ectodermal Dysplasia-Clefting Syndrome.

Science.gov (United States)

Barbaro, Vanessa; Nasti, Annamaria Assunta; Raffa, Paolo; Migliorati, Angelo; Nespeca, Patrizia; Ferrari, Stefano; Palumbo, Elisa; Bertolin, Marina; Breda, Claudia; Miceli, Francesco; Russo, Antonella; Caenazzo, Luciana; Ponzin, Diego; Palù, Giorgio; Parolin, Cristina; Di Iorio, Enzo

2016-08-01

: Ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome is a rare autosomal dominant disease caused by mutations in the p63 gene. To date, approximately 40 different p63 mutations have been identified, all heterozygous. No definitive treatments are available to counteract and resolve the progressive corneal degeneration due to a premature aging of limbal epithelial stem cells. Here, we describe a unique case of a young female patient, aged 18 years, with EEC and corneal dysfunction, who was, surprisingly, homozygous for a novel and de novo R311K missense mutation in the p63 gene. A detailed analysis of the degree of somatic mosaicism in leukocytes from peripheral blood and oral mucosal epithelial stem cells (OMESCs) from biopsies of buccal mucosa showed that approximately 80% were homozygous mutant cells and 20% were heterozygous. Cytogenetic and molecular analyses excluded genomic alterations, thus suggesting a de novo mutation followed by an allelic gene conversion of the wild-type allele by de novo mutant allele as a possible mechanism to explain the homozygous condition. R311K-p63 OMESCs were expanded in vitro and heterozygous holoclones selected following clonal analysis. These R311K-p63 OMESCs were able to generate well-organized and stratified epithelia in vitro, resembling the features of healthy tissues. This study supports the rationale for the development of cultured autologous oral mucosal epithelial stem cell sheets obtained by selected heterozygous R311K-p63 stem cells, as an effective and personalized therapy for reconstructing the ocular surface of this unique case of EEC syndrome, thus bypassing gene therapy approaches. This case demonstrates that in a somatic mosaicism context, a novel homozygous mutation in the p63 gene can arise as a consequence of an allelic gene conversion event, subsequent to a de novo mutation. The heterozygous mutant R311K-p63 stem cells can be isolated by means of clonal analysis and given their good regenerative

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

Directory of Open Access Journals (Sweden)

Bohannon Sean B

2004-12-01

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

Classical phenotype of Laron syndrome in a girl with a heterozygous mutation and heterozygous polymorphism of the growth hormone receptor gene.

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Shevah, Orit; Galli-Tsinopoulou, Assimina; Rubinstein, Menachem; Nousia-Arvanitakis, Sanda; Laron, Zvi

2004-03-01

We describe here a 19 month-old girl with classical Laron syndrome (LS). Molecular analysis of the GH receptor gene in the patient and her parents was performed. The patient was found to be heterozygous for a mutation in exon 4 (R43X) and heterozygous for a polymorphism in exon 6 (Gly168Gly). Her mother was also heterozygous for R43X but homozygous for the polymorphism. In the father, a heterozygous polymorphism was found. Contrary to previous assumptions that only homozygous patients express the typical phenotype, this patient shows all the classical features of LS, despite being a heterozygote for a pathological defect.

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

Science.gov (United States)

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

2018-06-30

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

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

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

2018-03-01

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

Fundus albipunctatus associated with compound heterozygous mutations in RPE65

DEFF Research Database (Denmark)

Schatz, Patrik; Preising, Markus; Lorenz, Birgit

2011-01-01

To describe a family with an 18-year-old woman with fundus albipunctatus and compound heterozygous mutations in RPE65 whose unaffected parents and 1 female sibling harbored single heterozygous RPE65 mutations.......To describe a family with an 18-year-old woman with fundus albipunctatus and compound heterozygous mutations in RPE65 whose unaffected parents and 1 female sibling harbored single heterozygous RPE65 mutations....

Andermann syndrome can be a phenocopy of hereditary motor and sensory neuropathy--report of a discordant sibship with a compound heterozygous mutation of the KCC3 gene.

Science.gov (United States)

Rudnik-Schöneborn, S; Hehr, U; von Kalle, T; Bornemann, A; Winkler, J; Zerres, K

2009-06-01

Andermann syndrome is a rare autosomal recessive disorder characterized by agenesis of the corpus callosum (ACC), progressive motor-sensory neuropathy, mental retardation and facial features. We report on two siblings with the clinical picture of a demyelinating hereditary motor and sensory neuropathy (HMSN), where only the presence of ACC in the younger brother pointed to the diagnosis of Andermann syndrome. Mutation analysis of the KCC3 (SLC12A6) gene showed a compound heterozygous mutation; a maternal missense mutation c.1616G>A (p.G539D) and a paternal splice mutation c.1118+1G>A in both siblings. We hypothesize that mutations of the KCC3 gene may result in non-syndromic childhood onset HMSN.

A novel heterozygous RIT1 mutation in a patient with Noonan syndrome, leukopenia, and transient myeloproliferation-a review of the literature.

Science.gov (United States)

Nemcikova, Michaela; Vejvalkova, Sarka; Fencl, Filip; Sukova, Martina; Krepelova, Anna

2016-04-01

Noonan syndrome (NS) is a genetic condition presenting with typical facies, cardiac defects, short stature, variable developmental deficit, cryptorchidism, skeletal, and other abnormalities. Germline mutations in genes involved in the RAS/MAPK signaling have been discovered to underlie NS. Recently, missense mutations in RIT1 have been reported as causative for individuals with clinical signs of NS. We report on a 2.5-year-old boy with NS phenotype with a novel heterozygous change in the RIT1 gene. The patient was born prematurely from pregnancy monitored for polyhydramnios. At 7 months of age, non-immune neutropenia and splenomegaly have been observed. During the severe pneumonia at 10 months, significant progression of hepatosplenomegaly, leukopenia with monocytosis (15-29 %), and thrombocytopenia occurred. Bone marrow evaluation showed myeloid hyperplasia and monocytosis, suggestive of myeloproliferative syndrome. Clinical phenotype (facial dysmorphism, soft hair, short neck, broad chest, widely spaced nipples, mild pectus carinatum, deep palmar creases, unilateral cryptorchidism), and moderate pulmonary valve stenosis with mild psychomotor delay were indicative of NS. DNA analysis identified a de novo heterozygous variant c.69A >T, p.(Lys23Asn) in exon 2 of the RIT1 gene, presumed to be causative. We present a patient with a clinical suspicion of NS carrying a novel substitution in RIT1 and hematologic findings not being observed in RIT1 positive patients to date. Thus, the case broadens variability of hematologic symptoms in RIT1 positive NS individuals. • Noonan syndrome is a common genetically heterogeneous disorder of autosomal dominant inheritance characterized by craniofacial dysmorphism, short stature, congenital heart defects, variable cognitive deficit, and other anomalies. What is new: • We report on a 2.5-year-old male patient with clinical signs of NS and hematologic abnormalities, in whom a novel heterozygous substitution in RIT1 with probable

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

Science.gov (United States)

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

2014-10-01

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

Novel USH2A compound heterozygous mutations cause RP/USH2 in a Chinese family.

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Liu, Xiaowen; Tang, Zhaohui; Li, Chang; Yang, Kangjuan; Gan, Guanqi; Zhang, Zibo; Liu, Jingyu; Jiang, Fagang; Wang, Qing; Liu, Mugen

2010-03-17

To identify the disease-causing gene in a four-generation Chinese family affected with retinitis pigmentosa (RP). Linkage analysis was performed with a panel of microsatellite markers flanking the candidate genetic loci of RP. These loci included 38 known RP genes. The complete coding region and exon-intron boundaries of Usher syndrome 2A (USH2A) were sequenced with the proband DNA to screen the disease-causing gene mutation. Restriction fragment length polymorphism (RFLP) analysis and direct DNA sequence analysis were done to demonstrate co-segregation of the USH2A mutations with the family disease. One hundred normal controls were used without the mutations. The disease-causing gene in this Chinese family was linked to the USH2A locus on chromosome 1q41. Direct DNA sequence analysis of USH2A identified two novel mutations in the patients: one missense mutation p.G1734R in exon 26 and a splice site mutation, IVS32+1G>A, which was found in the donor site of intron 32 of USH2A. Neither the p.G1734R nor the IVS32+1G>A mutation was found in the unaffected family members or the 100 normal controls. One patient with a homozygous mutation displayed only RP symptoms until now, while three patients with compound heterozygous mutations in the family of study showed both RP and hearing impairment. This study identified two novel mutations: p.G1734R and IVS32+1G>A of USH2A in a four-generation Chinese RP family. In this study, the heterozygous mutation and the homozygous mutation in USH2A may cause Usher syndrome Type II or RP, respectively. These two mutations expand the mutant spectrum of USH2A.

Penetrance of eye defects in mice heterozygous for mutation of Gli3 is enhanced by heterozygous mutation of Pax6

Directory of Open Access Journals (Sweden)

Price David J

2006-10-01

Full Text Available Abstract Background Knowledge of the consequences of heterozygous mutations of developmentally important genes is important for understanding human genetic disorders. The Gli3 gene encodes a zinc finger transcription factor and homozygous loss-of-function mutations of Gli3 are lethal. Humans heterozygous for mutations in this gene suffer Greig cephalopolysyndactyly or Pallister-Hall syndromes, in which limb defects are prominent, and mice heterozygous for similar mutations have extra digits. Here we examined whether eye development, which is abnormal in mice lacking functional Gli3, is defective in Gli3+/- mice. Results We showed that Gli3 is expressed in the developing eye but that Gli3+/- mice have only very subtle eye defects. We then generated mice compound heterozygous for mutations in both Gli3 and Pax6, which encodes another developmentally important transcription factor known to be crucial for eye development. Pax6+/-; Gli3+/- eyes were compared to the eyes of wild-type, Pax6+/- or Gli3+/- siblings. They exhibited a range of abnormalities of the retina, iris, lens and cornea that was more extensive than in single Gli3+/- or Pax6+/- mutants or than would be predicted by addition of their phenotypes. Conclusion These findings indicate that heterozygous mutations of Gli3 can impact on eye development. The importance of a normal Gli3 gene dosage becomes greater in the absence of a normal Pax6 gene dosage, suggesting that the two genes co-operate during eye morphogenesis.

BRCA2 Hypomorphic Missense Variants Confer Moderate Risks of Breast Cancer

NARCIS (Netherlands)

Shimelis, Hermela; Mesman, Romy L. S.; Von Nicolai, Catharina; Ehlen, Asa; Guidugli, Lucia; Martin, Charlotte; Calléja, Fabienne M. G. R.; Meeks, Huong; Hallberg, Emily; Hinton, Jamie; Lilyquist, Jenna; Hu, Chunling; Aalfs, Cora M.; Aittomäki, Kristiina; Andrulis, Irene; Anton-Culver, Hoda; Arndt, Volker; Beckmann, Matthias W.; Benitez, Javier; Bogdanova, Natalia V.; Bojesen, Stig E.; Bolla, Manjeet K.; Borresen-Dale, Anne-Lise; Brauch, Hiltrud; Brennan, Paul; Brenner, Hermann; Broeks, Annegien; Brouwers, Barbara; Brüning, Thomas; Burwinkel, Barbara; Chang-Claude, Jenny; Chenevix-Trench, Georgia; Cheng, Ching-Yu; Choi, Ji-Yeob; Collée, J. Margriet; Cox, Angela; Cross, Simon S.; Czene, Kamila; Darabi, Hatef; Dennis, Joe; Dörk, Thilo; Dos-Santos-Silva, Isabel; Dunning, Alison M.; Fasching, Peter A.; Figueroa, Jonine; Flyger, Henrik; García-Closas, Montserrat; Giles, Graham G.; Glendon, Gord; Guénel, Pascal; Haiman, Christopher A.; Hall, Per; Hamann, Ute; Hartman, Mikael; Hogervorst, Frans B.; Hollestelle, Antoinette; Hopper, John L.; Ito, Hidemi; Jakubowska, Anna; Kang, Daehee; Kosma, Veli-Matti; Kristensen, Vessela; Lai, Kah-Nyin; Lambrechts, Diether; Marchand, Loic Le; Li, Jingmei; Lindblom, Annika; Lophatananon, Artitaya; Lubinski, Jan; Machackova, Eva; Mannermaa, Arto; Margolin, Sara; Marme, Frederik; Matsuo, Keitaro; Miao, Hui; Michailidou, Kyriaki; Milne, Roger L.; Muir, Kenneth; Neuhausen, Susan L.; Nevanlinna, Heli; Olson, Janet E.; Olswold, Curtis; Oosterwijk, Jan J. C.; Osorio, Ana; Peterlongo, Paolo; Peto, Julian; Pharoah, Paul D. P.; Pylkäs, Katri; Radice, Paolo; Rashid, Muhammad Usman; Rhenius, Valerie; Rudolph, Anja; Sangrajrang, Suleeporn; Sawyer, Elinor J.; Schmidt, Marjanka K.; Schoemaker, Minouk J.; Seynaeve, Caroline; Shah, Mitul; Shen, Chen-Yang; Shrubsole, Martha; Shu, Xiao-Ou; Slager, Susan; Southey, Melissa C.; Stram, Daniel O.; Swerdlow, Anthony; teo, Soo H.; Tomlinson, Ian; Torres, Diana; Truong, Thérèse; van Asperen, Christi J.; van der Kolk, Lizet E.; Wang, Qin; Winqvist, Robert; Wu, Anna H.; Yu, Jyh-Cherng; Zheng, Wei; Zheng, Ying; Leary, Jennifer; Walker, Logan; Foretova, Lenka; Fostira, Florentia; Claes, Kathleen B. M.; Varesco, Liliana; Moghadasi, Setareh; Easton, Douglas F.; Spurdle, Amanda; Devilee, Peter; Vrieling, Harry; Monteiro, Alvaro N. A.; Goldgar, David E.; Carreira, Aura; Vreeswijk, Maaike P. G.; Couch, Fergus J.

2017-01-01

Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk

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

Science.gov (United States)

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

1998-02-01

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

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

Science.gov (United States)

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

2004-05-15

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

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

Directory of Open Access Journals (Sweden)

Scott Rodney J

2004-05-01

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

Chemotaxonomic study of undescribed species ofMyrmica ant from Idaho.

Science.gov (United States)

Jackson, B D; Keegans, S J; Morgan, E D; Clark, W H; Blom, P E

1991-02-01

An undescribed species ofMyrmica collected in Idaho has been shown to have the same substances in its mandibular glands (3-octanol and 3-octanone and related 3-alkanols and 3-alkanones) and in its Dufour gland (linear alkanes, alkenes, and farnesene isomers and homologs) as previously examined European species ofMyrmica. The poison gland contains the trail pheromone 3-ethyl-2,5-dimethylpyrazine, common to allMyrmica species studied so far. The Dufour gland contains large amounts of bishomofarnesene, which easily distinguishes it from some 13 otherMyrmica already known.

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

Science.gov (United States)

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

2017-01-01

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

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

Science.gov (United States)

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

2017-11-01

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

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

Science.gov (United States)

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

2008-11-01

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

HbA1c levels in individuals heterozygous for hemoglobin variants.

Science.gov (United States)

Tavares, Ricardo Silva; Souza, Fábio Oliveira de; Francescantonio, Isabel Cristina Carvalho Medeiros; Soares, Weslley Carvalho; Mesquita, Mauro Meira

2017-04-01

To evaluate the levels of glycated hemoglobin (HbA1c) in patients heterozygous for hemoglobin variants and compare the results of this test with those of a control group. This was an experimental study based on the comparison of HbA1c tests in two different populations, with a test group represented by individuals heterozygous for hemoglobin variants (AS and AC) and a control group consisting of people with electrophoretic profile AA. The two populations were required to meet the following inclusion criteria: Normal levels of fasting glucose, hemoglobin, urea and triglycerides, bilirubin > 20 mg/dL and non-use of acetylsalicylic acid. 50 heterozygous subjects and 50 controls were evaluated between August 2013 and May 2014. The comparison of HbA1c levels between heterozygous individuals and control subjects was performed based on standard deviation, mean and G-Test. The study assessed a test group and a control group, both with 39 adults and 11 children. The mean among heterozygous adults for HbA1c was 5.0%, while the control group showed a rate of 5.74%. Heterozygous children presented mean HbA1c at 5.11%, while the controls were at 5.78%. G-Test yielded p=0.93 for children and p=0.89 for adults. Our study evaluated HbA1c using ion exchange chromatography resins, and the patients heterozygous for hemoglobin variants showed no significant difference from the control group.

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

Directory of Open Access Journals (Sweden)

Marziyeh Alamatsaz

2018-02-01

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

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

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Rashid Ban Mousa

2013-01-01

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

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

Science.gov (United States)

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

2013-01-09

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

[Novel CHST6 compound heterozygous mutations cause macular corneal dystrophy in a Chinese family].

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Qi, Yan-hua; Dang, Xiu-hong; Su, Hong; Zhou, Nan; Liang, Ting; Wang, Zheng; Huang, Shang-zhi

2010-02-01

The aim of this study was to identify mutations of CHST6 gene in a Chinese family with macular corneal dystrophy (MCD) and to investigate the histopathological changes of MCD. Corneal button of the proband was obtained from penetrating keratoplasty for the treatment of severe corneal dystrophy. The sections and ultrathin sections of this specimen were examined under light microscope and transmission electron microscope (TEM). Genomic DNA was extracted from leukocytes in peripheral blood from the family members. The coding region of CHST6 was amplified by polymerase chain reaction (PCR). The PCR products were analyzed by direct sequencing and restriction enzyme digestion. Histochemical study revealed positive results of colloidal iron stain. TEM revealed enlargement of smooth endoplasmic reticulum and the presence of intracytoplasmic vacuoles. Two mutations, Q298X Y358H, were identified in exon 3 of CHST6. Three patients were compound heterozygotes of these two mutations. The C892T transversion occurred at codon 298 turned the codon of glutamine to a stop codon; the T1072C transversion occurred at codon 358 caused a missense mutation, tyrosine to histidine. All six unaffected family members were heterozygotes. These two mutations were not detected in any of the 100 control subjects. The novel compound heterozygous mutation results in loss of CHST6 function and causes the occurrence of MCD. This is the first report of this gene mutation.

[Haplotype Analysis of Coagulation Factor VII Gene in a Patient with Congenital Coagulation Factor VII Deficiency with Heterozygous p.Arg337Cys Mutation and o.Aro413Gin Polymorphism..

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Suzuki, Keijiro; Yoshioka, Tomoko; Obara, Takehiro; Suwabe, Akira

2016-05-01

Congenital coagulation factor VII (FVII) deficiency is a rare hemorrhagic disease with an autosomal reces- sive inheritance pattern. We analyzed coagulation factor VII gene (F7) of a patient with FVII deficiency and used expression studies to investigate the effect of a missense mutation on FVII secretion. The proband, a 69-year-old Japanese woman, had a history of postpartum bleeding and excessive bleeding after dental extrac- tion. She was found to have mildly increased PT-INR (1.17) before an ophthalmic operation. FVII activity and antigen were reduced (29.0% and 32.8%). Suspecting that the proband was FVII deficient, we analyzed F7 of the patient. Sequence analysis revealed that the patient was heterozygous for a point mutation (p.Arg337Cys) in the catalytic domain and polymorphisms: the decanucleotide insertion at the promoter re- gion, dimorphism (c.525C >T) in exon 5, and p.Arg413Gln in exon 8. Haplotype analysis clarified that p.Arg337Cys was located on the p.Arg413 allele (Ml allele). The other allele had the p.Arg413Gln polymor- phism(M2 allele) which is known to produce less FVII. Expression studies revealed that p.Arg337Cys causes impairment of FVII secretion. Insufficient secretion of FVII arising from both the p.Arg337Cys/M1 allele and the p.Arg337/M2 allele might lower the FVII level of this patient(<50%). The FVII level in a heterozygous FVII deficient patient might be influenced by F7 polymorphisms on the normal allele. There- fore, genetic analyses are important for the diagnosis of heterozygous FVII deficiency.

BRCA2 Hypomorphic Missense Variants Confer Moderate Risks of Breast Cancer.

OpenAIRE

Shimelis, Hermela; Mesman, Romy LS; Von, Nicolai Catharina; Ehlen, Asa; Guidugli, Lucia; Martin, Charlotte; Calléja, Fabienne MGR; Meeks, Huong; Hallberg, Emily; Hinton, Jamie; Lilyquist, Jenna; Hu, Chunling; Aalfs, Cora M; Aittomäki, Kristiina; Andrulis, Irene

2017-01-01

Breast cancer risks conferred by many germline missense variants in the $\\textit{BRCA1}$ and $\\textit{BRCA2}$ genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case-control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine ...

BRCA2 hypomorphic missense variants confer moderate risks of breast cancer

OpenAIRE

Shimelis, Hermela; Mesman, Romy L.s.; Von Nicolai, Catharina; Ehlen, Asa; Guidugli, Lucia; Martin, Charlotte; Calleja, Fabienne Mgr; Meeks, Huong; Hallberg, Emily; Hinton, Jamie; Lilyquist, Jenna; Hu, Chunling; Aalfs, Cora M; Aittomaki, Kristiina; Andrulis, Irene L.

2017-01-01

Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case–control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine studies of Asian ances...

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

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

2017-01-01

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

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

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Jung-Wook Kim

2017-04-01

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

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

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

2018-05-15

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

Calibration of Multiple In Silico Tools for Predicting Pathogenicity of Mismatch Repair Gene Missense Substitutions

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Thompson, Bryony A.; Greenblatt, Marc S.; Vallee, Maxime P.; Herkert, Johanna C.; Tessereau, Chloe; Young, Erin L.; Adzhubey, Ivan A.; Li, Biao; Bell, Russell; Feng, Bingjian; Mooney, Sean D.; Radivojac, Predrag; Sunyaev, Shamil R.; Frebourg, Thierry; Hofstra, Robert M.W.; Sijmons, Rolf H.; Boucher, Ken; Thomas, Alun; Goldgar, David E.; Spurdle, Amanda B.; Tavtigian, Sean V.

2015-01-01

Classification of rare missense substitutions observed during genetic testing for patient management is a considerable problem in clinical genetics. The Bayesian integrated evaluation of unclassified variants is a solution originally developed for BRCA1/2. Here, we take a step toward an analogous system for the mismatch repair (MMR) genes (MLH1, MSH2, MSH6, and PMS2) that confer colon cancer susceptibility in Lynch syndrome by calibrating in silico tools to estimate prior probabilities of pathogenicity for MMR gene missense substitutions. A qualitative five-class classification system was developed and applied to 143 MMR missense variants. This identified 74 missense substitutions suitable for calibration. These substitutions were scored using six different in silico tools (Align-Grantham Variation Grantham Deviation, multivariate analysis of protein polymorphisms [MAPP], Mut-Pred, PolyPhen-2.1, Sorting Intolerant From Tolerant, and Xvar), using curated MMR multiple sequence alignments where possible. The output from each tool was calibrated by regression against the classifications of the 74 missense substitutions; these calibrated outputs are interpretable as prior probabilities of pathogenicity. MAPP was the most accurate tool and MAPP + PolyPhen-2.1 provided the best-combined model (R2 = 0.62 and area under receiver operating characteristic = 0.93). The MAPP + PolyPhen-2.1 output is sufficiently predictive to feed as a continuous variable into the quantitative Bayesian integrated evaluation for clinical classification of MMR gene missense substitutions. PMID:22949387

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

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

2016-01-15

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

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

DEFF Research Database (Denmark)

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

2010-01-01

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

Heterozygous effects of irradiated chromosomes on viability in Drosophila melanogaster

International Nuclear Information System (INIS)

Simmons, M.J.

1976-01-01

Two large experiments were conducted in order to evaluate the heterozygous effects of irradiated chromosomes on viability. Mutations were accumulated on several hundred second chromosomes by delivering doses of 2,500R over either two or four generations for total x-ray exposures of 5,000R or 10,000R. Chromosomes treated with 5,000R were screened for lethals after the first treatment, and surviving nonlethals were used to generate families of fully treated chromosomes. The members of these families shared the effects of the first irradiation, but differed with respect to those of the second. The chromosomes treated with 10,000R were not grouped into families since mutations were accumulated independently on each chromosome in that experiment. Heterozygous effects on viability of the irradiated chromosomes were tested in both isogenic (homozygous) and nonisogenic (heterozygous) genetic backgrounds. In conjunction with these tests, homozygous viabilities were determined by the marked-inversion technique. This permitted a separation of the irradiated chromosomes into those which were drastic when made homozygous and those which were not. The results indicate that drastic chromosomes have deleterious effects in heterozygous condition, since viability was reduced by 2 to 4 percent in tests performed with the 10,000R chromosomes, and by 1 percent in those involving the 5,000R material. Within a series of tests, the effects were more pronounced when the genetic background was homozygous. These results suggest that the mutants induced by high doses of x-rays are principally drastic ones which show deleterious effects on viability in heterozygous condition

Behavioral and electrophysiological characterization of Dyt1 heterozygous knockout mice.

Science.gov (United States)

Yokoi, Fumiaki; Chen, Huan-Xin; Dang, Mai Tu; Cheetham, Chad C; Campbell, Susan L; Roper, Steven N; Sweatt, J David; Li, Yuqing

2015-01-01

DYT1 dystonia is an inherited movement disorder caused by mutations in DYT1 (TOR1A), which codes for torsinA. Most of the patients have a trinucleotide deletion (ΔGAG) corresponding to a glutamic acid in the C-terminal region (torsinA(ΔE)). Dyt1 ΔGAG heterozygous knock-in (KI) mice, which mimic ΔGAG mutation in the endogenous gene, exhibit motor deficits and deceased frequency of spontaneous excitatory post-synaptic currents (sEPSCs) and normal theta-burst-induced long-term potentiation (LTP) in the hippocampal CA1 region. Although Dyt1 KI mice show decreased hippocampal torsinA levels, it is not clear whether the decreased torsinA level itself affects the synaptic plasticity or torsinA(ΔE) does it. To analyze the effect of partial torsinA loss on motor behaviors and synaptic transmission, Dyt1 heterozygous knock-out (KO) mice were examined as a model of a frame-shift DYT1 mutation in patients. Consistent with Dyt1 KI mice, Dyt1 heterozygous KO mice showed motor deficits in the beam-walking test. Dyt1 heterozygous KO mice showed decreased hippocampal torsinA levels lower than those in Dyt1 KI mice. Reduced sEPSCs and normal miniature excitatory post-synaptic currents (mEPSCs) were also observed in the acute hippocampal brain slices from Dyt1 heterozygous KO mice, suggesting that the partial loss of torsinA function in Dyt1 KI mice causes action potential-dependent neurotransmitter release deficits. On the other hand, Dyt1 heterozygous KO mice showed enhanced hippocampal LTP, normal input-output relations and paired pulse ratios in the extracellular field recordings. The results suggest that maintaining an appropriate torsinA level is important to sustain normal motor performance, synaptic transmission and plasticity. Developing therapeutics to restore a normal torsinA level may help to prevent and treat the symptoms in DYT1 dystonia.

Behavioral and electrophysiological characterization of Dyt1 heterozygous knockout mice.

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Fumiaki Yokoi

Full Text Available DYT1 dystonia is an inherited movement disorder caused by mutations in DYT1 (TOR1A, which codes for torsinA. Most of the patients have a trinucleotide deletion (ΔGAG corresponding to a glutamic acid in the C-terminal region (torsinA(ΔE. Dyt1 ΔGAG heterozygous knock-in (KI mice, which mimic ΔGAG mutation in the endogenous gene, exhibit motor deficits and deceased frequency of spontaneous excitatory post-synaptic currents (sEPSCs and normal theta-burst-induced long-term potentiation (LTP in the hippocampal CA1 region. Although Dyt1 KI mice show decreased hippocampal torsinA levels, it is not clear whether the decreased torsinA level itself affects the synaptic plasticity or torsinA(ΔE does it. To analyze the effect of partial torsinA loss on motor behaviors and synaptic transmission, Dyt1 heterozygous knock-out (KO mice were examined as a model of a frame-shift DYT1 mutation in patients. Consistent with Dyt1 KI mice, Dyt1 heterozygous KO mice showed motor deficits in the beam-walking test. Dyt1 heterozygous KO mice showed decreased hippocampal torsinA levels lower than those in Dyt1 KI mice. Reduced sEPSCs and normal miniature excitatory post-synaptic currents (mEPSCs were also observed in the acute hippocampal brain slices from Dyt1 heterozygous KO mice, suggesting that the partial loss of torsinA function in Dyt1 KI mice causes action potential-dependent neurotransmitter release deficits. On the other hand, Dyt1 heterozygous KO mice showed enhanced hippocampal LTP, normal input-output relations and paired pulse ratios in the extracellular field recordings. The results suggest that maintaining an appropriate torsinA level is important to sustain normal motor performance, synaptic transmission and plasticity. Developing therapeutics to restore a normal torsinA level may help to prevent and treat the symptoms in DYT1 dystonia.

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

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Semerdjian Ronald J

2003-08-01

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

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

Science.gov (United States)

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

2015-10-26

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

PINK1 heterozygous mutations induce subtle alterations in dopamine-dependent synaptic plasticity

Science.gov (United States)

Madeo, G.; Schirinzi, T.; Martella, G.; Latagliata, E.C.; Puglisi, F.; Shen, J.; Valente, E.M.; Federici, M.; Mercuri, N.B.; Puglisi-Allegra, S.; Bonsi, P.; Pisani, A.

2014-01-01

Background Homozygous or compound heterozygous mutations in the PTEN-induced kinase 1 (PINK1) gene are causative of autosomal recessive, early onset PD. Single heterozygous mutations have been repeatedly detected in a subset of patients as well as in non-affected subjects, and their significance has long been debated. Several neurophysiological studies from non-manifesting PINK1 heterozygotes have shown the existence of neural plasticity abnormalities, indicating the presence of specific endophenotypic traits in the heterozygous state. Methods In the present study, we performed a functional analysis of corticostriatal synaptic plasticity in heterozygous PINK1 knock-out (PINK1+/−) mice by a multidisciplinary approach. Results We found that, despite a normal motor behavior, repetitive activation of cortical inputs to striatal neurons failed to induce long-term potentiation (LTP), whereas long-term depression (LTD) was normal. Although nigral dopaminergic neurons exhibited normal morphological and electrophysiological properties with normal responses to dopamine receptor activation, we measured a significantly lower dopamine release in the striatum of PINK1+/−, compared to control mice, suggesting that a decrease in stimulus-evoked dopamine overflow acts as a major determinant for the LTP deficit. Accordingly, pharmacological agents capable of increasing the availability of dopamine in the synaptic cleft restored a normal LTP in heterozygous mice. Moreover, MAO-B inhibitors rescued a physiological LTP and a normal dopamine release. Conclusions Our results provide novel evidence for striatal plasticity abnormalities even in the heterozygous disease state. These alterations might be considered an endophenotype to this monogenic form of PD, and a valid tool to characterize early disease stage and design possible disease-modifying therapies. PMID:24167038

Dominant missense mutations in ABCC9 cause Cantu syndrome

NARCIS (Netherlands)

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

2012-01-01

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

Dominant missense mutations in ABCC9 cause Cantu syndrome.

NARCIS (Netherlands)

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

2012-01-01

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

Cortical synaptic transmission in CaV2.1 knockin mice with the S218L missense mutation which causes a severe familial hemiplegic migraine syndrome in humans.

Directory of Open Access Journals (Sweden)

Dania eVecchia

2015-02-01

Full Text Available Familial hemiplegic migraine type 1 (FHM1 is caused by gain-of-function mutations in CaV2.1 (P/Q-type Ca2+ channels. Knockin (KI mice carrying the FHM1 R192Q missense mutation show enhanced cortical excitatory synaptic transmission at pyramidal cell synapses but unaltered cortical inhibitory neurotransmission at fast-spiking interneuron synapses. Enhanced cortical glutamate release was shown to cause the facilitation of cortical spreading depression (CSD in R192Q KI mice. It, however, remains unknown how other FHM1 mutations affect cortical synaptic transmission. Here, we studied neurotransmission in cortical neurons in microculture from KI mice carrying the S218L mutation, which causes a severe FHM syndrome in humans and an allele-dosage dependent facilitation of experimental CSD in KI mice, which is larger than that caused by the R192Q mutation. We show gain-of-function of excitatory neurotransmission, due to increased action-potential evoked Ca2+ influx and increased probability of glutamate release at pyramidal cell synapses, but unaltered inhibitory neurotransmission at multipolar interneuron synapses in S218L KI mice. In contrast with the larger gain-of-function of neuronal CaV2.1 current in homozygous than heterozygous S218L KI mice, the gain-of-function of evoked glutamate release, the paired-pulse ratio and the Ca2+ dependence of the EPSC were all similar in homozygous and heterozygous S218L KI mice, suggesting compensatory changes in the homozygous mice. Furthermore, we reveal a unique feature of S218L KI cortical synapses which is the presence of a fraction of mutant CaV2.1 channels being open at resting potential. Our data suggest that, while the gain-of-function of evoked glutamate release may explain the facilitation of CSD in heterozygous S218L KI mice, the further facilitation of CSD in homozygous S218L KI mice is due to other CaV2.1-dependent mechanisms, that likely include Ca2+ influx at voltages sub-threshold for action

Biological activities of undescribed North American lichen species.

Science.gov (United States)

Yeash, Erik A; Letwin, Lyndon; Malek, Lada; Suntres, Zacharias; Knudsen, Kerry; Christopher, Lew P

2017-11-01

Lichens provide a large array of compounds with the potential for pharmaceutical development. In the present study, extracts from three previously undescribed North American lichen species were examined for antioxidant, antibacterial and anticancer activities. The results from this study demonstrated the following: (i) Acarospora socialis ethanol extract exhibited significant DPPH antioxidant scavenging activities, which were concentration dependent; (ii) acetone and ethyl acetate extracts of Xanthoparmelia mexicana inhibited Gram-positive bacteria but had no effect on Gram-negative bacteria; X. mexicana acetone extract yielded a minimum inhibitory concentration (MIC) of 20.9 µg mL -1 against Staphylococcus aureus, and 41.9 µg mL -1 against Enterococcus faecalis; (iii) acetone extract of Lobothallia alphoplaca inhibited growth of cultured breast cancer MCF-7 cells with an effective concentration (EC 50 ) of 87 µg mL -1 ; the MCF-7 cell cycle appears arrested in the G2 phase, whereas the DNA synthesis cell cycle (S) may be inhibited. New lichen species that possess strong biological activities have been identified. These lichens comprise secondary metabolites that possess antioxidant, antibacterial and anticancer properties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Abnormal cortical synaptic transmission in CaV2.1 knockin mice with the S218L missense mutation which causes a severe familial hemiplegic migraine syndrome in humans

Science.gov (United States)

Vecchia, Dania; Tottene, Angelita; van den Maagdenberg, Arn M.J.M.; Pietrobon, Daniela

2015-01-01

Familial hemiplegic migraine type 1 (FHM1) is caused by gain-of-function mutations in CaV2.1 (P/Q-type) Ca2+ channels. Knockin (KI) mice carrying the FHM1 R192Q missense mutation show enhanced cortical excitatory synaptic transmission at pyramidal cell synapses but unaltered cortical inhibitory neurotransmission at fast-spiking interneuron synapses. Enhanced cortical glutamate release was shown to cause the facilitation of cortical spreading depression (CSD) in R192Q KI mice. It, however, remains unknown how other FHM1 mutations affect cortical synaptic transmission. Here, we studied neurotransmission in cortical neurons in microculture from KI mice carrying the S218L mutation, which causes a severe FHM syndrome in humans and an allele-dosage dependent facilitation of experimental CSD in KI mice, which is larger than that caused by the R192Q mutation. We show gain-of-function of excitatory neurotransmission, due to increased action-potential evoked Ca2+ influx and increased probability of glutamate release at pyramidal cell synapses, but unaltered inhibitory neurotransmission at multipolar interneuron synapses in S218L KI mice. In contrast with the larger gain-of-function of neuronal CaV2.1 current in homozygous than heterozygous S218L KI mice, the gain-of-function of evoked glutamate release, the paired-pulse ratio and the Ca2+ dependence of the excitatory postsynaptic current were similar in homozygous and heterozygous S218L KI mice, suggesting compensatory changes in the homozygous mice. Furthermore, we reveal a unique feature of S218L KI cortical synapses which is the presence of a fraction of mutant CaV2.1 channels being open at resting potential. Our data suggest that, while the gain-of-function of evoked glutamate release may explain the facilitation of CSD in heterozygous S218L KI mice, the further facilitation of CSD in homozygous S218L KI mice is due to other CaV2.1-dependent mechanisms, that likely include Ca2+ influx at voltages sub-threshold for action

Molecular and phenotypic abnormalities in individuals with germline heterozygous PTEN mutations and autism.

Science.gov (United States)

Frazier, T W; Embacher, R; Tilot, A K; Koenig, K; Mester, J; Eng, C

2015-09-01

PTEN is a tumor suppressor associated with an inherited cancer syndrome and an important regulator of ongoing neural connectivity and plasticity. The present study examined molecular and phenotypic characteristics of individuals with germline heterozygous PTEN mutations and autism spectrum disorder (ASD) (PTEN-ASD), with the aim of identifying pathophysiologic markers that specifically associate with PTEN-ASD and that may serve as targets for future treatment trials. PTEN-ASD patients (n=17) were compared with idiopathic (non-PTEN) ASD patients with (macro-ASD, n=16) and without macrocephaly (normo-ASD, n=38) and healthy controls (n=14). Group differences were evaluated for PTEN pathway protein expression levels, global and regional structural brain volumes and cortical thickness measures, neurocognition and adaptive behavior. RNA expression patterns and brain characteristics of a murine model of Pten mislocalization were used to further evaluate abnormalities observed in human PTEN-ASD patients. PTEN-ASD had a high proportion of missense mutations and showed reduced PTEN protein levels. Compared with the other groups, prominent white-matter and cognitive abnormalities were specifically associated with PTEN-ASD patients, with strong reductions in processing speed and working memory. White-matter abnormalities mediated the relationship between PTEN protein reductions and reduced cognitive ability. The Pten(m3m4) murine model had differential expression of genes related to myelination and increased corpus callosum. Processing speed and working memory deficits and white-matter abnormalities may serve as useful features that signal clinicians that PTEN is etiologic and prompting referral to genetic professionals for gene testing, genetic counseling and cancer risk management; and could reveal treatment targets in trials of treatments for PTEN-ASD.

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

Science.gov (United States)

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

2010-01-01

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

BRCA2 Hypomorphic Missense Variants Confer Moderate Risks of Breast Cancer

DEFF Research Database (Denmark)

Shimelis, Hermela; Mesman, Romy L S; Von Nicolai, Catharina

2017-01-01

Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk ......, moderately increased risks of breast cancer, with potential implications for risk management guidelines in women with these specific variants. Cancer Res; 77(11); 2789-99. ©2017 AACR....... were investigated through a breast cancer case-control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine studies of Asian ancestry (6,269 cases and 6,624 controls). The BRCA2 c.9104A>C, p.Tyr3035Ser (OR = 2.52; P = 0.04), and BRCA...... of breast cancer among Asians. Functional characterization of the BRCA2 variants using four quantitative assays showed reduced BRCA2 activity for p.Tyr3035Ser compared with wild-type. Overall, our results show how BRCA2 missense variants that influence protein function can confer clinically relevant...

Heterozygous Germline Mutations in the CBL Tumor-Suppressor Gene Cause a Noonan Syndrome-like Phenotype

Science.gov (United States)

Martinelli, Simone; De Luca, Alessandro; Stellacci, Emilia; Rossi, Cesare; Checquolo, Saula; Lepri, Francesca; Caputo, Viviana; Silvano, Marianna; Buscherini, Francesco; Consoli, Federica; Ferrara, Grazia; Digilio, Maria C.; Cavaliere, Maria L.; van Hagen, Johanna M.; Zampino, Giuseppe; van der Burgt, Ineke; Ferrero, Giovanni B.; Mazzanti, Laura; Screpanti, Isabella; Yntema, Helger G.; Nillesen, Willy M.; Savarirayan, Ravi; Zenker, Martin; Dallapiccola, Bruno; Gelb, Bruce D.; Tartaglia, Marco

2010-01-01

RAS signaling plays a key role in controlling appropriate cell responses to extracellular stimuli and participates in early and late developmental processes. Although enhanced flow through this pathway has been established as a major contributor to oncogenesis, recent discoveries have revealed that aberrant RAS activation causes a group of clinically related developmental disorders characterized by facial dysmorphism, a wide spectrum of cardiac disease, reduced growth, variable cognitive deficits, ectodermal and musculoskeletal anomalies, and increased risk for certain malignancies. Here, we report that heterozygous germline mutations in CBL, a tumor-suppressor gene that is mutated in myeloid malignancies and encodes a multivalent adaptor protein with E3 ubiquitin ligase activity, can underlie a phenotype with clinical features fitting or partially overlapping Noonan syndrome (NS), the most common condition of this disease family. Independent CBL mutations were identified in two sporadic cases and two families from among 365 unrelated subjects who had NS or suggestive features and were negative for mutations in previously identified disease genes. Phenotypic heterogeneity and variable expressivity were documented. Mutations were missense changes altering evolutionarily conserved residues located in the RING finger domain or the linker connecting this domain to the N-terminal tyrosine kinase binding domain, a known mutational hot spot in myeloid malignancies. Mutations were shown to affect CBL-mediated receptor ubiquitylation and dysregulate signal flow through RAS. These findings document that germline mutations in CBL alter development to cause a clinically variable condition that resembles NS and that possibly predisposes to malignancies. PMID:20619386

Selected missense mutations impair frataxin processing in Friedreich ataxia.

Science.gov (United States)

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

2017-08-01

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

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

DEFF Research Database (Denmark)

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

2009-01-01

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

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

Science.gov (United States)

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

2015-07-01

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

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

Science.gov (United States)

Zhang, Zhe; Schwatz, Charles; Alexov, Emil

2011-03-01

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

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

Science.gov (United States)

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

2009-05-01

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

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

Science.gov (United States)

2017-10-01

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

Characterization of Heterozygous HTRA1 Mutations in Taiwanese Patients With Cerebral Small Vessel Disease.

Science.gov (United States)

Lee, Yi-Chung; Chung, Chih-Ping; Chao, Nai-Chen; Fuh, Jong-Ling; Chang, Feng-Chi; Soong, Bing-Wing; Liao, Yi-Chu

2018-07-01

Homozygous and compound heterozygous mutations in the high temperature requirement serine peptidase A1 gene ( HTRA1 ) cause cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy. However, heterozygous HTRA1 mutations were recently identified to be associated with autosomal dominant cerebral small vessel disease (SVD). The present study aims at investigating the clinical features, frequency, and spectrum of HTRA1 mutations in a Taiwanese cohort with SVD. Mutational analyses of HTRA1 were performed by Sanger sequencing in 222 subjects, selected from a cohort of 337 unrelated patients with SVD after excluding those harboring a NOTCH3 mutation. The influence of these mutations on HTRA1 protease activities was characterized. Seven novel heterozygous mutations in HTRA1 were identified, including p.Gly120Asp, p.Ile179Asn, p.Ala182Profs*33, p.Ile256Thr, p.Gly276Ala, p.Gln289Ter, and p.Asn324Thr, and each was identified in 1 single index patient. All mutations significantly compromise the HTRA1 protease activities. For the 7 index cases and another 2 affected siblings carrying a heterozygous HTRA1 mutation, the common clinical presentations include lacunar infarction, intracerebral hemorrhage, cognitive decline, and spondylosis at the fifth to sixth decade of life. Among the 9 patients, 4 have psychiatric symptoms as delusion, depression, and compulsive behavior, 3 have leukoencephalopathy in anterior temporal poles, and 2 patients have alopecia. Heterozygous HTRA1 mutations account for 2.08% (7 of 337) of SVD in Taiwan. The clinical and neuroradiological features of HTRA1 -related SVD and sporadic SVD are similar. These findings broaden the mutational spectrum of HTRA1 and highlight the pathogenic role of heterozygous HTRA1 mutations in SVD. © 2018 American Heart Association, Inc.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Heterozygous RTEL1 mutations are associated with familial pulmonary fibrosis.

Science.gov (United States)

Kannengiesser, Caroline; Borie, Raphael; Ménard, Christelle; Réocreux, Marion; Nitschké, Patrick; Gazal, Steven; Mal, Hervé; Taillé, Camille; Cadranel, Jacques; Nunes, Hilario; Valeyre, Dominique; Cordier, Jean François; Callebaut, Isabelle; Boileau, Catherine; Cottin, Vincent; Grandchamp, Bernard; Revy, Patrick; Crestani, Bruno

2015-08-01

Pulmonary fibrosis is a fatal disease with progressive loss of respiratory function. Defective telomere maintenance leading to telomere shortening is a cause of pulmonary fibrosis, as mutations in the telomerase component genes TERT (reverse transcriptase) and TERC (RNA component) are found in 15% of familial pulmonary fibrosis (FPF) cases. However, so far, about 85% of FPF remain genetically uncharacterised.Here, in order to identify new genetic causes of FPF, we performed whole-exome sequencing, with a candidate-gene approach, of 47 affected subjects from 35 families with FPF without TERT and TERC mutations.We identified heterozygous mutations in regulator of telomere elongation helicase 1 (RTEL1) in four families. RTEL1 is a DNA helicase with roles in DNA replication, genome stability, DNA repair and telomere maintenance. The heterozygous RTEL1 mutations segregated as an autosomal dominant trait in FPF, and were predicted by structural analyses to severely affect the function and/or stability of RTEL1. In agreement with this, RTEL1-mutated patients exhibited short telomeres in comparison with age-matched controls.Our results provide evidence that heterozygous RTEL1 mutations are responsible for FPF and, thereby, extend the clinical spectrum of RTEL1 deficiency. Thus, RTEL1 enlarges the number of telomere-associated genes implicated in FPF. Copyright ©ERS 2015.

A Novel Double Heterozygous Hb D-Punjab/Hb J-Meerut Hemoglobinopathy.

Science.gov (United States)

Chandra, Dinesh; Tyagi, Seema; Deka, Roopam; Chauhan, Richa; Seth, Tulika; Saxena, Renu; Pati, H P

2017-12-01

A comprehensive laboratory diagnosis of hemoglobinopathies forms an integral part in workup of disorders of globin chain synthesis. Clinical findings, complete blood counts, peripheral smear examination along with hemoglobin (Hb) electrophoresis and/or cation exchange high performance liquid chromatography findings and parental study helps to clinch a final diagnosis. Compound heterozygous hemoglobinopathy presents with variable clinical findings and some of them are picked up on screening tests done as part of routine antenatal workup. Here we report a rare double heterozygous hemoglobinopathy of Hb D-Punjab and Hb J-Meerut in a 35 year antenatal female.

Filaggrin compound heterozygous patients carry mutations in trans position

DEFF Research Database (Denmark)

Carlsen, Berit C; Meldgaard, Michael; Johansen, Jeanne D

2013-01-01

by means of allele-specific PCR amplification and analysis of PCR products by agarose gel electrophoresis. All R501X/2282del4 compound heterozygous samples collected over a 4-year period of routine FLG mutation testing were investigated. In total, 37 samples were tested. All thirty-seven R501X/2282del4......More than 40 null mutations in the filaggrin (FLG) gene are described. It is therefore possible to find two different null mutations in one individual (compound heterozygosity). It has been generally perceived that homozygous and compound heterozygous individuals were genotypically comparable......; however, this has not been scientifically investigated. Two different FLG null mutations in the same individual may be in trans position, meaning that each mutation locates to a different allele functionally equivalent to homozygosity, or may be in cis position, meaning that both mutations locate...

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

Science.gov (United States)

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

2010-06-01

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

Mixed Sequence Reader: A Program for Analyzing DNA Sequences with Heterozygous Base Calling

Science.gov (United States)

Chang, Chun-Tien; Tsai, Chi-Neu; Tang, Chuan Yi; Chen, Chun-Houh; Lian, Jang-Hau; Hu, Chi-Yu; Tsai, Chia-Lung; Chao, Angel; Lai, Chyong-Huey; Wang, Tzu-Hao; Lee, Yun-Shien

2012-01-01

The direct sequencing of PCR products generates heterozygous base-calling fluorescence chromatograms that are useful for identifying single-nucleotide polymorphisms (SNPs), insertion-deletions (indels), short tandem repeats (STRs), and paralogous genes. Indels and STRs can be easily detected using the currently available Indelligent or ShiftDetector programs, which do not search reference sequences. However, the detection of other genomic variants remains a challenge due to the lack of appropriate tools for heterozygous base-calling fluorescence chromatogram data analysis. In this study, we developed a free web-based program, Mixed Sequence Reader (MSR), which can directly analyze heterozygous base-calling fluorescence chromatogram data in .abi file format using comparisons with reference sequences. The heterozygous sequences are identified as two distinct sequences and aligned with reference sequences. Our results showed that MSR may be used to (i) physically locate indel and STR sequences and determine STR copy number by searching NCBI reference sequences; (ii) predict combinations of microsatellite patterns using the Federal Bureau of Investigation Combined DNA Index System (CODIS); (iii) determine human papilloma virus (HPV) genotypes by searching current viral databases in cases of double infections; (iv) estimate the copy number of paralogous genes, such as β-defensin 4 (DEFB4) and its paralog HSPDP3. PMID:22778697

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

Science.gov (United States)

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

2018-01-24

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

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

African Journals Online (AJOL)

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

Heterozygous CDKL5 Knockout Female Mice Are a Valuable Animal Model for CDKL5 Disorder

Directory of Open Access Journals (Sweden)

Claudia Fuchs

2018-01-01

Full Text Available CDKL5 disorder is a severe neurodevelopmental disorder caused by mutations in the X-linked CDKL5 (cyclin-dependent kinase-like five gene. CDKL5 disorder primarily affects girls and is characterized by early-onset epileptic seizures, gross motor impairment, intellectual disability, and autistic features. Although all CDKL5 female patients are heterozygous, the most valid disease-related model, the heterozygous female Cdkl5 knockout (Cdkl5 +/− mouse, has been little characterized. The lack of detailed behavioral profiling of this model remains a crucial gap that must be addressed in order to advance preclinical studies. Here, we provide a behavioral and molecular characterization of heterozygous Cdkl5 +/− mice. We found that Cdkl5 +/− mice reliably recapitulate several aspects of CDKL5 disorder, including autistic-like behaviors, defects in motor coordination and memory performance, and breathing abnormalities. These defects are associated with neuroanatomical alterations, such as reduced dendritic arborization and spine density of hippocampal neurons. Interestingly, Cdkl5 +/− mice show age-related alterations in protein kinase B (AKT and extracellular signal-regulated kinase (ERK signaling, two crucial signaling pathways involved in many neurodevelopmental processes. In conclusion, our study provides a comprehensive overview of neurobehavioral phenotypes of heterozygous female Cdkl5 +/− mice and demonstrates that the heterozygous female might be a valuable animal model in preclinical studies on CDKL5 disorder.

Whole-Exome Sequencing Identified a Novel Compound Heterozygous Mutation of LRRC6 in a Chinese Primary Ciliary Dyskinesia Patient

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Lv Liu

2018-01-01

Full Text Available Primary ciliary dyskinesia (PCD is a clinical rare peculiar disorder, mainly featured by respiratory infection, tympanitis, nasosinusitis, and male infertility. Previous study demonstrated it is an autosomal recessive disease and by 2017 almost 40 pathologic genes have been identified. Among them are the leucine-rich repeat- (LRR- containing 6 (LRRC6 codes for a 463-amino-acid cytoplasmic protein, expressed distinctively in motile cilia cells, including the testis cells and the respiratory epithelial cells. In this study, we applied whole-exome sequencing combined with PCD-known genes filtering to explore the genetic lesion of a PCD patient. A novel compound heterozygous mutation in LRRC6 (c.183T>G/p.N61K; c.179-1G>A was identified and coseparated in this family. The missense mutation (c.183T>G/p.N61K may lead to a substitution of asparagine by lysine at position 61 in exon 3 of LRRC6. The splice site mutation (c.179-1G>A may cause a premature stop codon in exon 4 and decrease the mRNA levels of LRRC6. Both mutations were not present in our 200 local controls, dbSNP, and 1000 genomes. Three bioinformatics programs also predicted that both mutations are deleterious. Our study not only further supported the importance of LRRC6 in PCD, but also expanded the spectrum of LRRC6 mutations and will contribute to the genetic diagnosis and counseling of PCD patients.

Risk of asthma in heterozygous carriers for cystic fibrosis

DEFF Research Database (Denmark)

Nielsen, Anne Orholm; Qayum, Sadaf; Bouchelouche, Pierre Nourdine

2016-01-01

Background Patients with cystic fibrosis (CF) have a higher prevalence of asthma than the background population, however, it is unclear whether heterozygous CF carriers are susceptible to asthma. Given this, a meta-analysis is necessary to determine the veracity of the association of CF...

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

Science.gov (United States)

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

2017-09-01

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

Premature cardiovascular disease in young women with heterozygous familial hypercholesterolemia

NARCIS (Netherlands)

van der Graaf, Anouk; Hutten, Barbara A.; Kastelein, John J. P.; Vissers, Maud N.

2006-01-01

Heterozygous familial hypercholesterolemia is associated with elevated low-density lipoprotein cholesterol levels and the development of premature cardiovascular disease. Despite this general statement, data regarding the incidence of cardiovascular disease in young women with familial

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

Science.gov (United States)

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

2015-01-01

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

Heterozygous defects in PAX6 gene and congenital hypopituitarism.

Science.gov (United States)

Takagi, Masaki; Nagasaki, Keisuke; Fujiwara, Ikuma; Ishii, Tomohiro; Amano, Naoko; Asakura, Yumi; Muroya, Koji; Hasegawa, Yukihiro; Adachi, Masanori; Hasegawa, Tomonobu

2015-01-01

The prevalence of congenital hypopituitarism (CH) attributable to known transcription factor mutations appears to be rare and other causative genes for CH remain to be identified. Due to the sporadic occurrence of CH, de novo chromosomal rearrangements could be one of the molecular mechanisms participating in its etiology, especially in syndromic cases. To identify the role of copy number variations (CNVs) in the etiology of CH and to identify novel genes implicated in CH. We enrolled 88 (syndromic: 30; non-syndromic: 58) Japanese CH patients. We performed an array comparative genomic hybridization screening in the 30 syndromic CH patients. For all the 88 patients, we analyzed PAX6 by PCR-based sequencing. We identified one heterozygous 310-kb deletion of the PAX6 enhancer region in one patient showing isolated GH deficiency (IGHD), cleft palate, and optic disc cupping. We also identified one heterozygous 6.5-Mb deletion encompassing OTX2 in a patient with bilateral anophthalmia and multiple pituitary hormone deficiency. We identified a novel PAX6 mutation, namely p.N116S in one non-syndromic CH patient showing IGHD. The p.N116S PAX6 was associated with an impairment of the transactivation capacities of the PAX6-binding elements. This study showed that heterozygous PAX6 mutations are associated with CH patients. PAX6 mutations may be associated with diverse clinical features ranging from severely impaired ocular and pituitary development to apparently normal phenotype. Overall, this study identified causative CNVs with a possible role in the etiology of CH in <10% of syndromic CH patients. © 2015 European Society of Endocrinology.

Dictyosphaeric acids A and B: new decalactones from an undescribed Penicillium sp. obtained from the alga Dictyosphaeria versluyii.

Science.gov (United States)

Bugni, Tim S; Janso, Jeffrey E; Williamson, R Thomas; Feng, Xidong; Bernan, Valerie S; Greenstein, Michael; Carter, Guy T; Maiese, William M; Ireland, Chris M

2004-08-01

Fungal isolate F01V25 was obtained from the alga Dictyosphaeria versluyii collected near Dravuni, Fiji, in 2001 and represented a previously undescribed Penicillium sp. Fermentation of isolate F01V25 resulted in the production of two new polyketides, dictyosphaeric acids A and B, along with the known anthraquinone carviolin. The relative stereochemistry of dictyosphaeric acids A and B was determined using the J-based configuration analysis method in conjunction with ROE and NOE correlations.

Arterial intima-media thickness in children heterozygous for familial hypercholesterolaemia

NARCIS (Netherlands)

Wiegman, Albert; de Groot, Eric; Hutten, Barbara A.; Rodenburg, Jessica; Gort, Johan; Bakker, Henk D.; Sijbrands, Eric J. G.; Kastelein, John J. P.

2004-01-01

Patients with familial hypercholesterolaemia have severe coronary-artery disease early in adult life. Whether lipid-lowering treatment should be started in childhood remains to be established. We therefore assessed 201 children heterozygous for familial hypercholesterolaemia and 80 unaffected

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

Directory of Open Access Journals (Sweden)

Tammy M K Cheng

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

ACTG2 variants impair actin polymerization in sporadic Megacystis Microcolon Intestinal Hypoperistalsis Syndrome

NARCIS (Netherlands)

Halim, Danny; Hofstra, Robert M. W.; Signorile, Luca; Verdijk, Rob M.; van der Werf, Christine S.; Sribudiani, Yunia; Brouwer, Rutger W. W.; van IJcken, Wilfred F. J.; Dahl, Niklas; Verheij, Joke B. G. M.; Baumann, Clarisse; Kerner, John; van Bever, Yolande; Galjart, Niels; Wijnen, Rene M. H.; Tibboel, Dick; Burns, Alan J.; Muller, Franoise; Brooks, Alice S.; Alves, Maria M.

2016-01-01

Megacystis Microcolon Intestinal Hypoperistalsis Syndrome (MMIHS) is a rare congenital disorder, in which heterozygous missense variants in the Enteric Smooth Muscle actin gamma-2 (ACTG2) gene have been recently identified. To investigate the mechanism by which ACTG2 variants lead to MMIHS, we

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

NARCIS (Netherlands)

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

2013-01-01

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

Augmentation of phenotype in a transgenic Parkinson mouse heterozygous for a Gaucher mutation.

Science.gov (United States)

Fishbein, Ianai; Kuo, Yien-Ming; Giasson, Benoit I; Nussbaum, Robert L

2014-12-01

The involvement of the protein α-synuclein (SNCA) in the pathogenesis of Parkinson's disease is strongly supported by the facts that (i) missense and copy number mutations in the SNCA gene can cause inherited Parkinson's disease; and (ii) Lewy bodies in sporadic Parkinson's disease are largely composed of aggregated SNCA. Unaffected heterozygous carriers of Gaucher disease mutations have an increased risk for Parkinson's disease. As mutations in the GBA gene encoding glucocerebrosidase (GBA) are known to interfere with lysosomal protein degradation, GBA heterozygotes may demonstrate reduced lysosomal SNCA degradation, leading to increased steady-state SNCA levels and promoting its aggregation. We have created mouse models to investigate the interaction between GBA mutations and synucleinopathies. We investigated the rate of SNCA degradation in cultured primary cortical neurons from mice expressing wild-type mouse SNCA, wild-type human SNCA, or mutant A53T SNCA, in a background of either wild-type Gba or heterozygosity for the L444P GBA mutation associated with Gaucher disease. We also tested the effect of this Gaucher mutation on motor and enteric nervous system function in these transgenic animals. We found that human SNCA is stable, with a half-life of 61 h, and that the A53T mutation did not significantly affect its half-life. Heterozygosity for a naturally occurring Gaucher mutation, L444P, reduced GBA activity by 40%, reduced SNCA degradation and triggered accumulation of the protein in culture. This mutation also resulted in the exacerbation of motor and gastrointestinal deficits found in the A53T mouse model of Parkinson's disease. This study demonstrates that heterozygosity for a Gaucher disease-associated mutation in Gba interferes with SNCA degradation and contributes to its accumulation, and exacerbates the phenotype in a mouse model of Parkinson's disease. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain

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

Science.gov (United States)

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

2004-01-01

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

Homozygous and compound heterozygous mutations in the FBN1 gene: unexpected findings in molecular diagnosis of Marfan syndrome.

Science.gov (United States)

Arnaud, Pauline; Hanna, Nadine; Aubart, Mélodie; Leheup, Bruno; Dupuis-Girod, Sophie; Naudion, Sophie; Lacombe, Didier; Milleron, Olivier; Odent, Sylvie; Faivre, Laurence; Bal, Laurence; Edouard, Thomas; Collod-Beroud, Gwenaëlle; Langeois, Maud; Spentchian, Myrtille; Gouya, Laurent; Jondeau, Guillaume; Boileau, Catherine

2017-02-01

Marfan syndrome (MFS) is an autosomal-dominant connective tissue disorder usually associated with heterozygous mutations in the gene encoding fibrillin-1 (FBN1). Homozygous and compound heterozygous cases are rare events and have been associated with a clinical severe presentation. Report unexpected findings of homozygosity and compound heterozygosity in the course of molecular diagnosis of heterozygous MFS and compare the findings with published cases. In the context of molecular diagnosis of heterozygous MFS, systematic sequencing of the FBN1 gene was performed in 2500 probands referred nationwide. 1400 probands carried a heterozygous mutation in this gene. Unexpectedly, among them four homozygous cases (0.29%) and five compound heterozygous cases (0.36%) were identified (total: 0.64%). Interestingly, none of these cases carried two premature termination codon mutations in the FBN1 gene. Clinical features for these carriers and their families were gathered and compared. There was a large spectrum of severity of the disease in probands carrying two mutated FBN1 alleles, but none of them presented extremely severe manifestations of MFS in any system compared with carriers of only one mutated FBN1 allele. This observation is not in line with the severe clinical features reported in the literature for four homozygous and three compound heterozygous probands. Homozygotes and compound heterozygotes were unexpectedly identified in the course of molecular diagnosis of MFS. Contrary to previous reports, the presence of two mutated alleles was not associated with severe forms of MFS. Although homozygosity and compound heterozygosity are rarely found in molecular diagnosis, they should not be overlooked, especially among consanguineous families. However, no predictive evaluation of severity should be provided. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Treatment of intractable epilepsy in a female with SLC6A8 deficiency

NARCIS (Netherlands)

Mercimek-Mahmutoglu, S.; Connolly, M.B.; Poskitt, K.J.; Horvath, G.A.; Lowry, N.; Salomons, G.S.; Casey, B.; Sinclair, G.; Davis, C.; Jakobs, C.; Stockler-Ipsiroglu, S.

2010-01-01

A female heterozygous for a novel, disease causing, missense mutation in the X-linked cerebral creatine transporter (SLC6A8) gene (c.1067G > T, p.Gly356Val) presented with intractable epilepsy, mild intellectual disability and moderately reduced cerebral creatine levels. Treatment with creatine

Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity

NARCIS (Netherlands)

Saksens, N.T.; Krebs, M.P.; Schoenmaker, F.E.; Hicks, W.; Yu, M.; Shi, L.; Rowe, L.; Collin, G.B.; Charette, J.R.; Letteboer, S.J.; Neveling, K.; Moorsel, T.W. van; Abu-Ltaif, S.; Baere, E. De; Walraedt, S.; Banfi, S.; Simonelli, F.; Cremers, F.P.; Boon, C.J.; Roepman, R.; Leroy, B.P.; Peachey, N.S.; Hoyng, C.B.; Nishina, P.M.; Hollander, A.I. den

2016-01-01

Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here we report the identification of heterozygous missense mutations in the CTNNA1 gene (encoding alpha-catenin 1) in three families with butterfly-shaped pigment

A novel mutation in the connexin 26 gene (GJB2) in a child with clinical and histological features of keratitis-ichthyosis-deafness (KID) syndrome

DEFF Research Database (Denmark)

Koppelhus, Uffe; Tranebjaerg, L; Esberg, G

2011-01-01

Keratitis-ichthyosis-deafness (KID) syndrome is a rare congenital ectodermal disorder, caused by heterozygous missense mutation in GJB2, encoding the gap junction protein connexin 26. The commonest mutation is the p.Asp50Asn mutation, and only a few other mutations have been described to date....

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

Directory of Open Access Journals (Sweden)

Jeffrey C Lee

2006-12-01

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

Neurochemical and behavioral characterization of neuronal glutamate transporter EAAT3 heterozygous mice

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Luis F. González

2017-10-01

Full Text Available Abstract Background Obsessive–compulsive disorder (OCD is a severe neuropsychiatric condition affecting 1–3% of the worldwide population. OCD has a strong genetic component, and the SLC1A1 gene that encodes neuronal glutamate transporter EAAT3 is a strong candidate for this disorder. To evaluate the impact of reduced EAAT3 expression in vivo, we studied male EAAT3 heterozygous and wild-type littermate mice using a battery of behavioral paradigms relevant to anxiety (open field test, elevated plus maze and compulsivity (marble burying, as well as locomotor activity induced by amphetamine. Using high-performance liquid chromatography, we also determined tissue neurotransmitter levels in cortex, striatum and thalamus—brain areas that are relevant to OCD. Results Compared to wild-type littermates, EAAT3 heterozygous male mice have unaltered baseline anxiety-like, compulsive-like behavior and locomotor activity. Administration of acute amphetamine (5 mg/kg intraperitoneally increased locomotion with no differences across genotypes. Tissue levels of glutamate, GABA, dopamine and serotonin did not vary between EAAT3 heterozygous and wild-type mice. Conclusions Our results indicate that reduced EAAT3 expression does not impact neurotransmitter content in the corticostriatal circuit nor alter anxiety or compulsive-like behaviors.

A novel double heterozygous Hb Fontainebleau/HbD Punjab hemoglobinopathy.

Science.gov (United States)

Rodríguez-Capote, Karina; Estey, Mathew P; Barakauskas, Vilte; Bordeleau, Pierre; Christensen, Cathie-Lou; Zuberbuhler, Peter; Higgins, Trefor N

2015-09-01

To report the finding of a novel double heterozygous hemoglobinopathy, the coinheritance of Hb Fontainebleau (α-chain variant) with HbD-Punjab (β-chain variant) discovered upon investigation of unexplained microcytosis in an infant. Hemoglobinopathy investigation was performed by high performance liquid chromatography (HPLC) using the β-thalassemia Short Program on the Bio-Rad Variant II(TM) followed by gel electrophoresis at alkaline and acid pH (Sebia Hydrasys 2 Electrophoresis System) and molecular diagnostic testing. This study complied with our institutional board ethics requirements. HPLC and electrophoresis suggested a complex α- and β-chain hemoglobinopathy with presumptive identification of the beta Hb variant as Hb D-Punjab. DNA sequencing analysis revealed the presence of a double heterozygous status for Hb Fontainebleau/Hb D-Punjab. In this paper we report the coinheritance of Hb Fontainebleau with Hb D-Punjab. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Characterization of cancer-associated missense mutations in MDM2

OpenAIRE

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

2015-01-01

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

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

Indian Academy of Sciences (India)

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

Clinical and functional characterization of a patient carrying a compound heterozygous pericentrin mutation and a heterozygous IGF1 receptor mutation.

Directory of Open Access Journals (Sweden)

Eva Müller

Full Text Available Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X] were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration.

Clinical and functional characterization of a patient carrying a compound heterozygous pericentrin mutation and a heterozygous IGF1 receptor mutation.

Science.gov (United States)

Müller, Eva; Dunstheimer, Desiree; Klammt, Jürgen; Friebe, Daniela; Kiess, Wieland; Kratzsch, Jürgen; Kruis, Tassilo; Laue, Sandy; Pfäffle, Roland; Wallborn, Tillmann; Heidemann, Peter H

2012-01-01

Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA) with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X]) were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration.

Characterisation of the novel deleterious RAD51C p.Arg312Trp variant and prioritisation criteria for functional analysis of RAD51C missense changes.

Science.gov (United States)

Gayarre, Javier; Martín-Gimeno, Paloma; Osorio, Ana; Paumard, Beatriz; Barroso, Alicia; Fernández, Victoria; de la Hoya, Miguel; Rojo, Alejandro; Caldés, Trinidad; Palacios, José; Urioste, Miguel; Benítez, Javier; García, María J

2017-09-26

Despite a high prevalence of deleterious missense variants, most studies of RAD51C ovarian cancer susceptibility gene only provide in silico pathogenicity predictions of missense changes. We identified a novel deleterious RAD51C missense variant (p.Arg312Trp) in a high-risk family, and propose a criteria to prioritise RAD51C missense changes qualifying for functional analysis. To evaluate pathogenicity of p.Arg312Trp variant we used sequence homology, loss of heterozygosity (LOH) and segregation analysis, and a comprehensive functional characterisation. To define a functional-analysis prioritisation criteria, we used outputs for the known functionally confirmed deleterious and benign RAD51C missense changes from nine pathogenicity prediction algorithms. The p.Arg312Trp variant failed to correct mitomycin and olaparib hypersensitivity and to complement abnormal RAD51C foci formation according to functional assays, which altogether with LOH and segregation data demonstrated deleteriousness. Prioritisation criteria were based on the number of predictors providing a deleterious output, with a minimum of 5 to qualify for testing and a PredictProtein score greater than 33 to assign high-priority indication. Our study points to a non-negligible number of RAD51C missense variants likely to impair protein function, provides a guideline to prioritise and encourage their selection for functional analysis and anticipates that reference laboratories should have available resources to conduct such assays.

De novo mutations in the motor domain of KIF1A cause cognitive impairment, spastic paraparesis, axonal neuropathy, and cerebellar atrophy

NARCIS (Netherlands)

Lee, Jae Ran; Srour, Myriam; Kim, Doyoun; Hamdan, Fadi F.; Lim, So Hee; Brunel-Guitton, Catherine; Décarie, Jean Claude; Rossignol, Elsa; Mitchell, Grant A.; Schreiber, Allison; Moran, Rocio; Van Haren, Keith; Richardson, Randal; Nicolai, Joost; Oberndorff, Karin M E J; Wagner, Justin D.; Boycott, Kym M.; Rahikkala, Elisa; Junna, Nella; Tyynismaa, Henna; Cuppen, Inge; Verbeek, Nienke E.; Stumpel, Connie T R M; Willemsen, Michel A.; de Munnik, Sonja A.; Rouleau, Guy A.; Kim, Eunjoon; Kamsteeg, Erik Jan; Kleefstra, Tjitske; Michaud, Jacques L.

2015-01-01

KIF1A is a neuron-specific motor protein that plays important roles in cargo transport along neurites. Recessive mutations in KIF1A were previously described in families with spastic paraparesis or sensory and autonomic neuropathy type-2. Here, we report 11 heterozygous de novo missense mutations

Molar Tooth Sign with Deranged Liver Function Tests: An Indian Case with COACH Syndrome.

Science.gov (United States)

Sanjeev, Rama Krishna; Kapoor, Seema; Goyal, Manisha; Kapur, Rajiv; Gleeson, Joseph Gerard

2015-01-01

We report the first genetically proven case of COACH syndrome from the Indian subcontinent in a 6-year-old girl who presented with typical features of Joubert syndrome along with hepatic involvement. Mutation analysis revealed compound heterozygous missense mutation in the known gene TMEM67 (also called MKS3).

Clouston syndrome can mimic pachyonychia congenita

NARCIS (Netherlands)

van Steensel, MAM; Jonkman, MF; van Geel, M; Steijlen, PM; McLean, WHI; Smith, FJD

2003-01-01

We studied three families suffering from nail abnormalities who had previously been diagnosed as pachyonychia congenita. No keratin gene mutations were detected. Sequencing of connexin 30 (GJB6 gene) in these patients identified heterozygous missense mutations G11R and A88V that are known to be

Heterozygous CDKL5 Knockout Female Mice Are a Valuable Animal Model for CDKL5 Disorder

OpenAIRE

Fuchs, Claudia; Gennaccaro, Laura; Trazzi, Stefania; Bastianini, Stefano; Bettini, Simone; Martire, Viviana Lo; Ren, Elisa; Medici, Giorgio; Zoccoli, Giovanna; Rimondini, Roberto; Ciani, Elisabetta

2018-01-01

CDKL5 disorder is a severe neurodevelopmental disorder caused by mutations in the X-linked CDKL5 (cyclin-dependent kinase-like five) gene. CDKL5 disorder primarily affects girls and is characterized by early-onset epileptic seizures, gross motor impairment, intellectual disability, and autistic features. Although all CDKL5 female patients are heterozygous, the most valid disease-related model, the heterozygous female Cdkl5 knockout (Cdkl5 +/−) mouse, has been little characterized. The lack of...

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

DEFF Research Database (Denmark)

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

2017-01-01

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

Heterozygous RTEL1 variants in bone marrow failure and myeloid neoplasms.

Science.gov (United States)

Marsh, Judith C W; Gutierrez-Rodrigues, Fernanda; Cooper, James; Jiang, Jie; Gandhi, Shreyans; Kajigaya, Sachiko; Feng, Xingmin; Ibanez, Maria Del Pilar F; Donaires, Flávia S; Lopes da Silva, João P; Li, Zejuan; Das, Soma; Ibanez, Maria; Smith, Alexander E; Lea, Nicholas; Best, Steven; Ireland, Robin; Kulasekararaj, Austin G; McLornan, Donal P; Pagliuca, Anthony; Callebaut, Isabelle; Young, Neal S; Calado, Rodrigo T; Townsley, Danielle M; Mufti, Ghulam J

2018-01-09

Biallelic germline mutations in RTEL1 (regulator of telomere elongation helicase 1) result in pathologic telomere erosion and cause dyskeratosis congenita. However, the role of RTEL1 mutations in other bone marrow failure (BMF) syndromes and myeloid neoplasms, and the contribution of monoallelic RTEL1 mutations to disease development are not well defined. We screened 516 patients for germline mutations in telomere-associated genes by next-generation sequencing in 2 independent cohorts; one constituting unselected patients with idiopathic BMF, unexplained cytopenia, or myeloid neoplasms (n = 457) and a second cohort comprising selected patients on the basis of the suspicion of constitutional/familial BMF (n = 59). Twenty-three RTEL1 variants were identified in 27 unrelated patients from both cohorts: 7 variants were likely pathogenic, 13 were of uncertain significance, and 3 were likely benign. Likely pathogenic RTEL1 variants were identified in 9 unrelated patients (7 heterozygous and 2 biallelic). Most patients were suspected to have constitutional BMF, which included aplastic anemia (AA), unexplained cytopenia, hypoplastic myelodysplastic syndrome, and macrocytosis with hypocellular bone marrow. In the other 18 patients, RTEL1 variants were likely benign or of uncertain significance. Telomeres were short in 21 patients (78%), and 3' telomeric overhangs were significantly eroded in 4. In summary, heterozygous RTEL1 variants were associated with marrow failure, and telomere length measurement alone may not identify patients with telomere dysfunction carrying RTEL1 variants. Pathogenicity assessment of heterozygous RTEL1 variants relied on a combination of clinical, computational, and functional data required to avoid misinterpretation of common variants.

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

Science.gov (United States)

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

2016-04-11

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

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

Czech Academy of Sciences Publication Activity Database

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

2014-01-01

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

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

Science.gov (United States)

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

2018-02-01

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

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

Science.gov (United States)

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

2016-03-01

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

Homozygous missense mutation in the LMAN2L gene segregates with intellectual disability in a large consanguineous Pakistani family.

Science.gov (United States)

Rafiullah, Rafiullah; Aslamkhan, Muhammad; Paramasivam, Nagarajan; Thiel, Christian; Mustafa, Ghulam; Wiemann, Stefan; Schlesner, Matthias; Wade, Rebecca C; Rappold, Gudrun A; Berkel, Simone

2016-02-01

Intellectual disability (ID) is a neurodevelopmental disorder affecting 1%-3% of the population worldwide. It is characterised by high phenotypic and genetic heterogeneity and in most cases the underlying cause of the disorder is unknown. In our study we investigated a large consanguineous family from Baluchistan, Pakistan, comprising seven affected individuals with a severe form of autosomal recessive ID (ARID) and epilepsy, to elucidate a putative genetic cause. Whole exome sequencing (WES) of a trio, including a child with ID and epilepsy and its healthy parents that were part of this large family, revealed a homozygous missense variant p.R53Q in the lectin mannose-binding 2-like (LMAN2L) gene. This homozygous variant was co-segregating in the family with the phenotype of severe ID and infantile epilepsy; unaffected family members were heterozygous variant carriers. The variant was predicted to be pathogenic by five different in silico programmes and further three-dimensional structure modelling of the protein suggests that variant p.R53Q may impair protein-protein interaction. LMAN2L (OMIM: 609552) encodes for the lectin, mannose-binding 2-like protein which is a cargo receptor in the endoplasmic reticulum important for glycoprotein transport. Genome-wide association studies have identified an association of LMAN2L to different neuropsychiatric disorders. This is the first report linking LMAN2L to a phenotype of severe ARID and seizures, indicating that the deleterious homozygous p.R53Q variant very likely causes the disorder. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Novel and recurrent CIB2 variants, associated with nonsyndromic deafness, do not affect calcium buffering and localization in hair cells

NARCIS (Netherlands)

Seco, C.Z.; Giese, A.P.; Shafique, S.; Schraders, M.; Oonk, A.M.; Grossheim, M.; Oostrik, J.; Strom, T.; Hegde, R.; WIjk, E. van; Frolenkov, G.I.; Azam, M.; Yntema, H.G.; Free, R.H.; Riazuddin, S.; Verheij, J.B.; Admiraal, R.J.; Qamar, R.; Ahmed, Z.M.; Kremer, H.

2016-01-01

Variants in CIB2 can underlie either Usher syndrome type I (USH1J) or nonsyndromic hearing impairment (NSHI) (DFNB48). Here, a novel homozygous missense variant c.196C>T and compound heterozygous variants, c.[97C>T];[196C>T], were found, respectively, in two unrelated families of Dutch origin.

Novel and recurrent CIB2 variants, associated with nonsyndromic deafness, do not affect calcium buffering and localization in hair cells

NARCIS (Netherlands)

Seco, Celia Zazo; Giese, Arnaud P.; Shafique, Sobia; Schraders, Margit; Oonk, Anne M. M.; Grossheim, Mike; Oostrik, Jaap; Strom, Tim; Hegde, Rashmi; van Wijk, Erwin; Frolenkov, Gregory I.; Azam, Maleeha; Yntema, Helger G.; Free, Rolien H.; Riazuddin, Saima; Verheij, Joke B. G. M.; Admiraal, Ronald J.; Qamar, Raheel; Ahmed, Zubair M.; Kremer, Hannie

Variants in CIB2 can underlie either Usher syndrome type I (USH1J) or nonsyndromic hearing impairment (NSHI) (DFNB48). Here, a novel homozygous missense variant c.196C>T and compound heterozygous variants, c.[97C>T];[196C>T], were found, respectively, in two unrelated families of Dutch origin.

[Molecular characterization of heterozygous beta-thalassemia in Lanzarote, Spain].

Science.gov (United States)

Calvo-Villas, José Manuel; de la Iglesia Iñigo, Silvia; Ropero Gradilla, Paloma; Zapata Ramos, María Francisca; Cuesta Tovar, Jorge; Sicilia Guillén, Francisco

2008-04-05

The aim of this study was to determine the molecular defects of heterozygous beta thalassaemia and to ascertain their distribution in Lanzarote. Molecular characterization was achieved by real time polymerase chain reaction (RT-PCR LightCycler, Roche), PCR-ARMS (PCR-amplification reaction mutations system) and DNA sequencing on an automated DNA sequencer. Two hundred forty-three heterozygous beta thalassaemia carriers were included between July 1991 and February 2007. RT-PCR detected the molecular defect in 81% of the beta thalassaemia chromosomes analyzed [113 codon CD 39 (C --> T); 41 IVS-1-nt-110 (G --> A), 25 IVS 1-nt-1 (G --> A) and 19 IVS 1-nt-6 (T --> C)]. The remaining 12 molecular defects included the deletion 619 bp (7.8%) and the mutations -28 (A --> G), IVS1-nt-2 (T --> G), CD 41/42 (-TTCT), CD 8/9 (+G), CD 51 (-C), CD 22 (G --> T) and CD 24 (T --> A), CD 67 (-TG) and the novel mutation CD 20/21-TGGA. The distribution of the mutations is similar to that found in the Mediterranean area. The increasing migratory flow received in the Canary Islands may explain the emergence of new mutations not reported before in our area.

Quantitating PrP Polymorphisms Present in Prions from Heterozygous Scrapie-Infected Sheep.

Science.gov (United States)

Silva, Christopher J; Erickson-Beltran, Melissa L; Hui, Colleen; Badiola, Juan José; Nicholson, Eric M; Requena, Jesús R; Bolea, Rosa

2017-01-03

Scrapie is a prion (PrP Sc ) disease of sheep. The incubation period of sheep scrapie is strongly influenced by polymorphisms at positions 136, 154, and 171 of a sheep's normal cellular prion protein (PrP C ). Chymotrypsin was used to digest sheep recombinant PrP to identify a set of characteristic peptides [M 132 LGSXMSRPL 141 (X = A or V), Y 153 XENMY 158 (X,= H or R), and Y 166 RPVDXY 172 (X = H, K, Q, or R)] that could be used to detect and quantitate polymorphisms at positions 136, 154, and 171 of sheep PrP C or PrP Sc . These peptides were used to develop a multiple reaction monitoring method (MRM) to detect the amounts of a particular polymorphism in a sample of PrP Sc isolated from sheep heterozygous for their PrP C proteins. The limit of detection for these peptides was less than 50 attomole. Spinal cord tissue from heterozygous (ARQ/VRQ or ARH/ARQ) scrapie-infected Rasa Aragonesa sheep was analyzed using this MRM method. Both sets of heterozygotes show the presence of both polymorphisms in PrP Sc . This was true for samples containing both proteinase K (PK)-sensitive and PK-resistant PrP Sc and samples containing only the PK-resistant PrP Sc . These results show that heterozygous animals contain PrP Sc that is composed of significant amounts of both PrP polymorphisms.

Modulation of repetitive genes in the parent forms of heterozygous corn hybrids

International Nuclear Information System (INIS)

Gilyazetdinov, S.Ya.; Zimnitskii, A.N.; Yakhin, I.A.; Bikbaeva, E.S.

1987-01-01

The number of copies of the genes of high-molecular-weight rRNA, 5 S r RNA, and certain other families of repetitive sequences of DNA in the genome of different forms of corn is not coordinated but is stably inherited in the same strains. The authors present the results of their investigations into the repetition of the genes of tRNA, 5 S rRNA, histones, and the controlling element Ds of corn for the highly heterozygous hybrid Slava (VIR 44 x VIR 38), the medium-heterozygous hybrid Svetoch (VIR 40 x VIR 43), the low heterozygous hybrid Iskra (VIR 26 x VIR 27), and their parent strains. The relative content of these sequences was studied by the molecular hybridization of DNA immobilized on nitrocellulose filters with [ 125 I]tRNA labeled in vitro, 5 S rRNA, histone DNA of Drosophila, and the Ds-element of corn. The DNA preparations were isolated from the zones of the meristem (1.5-2mm), elongation (4-5mm), differentiation of the roots (3 cm), of 3-4 day seedlings, and from isolated embryos of 4 h and 24 h seedlings. The DNA of the embryos immobilized on the filters was preliminarily incubated with unlabeled high-molecular-weight rRNA in the experiments with tRNA and 5 S rRNA, while when histone DNA and the Ds element of corn were used in the hybridization reaction, it was preliminary incubated with plasmid DNA

X-linked adrenoleukodystrophy in heterozygous female patients: women are not just carriers

Directory of Open Access Journals (Sweden)

Charles Marques Lourenço

2012-07-01

Full Text Available X-linked adrenoleukodystrophy (X-ALD is a recessive X-linked disorder associated with marked phenotypic variability. Female carriers are commonly thought to be normal or only mildly affected, but their disease still needs to be better described and systematized. OBJECTIVES: To review and systematize the clinical features of heterozygous women followed in a Neurogenetics Clinic. METHODS: We reviewed the clinical, biochemical, and neuroradiological data of all women known to have X-ADL. RESULTS: The nine women identified were classified into three groups: with severe and aggressive diseases; with slowly progressive, spastic paraplegia; and with mildly decreased vibratory sensation, brisk reflexes, and no complaints. Many of these women did not have a known family history of X-ALD. CONCLUSIONS: Heterozygous women with X-ADL have a wide spectrum of clinical manifestations, ranging from mild to severe phenotypes.

Whole-genome sequencing reveals a potential causal mutation for dwarfism in the Miniature Shetland pony.

Science.gov (United States)

Metzger, Julia; Gast, Alana Christina; Schrimpf, Rahel; Rau, Janina; Eikelberg, Deborah; Beineke, Andreas; Hellige, Maren; Distl, Ottmar

2017-04-01

The Miniature Shetland pony represents a horse breed with an extremely small body size. Clinical examination of a dwarf Miniature Shetland pony revealed a lowered size at the withers, malformed skull and brachygnathia superior. Computed tomography (CT) showed a shortened maxilla and a cleft of the hard and soft palate which protruded into the nasal passage leading to breathing difficulties. Pathological examination confirmed these findings but did not reveal histopathological signs of premature ossification in limbs or cranial sutures. Whole-genome sequencing of this dwarf Miniature Shetland pony and comparative sequence analysis using 26 reference equids from NCBI Sequence Read Archive revealed three probably damaging missense variants which could be exclusively found in the affected foal. Validation of these three missense mutations in 159 control horses from different horse breeds and five donkeys revealed only the aggrecan (ACAN)-associated g.94370258G>C variant as homozygous wild-type in all control samples. The dwarf Miniature Shetland pony had the homozygous mutant genotype C/C of the ACAN:g.94370258G>C variant and the normal parents were heterozygous G/C. An unaffected full sib and 3/5 unaffected half-sibs were heterozygous G/C for the ACAN:g.94370258G>C variant. In summary, we could demonstrate a dwarf phenotype in a miniature pony breed perfectly associated with a missense mutation within the ACAN gene.

Assay for identification of heterozygous single-nucleotide polymorphism (Ala67Thr in human poliovirus receptor gene

Directory of Open Access Journals (Sweden)

Shyam Sundar Nandi

2016-01-01

Results: A new SNP assay for detection of heterozygous Ala67Thr genotype was developed and validated by testing 150 DNA samples. Heterozygous CD155 was detected in 27.33 per cent (41/150 of DNA samples tested by both SNP detection assay and sequencing. Interpretation & conclusions: The SNP detection assay was successfully developed for identification of Ala67Thr polymorphism in human PVR/CD155 gene. The SNP assay will be useful for large scale screening of DNA samples.

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

NARCIS (Netherlands)

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

2013-01-01

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

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

Science.gov (United States)

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

2001-04-01

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

Frequency of Gγ-globin promoter -158 (C>T) XmnI polymorphism in patients with homozygous/compound heterozygous beta thalassaemia.

Science.gov (United States)

Ali, Nadir; Ayyub, Muhammad; Khan, Saleem Ahmed; Ahmed, Suhaib; Abbas, Kazim; Malik, Hamid Saeed; Tashfeen, Sunila

2015-03-01

Response to hydroxyurea therapy in homozygous or compound heterozygous beta thalassaemia (BT) has been reported as more favourable in the presence of XmnI polymorphism. The prevalence of XmnI polymorphism may vary with BT phenotypes and genotypes, and differs geographically in distribution. Prevalence of XmnI polymorphism is not known in northern Pakistan. To determine the frequency of Gγ-globin promoter -158 (C>T) XmnI polymorphism (XmnI polymorphism) in patients with homozygous or compound heterozygous beta thalassaemia. Polymerase chain reaction (PCR) for common beta thalassaemia mutations and Gγ-globin promoter -158 (C>T) XmnI polymorphism was performed on 107 blood samples of transfusion dependent beta thalassaemia (BT) patients in Pakistan. One hundred samples of unrelated BT traits and 94 samples of healthy subjects as controls were also analysed for BT mutations and XmnI polymorphism. Out of 301 DNA samples, XmnI polymorphism was detected in 71(24%); in normal controls, XmnI polymorphism was detected in 34/94 (36%) subjects; while in homozygous/compound heterozygous BT, it was detected in 14/107(13%) patients (Fisher's exact test, p=.0002). In heterozygous BT group, XmnI polymorphism was detected in 23/100 subjects (Fisher's exact test, p=.03 with normal controls, and p=.049 with homozygous/compound heterozygous BT). The most common BT genotype was Frame Shift (Fr) 8-9/Fr 8-9, and none of the patients with this genotype had XmnI polymorphism. The second most common genotype was IVSI-5/IVSI-5; 4/26 (15%). Cases with this genotype had XmnI polymorphism. XmnI polymorphism in homozygous/compound heterozygous BT group is 13%. The most common genotype associated with XmnI polymorphism was IVSI-5/IVSI-5. Copyright © 2015 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

The Nance-Horan syndrome: a rare X-linked ocular-dental trait with expression in heterozygous females.

Science.gov (United States)

Bixler, D; Higgins, M; Hartsfield, J

1984-07-01

This report describes two families with the Nance-Horan syndrome, an X-linked trait featuring lenticular cataracts and anomalies of tooth shape and number. Previous reports have described blindness in affected males but posterior sutural cataracts with normal vision as the primary ocular expression in heterozygous females. In one of these two families, the affected female is not only blind in one eye but reportedly had supernumerary central incisors (mesiodens) removed. This constitutes the most severe ocular and dental expression of this gene in heterozygous females yet reported.

Heterozygous Mutations in TREX1 Cause Familial Chilblain Lupus and Dominant Aicardi-Goutières Syndrome

Science.gov (United States)

Rice, Gillian; Newman, William G.; Dean, John; Patrick, Teresa; Parmar, Rekha; Flintoff, Kim; Robins, Peter; Harvey, Scott; Hollis, Thomas; O’Hara, Ann; Herrick, Ariane L.; Bowden, Andrew P.; Perrino, Fred W.; Lindahl, Tomas; Barnes, Deborah E.; Crow, Yanick J.

2007-01-01

TREX1 constitutes the major 3′→5′ DNA exonuclease activity measured in mammalian cells. Recently, biallelic mutations in TREX1 have been shown to cause Aicardi-Goutières syndrome at the AGS1 locus. Interestingly, Aicardi-Goutières syndrome shows overlap with systemic lupus erythematosus at both clinical and pathological levels. Here, we report a heterozygous TREX1 mutation causing familial chilblain lupus. Additionally, we describe a de novo heterozygous mutation, affecting a critical catalytic residue in TREX1, that results in typical Aicardi-Goutières syndrome. PMID:17357087

Homozygous and heterozygous disruptions of ANK3: at the crossroads of neurodevelopmental and psychiatric disorders

NARCIS (Netherlands)

Iqbal, Z.; Vandeweyer, G.; Voet, M. van der; Waryah, A.M.; Zahoor, M.Y.; Besseling, J.A.; Roca, L.T.; Silfhout, A.T. van; Nijhof, B.; Kramer, J.M.; Aa, N. van der; Ansar, M.; Peeters, H.; Helsmoortel, C.; Gilissen, C.F.H.A.; Vissers, L.E.L.M.; Veltman, J.A.; Brouwer, A.P.M. de; Kooy, R. van; Riazuddin, S.; Schenck, A.; Bokhoven, H. van; Rooms, L.

2013-01-01

AnkyrinG, encoded by the ANK3 gene, is involved in neuronal development and signaling. It has previously been implicated in bipolar disorder and schizophrenia by association studies. Most recently, de novo missense mutations in this gene were identified in autistic patients. However, the causative

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

Directory of Open Access Journals (Sweden)

Yuko Numasawa-Kuroiwa

2014-05-01

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

Novel compound heterozygous mutations in SERPINH1 cause rare autosomal recessive osteogenesis imperfecta type X.

Science.gov (United States)

Song, Y; Zhao, D; Xu, X; Lv, F; Li, L; Jiang, Y; Wang, O; Xia, W; Xing, X; Li, M

2018-03-09

We identified novel compound heterozygous mutations in SERPINH1 in a Chinese boy suffering from recurrent fractures, femoral deformities, and growth retardation, which resulted in extremely rare autosomal recessive OI type X. Long-term treatment of BPs was effective in increasing BMD Z-score, reducing fracture incidence and reshaping vertebrae compression. Osteogenesis imperfecta (OI) is a heritable bone disorder characterized by low bone mineral density, recurrent fractures, and progressive bone deformities. Mutation in serpin peptidase inhibitor clade H, member 1 (SERPINH1), which encodes heat shock protein 47 (HSP47), leads to rare autosomal recessive OI type X. We aimed to detect the phenotype and the pathogenic mutation of OI type X in a boy from a non-consanguineous Chinese family. We investigated the pathogenic mutations and analyzed their relationship with the phenotype in the patient using next-generation sequencing (NGS) and Sanger sequencing. Moreover, the efficacy of long-term bisphosphonate treatment in this patient was evaluated. The patient suffered from multiple fractures, low bone mass, and bone deformities in the femur, without dentinogenesis imperfecta or hearing loss. Compound heterozygous variants were found in SERPINH1 as follows: c.149 T>G in exon 2 and c.1214G>A in exon 5. His parents were heterozygous carriers of each of these mutations, respectively. Bisphosphonates could be helpful in increasing BMD Z-score, reducing bone fracture risk and reshaping the compressed vertebral bodies of this patient. We reported novel compound heterozygous mutations in SERPINH1 in a Chinese OI patient for the first time, which expanded the spectrum of phenotype and genotype of extremely rare OI type X.

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

Directory of Open Access Journals (Sweden)

I. V. Sharkova

2018-01-01

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

Functional analysis of HNPCC-related missense mutations in MSH2

International Nuclear Information System (INIS)

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

2008-01-01

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

Functional analysis of HNPCC-related missense mutations in MSH2

Energy Technology Data Exchange (ETDEWEB)

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

2008-10-14

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

The NRG1 exon 11 missense variant is not associated with autism in the Central Valley of Costa Rica

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Fallas Marietha

2007-05-01

Full Text Available Abstract Background We are conducting a genetic study of autism in the isolated population of the Central Valley of Costa Rica (CVCR. A novel Neuregulin 1 (NRG1 missense variant (exon 11 G>T was recently associated with psychosis and schizophrenia (SCZ in the same population isolate. Methods We genotyped the NRG1 exon 11 missense variant in 146 cases with autism, or autism spectrum disorder, with CVCR ancestry, and both parents when available (N = 267 parents from 143 independent families. Additional microsatellites were genotyped to examine haplotypes bearing the exon 11 variant. Results The NRG1 exon 11 G>T variant was found in 4/146 cases including one de novo occurrence. The frequency of the variant in case chromosomes was 0.014 and 0.045 in the parental non-transmitted chromosomes. At least 6 haplotypes extending 0.229 Mb were associated with the T allele. Three independent individuals, with no personal or family history of psychiatric disorder, shared at least a 1 megabase haplotype 5' to the T allele. Conclusion The NRG1 exon 11 missense variant is not associated with autism in the CVCR.

Altered social cognition in male BDNF heterozygous mice and following chronic methamphetamine exposure.

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Manning, Elizabeth E; van den Buuse, Maarten

2016-05-15

Growing clinical evidence suggests that persistent psychosis which occurs in methamphetamine users is closely related to schizophrenia. However, preclinical studies in animal models have focussed on psychosis-related behaviours following methamphetamine, and less work has been done to assess endophenotypes relevant to other deficits observed in schizophrenia. Altered social behaviour is a feature of both the negative symptoms and cognitive deficits in schizophrenia, and significantly impacts patient functioning. We recently found that brain-derived neurotrophic factor (BDNF) heterozygous mice show disrupted sensitization to methamphetamine, supporting other work suggesting an important role of this neurotrophin in the pathophysiology of psychosis and the neuronal response to stimulant drugs. In the current study, we assessed social and cognitive behaviours in methamphetamine-treated BDNF heterozygous mice and wildtype littermate controls. Following chronic methamphetamine exposure male wildtype mice showed a 50% reduction in social novelty preference. Vehicle-treated male BDNF heterozygous mice showed a similar impairment in social novelty preference, with a trend for no further disruption by methamphetamine exposure. Female mice were unaffected in this task, and no groups showed any changes in sociability or short-term spatial memory. These findings suggest that chronic methamphetamine alters behaviour relevant to disruption of social cognition in schizophrenia, supporting other studies which demonstrate a close resemblance between persistent methamphetamine psychosis and schizophrenia. Together these findings suggest that dynamic regulation of BDNF signalling is necessary to mediate the effects of methamphetamine on behaviours relevant to schizophrenia. Copyright © 2016 Elsevier B.V. All rights reserved.

Heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance.

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Patel, Kashyap A; Kettunen, Jarno; Laakso, Markku; Stančáková, Alena; Laver, Thomas W; Colclough, Kevin; Johnson, Matthew B; Abramowicz, Marc; Groop, Leif; Miettinen, Päivi J; Shepherd, Maggie H; Flanagan, Sarah E; Ellard, Sian; Inagaki, Nobuya; Hattersley, Andrew T; Tuomi, Tiinamaija; Cnop, Miriam; Weedon, Michael N

2017-10-12

Finding new causes of monogenic diabetes helps understand glycaemic regulation in humans. To find novel genetic causes of maturity-onset diabetes of the young (MODY), we sequenced MODY cases with unknown aetiology and compared variant frequencies to large public databases. From 36 European patients, we identify two probands with novel RFX6 heterozygous nonsense variants. RFX6 protein truncating variants are enriched in the MODY discovery cohort compared to the European control population within ExAC (odds ratio = 131, P = 1 × 10 -4 ). We find similar results in non-Finnish European (n = 348, odds ratio = 43, P = 5 × 10 -5 ) and Finnish (n = 80, odds ratio = 22, P = 1 × 10 -6 ) replication cohorts. RFX6 heterozygotes have reduced penetrance of diabetes compared to common HNF1A and HNF4A-MODY mutations (27, 70 and 55% at 25 years of age, respectively). The hyperglycaemia results from beta-cell dysfunction and is associated with lower fasting and stimulated gastric inhibitory polypeptide (GIP) levels. Our study demonstrates that heterozygous RFX6 protein truncating variants are associated with MODY with reduced penetrance.Maturity-onset diabetes of the young (MODY) is the most common subtype of familial diabetes. Here, Patel et al. use targeted DNA sequencing of MODY patients and large-scale publically available data to show that RFX6 heterozygous protein truncating variants cause reduced penetrance MODY.

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

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

2008-03-01

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

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

DEFF Research Database (Denmark)

Nagirnaja, Liina; Venclovas, Česlovas; Rull, Kristiina

2012-01-01

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

Age-Dependent Deficits in Fear Learning in Heterozygous BDNF Knock-Out Mice

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Endres, Thomas; Lessmann, Volkmar

2012-01-01

Beyond its trophic function, the neurotrophin BDNF (brain-derived neurotrophic factor) is well known to crucially mediate synaptic plasticity and memory formation. Whereas recent studies suggested that acute BDNF/TrkB signaling regulates amygdala-dependent fear learning, no impairments of cued fear learning were reported in heterozygous BDNF…

Atm heterozygous mice are more sensitive to radiation-induced cataracts than are their wild-type counterparts

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Worgul, Basil V.; Smilenov, Lubomir; Brenner, David J.; Junk, Anna; Zhou, Wei; Hall, Eric J.

2002-01-01

It is important to know whether the human population includes genetically predisposed radiosensitive subsets. In vitro studies have shown that cells from individuals homozygous for ataxia telangiectasia (A-T) are much more radiosensitive than cells from unaffected individuals. Although cells heterozygous for the ATM gene (ATM(+/-)) may be slightly more radiosensitive in vitro, it remained to be determined whether the greater susceptibility of ATM(+/-) cells translates into an increased sensitivity for late effects in vivo, though there is a suggestion that radiotherapy patients that are heterozygous for the ATM gene may be more at risk of developing late normal tissue damage. We chose cataractogenesis in the lens as a means to assay for the effects of ATM deficiency in a late-responding tissue. One eye of wild-type, Atm heterozygous and homozygous knockout mice was exposed to 0.5-, 1.0-, 2.0-, or 4.0-Gy x rays. The animals were followed weekly for cataract development by conventional slit-lamp biomicroscopy. Cataract development in the animals of all three groups was strongly dependent on dose. The lenses of homozygous mice were the first to opacify at any given dose. Most important in the present context is that cataracts appeared earlier in the heterozygous versus wild-type animals. The data suggest that ATM heterozygotes in the human population may also be radiosensitive. This may influence the choice of individuals destined to be exposed to higher than normal doses of radiation, such as astronauts, and may also suggest that radiotherapy patients who are ATM heterozygotes could be predisposed to increased late normal tissue damage.

Heterozygous Che-1 KO mice show deficiencies in object recognition memory persistence.

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Zalcman, Gisela; Corbi, Nicoletta; Di Certo, Maria Grazia; Mattei, Elisabetta; Federman, Noel; Romano, Arturo

2016-10-06

Transcriptional regulation is a key process in the formation of long-term memories. Che-1 is a protein involved in the regulation of gene transcription that has recently been proved to bind the transcription factor NF-κB, which is known to be involved in many memory-related molecular events. This evidence prompted us to investigate the putative role of Che-1 in memory processes. For this study we newly generated a line of Che-1(+/-) heterozygous mice. Che-1 homozygous KO mouse is lethal during development, but Che-1(+/-) heterozygous mouse is normal in its general anatomical and physiological characteristics. We analyzed the behavioral characteristic and memory performance of Che-1(+/-) mice in two NF-κB dependent types of memory. We found that Che-1(+/-) mice show similar locomotor activity and thigmotactic behavior than wild type (WT) mice in an open field. In a similar way, no differences were found in anxiety-like behavior between Che-1(+/-) and WT mice in an elevated plus maze as well as in fear response in a contextual fear conditioning (CFC) and object exploration in a novel object recognition (NOR) task. No differences were found between WT and Che-1(+/-) mice performance in CFC training and when tested at 24h or 7days after training. Similar performance was found between groups in NOR task, both in training and 24h testing performance. However, we found that object recognition memory persistence at 7days was impaired in Che-1(+/-) heterozygous mice. This is the first evidence showing that Che-1 is involved in memory processes. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Heterozygous STAT1 gain-of-function mutations underlie an unexpectedly broad clinical phenotype

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Toubiana, Julie; Okada, Satoshi; Hiller, Julia; Oleastro, Matias; Lagos Gomez, Macarena; Aldave Becerra, Juan Carlos; Ouachée-Chardin, Marie; Fouyssac, Fanny; Girisha, Katta Mohan; Etzioni, Amos; van Montfrans, Joris M.; Camcioglu, Yildiz; Kerns, Leigh Ann; Belohradsky, Bernd; Blanche, Stéphane; Bousfiha, Aziz; Rodriguez-Gallego, Carlos; Meyts, Isabelle; Kisand, Kai; Reichenbach, Janine; Renner, Ellen D; Rosenzweig, Sergio; Grimbacher, Bodo; van de Veerdonk, Frank L; Traidl-Hoffmann, Claudia; Picard, Capucine; Marodi, Laszlo; Morio, Tomohiro; Kobayashi, Masao; Lilic, Desa; Milner, Joshua D; Holland, Steven; Casanova, Jean-Laurent; Puel, Anne

2016-01-01

Since their discovery in patients with autosomal dominant (AD) chronic mucocutaneous candidiasis (CMC) in 2011, heterozygous STAT1 gain-of-function (GOF) mutations have increasingly been identified worldwide. The clinical spectrum associated with them needed to be delineated. We enrolled 274

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

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Joana Simões-Correia

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

A case of recurrent encephalopathy with SCN2A missense mutation.

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

2015-06-01

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

Whole Genome Sequence of the Heterozygous Clinical Isolate Candida krusei 81-B-5

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Christina A. Cuomo

2017-09-01

Full Text Available Candida krusei is a diploid, heterozygous yeast that is an opportunistic fungal pathogen in immunocompromised patients. This species also is utilized for fermenting cocoa beans during chocolate production. One major concern in the clinical setting is the innate resistance of this species to the most commonly used antifungal drug fluconazole. Here, we report a high-quality genome sequence and assembly for the first clinical isolate of C. krusei, strain 81-B-5, into 11 scaffolds generated with PacBio sequencing technology. Gene annotation and comparative analysis revealed a unique profile of transporters that could play a role in drug resistance or adaptation to different environments. In addition, we show that, while 82% of the genome is highly heterozygous, a 2.0 Mb region of the largest scaffold has undergone loss of heterozygosity. This genome will serve as a reference for further genetic studies of this pathogen.

Analysis of the ABCR (ABCA4) gene in 4-aminoquinoline retinopathy: is retinal toxicity by chloroquine and hydroxychloroquine related to Stargardt disease?

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

2001-06-01

To determine if mutations in ABCR (ABCA4) are associated with chloroquine/hydroxychloroquine retinopathy. DNA from eight patients with chloroquine or hydroxychloroquine retinopathy was studied. Controls were 80 individuals over age 65 years with normal retinal examinations. Ophthalmoscopy, color vision testing, visual fields, retinal photography, and fluorescein angiography were performed on the eight patients. Direct DNA sequencing of the exons and flanking intronic regions of the ABCR gene was completed for all patients. Clinical evaluation confirmed the diagnosis of chloroquine/hydroxychloroquine retinopathy and excluded Stargardt disease in each patient. Two patients had heterozygous ABCR missense mutations previously associated with Stargardt disease. None of the controls had these missense mutations. Three other patients had other missense polymorphisms. Some individuals who have ABCR mutations may be predisposed to develop retinal toxicity when exposed to chloroquine/hydroxychloroquine. We urge further study of a larger cohort of patients with chloroquine/hydroxychloroquine retinopathy.

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

DEFF Research Database (Denmark)

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

2009-01-01

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

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

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

2015-12-01

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

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

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

2017-06-01

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

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

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

2011-08-01

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

Orthology Guided Assembly in highly heterozygous crops

DEFF Research Database (Denmark)

Ruttink, Tom; Sterck, Lieven; Rohde, Antje

2013-01-01

to outbreeding crop species hamper De Bruijn Graph-based de novo assembly algorithms, causing transcript fragmentation and the redundant assembly of allelic contigs. If multiple genotypes are sequenced to study genetic diversity, primary de novo assembly is best performed per genotype to limit the level......Despite current advances in next-generation sequencing data analysis procedures, de novo assembly of a reference sequence required for SNP discovery and expression analysis is still a major challenge in genetically uncharacterized, highly heterozygous species. High levels of polymorphism inherent...... of polymorphism and avoid transcript fragmentation. Here, we propose an Orthology Guided Assembly procedure that first uses sequence similarity (tBLASTn) to proteins of a model species to select allelic and fragmented contigs from all genotypes and then performs CAP3 clustering on a gene-by-gene basis. Thus, we...

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

Science.gov (United States)

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

2017-03-01

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

Multigeneration family with dominant SPG30 hereditary spastic paraplegia.

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Roda, Ricardo H; Schindler, Alice B; Blackstone, Craig

2017-11-01

Autosomal recessive KIF1A missense mutations cause hereditary spastic paraplegia (HSP) type SPG30, while recessive truncations lead to sensory and autonomic neuropathy (HSN2C) and many de novo missense mutations are associated with cognitive impairment. Here, we describe family members across three generations with pure HSP. A heterozygous p.Ser69Leu KIF1A mutation segregates with those afflicted. The same variant was previously reported in a Finnish father and son with pure HSP as well as four members of a Sicilian kindred with more intrafamilial phenotypic variability. This further validates the pathogenicity of the p.Ser69Leu mutation and suggests that it may represent a mutation hot spot.

A new mesophotic goby, Palatogobius incendius (Teleostei: Gobiidae, and the first record of invasive lionfish preying on undescribed biodiversity.

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Luke Tornabene

Full Text Available A new species of deep-reef fish in the goby genus Palatogobius is described from recent submersible collections off Curaçao and Dominica. Video footage of schools of this species reveal predation by the invasive Indo-Pacific lionfish (Pterois spp., the first record of undescribed fauna potentially being eaten by lionfish outside of its native range. We present molecular phylogenetic data for all valid species of Palatogobius and related genera, as well as a taxonomic key to the species of Palatogobius and a generic key to Palatogobius and related genera in the western Atlantic. Lastly, we discuss ecological and behavioral aspects of some deep-reef fishes in light of potential threats from invasive lionfish.

A new mesophotic goby, Palatogobius incendius (Teleostei: Gobiidae), and the first record of invasive lionfish preying on undescribed biodiversity.

Science.gov (United States)

Tornabene, Luke; Baldwin, Carole C

2017-01-01

A new species of deep-reef fish in the goby genus Palatogobius is described from recent submersible collections off Curaçao and Dominica. Video footage of schools of this species reveal predation by the invasive Indo-Pacific lionfish (Pterois spp.), the first record of undescribed fauna potentially being eaten by lionfish outside of its native range. We present molecular phylogenetic data for all valid species of Palatogobius and related genera, as well as a taxonomic key to the species of Palatogobius and a generic key to Palatogobius and related genera in the western Atlantic. Lastly, we discuss ecological and behavioral aspects of some deep-reef fishes in light of potential threats from invasive lionfish.

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

DEFF Research Database (Denmark)

Tommiska, Johanna; Känsäkoski, Johanna; Skibsbye, Lasse

2017-01-01

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

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

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

2010-01-01

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

Missense Mutations in CRYAB Are Liable for Recessive Congenital Cataracts.

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Xiaodong Jiao

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

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

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Nic Waddell

2008-05-01

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

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

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

2006-10-24

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

Exome sequencing reveals a de novo POLD1 mutation causing phenotypic variability in mandibular hypoplasia, deafness, progeroid features, and lipodystrophy syndrome (MDPL).

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Elouej, Sahar; Beleza-Meireles, Ana; Caswell, Richard; Colclough, Kevin; Ellard, Sian; Desvignes, Jean Pierre; Béroud, Christophe; Lévy, Nicolas; Mohammed, Shehla; De Sandre-Giovannoli, Annachiara

2017-06-01

Mandibular hypoplasia, deafness, progeroid features, and lipodystrophy syndrome (MDPL) is an autosomal dominant systemic disorder characterized by prominent loss of subcutaneous fat, a characteristic facial appearance and metabolic abnormalities. This syndrome is caused by heterozygous de novo mutations in the POLD1 gene. To date, 19 patients with MDPL have been reported in the literature and among them 14 patients have been characterized at the molecular level. Twelve unrelated patients carried a recurrent in-frame deletion of a single codon (p.Ser605del) and two other patients carried a novel heterozygous mutation in exon 13 (p.Arg507Cys). Additionally and interestingly, germline mutations of the same gene have been involved in familial polyposis and colorectal cancer (CRC) predisposition. We describe a male and a female patient with MDPL respectively affected with mild and severe phenotypes. Both of them showed mandibular hypoplasia, a beaked nose with bird-like facies, prominent eyes, a small mouth, growth retardation, muscle and skin atrophy, but the female patient showed such a severe and early phenotype that a first working diagnosis of Hutchinson-Gilford Progeria was made. The exploration was performed by direct sequencing of POLD1 gene exon 15 in the male patient with a classical MDPL phenotype and by whole exome sequencing in the female patient and her unaffected parents. Exome sequencing identified in the latter patient a de novo heterozygous undescribed mutation in the POLD1 gene (NM_002691.3: c.3209T>A), predicted to cause the missense change p.Ile1070Asn in the ZnF2 (Zinc Finger 2) domain of the protein. This mutation was not reported in the 1000 Genome Project, dbSNP and Exome sequencing databases. Furthermore, the Isoleucine1070 residue of POLD1 is highly conserved among various species, suggesting that this substitution may cause a major impairment of POLD1 activity. For the second patient, affected with a typical MDPL phenotype, direct sequencing

Molecular systematics and undescribed diversity of Madagascan scolecophidian snakes (Squamata: Serpentes).

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Nagy, Zoltán T; Marion, Angela B; Glaw, Frank; Miralles, Aurélien; Nopper, Joachim; Vences, Miguel; Hedges, S Blair

2015-11-10

We provide an updated molecular phylogenetic analysis of global diversity of typhlopid and xenotyphlopid blindsnakes, adding a set of Madagascan samples and sequences of an additional mitochondrial gene to an existing supermatrix of nuclear and mitochondrial gene segments. Our data suggest monophyly of Madagascan typhlopids, exclusive of introduced Indotyphlops braminus. The Madagascar-endemic typhlopid clade includes two species previously assigned to the genus Lemuriatyphlops (in the subfamily Asiatyphlopinae), which were not each others closest relatives. This contradicts a previous study that described Lemuriatyphlops based on a sequence of the cytochrome oxidase subunit 1 gene from a single species and found this species not forming a clade with the other Malagasy species included. Based on our novel phylogenetic assessment we include all species in this endemic typhlopid clade in the genus Madatyphlops and in the subfamily Madatyphlopinae and consider Lemuriatyphlops as junior synonym. Within Madatyphlops, we identify several candidate species. For some of these (those in the M. arenarius complex), our preliminary data suggest sympatric occurrence and morphological differentiation, thus the existence of undescribed species. We also comment on the genus-level classification of several non-Madagascan typhlopids. We suggest that African species included in Madatyphlops (Afrotyphlops calabresii, A. cuneirostris, A. platyrhynchus, and Rhinotyphlops leucocephalus) should not be included in this genus. We furthermore argue that recent claims of Sundatyphlops, Antillotyphlops, and Cubatyphlops being "undiagnosable" or "not monophyletic" were based on errors in tree reconstruction and failure to notice diagnostic characters, and thus regard these three genera as valid.

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

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Jia WX

2015-04-01

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

Acromelic frontonasal dysostosis and ZSWIM6 mutation

DEFF Research Database (Denmark)

Twigg, Stephen R F; Ousager, Lilian Bomme; Miller, Kerry A

2016-01-01

Acromelic frontonasal dysostosis (AFND) is a distinctive and rare frontonasal malformation that presents in combination with brain and limb abnormalities. A single recurrent heterozygous missense substitution in ZSWIM6, encoding a protein of unknown function, was previously shown to underlie this...... sequencing of DNA isolated from a variety of tissues, which each contain different levels of mutation. This has important implications for genetic counselling....

[A clinical and hereditary analysis of novel complex heterozygous KCNJ1 mutation in a Bartter syndrome type Ⅱ patient].

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Li, X Y; Jiang, Y; Xu, L J; Duan, L; Peng, X Y; Chen, L M; Xia, W B; Xing, X P

2017-10-01

Bartter syndrome (BS) is a hereditary condition transmitted as an autosomal recessive (Bartter type 1 to 4) or dominant trait (Bartter type 5). The disease associates hypokalemic alkalosis with varying degrees of hypercalciuria. Here we presented a case (BS type Ⅱ) of a 17 years old female presented with polyhydramnios, polyuria, nephrocalcinosis and hypokalemia, which was alleviated after treatment with celecoxib and vitamin D(3). DNA sequencing identified compound heterozygous KCNJ 1 gene mutations, c. 931C >T (p.R311W) and c. 445-446insCCTGAACAC (p.V149Afs, 150X), with the latter a novel mutation. Her father and mother were heterozygous carriers of c. 931C >T (p.R311W) and c. 445-446insCCTGAACAC (p.V149Afs, 150X), respectively. In conclusion, this case of BS type Ⅱ is caused by a novel compound heterozygous KCNJ 1 mutation. Further studies are needed to verify the effect of celecoxib in BS patients.

Primary microcephaly caused by novel compound heterozygous mutations in ASPM.

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Okamoto, Nobuhiko; Kohmoto, Tomohiro; Naruto, Takuya; Masuda, Kiyoshi; Imoto, Issei

2018-01-01

Autosomal recessive primary microcephaly (microcephaly primary hereditary, MCPH) is a genetically heterogeneous rare developmental disorder that is characterized by prenatal onset of abnormal brain growth, which leads to intellectual disability of variable severity. We report a 5-year-old male who presented with a severe form of primary microcephaly. Targeted panel sequencing revealed compound heterozygous truncating mutations of the abnormal spindle-like microcephaly-associated ( ASPM ) gene, which confirmed the MCPH5 diagnosis. A novel NM_018136.4: c.9742_9745del (p.Lys3248Serfs*13) deletion mutation was identified.

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

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Jing Sun

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

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

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Sophie A Comyn

2016-07-01

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

Efficient introduction of specific homozygous and heterozygous mutations using CRISPR/Cas9.

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Paquet, Dominik; Kwart, Dylan; Chen, Antonia; Sproul, Andrew; Jacob, Samson; Teo, Shaun; Olsen, Kimberly Moore; Gregg, Andrew; Noggle, Scott; Tessier-Lavigne, Marc

2016-05-05

The bacterial CRISPR/Cas9 system allows sequence-specific gene editing in many organisms and holds promise as a tool to generate models of human diseases, for example, in human pluripotent stem cells. CRISPR/Cas9 introduces targeted double-stranded breaks (DSBs) with high efficiency, which are typically repaired by non-homologous end-joining (NHEJ) resulting in nonspecific insertions, deletions or other mutations (indels). DSBs may also be repaired by homology-directed repair (HDR) using a DNA repair template, such as an introduced single-stranded oligo DNA nucleotide (ssODN), allowing knock-in of specific mutations. Although CRISPR/Cas9 is used extensively to engineer gene knockouts through NHEJ, editing by HDR remains inefficient and can be corrupted by additional indels, preventing its widespread use for modelling genetic disorders through introducing disease-associated mutations. Furthermore, targeted mutational knock-in at single alleles to model diseases caused by heterozygous mutations has not been reported. Here we describe a CRISPR/Cas9-based genome-editing framework that allows selective introduction of mono- and bi-allelic sequence changes with high efficiency and accuracy. We show that HDR accuracy is increased dramatically by incorporating silent CRISPR/Cas-blocking mutations along with pathogenic mutations, and establish a method termed 'CORRECT' for scarless genome editing. By characterizing and exploiting a stereotyped inverse relationship between a mutation's incorporation rate and its distance to the DSB, we achieve predictable control of zygosity. Homozygous introduction requires a guide RNA targeting close to the intended mutation, whereas heterozygous introduction can be accomplished by distance-dependent suboptimal mutation incorporation or by use of mixed repair templates. Using this approach, we generated human induced pluripotent stem cells with heterozygous and homozygous dominant early onset Alzheimer's disease-causing mutations in

Heterozygous CAV1 frameshift mutations (MIM 601047 in patients with atypical partial lipodystrophy and hypertriglyceridemia

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Alston Lindsay

2008-01-01

Full Text Available Abstract Background Mice with a deleted Cav1 gene encoding caveolin-1 develop adipocyte abnormalities and insulin resistance. From genomic DNA of patients with atypical lipodystrophy and hypertriglyceridemia who had no mutations in any known lipodystrophy gene, we used DNA sequence analysis to screen the coding regions of human CAV1 (MIM 601047. Results We found a heterozygous frameshift mutation in CAV1, designated I134fsdelA-X137, in a female patient who had atypical partial lipodystrophy, with subcutaneous fat loss affecting the upper part of her body and face, but sparing her legs, gluteal region and visceral fat stores. She had severe type 5 hyperlipoproteinemia, with recurrent pancreatitis. In addition, she had some atypical features, including congenital cataracts and neurological findings. Her father was also heterozygous for this mutation, and had a similar pattern of fat redistribution, hypertriglyceridemia and congenital cataracts, with milder neurological involvement. An unrelated patient had a different heterozygous frameshift mutation in the CAV1 gene, designated -88delC. He also had a partial lipodystrophy phenotype, with subcutaneous fat loss affecting the arms, legs and gluteal region, but sparing his face, neck and visceral fat stores. He also had severe type 5 hyperlipoproteinemia, with recurrent pancreatitis; however he had no clinically apparent neurological manifestations. The mutations were absent from the genomes of 1063 healthy individuals. Conclusion Thus, very rare CAV1 frameshift mutations appear to be associated with atypical lipodystrophy and hypertriglyceridemia.

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

Science.gov (United States)

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

2015-06-01

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

Heterozygous deficiency of endoglin decreases insulin and hepatic triglyceride levels during high fat diet.

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Daniel Beiroa

Full Text Available Endoglin is a transmembrane auxiliary receptor for transforming growth factor-beta (TGF-beta that is predominantly expressed on proliferating endothelial cells. It plays a wide range of physiological roles but its importance on energy balance or insulin sensitivity has been unexplored. Endoglin deficient mice die during midgestation due to cardiovascular defects. Here we report for first time that heterozygous endoglin deficiency in mice decreases high fat diet-induced hepatic triglyceride content and insulin levels. Importantly, these effects are independent of changes in body weight or adiposity. At molecular level, we failed to detect relevant changes in the insulin signalling pathway at basal levels in liver, muscle or adipose tissues that could explain the insulin-dependent effect. However, we found decreased triglyceride content in the liver of endoglin heterozygous mice fed a high fat diet in comparison to their wild type littermates. Overall, our findings indicate that endoglin is a potentially important physiological mediator of insulin levels and hepatic lipid metabolism.

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

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Kairong Li

2016-07-01

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

Protein structure and phenotypic analysis of pathogenic and population missense variants in STXBP1

OpenAIRE

Suri, Mohnish; Evers, Jochem M. G.; Laskowski, Roman A.; O'Brien, Sinead; Baker, Kate; Clayton‐Smith, Jill; Dabir, Tabib; Josifova, Dragana; Joss, Shelagh; Kerr, Bronwyn; Kraus, Alison; McEntagart, Meriel; Morton, Jenny; Smith, Audrey; Splitt, Miranda

2017-01-01

Abstract Background Syntaxin‐binding protein 1, encoded by STXBP1, is highly expressed in the brain and involved in fusing synaptic vesicles with the plasma membrane. Studies have shown that pathogenic loss‐of‐function variants in this gene result in various types of epilepsies, mostly beginning early in life. We were interested to model pathogenic missense variants on the protein structure to investigate the mechanism of pathogenicity and genotype–phenotype correlations. Methods We report 11...

Heterozygous deletion at the SOX10 gene locus in two patients from a Chinese family with Waardenburg syndrome type II.

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Wenzhi, He; Ruijin, Wen; Jieliang, Li; Xiaoyan, Ma; Haibo, Liu; Xiaoman, Wang; Jiajia, Xian; Shaoying, Li; Shuanglin, Li; Qing, Li

2015-10-01

Waardenburg syndrome (WS) is a rare disease characterized by sensorineural deafness and pigment disturbance. To date, almost 100 mutations have been reported, but few reports on cases with SOX10 gene deletion. The inheritance pattern of SOX10 gene deletion is still unclear. Our objective was to identify the genetic causes of Waardenburg syndrome type II in a two-generation Chinese family. Clinical evaluations were conducted in both of the patients. Microarray analysis and multiplex ligation-dependent probe amplification (MLPA) were performed to identify disease-related copy number variants (CNVs). DNA sequencing of the SOX10, MITF and SNAI2 genes was performed to identify the pathogenic mutation responsible for WS2. A 280kb heterozygous deletion at the 22q13.1 chromosome region (including SOX10) was detected in both of the patients. No mutation was found in the patients, unaffected family members and 30 unrelated healthy controls. This report is the first to describe SOX10 heterozygous deletions in Chinese WS2 patients. Our result conform the thesis that heterozygous deletions at SOX10 is an important pathogenicity for WS, and present as autosomal dominant inheritance. Nevertheless, heterozygous deletion of the SOX10 gene would be worth investigating to understand their functions and contributions to neurologic phenotypes. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Vibratory Urticaria Associated with a Missense Variant in ADGRE2.

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Boyden, Steven E; Desai, Avanti; Cruse, Glenn; Young, Michael L; Bolan, Hyejeong C; Scott, Linda M; Eisch, A Robin; Long, R Daniel; Lee, Chyi-Chia R; Satorius, Colleen L; Pakstis, Andrew J; Olivera, Ana; Mullikin, James C; Chouery, Eliane; Mégarbané, André; Medlej-Hashim, Myrna; Kidd, Kenneth K; Kastner, Daniel L; Metcalfe, Dean D; Komarow, Hirsh D

2016-02-18

Patients with autosomal dominant vibratory urticaria have localized hives and systemic manifestations in response to dermal vibration, with coincident degranulation of mast cells and increased histamine levels in serum. We identified a previously unknown missense substitution in ADGRE2 (also known as EMR2), which was predicted to result in the replacement of cysteine with tyrosine at amino acid position 492 (p.C492Y), as the only nonsynonymous variant cosegregating with vibratory urticaria in two large kindreds. The ADGRE2 receptor undergoes autocatalytic cleavage, producing an extracellular subunit that noncovalently binds a transmembrane subunit. We showed that the variant probably destabilizes an autoinhibitory subunit interaction, sensitizing mast cells to IgE-independent vibration-induced degranulation. (Funded by the National Institutes of Health.).

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

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

2018-01-01

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

Electroclinical presentation and genotype-phenotype relationships in patients with Unverricht-Lundborg disease carrying compound heterozygous CSTB point and indel mutations.

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Canafoglia, Laura; Gennaro, Elena; Capovilla, Giuseppe; Gobbi, Giuseppe; Boni, Antonella; Beccaria, Francesca; Viri, Maurizio; Michelucci, Roberto; Agazzi, Pamela; Assereto, Stefania; Coviello, Domenico A; Di Stefano, Maria; Rossi Sebastiano, Davide; Franceschetti, Silvana; Zara, Federico

2012-12-01

Unverricht-Lundborg disease (EPM1A) is frequently due to an unstable expansion of a dodecamer repeat in the CSTB gene, whereas other types of mutations are rare. EPM1A due to homozygous expansion has a rather stereotyped presentation with prominent action myoclonus. We describe eight patients with five different compound heterozygous CSTB point or indel mutations in order to highlight their particular phenotypical presentations and evaluate their genotype-phenotype relationships. We screened CSTB mutations by means of Southern blotting and the sequencing of the genomic DNA of each proband. CSTB messenger RNA (mRNA) aberrations were characterized by sequencing the complementary DNA (cDNA) of lymphoblastoid cells, and assessing the protein concentrations in the lymphoblasts. The patient evaluations included the use of a simplified myoclonus severity rating scale, multiple neurophysiologic tests, and electroencephalography (EEG)-polygraphic recordings. To highlight the particular clinical features and disease time-course in compound heterozygous patients, we compared some of their characteristics with those observed in a series of 40 patients carrying the common homozygous expansion mutation observed at the C. Besta Foundation, Milan, Italy. The eight compound heterozygous patients belong to six EPM1A families (out of 52; 11.5%) diagnosed at the Laboratory of Genetics of the Galliera Hospitals in Genoa, Italy. They segregated five different heterozygous point or indel mutations in association with the common dodecamer expansion. Four patients from three families had previously reported CSTB mutations (c.67-1G>C and c.168+1_18del); one had a novel nonsense mutation at the first exon (c.133C>T) leading to a premature stop codon predicting a short peptide; the other three patients from two families had a complex novel indel mutation involving the donor splice site of intron 2 (c.168+2_169+21delinsAA) and leading to an aberrant transcript with a partially retained intron

A novel heterozygous SOX2 mutation causing congenital bilateral anophthalmia, hypogonadotropic hypogonadism and growth hormone deficiency.

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Macchiaroli, Annamaria; Kelberman, Daniel; Auriemma, Renata Simona; Drury, Suzanne; Islam, Lily; Giangiobbe, Sara; Ironi, Gabriele; Lench, Nicholas; Sowden, Jane C; Colao, Annamaria; Pivonello, Rosario; Cavallo, Luciano; Gasperi, Maurizio; Faienza, Maria Felicia

2014-01-25

Heterozygous de novo mutations in SOX2 have been reported in approximately 10-20% of patients with unilateral or bilateral anophthalmia or microphthalmia. An additional phenotype of hypopituitarism, with anterior pituitary hypoplasia and hypogonadotropic hypogonadism, has been reported in patients carrying SOX2 alterations. We report a novel heterozygous mutation in the SOX2 gene in a male affected with congenital bilateral anophthalmia, hypogonadotrophic hypogonadism and growth hormone deficiency. The mutation we describe is a cytosine deletion in position 905 (c905delC) which causes frameshift and an aberrant C-terminal domain. Our report highlights the fact that subjects affected with eye anomalies and harboring SOX2 mutations are at high risk for gonadotropin deficiency, which has important implications for their clinical management. Copyright © 2013 Elsevier B.V. All rights reserved.

Duchenne muscular dystrophy in a female with compound heterozygous contiguous exon deletions.

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Takeshita, Eri; Minami, Narihiro; Minami, Kumiko; Suzuki, Mikiya; Awashima, Takeya; Ishiyama, Akihiko; Komaki, Hirofumi; Nishino, Ichizo; Sasaki, Masayuki

2017-06-01

Females with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) mutations rarely exhibit clinical symptoms from childhood, although potential mechanisms for symptoms associated with DMD and BMD in females have been reported. We report the case of a female DMD patient with a clinical course indistinguishable from that of a male DMD patient, and who possessed compound heterozygous contiguous exon deletions in the dystrophin gene. She exhibited Gowers' sign, calf muscle hypertrophy, and a high serum creatine kinase level at 2 years. Her muscle pathology showed most of the fibers were negative for dystrophin immunohistochemical staining. She lost ambulation at 11 years. Multiplex ligation-dependent probe amplification analysis of this gene detected one copy of exons 48-53; she was found to be a BMD carrier with an in-frame deletion. Messenger RNA from her muscle demonstrated out-of-frame deletions of exons 48-50 and 51-53 occurring on separate alleles. Genomic DNA from her lymphocytes demonstrated the accurate deletion region on each allele. To our knowledge, this is the first report on a female patient possessing compound heterozygous contiguous exon deletions in the dystrophin gene, leading to DMD. Copyright © 2017 Elsevier B.V. All rights reserved.

RAC1 Missense Mutations in Developmental Disorders with Diverse Phenotypes.

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

2017-09-07

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

[Molecular genetic analysis for a pedigree with severe hereditary coagulation factor VII deficiency].

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Ding, Qiu-lan; Wang, Hong-li; Wang, Xue-feng; Wang, Ming-shan; Fu, Qi-hua; Wu, Wen-man; Hu, Yi-qun; Wang, Zhen-yi

2003-10-01

To identify the genetic mutations of a severe inherited coagulation factor VII (FVII) deficiency pedigree. The diagnosis was validated by coagulant and haemostatic parameters. FVII gene mutations were screened in the propositus and his family members by DNA direct sequencing and confirmed by digestions of the restriction enzymes of the PCR production. Two heterozygous missense mutations were found in the propositus of the pedigree: a G to T transversion at position 9482 in exon 6 and a C to T mutation at position 11348 in exon 8 resulting in the amino acid substitution of Arg152 with Leu and Arg304 with Trp, respectively. A heterozygous single nucleotide deletion (C) at position 11487-11489(CCC) within exon 8 was identified, which predicted the frameshift mutation at position His351 followed by the changes of six corresponding amino acids and appearance of a premature protein caused by stop codon. The heterozygous mutations identified in the proband were derived from his father (Arg152 to Leu) and his mother (Arg304 to Trp mutation) and a heterozygous deletion (C) at position 11487-9(CCC). By tracing the other pedigree members, it was found that his grandmother had a heterozygous mutation of Arg304Trp and a heterozygous polymorphism of Arg353Gln and his grandfather had a heterozygous Arg152Leu mutation. Three heterozygous mutations were found in a pedigree with hereditary coagulation factor VII deficiency. Arg152Leu and deletion C at position 11487-9(CCC) were novel mutations.

Intrafamiliar clinical variability of circumferential skin creases Kunze type caused by a novel heterozygous mutation of N-terminal TUBB gene.

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Dentici, M L; Terracciano, A; Bellacchio, E; Capolino, R; Novelli, A; Digilio, M C; Dallapiccola, B

2018-02-10

Circumferential skin creases Kunze type (CSC-KT; OMIM 156610, 616734) is a rare disorder characterized by folding of excess skin, which leads to ringed creases, known as Michelin Tire Baby Syndrome (MTBS). CSC-KT patients also exhibit facial dysmorphism, growth retardation, intellectual disability (ID) and multiple congenital malformations. Recently, 2 heterozygous mutations in TUBB gene and 4 mutations (both homozygous and heterozygous) in MAPRE2 gene were identified in 3 and 4 CSC-KT patients, respectively. In the 3 TUBB gene-related CSC-KT patients, all mutations fall in the N-terminal gene domain and were de novo. Mutations in the C-terminal of TUBB gene have been associated to microcephaly and structural brain malformation, in the absence of CSC-KT features. We report a 9-year-old boy with a diagnosis of CSC-KT based on MTBS, facial dysmorphism, microcephaly, severe ID, cortical atrophy and corpus callosum hypoplasia. Sanger sequencing identified a novel heterozygous c.218T>C (p.Met73Thr) mutation in the N-terminal of TUBB gene, that was inherited from the mother affected by isolated MTBS. This is the first report of inherited TUBB gene-related CSC-KT resulting from a novel heterozygous mutation in the N-terminal domain. Present data support the role of TUBB mutations in CSC-KT and definitely includes CSC-KT syndrome within the tubulinopathies. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A new compound heterozygous CFTR mutation in a Chinese family with cystic fibrosis.

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Xie, Yingjun; Huang, Xueqiong; Liang, Yujian; Xu, Lingling; Pei, Yuxin; Cheng, Yucai; Zhang, Lidan; Tang, Wen

2017-11-01

Cystic fibrosis (CF) is the most common autosomal recessive disease among Caucasians but is rarer in the Chinese population, because mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. To elucidate the causative role of a novel compound heterozygous mutation of CF. In this study, clinical samples were obtained from two siblings with recurrent airway infections, clubbed fingers, salt-sweat and failure to gain weight in a non-consanguineous Chinese family. Next-generation sequencing was performed on the 27 coding exons of CFTR in both children, with confirmation by Sanger sequencing. Next-generation sequencing showed the same compound heterozygous CFTR mutation (c.865A>T p.Arg289X and c.3651_3652insAAAT p.Tyr1219X) in both children. As this mutation is consistent with the clinical manifestations of CF and no other mutations were detected after scanning the gene sequence, we suggest that the CF phenotype is caused by compound heterozygosity for c.865A>T and c.3651_3652insAAAT. As c865A>T is not currently listed in the "Cystic Fibrosis Mutation Database", this information about CF in a Chinese population is of interest. © 2015 John Wiley & Sons Ltd.

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

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

2017-06-01

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

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

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

2011-01-01

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

Compound heterozygous ASPM mutations in Pakistani MCPH families

DEFF Research Database (Denmark)

Muhammad, Farooq; Mahmood Baig, Shahid; Hansen, Lars

2009-01-01

Autosomal recessive primary microcephaly (MCPH) is characterized by reduced head circumference (50% of all reported families. In spite of the high frequency of MCPH in Pakistan only one case of compound heterozygosity for mutations in ASPM has been reported yet. In this large MCPH study we...... confirmed compound heterozygosity in two and homozygous mutations in 20 families, respectively, showing that up to 10% of families with MCPH caused by ASPM are compound heterozygous. In total we identified 16 different nonsense or frameshift mutations of which 12 were novel thereby increasing the number...... of mutations in ASPM significantly from 35 to 47. We found no correlation between the severity of the condition and the site of truncation. We suggest that the high frequency of compound heterozygosity observed in this study is taken into consideration as part of future genetic testing and counseling...

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

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

2013-02-01

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

Early-Onset X-Linked Retinitis Pigmentosa in a Heterozygous Female Harboring an Intronic Donor Splice Site Mutation in the Retinitis Pigmentosa GTPase Regulator Gene.

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Shifera, Amde Selassie; Kay, Christine Nichols

2015-01-01

To report a heterozygous female presenting with an early-onset and severe form of X-linked retinitis pigmentosa (XLRP). This is a case series presenting the clinical findings in a heterozygous female with XLRP and two of her family members. Fundus photography, fundus autofluorescence, ocular coherence tomography, and visual perimetry are presented. The proband reported here is a heterozygous female who presented at the age of 8 years with an early onset and aggressive form of XLRP. The patient belongs to a four-generation family with a total of three affected females and four affected males. The patient was initially diagnosed with retinitis pigmentosa (RP) at the age of 4 years. Genetic testing identified a heterozygous donor splice site mutation in intron 1 (IVS1 + 1G > A) of the retinitis pigmentosa GTPase regulator gene. The father of the proband was diagnosed with RP when he was a young child. The sister of the proband, evaluated at the age of 6 years, showed macular pigmentary changes. Although carriers of XLRP are usually asymptomatic or have a mild disease of late onset, the proband presented here exhibited an early-onset, aggressive form of the disease. It is not clear why some carrier females manifest a severe phenotype. A better understanding of the genetic processes involved in the penetrance and expressivity of XLRP in heterozygous females could assist in providing the appropriate counseling to affected families.

Novel compound heterozygous mutations of ALDH1A3 contribute to anophthalmia in a non-consanguineous Chinese family

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Yunqiang Liu

2017-06-01

Full Text Available Abstract Anophthalmia is a rare eye development anomaly resulting in absent ocular globes or tissue in the orbit since birth. Here, we investigated a newborn with bilateral anophthalmia in a Chinese family. Exome sequencing revealed that compound heterozygous mutations c.287G > A (p.(Arg96His and c.709G > A (p.(Gly237Arg of the ALDH1A3 gene were present in the affected newborn. Both mutations were absent in all of the searched databases, including 10,000 in-house Chinese exome sequences, and these mutations were confirmed as having been transmitted from the parents. Comparative amino acid sequence analysis across distantly related species revealed that the residues at positions 96 and 234 were evolutionarily highly conserved. In silico analysis predicted these changes to be damaging, and in vitro expression analysis revealed that the mutated alleles were associated with decreased protein production and impaired tetrameric protein formation. This study firstly reported that compound heterozygous mutations of the ALDH1A3 gene can result in anophthalmia in humans, thus highlighting those heterozygous mutations in ALDH1A3 should be considered for molecular screening in anophthalmia, particularly in cases from families without consanguineous relationships.

Panel-based whole exome sequencing identifies novel mutations in microphthalmia and anophthalmia patients showing complex Mendelian inheritance patterns.

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Riera, Marina; Wert, Ana; Nieto, Isabel; Pomares, Esther

2017-11-01

Microphthalmia and anophthalmia (MA) are congenital eye abnormalities that show an extremely high clinical and genetic complexity. In this study, we evaluated the implementation of whole exome sequencing (WES) for the genetic analysis of MA patients. This approach was used to investigate three unrelated families in which previous single-gene analyses failed to identify the molecular cause. A total of 47 genes previously associated with nonsyndromic MA were included in our panel. WES was performed in one affected patient from each family using the AmpliSeq TM Exome technology and the Ion Proton TM platform. A novel heterozygous OTX2 missense mutation was identified in a patient showing bilateral anophthalmia who inherited the variant from a parent who was a carrier, but showed no sign of the condition. We also describe a new PAX6 missense variant in an autosomal-dominant pedigree affected by mild bilateral microphthalmia showing high intrafamiliar variability, with germline mosaicism determined to be the most plausible molecular cause of the disease. Finally, a heterozygous missense mutation in RBP4 was found to be responsible in an isolated case of bilateral complex microphthalmia. This study highlights that panel-based WES is a reliable and effective strategy for the genetic diagnosis of MA. Furthermore, using this technique, the mutational spectrum of these diseases was broadened, with novel variants identified in each of the OTX2, PAX6, and RBP4 genes. Moreover, we report new cases of reduced penetrance, mosaicism, and variable phenotypic expressivity associated with MA, further demonstrating the heterogeneity of such disorders. © 2017 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.

Comparison of Spectrophotometry, Chromate Inhibition, and Cytofluorometry Versus Gene Sequencing for Detection of Heterozygously Glucose-6-Phosphate Dehydrogenase-Deficient Females.

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Peters, Anna L; Veldthuis, Martijn; van Leeuwen, Karin; Bossuyt, Patrick M M; Vlaar, Alexander P J; van Bruggen, Robin; de Korte, Dirk; Van Noorden, Cornelis J F; van Zwieten, Rob

2017-11-01

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency worldwide. Detection of heterozygously deficient females can be difficult as residual activity in G6PD-sufficient red blood cells (RBCs) can mask deficiency. In this study, we compared accuracy of 4 methods for detection of G6PD deficiency in females. Blood samples from females more than 3 months of age were used for spectrophotometric measurement of G6PD activity and for determination of the percentage G6PD-negative RBCs by cytofluorometry. An additional sample from females suspected to have G6PD deficiency based on the spectrophotometric G6PD activity was used for measuring chromate inhibition and sequencing of the G6PD gene. Of 165 included females, 114 were suspected to have heterozygous deficiency. From 75 females, an extra sample was obtained. In this group, mutation analysis detected 27 heterozygously deficient females. The sensitivity of spectrophotometry, cytofluorometry, and chromate inhibition was calculated to be 0.52 (confidence interval [CI]: 0.32-0.71), 0.85 (CI: 0.66-0.96), and 0.96 (CI: 0.71-1.00, respectively, and the specificity was 1.00 (CI: 0.93-1.00), 0.88 (CI: 0.75-0.95), and 0.98 (CI: 0.89-1.00), respectively. Heterozygously G6PD-deficient females with a larger percentage of G6PD-sufficient RBCs are missed by routine methods measuring total G6PD activity. However, the majority of these females can be detected with both chromate inhibition and cytofluorometry.

Heterozygous Hfe gene deletion leads to impaired glucose homeostasis, but not liver injury in mice fed a high-calorie diet.

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Britton, Laurence; Jaskowski, Lesley; Bridle, Kim; Santrampurwala, Nishreen; Reiling, Janske; Musgrave, Nick; Subramaniam, V Nathan; Crawford, Darrell

2016-06-01

Heterozygous mutations of the Hfe gene have been proposed as cofactors in the development and progression of nonalcoholic fatty liver disease (NAFLD). Homozygous Hfe deletion previously has been shown to lead to dysregulated hepatic lipid metabolism and accentuated liver injury in a dietary mouse model of NAFLD We sought to establish whether heterozygous deletion of Hfe is sufficient to promote liver injury when mice are exposed to a high-calorie diet (HCD). Eight-week-old wild-type and Hfe(+/-) mice received 8 weeks of a control diet or HCD Liver histology and pathways of lipid and iron metabolism were analyzed. Liver histology demonstrated that mice fed a HCD had increased NAFLD activity score (NAS), steatosis, and hepatocyte ballooning. However, liver injury was unaffected by Hfe genotype. Hepatic iron concentration (HIC) was increased in Hfe(+/-) mice of both dietary groups. HCD resulted in a hepcidin-independent reduction in HIC Hfe(+/-) mice demonstrated raised fasting serum glucose concentrations and HOMA-IR score, despite unaltered serum adiponectin concentrations. Downstream regulators of hepatic de novo lipogenesis (pAKT, SREBP-1, Fas, Scd1) and fatty acid oxidation (AdipoR2, Pparα, Cpt1) were largely unaffected by genotype. In summary, heterozygous Hfe gene deletion is associated with impaired iron and glucose metabolism. However, unlike homozygous Hfe deletion, heterozygous gene deletion did not affect lipid metabolism pathways or liver injury in this model. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Missense mutations in IHH impair Indian Hedgehog signaling in C3H10T1/2 cells: Implications for brachydactyly type A1, and new targets for Hedgehog signaling.

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Guo, Shengzhen; Zhou, Jian; Gao, Bo; Hu, Jianxin; Wang, Hongsheng; Meng, Junwei; Zhao, Xinzhi; Ma, Gang; Lin, Chuwen; Xiao, Yue; Tang, Wei; Zhu, Xuming; Cheah, Kathryn S E; Feng, Guoying; Chan, Danny; He, Lin

2010-01-01

Heterozygous missense mutations in IHH result in Brachydactyly type A1 (BDA1; OMIM 112500), a condition characterized by the shortening of digits due to hypoplasia/aplasia of the middle phalanx. Indian Hedgehog signaling regulates the proliferation and differentiation of chondrocytes and is essential for endochondral bone formation. Analyses of activated IHH signaling in C3H10T1/2 cells showed that three BDA1-associated mutations (p.E95K, p.D100E and p.E131K) severely impaired the induction of targets such as Ptch1 and Gli1. However, this was not a complete loss of function, suggesting that these mutations may affect the interaction with the receptor PTCH1 or its partners, with an impact on the induction potency. From comparative microarray expression analyses and quantitative real-time PCR, we identified three additional targets, Sostdc1, Penk1 and Igfbp5, which were also severely affected. Penk1 and Igfbp5 were confirmed to be regulated by GLI1, while the induction of Sostdc1 by IHH is independent of GLI1. SOSTDC1 is a BMP antagonist, and altered BMP signaling is known to affect digit formation. The role of Penk1 and Igfbp5 in skeletogenesis is not known. However, we have shown that both Penk1 and Igfbp5 are expressed in the interzone region of the developing joint of mouse digits, providing another link for a role for IHH signaling in the formation of the distal digits.

Identification of eight novel coagulation factor XIII subunit A mutations: implied consequences for structure and function.

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Ivaskevicius, Vytautas; Biswas, Arijit; Bevans, Carville; Schroeder, Verena; Kohler, Hans Peter; Rott, Hannelore; Halimeh, Susan; Petrides, Petro E; Lenk, Harald; Krause, Manuele; Miterski, Bruno; Harbrecht, Ursula; Oldenburg, Johannes

2010-06-01

Severe hereditary coagulation factor XIII deficiency is a rare homozygous bleeding disorder affecting one person in every two million individuals. In contrast, heterozygous factor XIII deficiency is more common, but usually not associated with severe hemorrhage such as intracranial bleeding or hemarthrosis. In most cases, the disease is caused by F13A gene mutations. Causative mutations associated with the F13B gene are rarer. We analyzed ten index patients and three relatives for factor XIII activity using a photometric assay and sequenced their F13A and F13B genes. Additionally, structural analysis of the wild-type protein structure from a previously reported X-ray crystallographic model identified potential structural and functional effects of the missense mutations. All individuals except one were heterozygous for factor XIIIA mutations (average factor XIII activity 51%), while the remaining homozygous individual was found to have severe factor XIII deficiency (<5% of normal factor XIII activity). Eight of the 12 heterozygous patients exhibited a bleeding tendency upon provocation. The identified missense (Pro289Arg, Arg611His, Asp668Gly) and nonsense (Gly390X, Trp664X) mutations are causative for factor XIII deficiency. A Gly592Ser variant identified in three unrelated index patients, as well as in 200 healthy controls (minor allele frequency 0.005), and two further Tyr167Cys and Arg540Gln variants, represent possible candidates for rare F13A gene polymorphisms since they apparently do not have a significant influence on the structure of the factor XIIIA protein. Future in vitro expression studies of the factor XIII mutations are required to confirm their pathological mechanisms.

Male Hypogonadism and Germ Cell Loss Caused by a Mutation in Polo-Like Kinase 4

Science.gov (United States)

Harris, Rebecca M.; Weiss, Jeffrey

2011-01-01

The genetic etiologies of male infertility remain largely unknown. To identify genes potentially involved in spermatogenesis and male infertility, we performed genome-wide mutagenesis in mice with N-ethyl-N-nitrosourea and identified a line with dominant hypogonadism and patchy germ cell loss. Genomic mapping and DNA sequence analysis identified a novel heterozygous missense mutation in the kinase domain of Polo-like kinase 4 (Plk4), altering an isoleucine to asparagine at residue 242 (I242N). Genetic complementation studies using a gene trap line with disruption in the Plk4 locus confirmed that the putative Plk4 missense mutation was causative. Plk4 is known to be involved in centriole formation and cell cycle progression. However, a specific role in mammalian spermatogenesis has not been examined. PLK4 was highly expressed in the testes both pre- and postnatally. In the adult, PLK4 expression was first detected in stage VIII pachytene spermatocytes and was present through step 16 elongated spermatids. Because the homozygous Plk4I242N/I242N mutation was embryonic lethal, all analyses were performed using the heterozygous Plk4+/I242N mice. Testis size was reduced by 17%, and histology revealed discrete regions of germ cell loss, leaving only Sertoli cells in these defective tubules. Testis cord formation (embryonic day 13.5) was normal. Testis histology was also normal at postnatal day (P)1, but germ cell loss was detected at P10 and subsequent ages. We conclude that the I242N heterozygous mutation in PLK4 is causative for patchy germ cell loss beginning at P10, suggesting a role for PLK4 during the initiation of spermatogenesis. PMID:21791561

The Coexpression of Reelin and Neuronal Nitric Oxide Synthase in a Subpopulation of Dentate Gyrus Neurons Is Downregulated in Heterozygous Reeler Mice

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Raquel Romay-Tallón

2010-01-01

Full Text Available Reelin is an extracellular matrix protein expressed in several interneuron subtypes in the hippocampus and dentate gyrus. Neuronal nitric oxide synthase (nNOS is also expressed by interneurons in these areas. We investigated whether reelin and nNOS are co-localized in the same population of hippocampal interneurons, and whether this colocalization is altered in the heterozygous reeler mouse. We found colocalization of nNOS in reelin-positive cells in the CA1 stratum radiatum and lacunosum moleculare, the CA3 stratum radiatum, and the dentate gyrus subgranular zone, molecular layer, and hilus. In heterozygous reeler mice, the colocalization of nNOS in reelin-positive cells was significantly decreased only in the subgranular zone and molecular layer. The coexpression of reelin and nNOS in several hippocampal regions suggests that reelin and nNOS may work synergistically to promote glutamatergic function, and the loss of this coexpression in heterozygous reeler mice may underlie some of the behavioral deficits observed in these animals.

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

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

2016-11-01

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

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

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Hong Yan Liu

2016-11-01

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

Heterozygous loss of TSC2 alters p53 signaling and human stem cell reprogramming.

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Armstrong, Laura C; Westlake, Grant; Snow, John P; Cawthon, Bryan; Armour, Eric; Bowman, Aaron B; Ess, Kevin C

2017-12-01

Tuberous sclerosis complex (TSC) is a pediatric disorder of dysregulated growth and differentiation caused by loss of function mutations in either the TSC1 or TSC2 genes, which regulate mTOR kinase activity. To study aberrations of early development in TSC, we generated induced pluripotent stem cells using dermal fibroblasts obtained from patients with TSC. During validation, we found that stem cells generated from TSC patients had a very high rate of integration of the reprogramming plasmid containing a shRNA against TP53. We also found that loss of one allele of TSC2 in human fibroblasts is sufficient to increase p53 levels and impair stem cell reprogramming. Increased p53 was also observed in TSC2 heterozygous and homozygous mutant human stem cells, suggesting that the interactions between TSC2 and p53 are consistent across cell types and gene dosage. These results support important contributions of TSC2 heterozygous and homozygous mutant cells to the pathogenesis of TSC and the important role of p53 during reprogramming. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Unusual xanthomas in a young patient with heterozygous familial hypercholesterolemia and type III hyperlipoproteinemia

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Feussner, G.; Dobmeyer, J. [Univ. of Heidelberg (Germany); Nissen, H.; Hansen, T.S. [Odense Univ. Hospital (Denmark)

1996-10-16

We report on a 20-year-old man with the combination of two independent familial lipoprotein disorders: heterozygous familial hypercholesterolemia (FH) and type III hyperlipoproteinemia (HLP). Familial hypercholesterolemia was diagnosed by elevated total and low density lipoprotein cholesterol levels and family history. By denaturing gradient gel electrophoresis, DNA sequencing and restriction fragment length polymorphism analysis, a G{r_arrow}A splice donor mutation in intron 3 of the proband`s low density lipoprotein receptor gene was identified as the underlying molecular defect. This mutation was described previously as a receptor-negative founder mutation in Norway (FH-Elverum) and subsequently in 6 unrelated heterozygous English patients, creating a severe phenotype of familial hypercholesterolemia. Type III HLP was confirmed by homozygosity for apolipoprotein (apo) E2 and an elevated ratio of very low density lipoprotein cholesterol to serum triglycerides (0.40; normal ratio about 0.20). The patient has unusual flat xanthomas in the interdigital webs of the hands which are normally not found in either disease. These dermatological findings might therefore be indicative of the rare combination of both disorders of lipoprotein metabolism in one individual. 29 refs., 5 figs., 1 tab.

A preliminary molecular phylogeny of shield-bearer moths (Lepidoptera: Adeloidea: Heliozelidae) highlights rich undescribed diversity.

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Milla, Liz; van Nieukerken, Erik J; Vijverberg, Ruben; Doorenweerd, Camiel; Wilcox, Stephen A; Halsey, Mike; Young, David A; Jones, Therésa M; Kallies, Axel; Hilton, Douglas J

2018-03-01

Heliozelidae are a widespread, evolutionarily early diverging family of small, day-flying monotrysian moths, for which a comprehensive phylogeny is lacking. We generated the first molecular phylogeny of the family using DNA sequences of two mitochondrial genes (COI and COII) and two nuclear genes (H3 and 28S) from 130 Heliozelidae specimens, including eight of the twelve known genera: Antispila, Antispilina, Coptodisca, Heliozela, Holocacista, Hoplophanes, Pseliastis, and Tyriozela. Our results provide strong support for five major Heliozelidae clades: (i) a large widespread clade containing the leaf-mining genera Antispilina, Coptodisca and Holocacista and some species of Antispila, (ii) a clade containing most of the described Antispila, (iii) a clade containing the leaf-mining genus Heliozela and the monotypic genus Tyriozela, (iv) an Australian clade containing Pseliastis and (v) an Australian clade containing Hoplophanes. Each clade includes several new species and potentially new genera. Collectively, our data uncover a rich and undescribed diversity that appears to be especially prevalent in Australia. Our work highlights the need for a major taxonomic revision of the family and for generating a robust molecular phylogeny using multi-gene approaches in order to resolve the relationships among clades. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Heterozygous and homozygous JAK2(V617F states modeled by induced pluripotent stem cells from myeloproliferative neoplasm patients.

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Joseph Saliba

Full Text Available JAK2(V617F is the predominant mutation in myeloproliferative neoplasms (MPN. Modeling MPN in a human context might be helpful for the screening of molecules targeting JAK2 and its intracellular signaling. We describe here the derivation of induced pluripotent stem (iPS cell lines from 2 polycythemia vera patients carrying a heterozygous and a homozygous mutated JAK2(V617F, respectively. In the patient with homozygous JAK2(V617F, additional ASXL1 mutation and chromosome 20 allowed partial delineation of the clonal architecture and assignation of the cellular origin of the derived iPS cell lines. The marked difference in the response to erythropoietin (EPO between homozygous and heterozygous cell lines correlated with the constitutive activation level of signaling pathways. Strikingly, heterozygous iPS cells showed thrombopoietin (TPO-independent formation of megakaryocytic colonies, but not EPO-independent erythroid colony formation. JAK2, PI3K and HSP90 inhibitors were able to block spontaneous and EPO-induced growth of erythroid colonies from GPA(+CD41(+ cells derived from iPS cells. Altogether, this study brings the proof of concept that iPS can be used for studying MPN pathogenesis, clonal architecture, and drug efficacy.

Detection of compound heterozygous of hb constant spring and hb q-Thailand by capillary electrophoresis and high performance liquid chromatography.

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Pornprasert, Sakorn; Punyamung, Manoo

2015-06-01

A capillary electrophoresis (CE) has proven to be superior to a high performance liquid chromatography (HPLC) in the detection of hemoglobin Constant Spring (Hb CS). Thus the aim of this study was to analyze the efficacy of CE and HPLC for the detection of Hb CS in samples with compound heterozygous of Hb CS and Hb Q-Thailand. Hemoglobin analysis was performed in blood samples of 2 patients with compound heterozygous of Hb CS and Hb Q-Thailand by using HPLC and CE. The HPLC chromatogram and CE electrophoregram of the two techniques were compared. Hb CS was not found on HPLC chromatogram while Hb QA2 (α2 (QT)δ2), a derivative of Hb Q-Thailand, was presented at the retention time of 4.70-4.80 min and it was close to the retention time of Hb CS. On CE electrophoregram, Hb CS was presented at zone 2 (Z2) and it was distinctly separated from Hb QA2 which was presented at Z1. Therefore, CE was more efficient to the HPLC for diagnosis of compound heterozygous of Hb CS and Hb Q-Thailand.

Compound heterozygous TYK2 mutations underlie primary immunodeficiency with T-cell lymphopenia.

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Nemoto, Michiko; Hattori, Hiroyoshi; Maeda, Naoko; Akita, Nobuhiro; Muramatsu, Hideki; Moritani, Suzuko; Kawasaki, Tomonori; Maejima, Masami; Ode, Hirotaka; Hachiya, Atsuko; Sugiura, Wataru; Yokomaku, Yoshiyuki; Horibe, Keizo; Iwatani, Yasumasa

2018-05-03

Complete tyrosine kinase 2 (TYK2) deficiency has been previously described in patients with primary immunodeficiency diseases. The patients were infected with various pathogens, including mycobacteria and/or viruses, and one of the patients developed hyper-IgE syndrome. A detailed immunological investigation of these patients revealed impaired responses to type I IFN, IL-10, IL-12 and IL-23, which are associated with increased susceptibility to mycobacterial and/or viral infections. Herein, we report a recessive partial TYK2 deficiency in two siblings who presented with T-cell lymphopenia characterized by low naïve CD4 + T-cell counts and who developed Epstein-Barr virus (EBV)-associated B-cell lymphoma. Targeted exome-sequencing of the siblings' genomes demonstrated that both patients carried novel compound heterozygous mutations (c.209_212delGCTT/c.691C > T, p.Cys70Serfs*21/p.Arg231Trp) in the TYK2. The TYK2 protein levels were reduced by 35% in the T cells of the patient. Unlike the response under complete TYK2 deficiency, the patient's T cells responded normally to type I IFN, IL-6, IL-10 and IL-12, whereas the cells displayed an impaired response to IL-23. Furthermore, the level of STAT1 was low in the cells of the patient. These studies reveal a new clinical entity of a primary immunodeficiency with T-cell lymphopenia that is associated with compound heterozygous TYK2 mutations in the patients.

A novel classification system to predict the pathogenic effects of CHD7 missense variants in CHARGE syndrome

DEFF Research Database (Denmark)

Bergman, Jorieke E H; Janssen, Nicole; van der Sloot, Almer M

2012-01-01

CHARGE syndrome is characterized by the variable occurrence of multisensory impairment, congenital anomalies, and developmental delay, and is caused by heterozygous mutations in the CHD7 gene. Correct interpretation of CHD7 variants is essential for genetic counseling. This is particularly diffic...

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

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

2017-04-01

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

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

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Hiroshi Kawakami

2014-10-01

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

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

Science.gov (United States)

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

2014-09-01

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

NDST1 missense mutations in autosomal recessive intellectual disability.

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

2014-11-01

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

Heterozygous truncation mutations of the SMC1A gene cause a severe early onset epilepsy with cluster seizures in females: Detailed phenotyping of 10 new cases.

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Symonds, Joseph D; Joss, Shelagh; Metcalfe, Kay A; Somarathi, Suresh; Cruden, Jamie; Devlin, Anita M; Donaldson, Alan; DiDonato, Nataliya; Fitzpatrick, David; Kaiser, Frank J; Lampe, Anne K; Lees, Melissa M; McLellan, Ailsa; Montgomery, Tara; Mundada, Vivek; Nairn, Lesley; Sarkar, Ajoy; Schallner, Jens; Pozojevic, Jelena; Parenti, Ilaria; Tan, Jeen; Turnpenny, Peter; Whitehouse, William P; Zuberi, Sameer M

2017-04-01

The phenotype of seizure clustering with febrile illnesses in infancy/early childhood is well recognized. To date the only genetic epilepsy consistently associated with this phenotype is PCDH19, an X-linked disorder restricted to females, and males with mosaicism. The SMC1A gene, which encodes a structural component of the cohesin complex is also located on the X chromosome. Missense variants and small in-frame deletions of SMC1A cause approximately 5% of Cornelia de Lange Syndrome (CdLS). Recently, protein truncating mutations in SMC1A have been reported in five females, all of whom have been affected by a drug-resistant epilepsy, and severe developmental impairment. Our objective was to further delineate the phenotype of SMC1A truncation. Female cases with de novo truncation mutations in SMC1A were identified from the Deciphering Developmental Disorders (DDD) study (n = 8), from postmortem testing of an affected twin (n = 1), and from clinical testing with an epilepsy gene panel (n = 1). Detailed information on the phenotype in each case was obtained. Ten cases with heterozygous de novo mutations in the SMC1A gene are presented. All 10 mutations identified are predicted to result in premature truncation of the SMC1A protein. All cases are female, and none had a clinical diagnosis of CdLS. They presented with onset of epileptic seizures between <4 weeks and 28 months of age. In the majority of cases, a marked preponderance for seizures to occur in clusters was noted. Seizure clusters were associated with developmental regression. Moderate or severe developmental impairment was apparent in all cases. Truncation mutations in SMC1A cause a severe epilepsy phenotype with cluster seizures in females. These mutations are likely to be nonviable in males. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

Rare and common variants in LPL and APOA5 in Thai subjects with severe hypertriglyceridemia: A resequencing approach.

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Khovidhunkit, Weerapan; Charoen, Supannika; Kiateprungvej, Arunrat; Chartyingcharoen, Palm; Muanpetch, Suwanna; Plengpanich, Wanee

2016-01-01

Severe hypertriglyceridemia usually results from a combination of genetic and environmental factors. Few data exist on the genetics of severe hypertriglyceridemia in Asian populations. To examine the genetic variants of 3 candidate genes known to influence triglyceride metabolism, LPL, APOC2, and APOA5, which encode lipoprotein lipase, apolipoprotein C-II, and apolipoprotein A-V, respectively, in a large group of Thai subjects with severe hypertriglyceridemia. We identified sequence variants of LPL, APOC2, and APOA5 by sequencing exons and exon-intron junctions in 101 subjects with triglyceride levels ≥ 10 mmol/L (886 mg/dL) and compared with those of 111 normotriglyceridemic subjects. Six different rare variants in LPL were found in 13 patients, 2 of which were novel (1 heterozygous missense variant: p.Arg270Gly and 1 frameshift variant: p.Asp308Glyfs*3). Four previously identified heterozygous missense variants in LPL were p.Ala98Thr, p.Leu279Val, p.Leu279Arg, and p.Arg432Thr. Collectively, these rare variants were found only in the hypertriglyceridemic group but not in the control group (13% vs 0%, P severe hypertriglyceridemia. A common p.Gly185Cys APOA5 variant, in particular, was quite prevalent and potentially contributed to hypertriglyceridemia in this group of patients. Copyright © 2015 National Lipid Association. Published by Elsevier Inc. All rights reserved.

NMR-based phytochemical analysis of Vitis vinifera cv Falanghina leaves. Characterization of a previously undescribed biflavonoid with antiproliferative activity.

Science.gov (United States)

Tartaglione, Luciana; Gambuti, Angelita; De Cicco, Paola; Ercolano, Giuseppe; Ianaro, Angela; Taglialatela-Scafati, Orazio; Moio, Luigi; Forino, Martino

2018-03-01

Vitis vinifera cv Falanghina is an ancient grape variety of Southern Italy. A thorough phytochemical analysis of the Falanghina leaves was conducted to investigate its specialised metabolite content. Along with already known molecules, such as caftaric acid, quercetin-3-O-β-d-glucopyranoside, quercetin-3-O-β-d-glucuronide, kaempferol-3-O-β-d-glucopyranoside and kaempferol-3-O-β-d-glucuronide, a previously undescribed biflavonoid was identified. For this last compound, a moderate bioactivity against metastatic melanoma cells proliferation was discovered. This datum can be of some interest to researchers studying human melanoma. The high content in antioxidant glycosylated flavonoids supports the exploitation of grape vine leaves as an inexpensive source of natural products for the food industry and for both pharmaceutical and nutraceutical companies. Additionally, this study offers important insights into the plant physiology, thus prompting possible technological researches of genetic selection based on the vine adaptation to specific pedo-climatic environments. Copyright © 2017 Elsevier B.V. All rights reserved.

In-frame mutations in exon 1 of SKI cause dominant Shprintzen-Goldberg syndrome.

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Carmignac, Virginie; Thevenon, Julien; Adès, Lesley; Callewaert, Bert; Julia, Sophie; Thauvin-Robinet, Christel; Gueneau, Lucie; Courcet, Jean-Benoit; Lopez, Estelle; Holman, Katherine; Renard, Marjolijn; Plauchu, Henri; Plessis, Ghislaine; De Backer, Julie; Child, Anne; Arno, Gavin; Duplomb, Laurence; Callier, Patrick; Aral, Bernard; Vabres, Pierre; Gigot, Nadège; Arbustini, Eloisa; Grasso, Maurizia; Robinson, Peter N; Goizet, Cyril; Baumann, Clarisse; Di Rocco, Maja; Sanchez Del Pozo, Jaime; Huet, Frédéric; Jondeau, Guillaume; Collod-Beroud, Gwenaëlle; Beroud, Christophe; Amiel, Jeanne; Cormier-Daire, Valérie; Rivière, Jean-Baptiste; Boileau, Catherine; De Paepe, Anne; Faivre, Laurence

2012-11-02

Shprintzen-Goldberg syndrome (SGS) is characterized by severe marfanoid habitus, intellectual disability, camptodactyly, typical facial dysmorphism, and craniosynostosis. Using family-based exome sequencing, we identified a dominantly inherited heterozygous in-frame deletion in exon 1 of SKI. Direct sequencing of SKI further identified one overlapping heterozygous in-frame deletion and ten heterozygous missense mutations affecting recurrent residues in 18 of the 19 individuals screened for SGS; these individuals included one family affected by somatic mosaicism. All mutations were located in a restricted area of exon 1, within the R-SMAD binding domain of SKI. No mutation was found in a cohort of 11 individuals with other marfanoid-craniosynostosis phenotypes. The interaction between SKI and Smad2/3 and Smad 4 regulates TGF-β signaling, and the pattern of anomalies in Ski-deficient mice corresponds to the clinical manifestations of SGS. These findings define SGS as a member of the family of diseases associated with the TGF-β-signaling pathway. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

A Foxp2 mutation implicated in human speech deficits alters sequencing of ultrasonic vocalizations in adult male mice

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Jonathan Chabout

2016-10-01

Full Text Available Development of proficient spoken language skills is disrupted by mutations of the FOXP2 transcription factor. A heterozygous missense mutation in the KE family causes speech apraxia, involving difficulty producing words with complex learned sequences of syllables. Manipulations in songbirds have helped to elucidate the role of this gene in vocal learning, but findings in non-human mammals have been limited or inconclusive. Here we performed a systematic study of ultrasonic vocalizations (USVs of adult male mice carrying the KE family mutation. Using novel statistical tools, we found that Foxp2 heterozygous mice did not have detectable changes in USV syllable acoustic structure, but produced shorter sequences and did not shift to more complex syntax in social contexts where wildtype animals did. Heterozygous mice also displayed a shift in the position of their rudimentary laryngeal motor cortex layer-5 neurons. Our findings indicate that although mouse USVs are mostly innate, the underlying contributions of FoxP2 to sequencing of vocalizations are conserved with humans.

A novel MKRN3 missense mutation causing familial precocious puberty.

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

2014-12-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

Science.gov (United States)

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

2017-01-01

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

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

Directory of Open Access Journals (Sweden)

Baundauna Bose

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

Two mutations in the same low-density lipoprotein receptor allele act in synergy to reduce receptor function in heterozygous familial hypercholesterolemia

DEFF Research Database (Denmark)

Jensen, H K; Jensen, T G; Faergeman, O

1997-01-01

Mutations in genes are not necessarily pathogenic. Expression of mutant genes in cells can therefore be required to demonstrate that mutations in fact disturb protein function. This applies especially to missense mutations, which cause an amino acid to be replaced by another amino acid. In the pr...

Delayed Recovery of Skeletal Muscle Mass following Hindlimb Immobilization in mTOR Heterozygous Mice

OpenAIRE

Lang, Susan M.; Kazi, Abid A.; Hong-Brown, Ly; Lang, Charles H.

2012-01-01

The present study addressed the hypothesis that reducing mTOR, as seen in mTOR heterozygous (+/-) mice, would exaggerate the changes in protein synthesis and degradation observed during hindlimb immobilization as well as impair normal muscle regrowth during the recovery period. Atrophy was produced by unilateral hindlimb immobilization and data compared to the contralateral gastrocnemius. In wild-type (WT) mice, the gradual loss of muscle mass plateaued by day 7. This response was associated ...

A legacy of tinnitus: multiple head and neck paragangliomas

Directory of Open Access Journals (Sweden)

Jeremy J. Turner

2009-12-01

Full Text Available We describe the case of a patient who presented with a right-sided glomus jugulare tumor and bilateral glomus vagale tumors. These proved to be nonmalignant paragangliomas on histopathological analysis. Genetic analysis revealed a germline heterozygous missense mutation (Pro81Leu in the succinate dehydrogenase subunit D (SDHD gene. We discuss the clinical presentations of the familial paraganglioma syndrome type 1, which is caused by mutations in SDHD, and the implications for the clinical diagnosis and care of such patients.

Expanding the clinical spectrum associated with defects in CNTNAP2 and NRXN1

Directory of Open Access Journals (Sweden)

Ullmann Reinhard

2011-08-01

Full Text Available Abstract Background Heterozygous copy-number and missense variants in CNTNAP2 and NRXN1 have repeatedly been associated with a wide spectrum of neuropsychiatric disorders such as developmental language and autism spectrum disorders, epilepsy and schizophrenia. Recently, homozygous or compound heterozygous defects in either gene were reported as causative for severe intellectual disability. Methods 99 patients with severe intellectual disability and resemblance to Pitt-Hopkins syndrome and/or suspected recessive inheritance were screened for mutations in CNTNAP2 and NRXN1. Molecular karyotyping was performed in 45 patients. In 8 further patients with variable intellectual disability and heterozygous deletions in either CNTNAP2 or NRXN1, the remaining allele was sequenced. Results By molecular karyotyping and mutational screening of CNTNAP2 and NRXN1 in a group of severely intellectually disabled patients we identified a heterozygous deletion in NRXN1 in one patient and heterozygous splice-site, frameshift and stop mutations in CNTNAP2 in four patients, respectively. Neither in these patients nor in eight further patients with heterozygous deletions within NRXN1 or CNTNAP2 we could identify a defect on the second allele. One deletion in NRXN1 and one deletion in CNTNAP2 occurred de novo, in another family the deletion was also identified in the mother who had learning difficulties, and in all other tested families one parent was shown to be healthy carrier of the respective deletion or mutation. Conclusions We report on patients with heterozygous defects in CNTNAP2 or NRXN1 associated with severe intellectual disability, which has only been reported for recessive defects before. These results expand the spectrum of phenotypic severity in patients with heterozygous defects in either gene. The large variability between severely affected patients and mildly affected or asymptomatic carrier parents might suggest the presence of a second hit, not

Heterozygous Lmna(delK32) mice develop dilated cardiomyopathy through a combined pathomechanism of haploinsufficiency and peptide toxicity

DEFF Research Database (Denmark)

Cattin, M. E.; Bertrand, A. T.; Schlossarek, S.

2013-01-01

itself has a clear deleterious effect on engineered heart tissues force of contraction, it also leads to the nuclear aggregation of viral-mediated expression of K32-lamin. In conclusion, Het mice are the first knock-in Lmna model with cardiac-specific phenotype at the heterozygous state. Altogether, our....... The pathomechanisms linking mutations to DCM remain to be elucidated. We investigated the phenotype and associated pathomechanisms of heterozygous Lmna(K32/) (Het) knock-in mice, which carry a human mutation. Het mice developed a cardiac-specific phenotype. Two phases, with two different pathomechanisms, could...... be observed that lead to the development of cardiac dysfunction, DCM and death between 35 and 70 weeks of age. In young Het hearts, there was a clear reduction in lamin A/C level, mainly due to the degradation of toxic K32-lamin. As a side effect, lamin A/C haploinsufficiency probably triggers the cardiac...

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

Science.gov (United States)

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

2014-03-01

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

Chronic Toxoplasma gondii in Nurr1-Null Heterozygous Mice Exacerbates Elevated Open Field Activity

OpenAIRE

Eells, Jeffrey B.; Varela-Stokes, Andrea; Guo-Ross, Shirley X.; Kummari, Evangel; Smith, Holly M.; Cox, Erin; Lindsay, David S.

2015-01-01

Latent infection with Toxoplasma gondii is common in humans (approximately 30% of the global population) and is a significant risk factor for schizophrenia. Since prevalence of T. gondii infection is far greater than prevalence of schizophrenia (0.5-1%), genetic risk factors are likely also necessary to contribute to schizophrenia. To test this concept in an animal model, Nurr1-null heterozygous (+/-) mice and wild-type (+/+) mice were evaluate using an emergence test, activity in an open fie...

Generalized pustular psoriasis in infant with heterozygous mutation in the IL36RN gene successfully treated with infliximab

DEFF Research Database (Denmark)

Glerup, Mia; Herlin, Troels; Veirum, Jens Erik

, but to our knowledge heterozygous IL36RN mutation related to severe generalized pustular psoriasis in early childhood has not been described. Case presentation: First child of non-consanguineous caucasian (Danish) parents prenatally diagnosed with tetralogy of Fallot. Array CGH revealed normal karyotype...

An Allelic Series of Trp63 Mutations Defines TAp63 as a Modifier of EEC Syndrome

Science.gov (United States)

Lindahl, Emma Vernersson; Garcia, Elvin L.; Mills, Alea A.

2014-01-01

Human Ectrodactyly, Ectodermal dysplasia, Clefting (EEC) syndrome is an autosomal dominant developmental disorder defined by limb deformities, skin defects, and craniofacial clefting. Although associated with heterozygous missense mutations in TP63, the genetic basis underlying the variable expressivity and incomplete penetrance of EEC is unknown. Here we show that mice heterozygous for an allele encoding the Trp63 p.Arg318His mutation, which corresponds to the human TP63 p.Arg279His mutation found in patients with EEC, have features of human EEC. Using an allelic series, we discovered that whereas clefting and skin defects are caused by loss of Trp63 function, limb anomalies are due to gain- and/or dominant-negative effects of Trp63. Furthermore, we identify TAp63 as a strong modifier of EEC-associated phenotypes with regard to both penetrance and expressivity. PMID:23775923

Missense polymorphisms in the MC1R gene of the dog, red fox, arctic fox and Chinese raccoon dog.

Science.gov (United States)

Nowacka-Woszuk, J; Salamon, S; Gorna, A; Switonski, M

2013-04-01

Coat colour variation is determined by many genes, one of which is the melanocortin receptor type 1 (MC1R) gene. In this study, we examined the whole coding sequence of this gene in four species belonging to the Canidae family (dog, red fox, arctic fox and Chinese raccoon dog). Although the comparative analysis of the obtained nucleotide sequences revealed a high conservation, which varied between 97.9 and 99.1%, we altogether identified 22 SNPs (10 in dogs, six in farmed red foxes, two in wild red foxes, three in arctic foxes and one in Chinese raccoon dog). Among them, seven appeared to be novel: one silent in the dog, three missense and one silent in the red fox, one in the 3'-flanking region in the arctic fox and one silent in the Chinese raccoon dog. In dogs and red foxes, the SNPs segregated as 10 and four haplotypes, respectively. Taking into consideration the published reports and results of this study, the highest number of missense polymorphisms was until now found in the dog (9) and red fox (7). © 2012 Blackwell Verlag GmbH.

High-resolution melting (HRM) re-analysis of a polyposis patients cohort reveals previously undetected heterozygous and mosaic APC gene mutations.

Science.gov (United States)

Out, Astrid A; van Minderhout, Ivonne J H M; van der Stoep, Nienke; van Bommel, Lysette S R; Kluijt, Irma; Aalfs, Cora; Voorendt, Marsha; Vossen, Rolf H A M; Nielsen, Maartje; Vasen, Hans F A; Morreau, Hans; Devilee, Peter; Tops, Carli M J; Hes, Frederik J

2015-06-01

Familial adenomatous polyposis is most frequently caused by pathogenic variants in either the APC gene or the MUTYH gene. The detection rate of pathogenic variants depends on the severity of the phenotype and sensitivity of the screening method, including sensitivity for mosaic variants. For 171 patients with multiple colorectal polyps without previously detectable pathogenic variant, APC was reanalyzed in leukocyte DNA by one uniform technique: high-resolution melting (HRM) analysis. Serial dilution of heterozygous DNA resulted in a lowest detectable allelic fraction of 6% for the majority of variants. HRM analysis and subsequent sequencing detected pathogenic fully heterozygous APC variants in 10 (6%) of the patients and pathogenic mosaic variants in 2 (1%). All these variants were previously missed by various conventional scanning methods. In parallel, HRM APC scanning was applied to DNA isolated from polyp tissue of two additional patients with apparently sporadic polyposis and without detectable pathogenic APC variant in leukocyte DNA. In both patients a pathogenic mosaic APC variant was present in multiple polyps. The detection of pathogenic APC variants in 7% of the patients, including mosaics, illustrates the usefulness of a complete APC gene reanalysis of previously tested patients, by a supplementary scanning method. HRM is a sensitive and fast pre-screening method for reliable detection of heterozygous and mosaic variants, which can be applied to leukocyte and polyp derived DNA.

Factor VII deficiency: a novel missense variant and genotype-phenotype correlation in patients from Southern Italy.

Science.gov (United States)

Tiscia, Giovanni; Favuzzi, Giovanni; Chinni, Elena; Colaizzo, Donatella; Fischetti, Lucia; Intrieri, Mariano; Margaglione, Maurizio; Grandone, Elvira

2017-01-01

This study aimed at attempting to correlate genotype and phenotype in factor VII deficiency. Here, we present molecular and clinical findings of 10 patients with factor VII deficiency. From 2013 to 2016, 10 subjects were referred to our center because of a prolonged prothrombin time identified during routine or presurgery examinations or after a laboratory assessment of a bleeding episode. Mutation characterization was performed using the bioinformatics applications PROMO, SIFT, and Polyphen-2. Structural changes in the factor VII protein were analyzed using the SPDB viewer tool. Of the 10 variants we identified, 1 was responsible for a novel missense change (c.1199G>C, p.Cys400Ser); in 2 cases we identified the c.-54G>A and c.509G>A (p.Arg170His) polymorphic variants in the 5'-upstream region of the factor VII gene and exon 6, respectively. To our knowledge, neither of these polymorphic variants has been described previously in factor VII-deficient patients. In silico predictions showed differences in binding sites for transcription factors caused by the c.-54G>A variant and a probable damaging effect of the p.Cys400Ser missense change on factor VII active conformation, leading to breaking of the Cys400-Cys428 disulfide bridge. Our findings further suggest that, independently of factor VII levels and of variants potentially affecting factor VII levels, environmental factors, e.g., trauma, could heavily influence the clinical phenotype of factor VII-deficient patients.

Three-dimensional spatial analysis of missense variants in RTEL1 identifies pathogenic variants in patients with Familial Interstitial Pneumonia.

Science.gov (United States)

Sivley, R Michael; Sheehan, Jonathan H; Kropski, Jonathan A; Cogan, Joy; Blackwell, Timothy S; Phillips, John A; Bush, William S; Meiler, Jens; Capra, John A

2018-01-23

Next-generation sequencing of individuals with genetic diseases often detects candidate rare variants in numerous genes, but determining which are causal remains challenging. We hypothesized that the spatial distribution of missense variants in protein structures contains information about function and pathogenicity that can help prioritize variants of unknown significance (VUS) and elucidate the structural mechanisms leading to disease. To illustrate this approach in a clinical application, we analyzed 13 candidate missense variants in regulator of telomere elongation helicase 1 (RTEL1) identified in patients with Familial Interstitial Pneumonia (FIP). We curated pathogenic and neutral RTEL1 variants from the literature and public databases. We then used homology modeling to construct a 3D structural model of RTEL1 and mapped known variants into this structure. We next developed a pathogenicity prediction algorithm based on proximity to known disease causing and neutral variants and evaluated its performance with leave-one-out cross-validation. We further validated our predictions with segregation analyses, telomere lengths, and mutagenesis data from the homologous XPD protein. Our algorithm for classifying RTEL1 VUS based on spatial proximity to pathogenic and neutral variation accurately distinguished 7 known pathogenic from 29 neutral variants (ROC AUC = 0.85) in the N-terminal domains of RTEL1. Pathogenic proximity scores were also significantly correlated with effects on ATPase activity (Pearson r = -0.65, p = 0.0004) in XPD, a related helicase. Applying the algorithm to 13 VUS identified from sequencing of RTEL1 from patients predicted five out of six disease-segregating VUS to be pathogenic. We provide structural hypotheses regarding how these mutations may disrupt RTEL1 ATPase and helicase function. Spatial analysis of missense variation accurately classified candidate VUS in RTEL1 and suggests how such variants cause disease. Incorporating

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

OpenAIRE

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

2000-01-01

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

Description of Three New α Variants and Four New β Variants: Hb Montluel [α110(G17)Ala → Val; HBA1: c.332C > T], Hb Cap d'Agde [α131(H14)Ser → Cys; HBA2: c.395C > G] and Hb Corsica [α100(G7)Leu → Pro; HBA1: 302T > C]; Hb Nîmes [β104(G6)Arg → Gly; HBB: c.313A > G], Hb Saint Marcellin [β112(G14)Cys → Gly; HBB: c.337T > G], Hb Saint Chamond [β80(EF4)Asn → 0; HBB: c.241_243delAAC] and Hb Dompierre [β29(B11)Gly → Arg; HBB: c.88G > C].

Science.gov (United States)

Renoux, Céline; Feray, Cécile; Joly, Philippe; Lacan, Philippe; Francina, Alain

2015-01-01

We present here seven new hemoglobin (Hb) variants identified during routine Hb analysis. All of them are caused by a missense mutation except Hb Saint Chamond, which results from an in-frame deletion of the asparagine residue at β80. All these variants are clinically silent in the heterozygous state but two of them (Hb Cap d'Agde and Hb Dompierre) may be unstable, whereas Hb Nîmes could present a very slightly elevated oxygen affinity. These data are to be confirmed by appropriate biochemical tests.

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

Science.gov (United States)

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

2009-08-01

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

Improved motor performance in Dyt1 ΔGAG heterozygous knock-in mice by cerebellar Purkinje-cell specific Dyt1 conditional knocking-out.

Science.gov (United States)

Yokoi, Fumiaki; Dang, Mai Tu; Li, Yuqing

2012-05-01

Early-onset generalized torsion dystonia (dystonia 1) is an inherited movement disorder caused by mutations in DYT1 (TOR1A), which codes for torsinA. Most patients have a 3-base pair deletion (ΔGAG) in one allele of DYT1, corresponding to a loss of a glutamic acid residue (ΔE) in the C-terminal region of the protein. Functional alterations in basal ganglia circuits and the cerebellum have been reported in dystonia. Pharmacological manipulations or mutations in genes that result in functional alterations of the cerebellum have been reported to have dystonic symptoms and have been used as phenotypic rodent models. Additionally, structural lesions in the abnormal cerebellar circuits, such as cerebellectomy, have therapeutic effects in these models. A previous study has shown that the Dyt1 ΔGAG heterozygous knock-in (KI) mice exhibit motor deficits in the beam-walking test. Both Dyt1 ΔGAG heterozygous knock-in (KI) and Dyt1 Purkinje cell-specific knockout (Dyt1 pKO) mice exhibit dendritic alterations of cerebellar Purkinje cells. Here, Dyt1 pKO mice exhibited significantly less slip numbers in the beam-walking test, suggesting better motor performance than control littermates, and normal gait. Furthermore, Dyt1 ΔGAG KI/Dyt1 pKO double mutant mice exhibited significantly lower numbers of slips than Dyt1 ΔGAG heterozygous KI mice, suggesting Purkinje-cell specific knockout of Dyt1 wild-type (WT) allele in Dyt1 ΔGAG heterozygous KI mice rescued the motor deficits. The results suggest that molecular lesions of torsinA in Purkinje cells by gene therapy or intervening in the signaling pathway downstream of the cerebellar Purkinje cells may rescue motor symptoms in dystonia 1. Copyright © 2012 Elsevier B.V. All rights reserved.

Identification of a previously undescribed divergent virus from the Flaviviridae family in an outbreak of equine serum hepatitis.

Science.gov (United States)

Chandriani, Sanjay; Skewes-Cox, Peter; Zhong, Weidong; Ganem, Donald E; Divers, Thomas J; Van Blaricum, Anita J; Tennant, Bud C; Kistler, Amy L

2013-04-09

Theiler's disease is an acute hepatitis in horses that is associated with the administration of equine blood products; its etiologic agent has remained unknown for nearly a century. Here, we used massively parallel sequencing to explore samples from a recent Theiler's disease outbreak. Metatranscriptomic analysis of the short sequence reads identified a 10.5-kb sequence from a previously undescribed virus of the Flaviviridae family, which we designate "Theiler's disease-associated virus" (TDAV). Phylogenetic analysis clusters TDAV with GB viruses of the recently proposed Pegivirus genus, although it shares only 35.3% amino acid identity with its closest relative, GB virus D. An epidemiological survey of additional horses from three separate locations supports an association between TDAV infection and acute serum hepatitis. Experimental inoculation of horses with TDAV-positive plasma provides evidence that several weeks of viremia preceded liver injury and that liver disease may not be directly related to the level of viremia. Like hepatitis C virus, the best characterized Flaviviridae species known to cause hepatitis, we find TDAV is capable of efficient parenteral transmission, engendering acute and chronic infections associated with a diversity of clinical presentations ranging from subclinical infection to clinical hepatitis.

Diagnosis of Compound Heterozygous Hb Tak/β-Thalassemia and HbD-Punjab/β-Thalassemia by HbA2 Levels on Capillary Electrophoresis.

Science.gov (United States)

Panyasai, Sitthichai; Sakkhachornphop, Supachai; Pornprasert, Sakorn

2018-01-01

A misdiagnosis of β-thalassemia carrier in samples with Hb Tak and HbD-Punjab, the β-variants, can be a cause of inappropriate genetic counseling thus having a new case of β-thalassemia major. A capillary electrophoresis (CE) is very efficient in separating and quantifying HbA 2 . In this study, HbA 2 levels of samples which were doubted for compound heterozygous Hb Tak/β-thalassemia or heterozygous HbD-Punjab/β-thalassemia were measured and compared between CE and high performance liquid chromatography (HPLC). The molecular confirmation for Hb Tak, HbD-Punjab and β-thalassemia codons 17 (A > T), 41/42 (-TCTT), 71/72 (+A) and IVSI-nt1 (G > T) mutations and 3.4 kb deletion were also performed. Based on DNA analysis, 3 cases were diagnosed as compound heterozygous Hb Tak/β-thalassemia and one for HbD-Punjab/β-thalassemia. The elevated HbA 2 levels were found in all 4 samples with rages of 4.6-7.3% on CE while those were not found on HPLC. Thus, the elevated HbA 2 measured by CE can be used as a screening parameter for differentiating the homozygote of Hb Tak and HbD-Punjab from the compound heterozygote of these hemoglobinopathies and β-thalassemia.

Implications of compound heterozygous insulin receptor mutations in congenital muscle fibre type disproportion myopathy for the receptor kinase activation

DEFF Research Database (Denmark)

Klein, H H; Müller, R; Vestergaard, H

1999-01-01

We studied insulin receptor kinase activation in two brothers with congenital muscle fibre type disproportion myopathy and compound heterozygous mutations of the insulin receptor gene, their parents, and their unaffected brother. In the father who has a heterozygote Arg1174-->Gln mutation, in sit...

Disruption of NBS1 gene leads to early embryonic lethality in homozygous null mice and induces specific cancer in heterozygous mice

Energy Technology Data Exchange (ETDEWEB)

Kurimasa, Akihiro; Burma, Sandeep; Henrie, Melinda; Ouyang, Honghai; Osaki, Mitsuhiko; Ito, Hisao; Nagasawa, Hatsumi; Little, John B.; Oshimura, Mitsuo; Li, Gloria C.; Chen, David J.

2002-04-15

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive chromosome instability syndrome characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition, with cellular features similar to that of ataxia telangiectasia (AT). NBS results from mutations in the mammalian gene Nbs1 that codes for a 95-kDa protein called nibrin, NBS1, or p95. To establish an animal model for NBS, we attempted to generate NBS1 knockout mice. However, NBS1 gene knockouts were lethal at an early embryonic stage. NBS1 homozygous(-/-) blastocyst cells cultured in vitro showed retarded growth and subsequently underwent growth arrest within 5 days of culture. Apoptosis, assayed by TUNEL staining, was observed in NBSI homozygous(-/-) blastocyst cells cultured for four days. NBSI heterozygous(+/-) mice were normal, and exhibited no specific phenotype for at least one year. However, fibroblast cells from NBSI heterozygous(+/-) mice displayed an enhanced frequency of spontaneous transformation to anchorage-independent growth as compared to NBS1 wild-type(+/+) cells. Furthermore, heterozygous(+/-) mice exhibited a high incidence of hepatocellular carcinoma after one year compared to wild-type mice, even though no significant differences in the incidence of other tumors such as lung adenocarcinoma and lymphoma were observed. Taken together, these results strongly suggest that NBS1 heterozygosity and reduced NBSI expression induces formation of specific tumors in mice.

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

NARCIS (Netherlands)

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

2018-01-01

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

Novel FGFR1 and KISS1R Mutations in Chinese Kallmann Syndrome Males with Cleft Lip/Palate

Directory of Open Access Journals (Sweden)

Hao Xu

2015-01-01

Full Text Available Kallmann syndrome (KS is characterized by isolated hypogonadotropic hypogonadism (IHH with anosmia and is sometimes associated with cleft lip/palate (CLP. In order to describe the clinical features, genetic etiology, and treatment outcome of KS males with CLP, we performed genetic screening for 15 known causal IHH genes (KAL1, FGFR1, NELF, FGF8, CHD7, WDR11, SEMA3A, KISS1R, KISS1, PROKR2, PROK2, TAC3, TACR3, GNRH1, and GNRHR in four KS with CLP patients and six IHH patients without CLP. Two novel heterozygous missense mutations in FGFR1, (NM_001174066: c.776G>A (p.G259E and (NM_001174066: c.358C>T (p.R120C, were identified in a 23-year-old KS male with cleft lip and an 18-year-old KS patient with cleft lip and palate, dental agenesis, and high arched palate, respectively. These two mutations were not presented in their healthy parents and 200 normal controls. One novel heterozygous missense mutation in KISS1R, (NM_032551: c.587C>A (p.P196H, was identified in an 18-year-old KS male with cleft lip and dental agenesis who developed sperm after being treated with gonadotropin. This mutation was also presented in his healthy father and grandfather. These results have implications for the diagnosis, genetic counseling, and treatment of KS and CLP males with mutations in FGFR1 gene.

A novel heterozygous SOX2 mutation causing anophthalmia/microphthalmia with genital anomalies.

Science.gov (United States)

Pedace, Lucia; Castori, Marco; Binni, Francesco; Pingi, Alberto; Grammatico, Barbara; Scommegna, Salvatore; Majore, Silvia; Grammatico, Paola

2009-01-01

Anophthalmia/microphthalmia is a rare developmental craniofacial defect, which recognizes a wide range of causes, including chromosomal abnormalities, single-gene mutations as well as environmental factors. Heterozygous mutations in the SOX2 gene are the most common monogenic form of anophthalmia/microphthalmia, as they are reported in up to 10-15% cases. Here, we describe a sporadic patient showing bilateral anophthalmia/microphthalmia and micropenis caused by a novel mutation (c.59_60insGG) in the SOX2 gene. Morphological and endocrinological evaluations excluded any anomaly of the hypothalamus-pituitary axis. Our finding supports the hypothesis that SOX2 is particularly prone to slipped-strand mispairing, which results in a high frequency of point deletions/insertions.

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

Science.gov (United States)

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

2017-01-01

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

Mutations in the gene for lipoprotein lipase. A cause for low HDL cholesterol levels in individuals heterozygous for familial hypercholesterolemia

NARCIS (Netherlands)

Pimstone, S. N.; Gagné, S. E.; Gagné, C.; Lupien, P. J.; Gaudet, D.; Williams, R. R.; Kotze, M.; Reymer, P. W.; Defesche, J. C.; Kastelein, J. J.

1995-01-01

Familial hypercholesterolemia (FH) is characterized by elevated plasma concentrations of LDL cholesterol resulting from mutations in the gene for the LDL receptor. Low HDL cholesterol levels are seen frequently in patients both heterozygous and homozygous for mutations in this gene. Suggested

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

DEFF Research Database (Denmark)

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

2009-01-01

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

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

DEFF Research Database (Denmark)

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

2010-01-01

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

Disruption of hippocampus-regulated behavioural and cognitive processes by heterozygous constitutive deletion of SynGAP.

Science.gov (United States)

Muhia, Mary; Yee, Benjamin K; Feldon, Joram; Markopoulos, Foivos; Knuesel, Irene

2010-02-01

The brain-specific Ras/Rap-GTPase activating protein (SynGAP) is a prime candidate linking N-methyl-d-aspartate receptors to the regulation of the ERK/MAP kinase signalling cascade, suggested to be essential for experience-dependent synaptic plasticity. Here, we evaluated the behavioural phenotype of SynGAP heterozygous knockout mice (SG(+/-)), expressing roughly half the normal levels of SynGAP. In the cognitive domain, SG(+/-) mice demonstrated severe working and reference memory deficits in the radial arm maze task, a mild impairment early in the transfer test of the water maze task, and a deficiency in spontaneous alternation in an elevated T-maze. In the non-cognitive domain, SG(+/-) mice were hyperactive in the open field and appeared less anxious in the elevated plus maze test. In contrast, object recognition memory performance was not impaired in SG(+/-) mice. The reduction in SynGAP thus resulted in multiple behavioural traits suggestive of aberrant cognitive and non-cognitive processes normally mediated by the hippocampus. Immunohistochemical evaluation further revealed a significant reduction in calbindin-positive interneurons in the hippocampus and doublecortin-positive neurons in the dentate gyrus of adult SG(+/-) mice. Heterozygous constitutive deletion of SynGAP is therefore associated with notable behavioural as well as morphological phenotypes indicative of hippocampal dysfunction. Any suggestion of a possible causal link between them however remains a matter for further investigation.

Autosomal dominant familial neurohypophyseal diabetes insipidus caused by a mutation in the arginine-vasopressin II gene in four generations of a Korean family

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Myo-Jing Kim

2014-12-01

Full Text Available Autosomal dominant neurohypophyseal diabetes insipidus is a rare form of central diabetes insipidus that is caused by mutations in the vasopressin-neurophysin II (AVP-NPII gene. It is characterized by persistent polydipsia and polyuria induced by deficient or absent secretion of arginine vasopressin (AVP. Here we report a case of familial neurohypophyseal diabetes insipidus in four generations of a Korean family, caused by heterozygous missense mutation in exon 2 of the AVP-NPII gene (c.286G>T. This is the first report of such a case in Korea.

Identification of Novel Mutations in FAH Gene and Prenatal Diagnosis of Tyrosinemia in Indian Family

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Jayesh J. Sheth

2012-01-01

Full Text Available Carrier of tyrosinemia type I was diagnosed by sequencing FAH (fumarylacetoacetate hydrolase gene. It leads to the identification of heterozygous status for both c.648C>G (p.Ile216Met and c.1159G>A (p.Gly387Arg mutations in exons 8 and 13, respectively, in the parents. The experimental program PolyPhen, SIFT, and MT predicts former missense point mutation as “benign” that creates a potential donor splice site and later one as “probably damaging” which disrupts secondary structure of protein.

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

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Wang Xiaoqin

2007-12-01

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

Double heterozygous mutations of MITF and PAX3 result in Waardenburg syndrome with increased penetrance in pigmentary defects.

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Yang, T; Li, X; Huang, Q; Li, L; Chai, Y; Sun, L; Wang, X; Zhu, Y; Wang, Z; Huang, Z; Li, Y; Wu, H

2013-01-01

Waardenburg syndrome (WS) is characterized by sensorineural hearing loss and pigmentary defects of the hair, skin, and iris. Heterozygous mutations of MITF and its transactivator gene PAX3 are associated with Waardenburg syndrome type II (WS2) and type I (WS1), respectively. Most patients with MITF or PAX3 mutations, however, show variable penetrance of WS-associated phenotypes even within families segregating the same mutation, possibly mediated by genetic background or specific modifiers. In this study, we reported a rare Waardenburg syndrome simplex family in which a pair of WS parents gave birth to a child with double heterozygous mutations of MITF and PAX3. Compared to his parents who carried a single mutation in either MITF or PAX3, this child showed increased penetrance of pigmentary defects including white forelock, white eyebrows and eyelashes, and patchy facial depigmentation. This observation suggested that the expression level of MITF is closely correlated to the penetrance of WS, and variants in transcription regulator genes of MITF may modify the relevant clinical phenotypes. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Molecular characterization of a genetic variant of the steroid hormone-binding globulin gene in heterozygous subjects

Energy Technology Data Exchange (ETDEWEB)

Hardy, D.O.; Catterall, J.F. [Population Council, New York, NY (United States); Carino, C. [Instituto National de la Nutricion, Mexico City, MX (United States)] [and others

1995-04-01

Steroid hormone-binding globulin in human serum displays different isoelectric focusing (IEF) patterns among individuals, suggesting genetic variation in the gene for this extracellular steroid carrier protein. Analysis of allele frequencies and family studies suggested the existence of two codominant alleles of the gene. Subsequent determination of the molecular basis of a variant of the gene was carried out using DNA from homozygous individuals from a single Belgian family. It was of interest to characterize other variant individuals to determine whether all variants identified by IEF phenotyping were caused by the same mutation or whether other mutations occurred in the gene in different populations. Previous studies identified Mexican subjects who were heterozygous for the variant IEF phenotype. Denaturing gradient gel electrophoresis was used to localize the mutation in these subjects and to purify the variant allele for DNA sequence analysis. The results show that the mutation in this population is identical to that identified in the Belgian family, and no other mutations were detected in the gene. These data represent the first analysis of steroid hormone-binding globulin gene variation in heterozygous subjects and further support the conclusion of biallelism of the gene worldwide. 11 refs., 2 figs., 1 tab.

Genetic Analysis of PARK2 and PINK1 Genes in Brazilian Patients with Early-Onset Parkinson's Disease

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Karla Cristina Vasconcelos Moura

2013-01-01

Full Text Available Parkinson's disease is the second most frequent neurodegenerative disorder in the world, affecting 1-2% of individuals over the age of 65. The etiology of Parkinson's disease is complex, with the involvement of gene-environment interactions. Although it is considered a disease of late manifestation, early-onset forms of parkinsonism contribute to 5–10% of all cases. In the present study, we screened mutations in coding regions of PARK2 and PINK1 genes in 136 unrelated Brazilian patients with early-onset Parkinson's disease through automatic sequencing. We identified six missense variants in PARK2 gene: one known pathogenic mutation, two variants of uncertain role, and three nonpathogenic changes. No pathogenic mutation was identified in PINK1 gene, only benign polymorphisms. All putative pathogenic variants found in this study were in heterozygous state. Our data show that PARK2 point mutations are more common in Brazilian early-onset Parkinson's disease patients (2.9% than PINK1 missense variants (0%, corroborating other studies worldwide.

Estimated carrier frequency of creatine transporter deficiency in females in the general population using functional characterization of novel missense variants in the SLC6A8 gene.

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DesRoches, Caro-Lyne; Patel, Jaina; Wang, Peixiang; Minassian, Berge; Salomons, Gajja S; Marshall, Christian R; Mercimek-Mahmutoglu, Saadet

2015-07-10

Creatine transporter deficiency (CRTR-D) is an X-linked inherited disorder of creatine transport. All males and about 50% of females have intellectual disability or cognitive dysfunction. Creatine deficiency on brain proton magnetic resonance spectroscopy and elevated urinary creatine to creatinine ratio are important biomarkers. Mutations in the SLC6A8 gene occur de novo in 30% of males. Despite reports of high prevalence of CRTR-D in males with intellectual disability, there are no true prevalence studies in the general population. To determine carrier frequency of CRTR-D in the general population we studied the variants in the SLC6A8 gene reported in the Exome Variant Server database and performed functional characterization of missense variants. We also analyzed synonymous and intronic variants for their predicted pathogenicity using in silico analysis tools. Nine missense variants were functionally analyzed using transient transfection by site-directed mutagenesis with In-Fusion HD Cloning in HeLa cells. Creatine uptake was measured by liquid chromatography tandem mass spectrometry for creatine measurement. The c.1654G>T (p.Val552Leu) variant showed low residual creatine uptake activity of 35% of wild type transfected HeLa cells and was classified as pathogenic. Three variants (c.808G>A; p.Val270Met, c.942C>G; p.Phe314Leu and c.952G>A; p.Ala318Thr) were predicted to be pathogenic based on in silico analysis, but proved to be non-pathogenic by our functional analysis. The estimated carrier frequency of CRTR-D was 0.024% in females in the general population. We recommend functional studies for all novel missense variants by transient transfection followed by creatine uptake measurement by liquid chromatography tandem mass spectrometry as fast and cost effective method for the functional analysis of missense variants in the SLC6A8 gene. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

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

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Gemenetzi, M; Lotery, A J

2013-11-01

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

Risk of cancer by ATM missense mutations in the general population

DEFF Research Database (Denmark)

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

2008-01-01

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

Identification of Heterozygous Single- and Multi-exon Deletions in IL7R by Whole Exome Sequencing.

OpenAIRE

Engelhardt, Karin R; Xu, Yaobo; Grainger, Angela; Germani Batacchi, Mila G C; Swan, David J; Willet, Joseph D P; Abd Hamid, Intan J; Agyeman, Philipp; Barge, Dawn; Bibi, Shahnaz; Jenkins, Lucy; Flood, Terence J; Abinun, Mario; Slatter, Mary A; Gennery, Andrew R

2017-01-01

Purpose We aimed to achieve a retrospective molecular diagnosis by applying state-of-the-art genomic sequencing methods to past patients with T-B+NK+ severe combined immunodeficiency (SCID). We included identification of copy number variations (CNVs) by whole exome sequencing (WES) using the CNV calling method ExomeDepth to detect gene alterations for which routine Sanger sequencing analysis is not suitable, such as large heterozygous deletions. Methods Of a total of 12 undiagnosed patients w...

Lifetime exercise intolerance with lactic acidosis as key manifestation of novel compound heterozygous ACAD9 mutations causing complex I deficiency.

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Schrank, Bertold; Schoser, Benedikt; Klopstock, Thomas; Schneiderat, Peter; Horvath, Rita; Abicht, Angela; Holinski-Feder, Elke; Augustis, Sarunas

2017-05-01

We report a 36-year-old female having lifetime exercise intolerance and lactic acidosis with nausea associated with novel compound heterozygous Acyl-CoA dehydrogenase 9 gene (ACAD9) mutations (p.Ala390Thr and p.Arg518Cys). ACAD9 is an assembly factor for the mitochondrial respiratory chain complex I. ACAD9 mutations are recognized as frequent causes of complex I deficiency. Our patient presented with exercise intolerance, rapid fatigue, and nausea since early childhood. Mild physical workload provoked the occurrence of nausea and vomiting repeatedly. Her neurological examination, laboratory findings and muscle biopsy demonstrated no abnormalities. A bicycle spiroergometry provoked significant lactic acidosis during and following exercise pointing towards a mitochondrial disorder. Subsequently, the analysis of respiratory chain enzyme activities in muscle revealed severe isolated complex I deficiency. Candidate gene sequencing revealed two novel heterozygous ACAD9 mutations. This patient report expands the mutational and phenotypic spectrum of diseases associated with mutations in ACAD9. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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Greer S Kirshenbaum

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

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

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Md. Zahidus Sayeed

2014-01-01

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

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

DEFF Research Database (Denmark)

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

2010-01-01

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

Comprehensive behavioral analysis of RNG105 (Caprin1) heterozygous mice: Reduced social interaction and attenuated response to novelty

Science.gov (United States)

Ohashi, Rie; Takao, Keizo; Miyakawa, Tsuyoshi; Shiina, Nobuyuki

2016-01-01

RNG105 (also known as Caprin1) is a major RNA-binding protein in neuronal RNA granules, and is responsible for mRNA transport to dendrites and neuronal network formation. A recent study reported that a heterozygous mutation in the Rng105 gene was found in an autism spectrum disorder (ASD) patient, but it remains unclear whether there is a causal relation between RNG105 deficiency and ASD. Here, we subjected Rng105+/− mice to a comprehensive behavioral test battery, and revealed the influence of RNG105 deficiency on mouse behavior. Rng105+/− mice exhibited a reduced sociality in a home cage and a weak preference for social novelty. Consistently, the Rng105+/− mice also showed a weak preference for novel objects and novel place patterns. Furthermore, although the Rng105+/− mice exhibited normal memory acquisition, they tended to have relative difficulty in reversal learning in the spatial reference tasks. These findings suggest that the RNG105 heterozygous knockout leads to a reduction in sociality, response to novelty and flexibility in learning, which are implicated in ASD-like behavior. PMID:26865403

Heterozygous inactivation of tsc2 enhances tumorigenesis in p53 mutant zebrafish

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Seok-Hyung Kim

2013-07-01

Tuberous sclerosis complex (TSC is a multi-organ disorder caused by mutations of the TSC1 or TSC2 genes. A key function of these genes is to inhibit mTORC1 (mechanistic target of rapamycin complex 1 kinase signaling. Cells deficient for TSC1 or TSC2 have increased mTORC1 signaling and give rise to benign tumors, although, as a rule, true malignancies are rarely seen. In contrast, other disorders with increased mTOR signaling typically have overt malignancies. A better understanding of genetic mechanisms that govern the transformation of benign cells to malignant ones is crucial to understand cancer pathogenesis. We generated a zebrafish model of TSC and cancer progression by placing a heterozygous mutation of the tsc2 gene in a p53 mutant background. Unlike tsc2 heterozygous mutant zebrafish, which never exhibited cancers, compound tsc2;p53 mutants had malignant tumors in multiple organs. Tumorigenesis was enhanced compared with p53 mutant zebrafish. p53 mutants also had increased mTORC1 signaling that was further enhanced in tsc2;p53 compound mutants. We found increased expression of Hif1-α, Hif2-α and Vegf-c in tsc2;p53 compound mutant zebrafish compared with p53 mutant zebrafish. Expression of these proteins probably underlies the increased angiogenesis seen in compound mutant zebrafish compared with p53 mutants and might further drive cancer progression. Treatment of p53 and compound mutant zebrafish with the mTORC1 inhibitor rapamycin caused rapid shrinkage of tumor size and decreased caliber of tumor-associated blood vessels. This is the first report using an animal model to show interactions between tsc2, mTORC1 and p53 during tumorigenesis. These results might explain why individuals with TSC rarely have malignant tumors, but also suggest that cancer arising in individuals without TSC might be influenced by the status of TSC1 and/or TSC2 mutations and be potentially treatable with mTORC1 inhibitors.

Hay-Wells syndrome is caused by heterozygous missense mutations in the SAM domain of p63.

NARCIS (Netherlands)

McGrath, J.A.; Duijf, P.H.; Doetsch, V.; Irvine, A.D.; Waal, R.M.W. de; Vanmolkot, K.R.; Wessagowit, V.; Kelly, A.E.; Atherton, D.J.; Griffiths, W.A.; Orlow, S.J.; Haeringen, A. van; Ausems, M.G.E.M.; Yang, A.; McKeon, F.; Bamshad, M.; Brunner, H.G.; Hamel, B.C.J.; Bokhoven, J.H.L.M. van

2001-01-01

Hay-Wells syndrome, also known as ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome (OMIM 106260), is a rare autosomal dominant disorder characterized by congenital ectodermal dysplasia, including alopecia, scalp infections, dystrophic nails, hypodontia, ankyloblepharon and cleft lip

Hay-Wells syndrome is caused by heterozygous missense mutations in the SAM domain of p63

NARCIS (Netherlands)

McGrath, JA; Duijf, PHG; Doetsch, [No Value; Irvine, AD; de Waal, R; Vanmolkot, KRJ; Wessagowit, [No Value; Kelly, A; Atherton, DJ; Griffiths, WAD; Orlow, SJ; van Haeringen, A; Ausems, MGEM; Yang, A; McKeon, F; Bamshad, MA; Brunner, HG; Hamel, BCJ; van Bokhoven, H

2001-01-01

Hay-Wells syndrome, also known as ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome (OMIM 106260), is a rare autosomal dominant disorder characterized by congenital ectodermal dysplasia, including alopecia, scalp infections, dystrophic nails, hypodontia, ankyloblepharon and cleft lip

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

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Devroop Sarkar

2014-01-01

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

Homozygous variegate porphyria presenting with developmental and language delay in childhood.

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Pinder, V A E; Holden, S T; Deshpande, C; Siddiqui, A; Mellerio, J E; Wraige, E; Powell, A M

2013-10-01

Variegate porphyria is an autosomal dominant disorder that usually presents with photosensitivity and acute neurological crises in adulthood. It is caused by heterozygous mutations in the protoporphyrinogen oxidase gene (PPOX). A rarer variant, homozygous variegate porphyria (HVP), presents in childhood with recurrent skin blisters and scarring. More variable features of HVP are short stature, brachydactyly, nystagmus, epilepsy, developmental delay and mental retardation. We describe a child who presented with nystagmus, developmental delay and ataxia, combined with a photosensitive eruption. Analysis of porphyrins in plasma, urine and stool supported a clinical diagnosis of HVP. DNA from the patient showed that he is compound heterozygous for two novel missense mutations in the PPOX coding region: c.169G>C (p.Gly57Arg) and c.1259C>G (Pro420Arg). Interestingly, cranial magnetic resonance imaging showed an absence of myelin, a feature not previously reported in HVP, which expands the differential diagnosis of childhood hypomyelinating leucoencephalopathies. © 2013 British Association of Dermatologists.

Gene screening in a Chinese family with Marfan syndrome

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Wen-Jiao Xia

2016-05-01

Full Text Available AIM:To analyze the causative gene mutation for Marfan syndrome(MFSwith autosomal dominant hereditary in a Chinese family in Liaoning Province,China. METHODS: Venous blood was collected and candidate gene was selected to design primers according to the clinical phenotype. With genomic polymerase chain reaction(PCRperformed, the coding exons and their flanking intron in sequences of candidate gene were sequenced,DNA fragments separated by agarose gel electrophoresis and direct sequencing method was used to determine the pathogenic gene.RESULTS:Phenotype of the proband was presented as ectopic lentis. Sequencing of the coding regions of FBN1 gene showed the presence of a heterozygous A→G transversion at nucleotide 640 in the 7 exon of FBN1 and the missense mutation made for Glycine into Serine(G214S. CONCLUSION:A heterozygous mutation of FBN1 c.A640G(p.G214Sis responsible for the Marfan syndrome in the four generation Chinese pedigree.

FANCA Gene Mutations with 8 Novel Molecular Changes in Indian Fanconi Anemia Patients.

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Avani Solanki

Full Text Available Fanconi anemia (FA, a rare heterogeneous genetic disorder, is known to be associated with 19 genes and a spectrum of clinical features. We studied FANCA molecular changes in 34 unrelated and 2 siblings of Indian patients with FA and have identified 26 different molecular changes of FANCA gene, of which 8 were novel mutations (a small deletion c.2500delC, 4 non-sense mutations c.2182C>T, c.2630C>G, c.3677C>G, c.3189G>A; and 3 missense mutations; c.1273G>C, c.3679 G>C, and c.3992 T>C. Among these only 16 patients could be assigned FA-A complementation group, because we could not confirm single exon deletions detected by MLPA or cDNA amplification by secondary confirmation method and due to presence of heterozygous non-pathogenic variations or heterozygous pathogenic mutations. An effective molecular screening strategy should be developed for confirmation of these mutations and determining the breakpoints for single exon deletions.

FANCA Gene Mutations with 8 Novel Molecular Changes in Indian Fanconi Anemia Patients.

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Solanki, Avani; Mohanty, Purvi; Shukla, Pallavi; Rao, Anita; Ghosh, Kanjaksha; Vundinti, Babu Rao

2016-01-01

Fanconi anemia (FA), a rare heterogeneous genetic disorder, is known to be associated with 19 genes and a spectrum of clinical features. We studied FANCA molecular changes in 34 unrelated and 2 siblings of Indian patients with FA and have identified 26 different molecular changes of FANCA gene, of which 8 were novel mutations (a small deletion c.2500delC, 4 non-sense mutations c.2182C>T, c.2630C>G, c.3677C>G, c.3189G>A; and 3 missense mutations; c.1273G>C, c.3679 G>C, and c.3992 T>C). Among these only 16 patients could be assigned FA-A complementation group, because we could not confirm single exon deletions detected by MLPA or cDNA amplification by secondary confirmation method and due to presence of heterozygous non-pathogenic variations or heterozygous pathogenic mutations. An effective molecular screening strategy should be developed for confirmation of these mutations and determining the breakpoints for single exon deletions.

Ciliopathies with Skeletal Anomalies and Renal Insufficiency due to Mutations in the IFT-A Gene WDR19

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Bredrup, Cecilie; Saunier, Sophie; Oud, Machteld M.; Fiskerstrand, Torunn; Hoischen, Alexander; Brackman, Damien; Leh, Sabine M.; Midtbø, Marit; Filhol, Emilie; Bole-Feysot, Christine; Nitschké, Patrick; Gilissen, Christian; Haugen, Olav H.; Sanders, Jan-Stephan F.; Stolte-Dijkstra, Irene; Mans, Dorus A.; Steenbergen, Eric J.; Hamel, Ben C.J.; Matignon, Marie; Pfundt, Rolph; Jeanpierre, Cécile; Boman, Helge; Rødahl, Eyvind; Veltman, Joris A.; Knappskog, Per M.; Knoers, Nine V.A.M.; Roepman, Ronald; Arts, Heleen H.

2011-01-01

A subset of ciliopathies, including Sensenbrenner, Jeune, and short-rib polydactyly syndromes are characterized by skeletal anomalies accompanied by multiorgan defects such as chronic renal failure and retinitis pigmentosa. Through exome sequencing we identified compound heterozygous mutations in WDR19 in a Norwegian family with Sensenbrenner syndrome. In a Dutch family with the clinically overlapping Jeune syndrome, a homozygous missense mutation in the same gene was found. Both families displayed a nephronophthisis-like nephropathy. Independently, we also identified compound heterozygous WDR19 mutations by exome sequencing in a Moroccan family with isolated nephronophthisis. WDR19 encodes IFT144, a member of the intraflagellar transport (IFT) complex A that drives retrograde ciliary transport. We show that IFT144 is absent from the cilia of fibroblasts from one of the Sensenbrenner patients and that ciliary abundance and morphology is perturbed, demonstrating the ciliary pathogenesis. Our results suggest that isolated nephronophthisis, Jeune, and Sensenbrenner syndromes are clinically overlapping disorders that can result from a similar molecular cause. PMID:22019273

Splicing analysis of 14 BRCA1 missense variants classifies nine variants as pathogenic

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Ahlborn, Lise B; Dandanell, Mette; Steffensen, Ane Y

2015-01-01

by functional analysis at the protein level. Results from a validated mini-gene splicing assay indicated that nine BRCA1 variants resulted in splicing aberrations leading to truncated transcripts and thus can be considered pathogenic (c.4987A>T/p.Met1663Leu, c.4988T>A/p.Met1663Lys, c.5072C>T/p.Thr1691Ile, c......Pathogenic germline mutations in the BRCA1 gene predispose carriers to early onset breast and ovarian cancer. Clinical genetic screening of BRCA1 often reveals variants with uncertain clinical significance, complicating patient and family management. Therefore, functional examinations are urgently...... needed to classify whether these uncertain variants are pathogenic or benign. In this study, we investigated 14 BRCA1 variants by in silico splicing analysis and mini-gene splicing assay. All 14 alterations were missense variants located within the BRCT domain of BRCA1 and had previously been examined...

A mouse model for inherited renal fibrosis associated with endoplasmic reticulum stress

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Sian E. Piret

2017-06-01

Full Text Available Renal fibrosis is a common feature of renal failure resulting from multiple etiologies, including diabetic nephropathy, hypertension and inherited renal disorders. However, the mechanisms of renal fibrosis are incompletely understood and we therefore explored these by establishing a mouse model for a renal tubular disorder, referred to as autosomal dominant tubulointerstitial kidney disease (ADTKD due to missense uromodulin (UMOD mutations (ADTKD-UMOD. ADTKD-UMOD, which is associated with retention of mutant uromodulin in the endoplasmic reticulum (ER of renal thick ascending limb cells, is characterized by hyperuricemia, interstitial fibrosis, inflammation and renal failure, and we used targeted homologous recombination to generate a knock-in mouse model with an ADTKD-causing missense cysteine to arginine uromodulin mutation (C125R. Heterozygous and homozygous mutant mice developed reduced uric acid excretion, renal fibrosis, immune cell infiltration and progressive renal failure, with decreased maturation and excretion of uromodulin, due to its retention in the ER. The ER stress marker 78 kDa glucose-regulated protein (GRP78 was elevated in cells expressing mutant uromodulin in heterozygous and homozygous mutant mice, and this was accompanied, both in vivo and ex vivo, by upregulation of two unfolded protein response pathways in primary thick ascending limb cells from homozygous mutant mice. However, this did not lead to an increase in apoptosis in vivo. Thus, we have developed a novel mouse model for renal fibrosis, which will be a valuable resource to decipher the mechanisms linking uromodulin mutations with ER stress and renal fibrosis.

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

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

2018-03-27

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

Novel Missense Mitochondrial ND4L Gene Mutations in Friedreich's Ataxia

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Mohammad Mehdi Heidari

2011-05-01

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

Metabonomic study of the biochemical profiles of heterozygous myostatin knockout swine

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Jianxiang XU,Dengke PAN,Jie ZHAO,Jianwu WANG,Xiaohong HE,Yuehui MA,Ning LI

2015-03-01

Full Text Available Myostatin is a transforming growth factor-β family member that normally acts to limit skeletal muscle growth. Myostatin gene (MSTN knockout (KO mice show possible effects for the prevention or treatment of metabolic disorders such as obesity and type 2 diabetes. We applied chromatography and mass spectrometry based metabonomics to assess system-wide metabolic response of heterozygous MSTN KO (MSTN+/- swine. Most of the metabolic data for MSTN+/- swine were similar to the data for wild type (WT control swine. There were, however, metabolic changes related to fatty acid metabolism, glucose utilization, lipid metabolism, as well as BCAA catabolism caused by monoallelic MSTN depletion.The statistical analyses suggested that: (1 most metabolic changes were not significant in MSTN+/- swine compared to WT swine; (2 only a few metabolic properties were significantly different between KO and WT swine, especially for lipid metabolism. Significantly, these minor changes were most evident in female KO swine and suggested differences in gender sensitivity to myostatin.

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

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Veronica Sansoni

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

Prickly pear induces upregulation of liver LDL binding in familial heterozygous hypercholesterolemia

International Nuclear Information System (INIS)

Palumbo, B.; Palumbo, R.; Efthimiou, Y.; Stamatopoulos, J.; Sinzinger, H.; Oguogho, A.; Budinsky, A.; Sinzinger, H.

2003-01-01

The hypoglycemic effect of prickly pear is well known by native local Indian population since a long time. Beside the beneficial effects on lipid metabolism, oxidation injury and platelet function has been claimed in experimental animals. We recently found an upregulation of apo-B/E receptor. We therefore examined 10 patients with isolated heterozygous familial hypercholesterolemia (FH) being enrolled in a dietary run-in phase of 6 weeks after dietary counselling and a further 6 weeks of prickly pear addition. Uptake of autologous 123 I-radiolabeled LDL was determined at entry as well as after 6 weeks of daily prickly pear ingestion. We found a significant (p 176.4 mg/dl; p 123 I-LDL binding by prickly pear in FH-patients in vivo and indicate that prickly pear exerts a significant hypolipidemic action via receptor upregulation. (author)

A novel heterozygous mutation in the STAT1 SH2 domain causes chronic mucocutaneous candidiasis, atypically diverse infections, autoimmunity, and impaired cytokine regulation

NARCIS (Netherlands)

K. Meesilpavikkai (Kornvalee); W.A. Dik (Willem); B. Schrijver (Benjamin); N.M. Nagtzaam (Nicole); A.L. Rijswijk (Angelique); G.J.A. Driessen (Gertjan); P.J. van der Spek (Peter); P.M. van Hagen (Martin); V.A.S.H. Dalm (Virgil)

2017-01-01

textabstractChronic mucocutaneous candidiasis (CMC) is a primary immunodeficiency characterized by persistent or recurrent skin and mucosal surface infections with Candida species. Different gene mutations leading to CMC have been identified. These include various heterozygous gain-of-function (GOF)

A Recurrent De Novo Variant in NACC1 Causes a Syndrome Characterized by Infantile Epilepsy, Cataracts, and Profound Developmental Delay.

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Schoch, Kelly; Meng, Linyan; Szelinger, Szabolcs; Bearden, David R; Stray-Pedersen, Asbjorg; Busk, Oyvind L; Stong, Nicholas; Liston, Eriskay; Cohn, Ronald D; Scaglia, Fernando; Rosenfeld, Jill A; Tarpinian, Jennifer; Skraban, Cara M; Deardorff, Matthew A; Friedman, Jeremy N; Akdemir, Zeynep Coban; Walley, Nicole; Mikati, Mohamad A; Kranz, Peter G; Jasien, Joan; McConkie-Rosell, Allyn; McDonald, Marie; Wechsler, Stephanie Burns; Freemark, Michael; Kansagra, Sujay; Freedman, Sharon; Bali, Deeksha; Millan, Francisca; Bale, Sherri; Nelson, Stanley F; Lee, Hane; Dorrani, Naghmeh; Goldstein, David B; Xiao, Rui; Yang, Yaping; Posey, Jennifer E; Martinez-Agosto, Julian A; Lupski, James R; Wangler, Michael F; Shashi, Vandana

2017-02-02

Whole-exome sequencing (WES) has increasingly enabled new pathogenic gene variant identification for undiagnosed neurodevelopmental disorders and provided insights into both gene function and disease biology. Here, we describe seven children with a neurodevelopmental disorder characterized by microcephaly, profound developmental delays and/or intellectual disability, cataracts, severe epilepsy including infantile spasms, irritability, failure to thrive, and stereotypic hand movements. Brain imaging in these individuals reveals delay in myelination and cerebral atrophy. We observe an identical recurrent de novo heterozygous c.892C>T (p.Arg298Trp) variant in the nucleus accumbens associated 1 (NACC1) gene in seven affected individuals. One of the seven individuals is mosaic for this variant. NACC1 encodes a transcriptional repressor implicated in gene expression and has not previously been associated with germline disorders. The probability of finding the same missense NACC1 variant by chance in 7 out of 17,228 individuals who underwent WES for diagnoses of neurodevelopmental phenotypes is extremely small and achieves genome-wide significance (p = 1.25 × 10 -14 ). Selective constraint against missense variants in NACC1 makes this excess of an identical missense variant in all seven individuals more remarkable. Our findings are consistent with a germline recurrent mutational hotspot associated with an allele-specific neurodevelopmental phenotype in NACC1. Copyright © 2017 American Society of Human Genetics. All rights reserved.

Association of the Lipoprotein Receptor SCARB1 Common Missense Variant rs4238001 with Incident Coronary Heart Disease.

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Ani Manichaikul

Full Text Available Previous studies in mice and humans have implicated the lipoprotein receptor SCARB1 in association with atherosclerosis and lipid levels. In the current study, we sought to examine association of SCARB1 missense single nucleotide polymorphism (SNP rs4238001 with incident coronary heart disease (CHD.Genotypes for rs4238001 were imputed for 2,319 White, 1,570 African American, and 1,292 Hispanic-American MESA participants using the 1,000 Genomes reference set. Cox proportional hazards models were used to determine association of rs4238001 with incident CHD, with adjustments for age, sex, study site, principal components of ancestry, body mass index, diabetes status, serum creatinine, lipid levels, hypertension status, education and smoking exposure. Meta-analysis across race/ethnic groups within MESA showed statistically significant association of the T allele with higher risk of CHD under a consistent and formally adjudicated definition of CHD events in this contemporary cohort study (hazard ratio [HR] = 1.49, 95% CI [1.04, 2.14], P = 0.028. Analyses combining MESA with additional population-based cohorts expanded our samples in Whites (total n = 11,957 with 871 CHD events and African Americans (total n = 5,962 with 355 CHD events and confirmed an increased risk of CHD overall (HR of 1.19 with 95% CI [1.04, 1.37], P = 0.013, in African Americans (HR of 1.49 with 95% CI [1.07, 2.06], P = 0.019, in males (HR of 1.29 with 95% CI [1.08, 1.54], P = 4.91 x 10(-3 and in White males (HR of 1.24 with 95% CI [1.03, 1.51], P = 0.026.SCARB1 missense rs4238001 is statistically significantly associated with incident CHD across a large population of multiple race/ethnic groups.

Role of heterozygous APC mutation in niche succession and initiation of colorectal cancer--a computational study.

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Roschen Sasikumar

Full Text Available Mutations in the adenomatous polyposis coli (APC gene are found in most colorectal cancers. They cause constitutive activation of proliferative pathways when both alleles of the gene are mutated. However studies on individuals with familial adenomatous polyposis (FAP have shown that a single mutated APC allele can also create changes in the precancerous colon crypt, like increased number of stem cells, increased crypt fission, greater variability of DNA methylation patterns, and higher somatic mutation rates. In this paper, using a computational model of colon crypt dynamics, we evolve and investigate a hypothesis on the effect of heterozygous APC mutation that explains these different observations. Based on previous reports and the results from the computational model we propose the hypothesis that heterozygous APC mutation has the effect of increasing the chances for a stem cell to divide symmetrically, producing two stem cell daughters. We incorporate this hypothesis into the model and perform simulation experiments to investigate the consequences of the hypothesis. Simulations show that this hypothesis links together the changes in FAP crypts observed in previous studies. The simulations also show that an APC(+/- stem cell gets selective advantages for dominating the crypt and progressing to cancer. This explains why most colon cancers are initiated by APC mutation. The results could have implications for preventing or retarding the onset of colon cancer in people with inherited or acquired mutation of one APC allele. Experimental validation of the hypothesis as well as investigation into the molecular mechanisms of this effect may therefore be worth undertaking.

Interaction of Hb Grey Lynn (Vientiane) [α91(FG3)Leu>Phe (α1)] with Hb E [β26(B8) Glu>Lys] and α(+)-thalassemia: Molecular and Hematological Analysis.

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Singha, Kritsada; Fucharoen, Goonnapa; Fucharoen, Supan

2015-01-01

Hemoglobin (Hb) Grey Lynn is a Hb variant caused by a mutation at codon 91 of α1-globin gene whereas Hb E is a common β-globin chain variant among Southeast Asian population. We report two hitherto undescribed conditions of Hb Grey Lynn found in Thai individuals. The study was done on two unrelated Thai subjects. Hematological parameters were recorded and Hb analysis was carried out using automated Hb analyzers. Mutations were identified by DNA analysis. Hematological features of the patients were compared with those of various forms of Hb Grey Lynn documented previously. Hb and DNA analyses identified a heterozygous Hb Grey Lynn in one patient and a double heterozygous Hb Grey Lynn and Hb E with α(+)-thalassemia in another. Interaction of α(Grey Lynn) with β(E) chains leads to the formation of a new Hb variant, namely the Hb Grey Lynn E (α(GL)2β(E)2), detectable by liquid chromatography (10.3%) but masked by Hb E on capillary electrophoresis. Interaction of these multiple globin gene defects could lead to complex hemoglobinopathies requiring combined analysis with multiple Hb analyzers followed by DNA testing to provide accurate diagnosis of the cases.

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

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Sofie V Nielsen

2017-04-01

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

A novel homozygous missense variant in NECTIN4 (PVRL4) causing ectodermal dysplasia cutaneous syndactyly syndrome.

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Ahmad, Farooq; Nasir, Abdul; Thiele, Holger; Umair, Muhammad; Borck, Guntram; Ahmad, Wasim

2018-02-12

Ectodermal dysplasia syndactyly syndrome 1 (EDSS1) is a rare form of ectodermal dysplasia including anomalies of hair, nails, and teeth along with bilateral cutaneous syndactyly of hands and feet. In the present report, we performed a clinical and genetic characterization of a consanguineous Pakistani family with four individuals affected by EDSS1. We performed exome sequencing using DNA of one affected individual. Exome data analysis identified a novel homozygous missense variant (c.242T>C; p.(Leu81Pro)) in NECTIN4 (PVRL4). Sanger sequencing validated this variant and confirmed its cosegregation with the disease phenotype in the family members. Thus, our report adds a novel variant to the NECTIN4 mutation spectrum and contributes to the NECTIN4-related clinical characterization. © 2018 John Wiley & Sons Ltd/University College London.

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

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

2001-04-15

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

Phenotype-genotype correlation in Wilson disease in a large Lebanese family: association of c.2299insC with hepatic and of p. Ala1003Thr with neurologic phenotype.

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Julnar Usta

Full Text Available Genotype phenotype correlations in Wilson disease (WD are best established in homozygous patients or in compound heterozygous patients carrying the same set of mutations. We determined the clinical phenotype of patients with WD carrying the c.2298_2299insC in Exon 8 (c.2299insC or the p. Ala1003Thr missense substitution in Exon 13 mutations in the homozygous or compound heterozygous state. We investigated 76 members of a single large Lebanese family. Their genotypes were determined, and clinical assessments were carried out for affected subjects. We also performed a literature search retrieving the phenotypes of patients carrying the same mutations of our patients in the homozygous or compound heterozygous state. There were 7 consanguineous marriages in this family and the prevalence of WD was 8.9% and of carriers of ATP7B mutation 44.7%. WD was confirmed in 9 out of 76 subjects. All 9 had the c.2299insC mutation, 5 homozygous and 4-compound heterozygous with p. Ala1003Thr. Six of our patients had hepatic, 2 had neurologic and 1 had asymptomatic phenotype. Based on our data and a literature review, clear phenotypes were reported for 38 patients worldwide carrying the c.2299insC mutation. About 53% of those have hepatic and 29% have neurologic phenotype. Furthermore, there were 10 compound heterozygous patients carrying the p. Ala1003Thr mutation. Among those, 80% having c.2299insC as the second mutation had hepatic phenotype, and all others had neurologic phenotype. We hereby report an association between the c.2299insC mutation and hepatic phenotype and between the p. Ala1003Thr mutation and neurologic phenotype.

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

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

2009-05-01

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

A novel mutation in KIF5A in a Malian family with spastic paraplegia and sensory loss.

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Guinto, Cheick O; Diarra, Salimata; Diallo, Salimata; Cissé, Lassana; Coulibaly, Thomas; Diallo, Seybou H; Taméga, Abdoulaye; Chen, Ke-Lian; Schindler, Alice B; Bagayoko, Koumba; Simaga, Assiatou; Blackstone, Craig; Fischbeck, Kenneth H; Landouré, Guida

2017-04-01

Hereditary spastic paraplegias (HSPs) are well-characterized disorders but rarely reported in Africa. We evaluated a Malian family in which three individuals had HSP and distal muscle atrophy and sensory loss. HSP panel testing identified a novel heterozygous missense mutation in KIF5A (c.1086G>C, p.Lys362Asn) that segregated with the disease (SPG10). Lys362 is highly conserved across species and Lys362Asn is predicted to be damaging. This study shows that HSPs are present in sub-Saharan Africa, although likely underdiagnosed. Increasing efficiency and decreasing costs of DNA sequencing will make it more feasible to diagnose HSPs in developing countries.

Cytophagic histiocytic panniculitis, hemophagocytic lymphohistiocytosis and undetermined autoimmune disorder: reconciling the puzzle.

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Pasqualini, Claudia; Jorini, Mauro; Carloni, Ines; Giangiacomi, Mirella; Cetica, Valentina; Aricò, Maurizio; de Benedictis, Fernando Maria

2014-02-13

Cytophagic histiocytic panniculitis is a rare disease, associated with either nonmalignant conditions or subcutaneous panniculitis-like T-cell lymphoma, and often also associated with hemophagocytic lymphohistiocytosis (HLH). We report the case of a 11-year-old boy with a history of secondary HLH who, after a local trauma, developed a painful, indurated plaque over the right thigh associated with relapsing HLH. Histopathologic findings from skin biopsy specimens revealed significant lobular panniculitis with benign histiocytes showing hemophagocytosis. High-dose intravenous methylprednisolone and cyclosporine A treatment was highly effective. A genetic study after a new, relapsing episode of HLH revealed an heterozygous missense mutation on STX 11 gene inherited from the mother.

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

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

2017-08-02

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

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

DEFF Research Database (Denmark)

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

2017-01-01

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

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

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Sneha P

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

Age-Related Hearing Loss in Mn-SOD Heterozygous Knockout Mice

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Makoto Kinoshita

2013-01-01

Full Text Available Age-related hearing loss (AHL reduces the quality of life for many elderly individuals. Manganese superoxide dismutase (Mn-SOD, one of the antioxidant enzymes acting within the mitochondria, plays a crucial role in scavenging reactive oxygen species (ROS. To determine whether reduction in Mn-SOD accelerates AHL, we evaluated auditory function in Mn-SOD heterozygous knockout (HET mice and their littermate wild-type (WT C57BL/6 mice by means of auditory brainstem response (ABR. Mean ABR thresholds were significantly increased at 16 months when compared to those at 4 months in both WT and HET mice, but they did not significantly differ between them at either age. The extent of hair cell loss, spiral ganglion cell density, and thickness of the stria vascularis also did not differ between WT and HET mice at either age. At 16 months, immunoreactivity of 8-hydroxydeoxyguanosine was significantly greater in the SGC and SV in HET mice compared to WT mice, but that of 4-hydroxynonenal did not differ between them. These findings suggest that, although decrease of Mn-SOD by half may increase oxidative stress in the cochlea to some extent, it may not be sufficient to accelerate age-related cochlear damage under physiological aging process.

Heterozygous carriers of a Parkin or PINK1 mutation share a common functional endophenotype

DEFF Research Database (Denmark)

van Nuenen, BF; Siebner, Hartwig; Weiss, MM

2008-01-01

inherited Parkinson disease alters the cortical control of sequential finger movements. METHODS: Nonmanifesting individuals carrying a single heterozygous Parkin (n = 13) or PINK1 (n = 9) mutation and 23 healthy controls without these mutations were studied with functional MRI (fMRI). During f...... rostral dorsal premotor cortex in mutation carriers but not in controls. Task-related activation of these premotor areas was similar in carriers of a Parkin or PINK1 mutation. CONCLUSION: Mutations in different genes linked to recessively inherited Parkinson disease are associated with an additional...... recruitment of rostral supplementary motor area and rostral dorsal premotor cortex during a simple motor sequence task. These premotor areas were recruited independently of the underlying genotype. The observed activation most likely reflects a "generic" compensatory mechanism to maintain motor function...

Identification of two novel mutations in the SLC45A2 gene in a Hungarian pedigree affected by unusual OCA type 4.

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Tóth, Lola; Fábos, Beáta; Farkas, Katalin; Sulák, Adrienn; Tripolszki, Kornélia; Széll, Márta; Nagy, Nikoletta

2017-03-15

Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities. OCA type IV (OCA4, OMIM 606574) develops due to homozygous or compound heterozygous mutations in the solute carrier family 45, member 2 (SLC45A2) gene. This gene encodes a membrane-associated transport protein, which regulates tyrosinase activity and, thus, melanin content by changing melanosomal pH and disrupting the incorporation of copper into tyrosinase. Here we report two Hungarian siblings affected by an unusual OCA4 phenotype. After genomic DNA was isolated from peripheral blood of the patients, the coding regions of the SLC45A2 gene were sequenced. In silico tools were applied to identify the functional impact of the newly detected mutations. Direct sequencing of the SLC45A2 gene revealed two novel, heterozygous mutations, one missense (c.1226G > A, p.Gly409Asp) and one nonsense (c.1459C > T, p.Gln437*), which were present in both patients, suggesting the mutations were compound heterozygous. In silico tools suggest that these variations are disease causing mutations. The newly identified mutations may affect the transmembrane domains of the protein, and could impair transport function, resulting in decreases in both melanosomal pH and tyrosinase activity. Our study provides expands on the mutation spectrum of the SLC45A2 gene and the genetic background of OCA4.

CRISPR/Cas9 DNA cleavage at SNP-derived PAM enables both in vitro and in vivo KRT12 mutation-specific targeting.

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Courtney, D G; Moore, J E; Atkinson, S D; Maurizi, E; Allen, E H A; Pedrioli, D M L; McLean, W H I; Nesbit, M A; Moore, C B T

2016-01-01

CRISPR/Cas9-based therapeutics hold the possibility for permanent treatment of genetic disease. The potency and specificity of this system has been used to target dominantly inherited conditions caused by heterozygous missense mutations through inclusion of the mutated base in the short-guide RNA (sgRNA) sequence. This research evaluates a novel approach for targeting heterozygous single-nucleotide polymorphisms (SNPs) using CRISPR/Cas9. We determined that a mutation within KRT12, which causes Meesmann's epithelial corneal dystrophy (MECD), leads to the occurrence of a novel protospacer adjacent motif (PAM). We designed an sgRNA complementary to the sequence adjacent to this SNP-derived PAM and evaluated its potency and allele specificity both in vitro and in vivo. This sgRNA was found to be highly effective at reducing the expression of mutant KRT12 mRNA and protein in vitro. To assess its activity in vivo we injected a combined Cas9/sgRNA expression construct into the corneal stroma of a humanized MECD mouse model. Sequence analysis of corneal genomic DNA revealed non-homologous end-joining repair resulting in frame-shifting deletions within the mutant KRT12 allele. This study is the first to demonstrate in vivo gene editing of a heterozygous disease-causing SNP that results in a novel PAM, further highlighting the potential for CRISPR/Cas9-based therapeutics.

A homozygous missense mutation in human KLOTHO causes severe tumoral calcinosis

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

2007-01-01

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

Induced mutations in highly heterozygous vegetatively propagated grasses

International Nuclear Information System (INIS)

Powell, J.B.

1976-01-01

Experience with mutation induction of turf and forage grasses indicates that much progress can be achieved by this method. More than 300 mutations have been produced in our laboratory in the cultivars Tifgreen and Tifdwarf bermudagrass (Cynodon sp.). In the Tifway and Tifcote bermudagrasses we have demonstrated similar mutation responses. The first three clones are triploids and Tifcote is a probable tetraploid. No seeds are set on these clones. Two clones of bermudagrass, Coastal and Coastcross-1, occupy millions of hectares in the USA. Both are mutable and are known to be hybrids with 36 chromosomes. Biotypes of dallisgrass (Paspalum dilatatum Poir.) exist with 40 and 50 chromosomes and reproduce as sexual and obligate apomictic forms. Gamma-ray and thermal-neutron treatment of seed of these biotypes produced mutants that maintained the maternal characteristics in subsequent generations. Bahiagrass (Paspalum notatum Fluegge) also has sexual and apomictic biotypes. Some success was indicated for increased seed set by mutagen treatment. Kentucky bluegrass (Poa pratensis L.) is a facultative apomict with varying numbers of chromosomes in different cultivars. Gamma-ray mutagen treatment of rhizomes produced numerous mutations for plant type and disease reaction. Most mutations perpetuate themselves through the seed. The characteristic in common with all these grasses is their heterozygosity, which is maintained by the vegetative propagation or apomictic mode of reproduction. The experience in using ionizing radiation to induce heritable changes in these vegetatively propagated grasses is one of considerable success. Mutation rates in some of these irradiated grasses exceeded 65% and aberrant plants with characteristics previously never observed were found. Numerous hemizygous and heterozygous loci seem to be a sensitive target for mutagens. (author)

Hirschsprung disease as a yet undescribed phenotype in a patient with ARID1B mutation.

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Takenouchi, Toshiki; Yoshihashi, Hiroshi; Sakaguchi, Yuri; Uehara, Tomoko; Honda, Masataka; Takahashi, Takao; Kosaki, Kenjiro; Miyama, Sahoko

2016-12-01

Mutations in the BAF complex (mammalian SWI/SNF complex) are responsible for Coffin-Siris syndrome, which is characterized by developmental delay, distinctive facial features, hirsutism, and hypoplasia/aplasia of the fifth finger/fingernails. Hirschsprung disease is characterized by defective stem cells in the enteric neural system, and the involvement of multiple signaling cascades has been implicated. So far, the roles of the BAF complex in the genesis of Hirschsprung disease have remained unknown. Here, we document a patient with coarse facial features, postnatal growth failure, developmental delay, epilepsy, and hypoplasia of the corpus callosum and cerebellum but without a hypoplastic fifth finger/fingernail. In addition, he had Hirschsprung disease. Exome sequencing with a gene set representing a total of 4,813 genes with known relationships to human diseases revealed a heterozygous frameshift mutation in ARID1B (c.5789delC p.Pro1930Leufs*44). The presence of a congenital cataract and Hirschsprung disease in the presently reported patient further expands the phenotypic spectrum of patients with ARID1B mutations and may suggest the potential role of the BAF complex in the pathogenesis of the enteric neural system. The present observation is in agreement with a recent study of Drosophila neuroblasts showing that the dysregulated BAF complex leads to an abnormal lineage progression of neural stem cell lineages and that Hirschsprung disease is caused by abnormal stem cell lineages in the peripheral neural tissues. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

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

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Hegele Robert A

2007-09-01

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

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

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

2011-09-01

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

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

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Paul Guéguen

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

Naturally Occurring Missense MRGPRX2 Variants Display Loss of Function Phenotype for Mast Cell Degranulation in Response to Substance P, Hemokinin-1, Human β-Defensin-3, and Icatibant.

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Alkanfari, Ibrahim; Gupta, Kshitij; Jahan, Tahsin; Ali, Hydar

2018-05-23

Human mast cells (MCs) express a novel G protein-coupled receptor (GPCR) known as Mas-related GPCR X2 (MRGPRX2). Activation of this receptor by a diverse group of cationic ligands such as neuropeptides, host defense peptides, and Food and Drug Administration-approved drugs contributes to chronic inflammatory diseases and pseudoallergic drug reactions. For most GPCRs, the extracellular (ECL) domains and their associated transmembrane (TM) domains display the greatest structural diversity and are responsible for binding different ligands. The goal of the current study was to determine if naturally occurring missense variants within MRGPRX2's ECL/TM domains contribute to gain or loss of function phenotype for MC degranulation in response to neuropeptides (substance P and hemokinin-1), a host defense peptide (human β-defensin-3) and a Food and Drug Administration-approved cationic drug (bradykinin B2 receptor antagonist, icatibant). We have identified eight missense variants within MRGPRX2's ECL/TM domains from publicly available exome-sequencing databases. We investigated the ability of MRGPRX2 ligands to induce degranulation in rat basophilic leukemia-2H3 cells individually expressing these naturally occurring MRGPRX2 missense variants. Using stable and transient transfections, we found that all variants express in rat basophilic leukemia cells. However, four natural MRGPRX2 variants, G165E (rs141744602), D184H (rs372988289), W243R (rs150365137), and H259Y (rs140862085) failed to respond to any of the ligands tested. Thus, diverse MRGPRX2 ligands use common sites on the receptor to induce MC degranulation. These findings have important clinical implications for MRGPRX2 and MC-mediated pseudoallergy and chronic inflammatory diseases. Copyright © 2018 by The American Association of Immunologists, Inc.

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

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Dongmao Wang

2017-07-01

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

Rett-like phenotypes: expanding the genetic heterogeneity to the KCNA2 gene and first familial case of CDKL5-related disease.

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Allou, L; Julia, S; Amsallem, D; El Chehadeh, S; Lambert, L; Thevenon, J; Duffourd, Y; Saunier, A; Bouquet, P; Pere, S; Moustaïne, A; Ruaud, L; Roth, V; Jonveaux, P; Philippe, C

2017-03-01

Several genes have been implicated in Rett syndrome (RTT) in its typical and variant forms. We applied next-generation sequencing (NGS) to evaluate for mutations in known or new candidate genes in patients with variant forms of Rett or Rett-like phenotypes of unknown molecular aetiology. In the first step, we used NGS with a custom panel including MECP2, CDKL5, FOXG1, MEF2C and IQSEC2. In addition to a FOXG1 mutation in a patient with all core features of the congenital variant of RTT, we identified a missense (p.Ser240Thr) in CDKL5 in a patient who appeared to be seizure free. This missense was maternally inherited with opposite allele expression ratios in the proband and her mother. In the asymptomatic mother, the mutated copy of the CDKL5 gene was inactivated in 90% of blood cells. We also identified a premature stop codon (p.Arg926*) in IQSEC2 in a patient with a Rett-like phenotype. Finally, exome sequencing enabled us to characterize a heterozygous de novo missense (p.Val408Ala) in KCNA2 encoding the potassium channel Kv 1.2 in a girl with infantile-onset seizures variant of RTT. Our study expands the genetic heterogeneity of RTT and RTT-like phenotypes. Moreover, we report the first familial case of CDKL5-related disease. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Heterozygous M1V variant of ELA-2 gene mutation associated with G-CSF refractory severe congenital neutropenia.

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Setty, Bhuvana A; Yeager, Nicholas D; Bajwa, Rajinder P

2011-09-01

Severe congenital neutropenia is an autosomal recessive disorder characterized by maturation arrest at the promyelocyte/myelocyte phase in the bone marrow, absolute neutrophil count ELA-2 have been described. We report the case of a premature male infant with congenital neutropenia, associated with multiple infections, refractory to treatment with granulocyte colony stimulating factor who subsequently underwent matched sibling donor stem-cell transplant. He was found to be heterozygous for the M1V variant of the ELA-2 gene that we postulate to be causative for his severe neutropenia Copyright © 2011 Wiley-Liss, Inc.

Expression of embryonic hemoglobin genes in mice heterozygous for α-thalassemia or β-duplication traits and in mice heterozygous for both traits

International Nuclear Information System (INIS)

Popp, R.A.; Marsh, C.L.; Skow, L.C.

1981-01-01

Hemoglobins of mouse embryos at 11.5 through 16.5 days of gestation were separated by electrophoresis on cellulose acetate and quantitated by a scanning densitometer to study the effects of two radiation-induced mutations on the expression of embryonic hemoglobin genes in mice. Normal mice produce three kinds of embryonic hemoglobins. In heterozygous α-thalassemic embryos, expression of EI (x 2 y 2 ) and EII (α 2 y 2 ) is deficient because the x- and α-globin genes of one of the allelic pairs of Hba on chromosome 11 was deleted or otherwise inactivated by X irradiation. Simultaneous inactivation of the x- and α-globin genes indicates that these genes must be closely linked. Reduced x- and α-chain synthesis results in an excess of y chains that associate as homotetramers. This unique y 4 hemoglobin also appears in β-duplication embryos where excess y chains are produced by the presence of three rather than two functional alleles of y- and β-globin genes. In double heterozygotes, which have a single functional allele of x- and α-globin genes and three functional alleles of y- and β-globin genes, synthesis of α and non-α chains is severely imbalanced and half of the total hemoglobin is y 4 . Mouse y 4 has a high affinity for oxygen, P 50 of less than 10 mm Hg, but it lacks cooperativity so is inefficient for oxygen transport. The death of double heterozygotes in late fetal or neonatal life may be in large part to oxygen deprivation to the tissues

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

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

2005-01-01

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

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

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

2017-04-01

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

Spectrum of rhodopsin mutations in Korean patients with retinitis pigmentosa

Science.gov (United States)

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

2011-01-01

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

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

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

2009-12-01

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

Phylogenetic assessment of global Suillus ITS sequences supports morphologically defined species and reveals synonymous and undescribed taxa.

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Nguyen, Nhu H; Vellinga, Else C; Bruns, Thomas D; Kennedy, Peter G

The genus Suillus represents one of the most recognizable groups of mushrooms in conifer forests throughout the Northern Hemisphere. Although for decades the genus has been relatively well defined morphologically, previous molecular phylogenetic assessments have provided important yet preliminary insights into its evolutionary history. We present the first large-scale phylogenetic study of the boundaries of each species in the genus Suillus based on the most current internal transcribed spacer (ITS) barcode sequences available inPUBLIC databases, as well as sequencing of 224 vouchered specimens and cultures, 15 of which were type specimens from North America. We found that species boundaries delimited by morphological data are broadly congruent with those based on ITS sequences. However, some species appear to have been described several times under different names, several species groups cannot be resolved by ITS sequences alone, and undescribed taxa are apparent, especially in Asia. Therefore, we elevated S. tomentosus var. discolor to S. discolor; proposed synonymies of S. neoalbidipes with S. glandulosipes, S. borealis with S. brunnescens, Boletus serotinus and B. solidipes with Suillus elbensis, S. lactifluus with S. granulatus, S. himalayensis with S. americanus; and proposed usage of the names S. clintonianus in the place of the North American S. grevillei, S. weaverae for North American S. granulatus, S. ampliporus in the place of the North American S. cavipes, and S. elbensis in place of the North American S. viscidus. We showed that the majority of Suillus species have strong affinities for particular host genera. Although deep node support was low, geographic differentiation was apparent, with species from North America, Eurasia, and Asia often forming their own clades. Collectively, this comprehensive genus-level phylogenetic integration of currently available Suillus ITS molecular data and metadata will aid future taxonomic and ecological work on an

A heterozygous mutation in RPGR associated with X-linked retinitis pigmentosa in a patient with Turner syndrome mosaicism (45,X/46,XX).

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Zhou, Qi; Yao, Fengxia; Wang, Feng; Li, Hui; Chen, Rui; Sui, Ruifang

2018-01-01

Turner syndrome with retinitis pigmentosa (RP) is rare, with only three cases reported based on clinical examination alone. We summarized the 4-year follow-up and molecular findings in a 28-year-old patient with Turner syndrome and the typical features of short stature and neck webbing, who also had X-linked RP. Her main complaints were night blindness and progressive loss of vision since the age of 9 years. Ophthalmologic examination, optical coherent tomographic imaging, and visual electrophysiology tests showed classic manifestations of RP. The karyotype of peripheral blood showed mosaicism (45,X [72%]/46,XX[28%]). A novel heterozygous frameshift mutation (c.2403_2406delAGAG, p.T801fsX812) in the RP GTPase regulator (RPGR) gene was detected using next generation sequencing and validated by Sanger sequencing. We believe that this is the first report of X-linked RP in a patient with Turner syndrome associated with mosaicism, and an RPGR heterozygous mutation. We hypothesize that X-linked RP in this woman is not related to Turner syndrome, but may be a manifestation of the lack of a normal paternal X chromosome with intact but mutated RPGR. © 2017 Wiley Periodicals, Inc.

Identification of a Novel De Novo Heterozygous Deletion in the SOX10 Gene in Waardenburg Syndrome Type II Using Next-Generation Sequencing.

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Li, Haonan; Jin, Peng; Hao, Qian; Zhu, Wei; Chen, Xia; Wang, Ping

2017-11-01

Waardenburg syndrome (WS) is a rare autosomal dominant disorder associated with pigmentation abnormalities and sensorineural hearing loss. In this study, we investigated the genetic cause of WSII in a patient and evaluated the reliability of the targeted next-generation exome sequencing method for the genetic diagnosis of WS. Clinical evaluations were conducted on the patient and targeted next-generation sequencing (NGS) was used to identify the candidate genes responsible for WSII. Multiplex ligation-dependent probe amplification (MLPA) and real-time quantitative polymerase chain reaction (qPCR) were performed to confirm the targeted NGS results. Targeted NGS detected the entire deletion of the coding sequence (CDS) of the SOX10 gene in the WSII patient. MLPA results indicated that all exons of the SOX10 heterozygous deletion were detected; no aberrant copy number in the PAX3 and microphthalmia-associated transcription factor (MITF) genes was found. Real-time qPCR results identified the mutation as a de novo heterozygous deletion. This is the first report of using a targeted NGS method for WS candidate gene sequencing; its accuracy was verified by using the MLPA and qPCR methods. Our research provides a valuable method for the genetic diagnosis of WS.

Draft Sequencing of the Heterozygous Diploid Genome of Satsuma (Citrus unshiu Marc. Using a Hybrid Assembly Approach

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Tokurou Shimizu

2017-12-01

Full Text Available Satsuma (Citrus unshiu Marc. is one of the most abundantly produced mandarin varieties of citrus, known for its seedless fruit production and as a breeding parent of citrus. De novo assembly of the heterozygous diploid genome of Satsuma (“Miyagawa Wase” was conducted by a hybrid assembly approach using short-read sequences, three mate-pair libraries, and a long-read sequence of PacBio by the PLATANUS assembler. The assembled sequence, with a total size of 359.7 Mb at the N50 length of 386,404 bp, consisted of 20,876 scaffolds. Pseudomolecules of Satsuma constructed by aligning the scaffolds to three genetic maps showed genome-wide synteny to the genomes of Clementine, pummelo, and sweet orange. Gene prediction by modeling with MAKER-P proposed 29,024 genes and 37,970 mRNA; additionally, gene prediction analysis found candidates for novel genes in several biosynthesis pathways for gibberellin and violaxanthin catabolism. BUSCO scores for the assembled scaffold and predicted transcripts, and another analysis by BAC end sequence mapping indicated the assembled genome consistency was close to those of the haploid Clementine, pummel, and sweet orange genomes. The number of repeat elements and long terminal repeat retrotransposon were comparable to those of the seven citrus genomes; this suggested no significant failure in the assembly at the repeat region. A resequencing application using the assembled sequence confirmed that both kunenbo-A and Satsuma are offsprings of Kishu, and Satsuma is a back-crossed offspring of Kishu. These results illustrated the performance of the hybrid assembly approach and its ability to construct an accurate heterozygous diploid genome.

No evidence for association of autism with rare heterozygous point mutations in Contactin-Associated Protein-Like 2 (CNTNAP2, or in Other Contactin-Associated Proteins or Contactins.

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John D Murdoch

2015-01-01

Full Text Available Contactins and Contactin-Associated Proteins, and Contactin-Associated Protein-Like 2 (CNTNAP2 in particular, have been widely cited as autism risk genes based on findings from homozygosity mapping, molecular cytogenetics, copy number variation analyses, and both common and rare single nucleotide association studies. However, data specifically with regard to the contribution of heterozygous single nucleotide variants (SNVs have been inconsistent. In an effort to clarify the role of rare point mutations in CNTNAP2 and related gene families, we have conducted targeted next-generation sequencing and evaluated existing sequence data in cohorts totaling 2704 cases and 2747 controls. We find no evidence for statistically significant association of rare heterozygous mutations in any of the CNTN or CNTNAP genes, including CNTNAP2, placing marked limits on the scale of their plausible contribution to risk.

Recessive cardiac phenotypes in induced pluripotent stem cell models of Jervell and Lange-Nielsen syndrome: disease mechanisms and pharmacological rescue.

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Zhang, Miao; D'Aniello, Cristina; Verkerk, Arie O; Wrobel, Eva; Frank, Stefan; Ward-van Oostwaard, Dorien; Piccini, Ilaria; Freund, Christian; Rao, Jyoti; Seebohm, Guiscard; Atsma, Douwe E; Schulze-Bahr, Eric; Mummery, Christine L; Greber, Boris; Bellin, Milena

2014-12-16

Jervell and Lange-Nielsen syndrome (JLNS) is one of the most severe life-threatening cardiac arrhythmias. Patients display delayed cardiac repolarization, associated high risk of sudden death due to ventricular tachycardia, and congenital bilateral deafness. In contrast to the autosomal dominant forms of long QT syndrome, JLNS is a recessive trait, resulting from homozygous (or compound heterozygous) mutations in KCNQ1 or KCNE1. These genes encode the α and β subunits, respectively, of the ion channel conducting the slow component of the delayed rectifier K(+) current, IKs. We used complementary approaches, reprogramming patient cells and genetic engineering, to generate human induced pluripotent stem cell (hiPSC) models of JLNS, covering splice site (c.478-2A>T) and missense (c.1781G>A) mutations, the two major classes of JLNS-causing defects in KCNQ1. Electrophysiological comparison of hiPSC-derived cardiomyocytes (CMs) from homozygous JLNS, heterozygous, and wild-type lines recapitulated the typical and severe features of JLNS, including pronounced action and field potential prolongation and severe reduction or absence of IKs. We show that this phenotype had distinct underlying molecular mechanisms in the two sets of cell lines: the previously unidentified c.478-2A>T mutation was amorphic and gave rise to a strictly recessive phenotype in JLNS-CMs, whereas the missense c.1781G>A lesion caused a gene dosage-dependent channel reduction at the cell membrane. Moreover, adrenergic stimulation caused action potential prolongation specifically in JLNS-CMs. Furthermore, sensitivity to proarrhythmic drugs was strongly enhanced in JLNS-CMs but could be pharmacologically corrected. Our data provide mechanistic insight into distinct classes of JLNS-causing mutations and demonstrate the potential of hiPSC-CMs in drug evaluation.

MYO7A and USH2A gene sequence variants in Italian patients with Usher syndrome.

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Sodi, Andrea; Mariottini, Alessandro; Passerini, Ilaria; Murro, Vittoria; Tachyla, Iryna; Bianchi, Benedetta; Menchini, Ugo; Torricelli, Francesca

2014-01-01

To analyze the spectrum of sequence variants in the MYO7A and USH2A genes in a group of Italian patients affected by Usher syndrome (USH). Thirty-six Italian patients with a diagnosis of USH were recruited. They received a standard ophthalmologic examination, visual field testing, optical coherence tomography (OCT) scan, and electrophysiological tests. Fluorescein angiography and fundus autofluorescence imaging were performed in selected cases. All the patients underwent an audiologic examination for the 0.25-8,000 Hz frequencies. Vestibular function was evaluated with specific tests. DNA samples were analyzed for sequence variants of the MYO7A gene (for USH1) and the USH2A gene (for USH2) with direct sequencing techniques. A few patients were analyzed for both genes. In the MYO7A gene, ten missense variants were found; three patients were compound heterozygous, and two were homozygous. Thirty-four USH2A gene variants were detected, including eight missense variants, nine nonsense variants, six splicing variants, and 11 duplications/deletions; 19 patients were compound heterozygous, and three were homozygous. Four MYO7A and 17 USH2A variants have already been described in the literature. Among the novel mutations there are four USH2A large deletions, detected with multiplex ligation dependent probe amplification (MLPA) technology. Two potentially pathogenic variants were found in 27 patients (75%). Affected patients showed variable clinical pictures without a clear genotype-phenotype correlation. Ten variants in the MYO7A gene and 34 variants in the USH2A gene were detected in Italian patients with USH at a high detection rate. A selective analysis of these genes may be valuable for molecular analysis, combining diagnostic efficiency with little time wastage and less resource consumption.

Targeted next-generation sequencing analysis identifies novel mutations in families with severe familial exudative vitreoretinopathy

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Huang, Xiao-Yan; Zhuang, Hong; Wu, Ji-Hong; Li, Jian-Kang; Hu, Fang-Yuan; Zheng, Yu; Tellier, Laurent Christian Asker M.; Zhang, Sheng-Hai; Gao, Feng-Juan; Zhang, Jian-Guo

2017-01-01

Purpose Familial exudative vitreoretinopathy (FEVR) is a genetically and clinically heterogeneous disease, characterized by failure of vascular development of the peripheral retina. The symptoms of FEVR vary widely among patients in the same family, and even between the two eyes of a given patient. This study was designed to identify the genetic defect in a patient cohort of ten Chinese families with a definitive diagnosis of FEVR. Methods To identify the causative gene, next-generation sequencing (NGS)-based target capture sequencing was performed. Segregation analysis of the candidate variant was performed in additional family members by using Sanger sequencing and quantitative real-time PCR (QPCR). Results Of the cohort of ten FEVR families, six pathogenic variants were identified, including four novel and two known heterozygous mutations. Of the variants identified, four were missense variants, and two were novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del]. The two novel heterozygous deletion mutations were not observed in the control subjects and could give rise to a relatively severe FEVR phenotype, which could be explained by the protein function prediction. Conclusions We identified two novel heterozygous deletion mutations [LRP5, c.4053 DelC (p.Ile1351IlefsX88); TSPAN12, EX8Del] using targeted NGS as a causative mutation for FEVR. These genetic deletion variations exhibit a severe form of FEVR, with tractional retinal detachments compared with other known point mutations. The data further enrich the mutation spectrum of FEVR and enhance our understanding of genotype–phenotype correlations to provide useful information for disease diagnosis, prognosis, and effective genetic counseling. PMID:28867931

Macrosomia and hyperinsulinaemic hypoglycaemia in patients with heterozygous mutations in the HNF4A gene.

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Ewan R Pearson

2007-04-01

Full Text Available Macrosomia is associated with considerable neonatal and maternal morbidity. Factors that predict macrosomia are poorly understood. The increased rate of macrosomia in the offspring of pregnant women with diabetes and in congenital hyperinsulinaemia is mediated by increased foetal insulin secretion. We assessed the in utero and neonatal role of two key regulators of pancreatic insulin secretion by studying birthweight and the incidence of neonatal hypoglycaemia in patients with heterozygous mutations in the maturity-onset diabetes of the young (MODY genes HNF4A (encoding HNF-4alpha and HNF1A/TCF1 (encoding HNF-1alpha, and the effect of pancreatic deletion of Hnf4a on foetal and neonatal insulin secretion in mice.We examined birthweight and hypoglycaemia in 108 patients from families with diabetes due to HNF4A mutations, and 134 patients from families with HNF1A mutations. Birthweight was increased by a median of 790 g in HNF4A-mutation carriers compared to non-mutation family members (p < 0.001; 56% (30/54 of HNF4A-mutation carriers were macrosomic compared with 13% (7/54 of non-mutation family members (p < 0.001. Transient hypoglycaemia was reported in 8/54 infants with heterozygous HNF4A mutations, but was reported in none of 54 non-mutation carriers (p = 0.003. There was documented hyperinsulinaemia in three cases. Birthweight and prevalence of neonatal hypoglycaemia were not increased in HNF1A-mutation carriers. Mice with pancreatic beta-cell deletion of Hnf4a had hyperinsulinaemia in utero and hyperinsulinaemic hypoglycaemia at birth.HNF4A mutations are associated with a considerable increase in birthweight and macrosomia, and are a novel cause of neonatal hypoglycaemia. This study establishes a key role for HNF4A in determining foetal birthweight, and uncovers an unanticipated feature of the natural history of HNF4A-deficient diabetes, with hyperinsulinaemia at birth evolving to decreased insulin secretion and diabetes later in life.

Infantile onset Vanishing White Matter disease associated with a novel EIF2B5 variant, remarkably long life span, severe epilepsy, and hypopituitarism.

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Woody, April L; Hsieh, David T; McIver, Harkirtin K; Thomas, Linda P; Rohena, Luis

2015-04-01

Vanishing White Matter disease (VWM) is an inherited progressive leukoencephalopathy caused by mutations in the genes EIF2B1-5, which encode for the 5 subunits of the eukaryotic initiation factor 2B (eIF2B), a regulator of protein synthesis. VWM typically presents with acute neurological decline following febrile infections or minor head trauma, and subsequent progressive neurological and cognitive regression. There is a varied clinical spectrum of VWM, with earlier onset associated with more severe phenotypes. Brain magnetic resonance imaging is usually diagnostic with diffusely abnormal white matter, progressing over time to cystic degeneration. We are reporting on a patient with infantile onset VWM associated with three heterozygous missense variants in EIF2B5, including a novel missense variant on exon 6 of EIF2B5 (D262N), as well as an interstitial duplication at 7q21.12. In addition, our case is unusual because of a severe epilepsy course, a novel clinical finding of hypopituitarism manifested by hypothyroidism and adrenal insufficiency, and a prolonged life span with current age of survival of 4 years and 11 months. © 2015 Wiley Periodicals, Inc.

A CADASIL-Like Case with a Novel Noncysteine Mutation of the NOTCH3 Gene and Granular Deposits in the Renal Arterioles

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Kuniyuki Nakamura

2015-01-01

Full Text Available We herein report the finding of a 62-year-old male, who developed dysarthria and dysphagia, with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy- (CADASIL- like cerebral lesions. He also suffered from slowly progressive renal failure with the findings of granular deposits similar to electron-dense granular osmiophilic material in the renal arterioles. We found a novel heterozygous missense mutation of the NOTCH3 gene, c.4039G>C in exon 24, resulting in a p.Gly1347Arg substitution in its extracellular domain. The noncysteine substitution may underlie the pathogenesis of white matter lesions in the brain and of the chronic renal failure in the present case.

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

DEFF Research Database (Denmark)

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

2010-01-01

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

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

NARCIS (Netherlands)

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

2010-01-01

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

Partial rescue of in vivo insulin signalling in skeletal muscle by impaired insulin clearance in heterozygous carriers of a mutation in the insulin receptor gene

DEFF Research Database (Denmark)

Højlund, K.; Wojtaszewski, Jørgen; Birk, Jesper Bratz

2006-01-01

AIMS/HYPOTHESIS: Recently we reported the coexistence of postprandial hypoglycaemia and moderate insulin resistance in heterozygous carriers of the Arg1174Gln mutation in the insulin receptor gene (INSR). Controlled studies of in vivo insulin signalling in humans with mutant INSR are unavailable,...

The streptomycin-treated mouse intestine selects Escherichia coli envZ missense mutants that interact with dense and diverse intestinal microbiota.

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Leatham-Jensen, Mary P; Frimodt-Møller, Jakob; Adediran, Jimmy; Mokszycki, Matthew E; Banner, Megan E; Caughron, Joyce E; Krogfelt, Karen A; Conway, Tyrrell; Cohen, Paul S

2012-05-01

Previously, we reported that the streptomycin-treated mouse intestine selected nonmotile Escherichia coli MG1655 flhDC deletion mutants of E. coli MG1655 with improved colonizing ability that grow 15% faster in vitro in mouse cecal mucus and 15 to 30% faster on sugars present in mucus (M. P. Leatham et al., Infect. Immun. 73:8039-8049, 2005). Here, we report that the 10 to 20% remaining motile E. coli MG1655 are envZ missense mutants that are also better colonizers of the mouse intestine than E. coli MG1655. One of the flhDC mutants, E. coli MG1655 ΔflhD, and one of the envZ missense mutants, E. coli MG1655 mot-1, were studied further. E. coli MG1655 mot-1 is more resistant to bile salts and colicin V than E. coli MG1655 ΔflhD and grows ca. 15% slower in vitro in mouse cecal mucus and on several sugars present in mucus compared to E. coli MG1655 ΔflhD but grows 30% faster on galactose. Moreover, E. coli MG1655 mot-1 and E. coli MG1655 ΔflhD appear to colonize equally well in one intestinal niche, but E. coli MG1655 mot-1 appears to use galactose to colonize a second, smaller intestinal niche either not colonized or colonized poorly by E. coli MG1655 ΔflhD. Evidence is also presented that E. coli MG1655 is a minority member of mixed bacterial biofilms in the mucus layer of the streptomycin-treated mouse intestine. We offer a hypothesis, which we call the "Restaurant" hypothesis, that explains how nutrient acquisition in different biofilms comprised of different anaerobes can account for our results.

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

KAUST Repository

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

2012-01-01

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

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

KAUST Repository

Haywood, Annika

2012-11-15

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

Specific combination of compound heterozygous mutations in 17β-hydroxysteroid dehydrogenase type 4 (HSD17B4 defines a new subtype of D-bifunctional protein deficiency

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McMillan Hugh J

2012-11-01

Full Text Available Abstract Background D-bifunctional protein (DBP deficiency is typically apparent within the first month of life with most infants demonstrating hypotonia, psychomotor delay and seizures. Few children survive beyond two years of age. Among patients with prolonged survival all demonstrate severe gross motor delay, absent language development, and severe hearing and visual impairment. DBP contains three catalytically active domains; an N-terminal dehydrogenase, a central hydratase and a C-terminal sterol carrier protein-2-like domain. Three subtypes of the disease are identified based upon the domain affected; DBP type I results from a combined deficiency of dehydrogenase and hydratase activity; DBP type II from isolated hydratase deficiency and DBP type III from isolated dehydrogenase deficiency. Here we report two brothers (16½ and 14 years old with DBP deficiency characterized by normal early childhood followed by sensorineural hearing loss, progressive cerebellar and sensory ataxia and subclinical retinitis pigmentosa. Methods and results Biochemical analysis revealed normal levels of plasma VLCFA, phytanic acid and pristanic acid, and normal bile acids in urine; based on these results no diagnosis was made. Exome analysis was performed using the Agilent SureSelect 50Mb All Exon Kit and the Illumina HiSeq 2000 next-generation-sequencing (NGS platform. Compound heterozygous mutations were identified by exome sequencing and confirmed by Sanger sequencing within the dehydrogenase domain (c.101C>T; p.Ala34Val and hydratase domain (c.1547T>C; p.Ile516Thr of the 17β-hydroxysteroid dehydrogenase type 4 gene (HSD17B4. These mutations have been previously reported in patients with severe-forms of DBP deficiency, however each mutation was reported in combination with another mutation affecting the same domain. Subsequent studies in fibroblasts revealed normal VLCFA levels, normal C26:0 but reduced pristanic acid beta-oxidation activity. Both DBP

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

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

2000-06-01

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

Missense variants in AIMP1 gene are implicated in autosomal recessive intellectual disability without neurodegeneration.

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Iqbal, Zafar; Püttmann, Lucia; Musante, Luciana; Razzaq, Attia; Zahoor, Muhammad Yasir; Hu, Hao; Wienker, Thomas F; Garshasbi, Masoud; Fattahi, Zohreh; Gilissen, Christian; Vissers, Lisenka E L M; de Brouwer, Arjan P M; Veltman, Joris A; Pfundt, Rolph; Najmabadi, Hossein; Ropers, Hans-Hilger; Riazuddin, Sheikh; Kahrizi, Kimia; van Bokhoven, Hans

2016-03-01

AIMP1/p43 is a multifunctional non-catalytic component of the multisynthetase complex. The complex consists of nine catalytic and three non-catalytic proteins, which catalyze the ligation of amino acids to their cognate tRNA isoacceptors for use in protein translation. To date, two allelic variants in the AIMP1 gene have been reported as the underlying cause of autosomal recessive primary neurodegenerative disorder. Here, we present two consanguineous families from Pakistan and Iran, presenting with moderate to severe intellectual disability, global developmental delay, and speech impairment without neurodegeneration. By the combination of homozygosity mapping and next generation sequencing, we identified two homozygous missense variants, p.(Gly299Arg) and p.(Val176Gly), in the gene AIMP1 that co-segregated with the phenotype in the respective families. Molecular modeling of the variants revealed deleterious effects on the protein structure that are predicted to result in reduced AIMP1 function. Our findings indicate that the clinical spectrum for AIMP1 defects is broader than witnessed so far.

Missense variants in AIMP1 gene are implicated in autosomal recessive intellectual disability without neurodegeneration

Science.gov (United States)

Iqbal, Zafar; Püttmann, Lucia; Musante, Luciana; Razzaq, Attia; Zahoor, Muhammad Yasir; Hu, Hao; Wienker, Thomas F; Garshasbi, Masoud; Fattahi, Zohreh; Gilissen, Christian; Vissers, Lisenka ELM; de Brouwer, Arjan PM; Veltman, Joris A; Pfundt, Rolph; Najmabadi, Hossein; Ropers, Hans-Hilger; Riazuddin, Sheikh; Kahrizi, Kimia; van Bokhoven, Hans

2016-01-01

AIMP1/p43 is a multifunctional non-catalytic component of the multisynthetase complex. The complex consists of nine catalytic and three non-catalytic proteins, which catalyze the ligation of amino acids to their cognate tRNA isoacceptors for use in protein translation. To date, two allelic variants in the AIMP1 gene have been reported as the underlying cause of autosomal recessive primary neurodegenerative disorder. Here, we present two consanguineous families from Pakistan and Iran, presenting with moderate to severe intellectual disability, global developmental delay, and speech impairment without neurodegeneration. By the combination of homozygosity mapping and next generation sequencing, we identified two homozygous missense variants, p.(Gly299Arg) and p.(Val176Gly), in the gene AIMP1 that co-segregated with the phenotype in the respective families. Molecular modeling of the variants revealed deleterious effects on the protein structure that are predicted to result in reduced AIMP1 function. Our findings indicate that the clinical spectrum for AIMP1 defects is broader than witnessed so far. PMID:26173967

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

Science.gov (United States)

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

1997-05-01

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

Clinical Features and Long-Term Outcome of Nephrotic Syndrome Associated with Heterozygous NPHS1 and NPHS2 Mutations

Science.gov (United States)

Caridi, Gianluca; Gigante, Maddalena; Ravani, Pietro; Trivelli, Antonella; Barbano, Giancarlo; Scolari, Francesco; Dagnino, Monica; Murer, Luisa; Murtas, Corrado; Edefonti, Alberto; Allegri, Landino; Amore, Alessandro; Coppo, Rosanna; Emma, Francesco; De Palo, Tommaso; Penza, Rosa; Gesualdo, Loreto; Ghiggeri, Gian Marco

2009-01-01

Background and objectives: Mutations in nephrin (NPHS1) and podocin (NPHS2) genes represent a major cause of idiopathic nephrotic syndrome (NS) in children. It is not yet clear whether the presence of a single mutation acts as a modifier of the clinical course of NS. Design, setting, participants, & measurements: We reviewed the clinical features of 40 patients with NS associated with heterozygous mutations or variants in NPHS1 (n = 7) or NPHS2 (n = 33). Long-term renal survival probabilities were compared with those of a concurrent cohort with idiopathic NS. Results: Patients with a single mutation in NPHS1 received a diagnosis before those with potentially nongenetic NS and had a good response to therapies. Renal function was normal in all cases. For NPHS2, six patients had single heterozygous mutations, six had a p.P20L variant, and 21 had a p.R229Q variant. Age at diagnosis and the response to drugs were comparable in all NS subgroups. Overall, they had similar renal survival probabilities as non-NPHS1/NPHS2 cases (log-rank χ2 0.84, P = 0.656) that decreased in presence of resistance to therapy (P < 0.001) and in cases with renal lesions of glomerulosclerosis and IgM deposition (P < 0.001). Cox regression confirmed that the only significant predictor of dialysis was resistance to therapy. Conclusions: Our data indicate that single mutation or variant in NPHS1 and NPHS2 does not modify the outcome of primary NS. These patients should be treated following consolidated schemes and have good chances for a good long-term outcome. PMID:19406966

A novel missense mutation close to the charge-stabilizing system in a patient with congenital factor VII deficiency.

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Jiang, Minghua; Wang, Zhaoyue; Yu, Ziqiang; Bai, Xia; Su, Jian; Cao, Lijuan; Zhang, Wei; Ruan, Changgeng

2011-06-01

Congenital factor VII (FVII) deficiency is a rare autosomal recessive bleeding disorder. Its clinical manifestation and mutational spectrum are highly variable. The purpose of this study was to identify and characterize the mutation causing the FVII deficiency in a Chinese patient and his family. The FVII gene was analyzed by genomic DNA sequencing, and the FVII levels in patient's plasma were measured with an enzyme-linked immunoabsorbent assay (ELISA) and one-stage prothrombin time based method. In addition, the FVII-Phe190 mutant identified in the pedigree was expressed in the HEK293 cells, and the subcellular localization experiments in the Chinese hamster ovary (CHO) cells were performed. The patient had a prolonged prothrombin time and low levels of both FVII antigen and activity, and two heterozygous mutations were identified in F7 gene (NG-009262.1): a g.15975 G>A in the splice receptor site of intron 6 and a novel g.16750 C>T in exon 8 resulting in Ser190 to Phe190 replacement. In expression experiments, the reduced antigen and activity levels of FVII-Phe190 in the culture medium were found, whereas an ELISA and Western blotting analysis of FVII revealed that mutant FVII-Phe190 was synthesized in the cells as the wild-type FVII-Ser190. And FVII-Phe190 was found in endoplasmic reticulum and Golgi apparatus. Compound heterozygous mutations in F7 gene should be responsible for the FVII deficiency in this patient. The FVII-Phe190 can normally be synthesized and transported from endoplasmic reticulum to Golgi apparatus, but degraded or inefficiently secreted.

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

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

2008-10-01

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

Nature vs. nurture: can enrichment rescue the behavioural phenotype of BDNF heterozygous mice?

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Chourbaji, Sabine; Brandwein, Christiane; Vogt, Miriam A; Dormann, Christof; Hellweg, Rainer; Gass, Peter

2008-10-10

In earlier experiments we have demonstrated that group-housing in a rather impoverished "standard" environment can be a crucial stress factor in male C57Bl/6 mice. The present study aimed at investigating the effect of combining a probable genetic vulnerability--postulated by the "Neurotrophin Hypothesis of Depression"--with the potentially modulating influence of a stressful environment such as "impoverished" standard housing conditions. For that purpose mice with a partial deletion of brain-derived neurotrophic factor (BDNF) were group-housed under standard and enriched housing conditions and analysed in a well-established test battery for emotional behaviours. Standard group-housing affected emotional behaviour in male and female BDNF heterozygous mice, causing an increase in anxiety, changes in exploration as well as nociception. Providing the animals' cages with supplementary enrichment, however, led to a rescue of emotional alterations, which emphasises the significance of external factors and their relevance for a valid investigation of genetic aspects in these mutants as well as others, which may be examined in terms of stress-responsiveness or emotionality.

Loss of Association of REEP2 with Membranes Leads to Hereditary Spastic Paraplegia

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Esteves, Typhaine; Durr, Alexandra; Mundwiller, Emeline; Loureiro, José L.; Boutry, Maxime; Gonzalez, Michael A.; Gauthier, Julie; El-Hachimi, Khalid H.; Depienne, Christel; Muriel, Marie-Paule; Acosta Lebrigio, Rafael F.; Gaussen, Marion; Noreau, Anne; Speziani, Fiorella; Dionne-Laporte, Alexandre; Deleuze, Jean-François; Dion, Patrick; Coutinho, Paula; Rouleau, Guy A.; Zuchner, Stephan; Brice, Alexis; Stevanin, Giovanni; Darios, Frédéric

2014-01-01

Hereditary spastic paraplegias (HSPs) are clinically and genetically heterogeneous neurological conditions. Their main pathogenic mechanisms are thought to involve alterations in endomembrane trafficking, mitochondrial function, and lipid metabolism. With a combination of whole-genome mapping and exome sequencing, we identified three mutations in REEP2 in two families with HSP: a missense variant (c.107T>A [p.Val36Glu]) that segregated in the heterozygous state in a family with autosomal-dominant inheritance and a missense change (c.215T>A [p.Phe72Tyr]) that segregated in trans with a splice site mutation (c.105+3G>T) in a family with autosomal-recessive transmission. REEP2 belongs to a family of proteins that shape the endoplasmic reticulum, an organelle that was altered in fibroblasts from an affected subject. In vitro, the p.Val36Glu variant in the autosomal-dominant family had a dominant-negative effect; it inhibited the normal binding of wild-type REEP2 to membranes. The missense substitution p.Phe72Tyr, in the recessive family, decreased the affinity of the mutant protein for membranes that, together with the splice site mutation, is expected to cause complete loss of REEP2 function. Our findings illustrate how dominant and recessive inheritance can be explained by the effects and nature of mutations in the same gene. They have also important implications for genetic diagnosis and counseling in clinical practice because of the association of various modes of inheritance to this new clinico-genetic entity. PMID:24388663

The Presenilin-1 ΔE9 Mutation Results in Reduced γ-Secretase Activity, but Not Total Loss of PS1 Function, in Isogenic Human Stem Cells

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Grace Woodruff

2013-11-01

Full Text Available Presenilin 1 (PS1 is the catalytic core of γ-secretase, which cleaves type 1 transmembrane proteins, including the amyloid precursor protein (APP. PS1 also has γ-secretase-independent functions, and dominant PS1 missense mutations are the most common cause of familial Alzheimer’s disease (FAD. Whether PS1 FAD mutations are gain- or loss-of-function remains controversial, primarily because most studies have relied on overexpression in mouse and/or nonneuronal systems. We used isogenic euploid human induced pluripotent stem cell lines to generate and study an allelic series of PS1 mutations, including heterozygous null mutations and homozygous and heterozygous FAD PS1 mutations. Rigorous analysis of this allelic series in differentiated, purified neurons allowed us to resolve this controversy and to conclude that FAD PS1 mutations, expressed at normal levels in the appropriate cell type, impair γ-secretase activity but do not disrupt γ-secretase-independent functions of PS1. Thus, FAD PS1 mutations do not act as simple loss of PS1 function but instead dominantly gain an activity toxic to some, but not all, PS1 functions.

Diseases associated with growth hormone-releasing hormone receptor (GHRHR) mutations.

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Martari, Marco; Salvatori, Roberto

2009-01-01

The growth hormone (GH)-releasing hormone (GHRH) receptor (GHRHR) belongs to the G protein-coupled receptors family. It is expressed almost exclusively in the anterior pituitary, where it is necessary for somatotroph cells proliferation and for GH synthesis and secretion. Mutations in the human GHRHR gene (GHRHR) can impair ligand binding and signal transduction, and have been estimated to cause about 10% of autosomal recessive familial isolated growth hormone deficiency (IGHD). Mutations reported to date include five splice donor site mutations, two microdeletions, two nonsense mutations, seven missense mutations, and one mutation in the promoter. These mutations have an autosomal recessive mode of inheritance, and heterozygous individuals do not show signs of IGHD, although the presence of an intermediate phenotype has been hypothesized. Conversely, patients with biallelic mutations have low serum insulin-like growth factor-1 and GH levels (with absent or reduced GH response to exogenous stimuli), resulting--if not treated--in proportionate dwarfism. This chapter reviews the biology of the GHRHR, the mutations that affect its gene and their effects in homozygous and heterozygous individuals. Copyright © 2009 Elsevier Inc. All rights reserved.

Generation of an ASS1 heterozygous knockout human embryonic stem cell line, WAe001-A-13, using CRISPR/Cas9

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Fang Yuan

2018-01-01

Full Text Available The ASS1 gene encodes argininosuccinate synthetase-1, a cytosolic enzyme with a critical role in the urea cycle. Mutations are found in all ASS1 exons and cause the autosomal recessive disorder citrullinemia. Using CRISPR/Cas9-editing, we established the WAe001-A-13 cell line, which was heterozygous for an ASS1 mutation, from the human embryonic stem cell line H1. The WAe001-A-13 cell line maintained the pluripotent phenotype, the ability to differentiate into all three germ layers and a normal karyotype.

Who's for dinner? High-throughput sequencing reveals bat dietary differentiation in a biodiversity hotspot where prey taxonomy is largely undescribed.

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Burgar, Joanna M; Murray, Daithi C; Craig, Michael D; Haile, James; Houston, Jayne; Stokes, Vicki; Bunce, Michael

2014-08-01

Effective management and conservation of biodiversity requires understanding of predator-prey relationships to ensure the continued existence of both predator and prey populations. Gathering dietary data from predatory species, such as insectivorous bats, often presents logistical challenges, further exacerbated in biodiversity hot spots because prey items are highly speciose, yet their taxonomy is largely undescribed. We used high-throughput sequencing (HTS) and bioinformatic analyses to phylogenetically group DNA sequences into molecular operational taxonomic units (MOTUs) to examine predator-prey dynamics of three sympatric insectivorous bat species in the biodiversity hotspot of south-western Australia. We could only assign between 4% and 20% of MOTUs to known genera or species, depending on the method used, underscoring the importance of examining dietary diversity irrespective of taxonomic knowledge in areas lacking a comprehensive genetic reference database. MOTU analysis confirmed that resource partitioning occurred, with dietary divergence positively related to the ecomorphological divergence of the three bat species. We predicted that bat species' diets would converge during times of high energetic requirements, that is, the maternity season for females and the mating season for males. There was an interactive effect of season on female, but not male, bat species' diets, although small sample sizes may have limited our findings. Contrary to our predictions, females of two ecomorphologically similar species showed dietary convergence during the mating season rather than the maternity season. HTS-based approaches can help elucidate complex predator-prey relationships in highly speciose regions, which should facilitate the conservation of biodiversity in genetically uncharacterized areas, such as biodiversity hotspots. © 2013 John Wiley & Sons Ltd.

USING TAXONOMIC REVISION DATA TO ESTIMATE THE GLOBAL SPECIES RICHNESS AND CHARACTERISTICS OF UNDESCRIBED SPECIES OF DIVING BEETLES (COLEOPTERA: DYTISCIDAE

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Viktor Nilsson-Örtman

2010-06-01

Full Text Available Many methods used for estimating species richness are either difficult to use on poorly known taxa or require input data that are laborious and expensive to collect. In this paper we apply a method which takes advantage of the carefully conducted tests of how the described diversity compares to real species richness that are inherent in taxonomic revisions. We analyze the quantitative outcome from such revisions with respect to body size, zoogeographical region and phylogenetic relationship. The best fitting model is used to predict the diversity of unrevised groups if these would have been subject to as rigorous species level hypothesis-testing as the revised groups. The sensitivity of the predictive model to single observations is estimated by bootstrapping over resampled subsets of the original data. The Dytiscidae is with its 4080 described species (end of May 2009 the most diverse group of aquatic beetles and have a world-wide distribution. Extensive taxonomic work has been carried out on the family but still the number of described species increases exponentially in most zoogeographical regions making many commonly used methods of estimation difficult to apply. We provide independent species richness estimates of subsamples for which species richness estimates can be reached through extrapolation and compare these to the species richness estimates obtained through the method using revision data. We estimate there to be 5405 species of dytiscids, a 1.32-fold increase over the present number of described species. The undescribed diversity is likely to be biased towards species with small body size from tropical regions outside of Africa.

Autosomal-dominant Leber Congenital Amaurosis Caused by a Heterozygous CRX Mutation in a Father and Son.

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Arcot Sadagopan, Karthikeyan; Battista, Robert; Keep, Rosanne B; Capasso, Jenina E; Levin, Alex V

2015-06-01

Leber congenital amaurosis (LCA) is most often an autosomal recessive disorder. We report a father and son with autosomal dominant LCA due to a mutation in the CRX gene. DNA screening using an allele specific assay of 90 of the most common LCA-causing variations in the coding sequences of AIPL1, CEP290, CRB1, CRX, GUCY2D, RDH12 and RPE65 was performed on the father. Automated DNA sequencing of his son examining exon 3 of the CRX gene was subsequently performed. Both father and son have a heterozygous single base pair deletion of an adenine at codon 153 in the coding sequence of the CRX gene resulting in a frameshift mutation. Mutations involving the CRX gene may demonstrate an autosomal dominant inheritance pattern for LCA.

Over-Expression of Porcine Myostatin Missense Mutant Leads to A Gender Difference in Skeletal Muscle Growth between Transgenic Male and Female Mice.

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Ma, Dezun; Gao, Pengfei; Qian, Lili; Wang, Qingqing; Cai, Chunbo; Jiang, Shengwang; Xiao, Gaojun; Cui, Wentao

2015-08-24

Myostatin, a transforming growth factor-β family member, is a negative regulator of skeletal muscle development and growth. Piedmontese cattle breeds have a missense mutation, which results in a cysteine to tyrosine substitution in the mature myostatin protein (C313Y). This loss-of-function mutation in myostatin results in a double-muscled phenotype in cattle. Myostatin propeptide is an inhibitor of myostatin activity and is considered a potential agent to stimulate muscle growth in livestock. In this study, we generated transgenic mice overexpressing porcine myostatin missense mutant (pmMS), C313Y, and wild-type porcine myostatin propeptide (ppMS), respectively, to examine their effects on muscle growth in mice. Enhanced muscle growth was observed in both pmMS and ppMS transgenic female mice and also in ppMS transgenic male mice. However, there was no enhanced muscle growth observed in pmMS transgenic male mice. To explore why there is such a big difference in muscle growth between pmMS and ppMS transgenic male mice, the expression level of androgen receptor (AR) mutant AR45 was measured by Western blot. Results indicated that AR45 expression significantly increased in pmMS transgenic male mice while it decreased dramatically in ppMS transgenic male mice. Our data demonstrate that both pmMS and ppMS act as myostatin inhibitors in the regulation of muscle growth, but the effect of pmMS in male mice is reversed by an increased AR45 expression. These results provide useful insight and basic theory to future studies on improving pork quality by genetically manipulating myostatin expression or by regulating myostatin activity.

The detection of heterozygous familial hypercholesterolemia in Ireland.

LENUS (Irish Health Repository)

O'Kane, Maurice J

2012-05-01

Heterozygous familial hypercholesterolemia (HeFH) is an autosomal dominant condition with a population prevalence of 1 in 500, and is associated with significant cardiovascular morbidity and mortality. It may be caused by mutations in the low-density lipoprotein (LDL) receptor, apolipoprotein B100 (Apo B100), or proprotein convertase subtilisin\\/kexin type 9 (PCSK9) genes, with over 1,000 causative mutations described. Statin therapy in HeFH is considered effective and safe. Audit data suggest that approximately 80% of the putative HeFH population remains unidentified and, therefore, there is a need to develop a strategy for the identification of affected individuals so that early lipid-lowering treatment may be offered. There is good evidence showing the effectiveness and acceptability of HeFH screening programs in Europe. The authors describe a protocol for an all island approach to HeFH detection in the Republic of Ireland\\/Northern Ireland. Index cases will be identified by opportunistic screening using the Simon Broome, or Make Early Diagnosis to Prevent Early Death (MedPed) and World Health Organization (WHO) criteria. Patients identified as "definite," "probable," or "possible" HeFH criteria will be offered genetic testing. The authors expect causative mutations to be identified in approximately 80% of patients with "definite" HeFH but in only approximately 20% of patients with "possible" HeFH. Cascade screening will be undertaken in first-degree relatives of the index case using genetic testing (where a causative mutation has been identified), or otherwise using LDL cholesterol concentration. The establishment of a HeFH screening program on an all-island basis will require: expansion of the existing molecular genetics diagnostic services, the establishment of a cohort of nurses\\/genetic counselors, a HeFH database to support cascade testing, the development of a network of lipid clinics (in a primary or secondary care setting), and an educational

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

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

2011-01-01

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

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

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Xiaodong Gu

2016-01-01

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

Altered hippocampal replay is associated with memory impairment in mice heterozygous for the Scn2a gene.

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Middleton, Steven J; Kneller, Emily M; Chen, Shuo; Ogiwara, Ikuo; Montal, Mauricio; Yamakawa, Kazuhiro; McHugh, Thomas J

2018-06-04

An accumulating body of experimental evidence has implicated hippocampal replay occurring within sharp wave ripples (SPW-Rs) as crucial for learning and memory in healthy subjects. This raises speculation that neurological disorders impairing memory disrupt either SPW-Rs or their underlying neuronal activity. We report that mice heterozygous for the gene Scn2a, a site of frequent de novo mutations in humans with intellectual disability, displayed impaired spatial memory. While we observed no changes during encoding, to either single place cells or cell assemblies, we identified abnormalities restricted to SPW-R episodes that manifest as decreased cell assembly reactivation strengths and truncated hippocampal replay sequences. Our results suggest that alterations to hippocampal replay content may underlie disease-associated memory deficits.

Identification and functional characterization of a novel bipartite nuclear localization sequence in ARID1A

Energy Technology Data Exchange (ETDEWEB)

Bateman, Nicholas W. [Women' s Health Integrated Research Center at Inova Health System, Gynecologic Cancer Center of Excellence, Annandale 22003, VA (United States); The John P. Murtha Cancer Center, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda 20889, MD (United States); Shoji, Yutaka [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids 49503, MI (United States); Conrads, Kelly A.; Stroop, Kevin D. [Women' s Health Integrated Research Center at Inova Health System, Gynecologic Cancer Center of Excellence, Annandale 22003, VA (United States); Hamilton, Chad A. [Women' s Health Integrated Research Center at Inova Health System, Gynecologic Cancer Center of Excellence, Annandale 22003, VA (United States); The John P. Murtha Cancer Center, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda 20889, MD (United States); Gynecologic Oncology Service, Department of Obstetrics and Gynecology, Walter Reed National Military Medical Center, 8901 Wisconsin Ave, MD, Bethesda, 20889 (United States); Department of Obstetrics and Gynecology, Uniformed Services University of the Health Sciences, Bethesda 20814, MD (United States); Darcy, Kathleen M. [Women' s Health Integrated Research Center at Inova Health System, Gynecologic Cancer Center of Excellence, Annandale 22003, VA (United States); The John P. Murtha Cancer Center, Walter Reed National Military Medical Center, 8901 Wisconsin Avenue, Bethesda 20889, MD (United States); Maxwell, George L. [Department of Obstetrics and Gynecology, Inova Fairfax Hospital, Falls Church, VA 22042 (United States); Risinger, John I. [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids 49503, MI (United States); and others

2016-01-01

AT-rich interactive domain-containing protein 1A (ARID1A) is a recently identified nuclear tumor suppressor frequently altered in solid tumor malignancies. We have identified a bipartite-like nuclear localization sequence (NLS) that contributes to nuclear import of ARID1A not previously described. We functionally confirm activity using GFP constructs fused with wild-type or mutant NLS sequences. We further show that cyto-nuclear localized, bipartite NLS mutant ARID1A exhibits greater stability than nuclear-localized, wild-type ARID1A. Identification of this undescribed functional NLS within ARID1A contributes vital insights to rationalize the impact of ARID1A missense mutations observed in patient tumors. - Highlights: • We have identified a bipartite nuclear localization sequence (NLS) in ARID1A. • Confirmation of the NLS was performed using GFP constructs. • NLS mutant ARID1A exhibits greater stability than wild-type ARID1A.

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

Science.gov (United States)

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

2016-01-01

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

Selection on viability of individuals heterozygous for the temperature-sensitive lethal mutation l(2)M167DTS in experimental populations of Drosophila melanogaster

Czech Academy of Sciences Publication Activity Database

Kulikov, A. M.; Marec, František; Mitrofanov, V. G.

2005-01-01

Roč. 41, č. 6 (2005), s. 613-619 ISSN 1022-7954 Grant - others:Russian Foundation for Basic Research(RU) 02-04-50021; Program of the Presidium of the Russian Academy of Sciences "Dynamics of Gene Pools in Plants, Animals, and Humans"(RU) 10002-251/P-24/154-150/2004-04-111 Institutional research plan: CEZ:AV0Z50070508 Keywords : heterozygous Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.240, year: 2005

TBC1D24 Mutations in a Sibship with Multifocal Polymyoclonus

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Adeline Ngoh

2017-04-01

Full Text Available Background: Advances in molecular genetic technologies have improved our understanding of genetic causes of rare neurological disorders with features of myoclonus.Case Report: A family with two affected siblings, presenting with multifocal polymyoclonus and neurodevelopmental delay, was recruited for whole-exome sequencing following unyielding diagnostic neurometabolic investigations. Compound heterozygous mutations in TBC1D24, a gene previously associated with various epilepsy phenotypes and hearing loss, were identified in both siblings. The mutations included a missense change c.457G>A (p.Glu157Lys, and a novel frameshift mutation c.545del (p.Thr182Serfs*6.Discussion: We propose that TBC1D24-related diseases should be in the differential diagnosis for children with polymyoclonus. 

Hereditary chronic pancreatitis in a patient with type 1 diabetes mellitus

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Varalakshmi Muthukrishnan

2018-01-01

Full Text Available In this case report, we present a young patient with type 1 diabetes who had hereditary chronic pancreatitis. We evaluated him for the cause of pancreatitis, but it was inconclusive and finally the genetic testing was done for him, which revealed heterozygous missense mutation in exon 3 of the PRSS1 gene (protease serine 1 gene on chromosome 7. Hence, we were able to make the diagnosis of hereditary chronic pancreatitis. Chronic pancreatitis secondary to any cause can lead to permanent diabetes, which is typically difficult to control. However, in this case, the episodes of recurrent pancreatitis were present after the onset of type 1 diabetes as compared to the usual presentation of diabetes after the advancement of chronic pancreatitis.

Wilson's disease: Rapid diagnosis and differentiation of heterozygous and homozygous carriers with 64CuCl2

International Nuclear Information System (INIS)

Wesch, H.; Przuntek, H.; Feist, D.; Wuerzburg Univ.; Heidelberg Univ.

1980-01-01

In the modified radiocopper test, a constant amount of copper and not of radioactivity is injected, a difference being made between males and females. The rate of incorporation of 64 Cu into caeruloplasmin and urinary excretion of nuclides is measured. It is a method with low radiation exposure, providing a definite diagnosis after 30 hours. This was demonstrated in 27 homozygous patients, 30 parents and 33 siblings, and 25 controls: a clear-cut diagnosis was made in all untreated homozygous patients. In five of eight patients treated with D-penicillamine for several years, the values were in the range of heterozygotes, so that the test makes treatment control possible. The recognition of heterozygous carriers is interfered with by contraceptives and infections. The results in control subjects were all widely outside the range for patients with Wilson's disease. (orig.) [de

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

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Marjan Saeedi

2014-01-01

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

Novel compound heterozygous mutations in MYO7A in a Chinese family with Usher syndrome type 1.

Science.gov (United States)

Liu, Fei; Li, Pengcheng; Liu, Ying; Li, Weirong; Wong, Fulton; Du, Rong; Wang, Lei; Li, Chang; Jiang, Fagang; Tang, Zhaohui; Liu, Mugen

2013-01-01

To identify the disease-causing mutation(s) in a Chinese family with autosomal recessive Usher syndrome type 1 (USH1). An ophthalmic examination and an audiometric test were conducted to ascertain the phenotype of two affected siblings. The microsatellite marker D11S937, which is close to the candidate gene MYO7A (USH1B locus), was selected for genotyping. From the DNA of the proband, all coding exons and exon-intron boundaries of MYO7A were sequenced to identify the disease-causing mutation(s). Restriction fragment length polymorphism (RFLP) analysis was performed to exclude the alternative conclusion that the mutations are non-pathogenic rare polymorphisms. Based on severe hearing impairment, unintelligible speech, and retinitis pigmentosa, a clinical diagnosis of Usher syndrome type 1 was made. The genotyping results did not exclude the USH1B locus, which suggested that the MYO7A gene was likely the gene associated with the disease-causing mutation(s) in the family. With direct DNA sequencing of MYO7A, two novel compound heterozygous mutations (c.3742G>A and c.6051+1G>A) of MYO7A were identified in the proband. DNA sequence analysis and RFLP analysis of other family members showed that the mutations cosegregated with the disease. Unaffected members, including the parents, uncle, and sister of the proband, carry only one of the two mutations. The mutations were not present in the controls (100 normal Chinese subjects=200 chromosomes) according to the RFLP analysis. In this study, we identified two novel mutations, c.3742G>A (p.E1248K) and c.6051+1G>A (donor splice site mutation in intron 44), of MYO7A in a Chinese non-consanguineous family with USH1. The mutations cosegregated with the disease and most likely cause the phenotype in the two affected siblings who carry these mutations compound heterozygously. Our finding expands the mutational spectrum of MYO7A.

Novel heterozygous nonsense mutation of the OPTN gene segregating in a Danish family with ALS

DEFF Research Database (Denmark)

Tümer, Zeynep; Bertelsen, Birgitte; Gredal, Ole

2012-01-01

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. About 10% of ALS cases are familial (FALS) and the genetic defect is known only in approximately 20%-30% of these cases. The most common genetic cause of ALS is SOD1 (superoxide dismutase 1) mutation. Very recently......, mutations of the optineurin gene (OPTN), which is involved in open-angle glaucoma, were identified in 3 Japanese patients/families with ALS, and subsequently in a few FALS patients of European descent. We found a heterozygous nonsense mutation (c.493C>T, p.Gln165X, exon 6) in the OPTN gene in a Danish...... patient with ALS, and the mutation segregated from his affected father. The p.Gln165X mutation could not be detected in 1070 healthy Danish controls, in 1000 Danish individuals with metabolic phenotypes or in 64 sporadic ALS (SALS) cases. The p.Gln165X mutation described in this study is the first...

Generation of a heterozygous knockout human embryonic stem cell line for the OCIAD1 locus using CRISPR/CAS9 mediated targeting: BJNhem20-OCIAD1-CRISPR-20

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Deeti K. Shetty

2016-03-01

Full Text Available Ovarian carcinoma immuno-reactive antigen domain containing 1(OCIAD1 single copy was knocked out generating an OCIAD1 heterozygous knockout human embryonic stem line named BJNhem20-OCIAD1-CRISPR-20. The line was generated using CRISPR-Cas9D10A double nickase knockout strategy (Mali et al., 2013.

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

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

2016-09-01

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

Low oxygen saturation and severe anemia in compound heterozygous Hb Louisville [β42(CD1)Phe→Leu] and Hb La Desirade [β129(H7)Ala→Val].

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Kamseng, Parin; Trakulsrichai, Satariya; Trachoo, Objoon; Yimniam, Walaiporn; Panthan, Bhakbhoom; Jittorntam, Paisan; Niparuck, Pimjai; Sanguanwit, Pitsucha; Wananukul, Winai; Jindadamrongwech, Sumalee

2017-03-01

To investigate the cause(s) of a Thai male proband presenting low oxygen saturation by pulse oximetry (SpO 2 ) and severe anemia. As Hb variant was suspected, Hb typing was determined by high-performance liquid chromatography and capillary electrophoresis, and subsequently Hb variant was identified by DNA sequencing. Complete blood counts were performed using automated blood cell counter and oxygen saturation was measured by pulse oximetry. Proband was compound heterozygous for Hb Louisville [β42(CD1)Phe→Leu] and Hb La Desirade [β129(H7)Ala→Val]. Of the proband's two sons, one was compound heterozygous for Hb Louisville and Hb E and the other for Hb La Desirade and Hb E. The former son had similar clinical features and laboratory findings with those of the proband while the latter showed had no abnormal clinical manifestations. This the first report of compound heterozygosity of Hb Louisville and Hb La Desirade in an individual of Southeast Asian ethnicity. Hb variant identification is crucial for genetic counseling and appropriate treatment in regions where hemoglobinopathies are common.

Sequence alterations in RX in patients with microphthalmia, anophthalmia, and coloboma

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London, Nikolas J.S.; Kessler, Patricia; Williams, Bryan; Pauer, Gayle J.; Hagstrom, Stephanie A.

2009-01-01

Purpose Microphthalmia, anophthalmia, and coloboma are ocular malformations with a significant genetic component. Rx is a homeobox gene expressed early in the developing retina and is important in retinal cell fate specification as well as stem cell proliferation. We screened a group of 24 patients with microphthalmia, coloboma, and/or anophthalmia for RX mutations. Methods We used standard PCR and automated sequencing techniques to amplify and sequence each of the three RX exons. Patients’ charts were reviewed for clinical information. The pathologic impact of the identified sequence variant was analyzed by computational methods using PolyPhen and PMut algorithms. Results In addition to the polymorphisms we identified a single patient with coloboma having a heterozygous nucleotide change (g.197G>C) in the first exon that results in a missense mutation of arginine to threonine at amino acid position 66 (R66T). In silico analysis predicted R66T to be a deleterious mutation. Conclusions Sequence variations in RX are uncommon in patients with congenital ocular malformations, but may play a role in disease pathogenesis. We observed a missense mutation in RX in a patient with a small, typical chorioretinal coloboma, and postulate that the mutation is responsible for the patient’s phenotype. PMID:19158959

Clinical intrafamilial variability in lethal familial neonatal seizure disorder caused by TBC1D24 mutations.

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Lozano, Reymundo; Herman, Kristin; Rothfuss, Melanie; Rieger, Hillary; Bayrak-Toydemir, Pinar; Aprile, Davide; Fruscione, Floriana; Zara, Federico; Fassio, Anna

2016-12-01

TBC1D24-related disorders include a wide phenotypic ranging from mild to lethal seizure disorders, non-syndromic deafness, and composite syndromes such as DOORS (deafness, onychodystrophy, osteodystrophy, mental retardation, and seizures). The TBC1D24 gene has a role in cerebral cortex development and in presynaptic neurotransmission. Here, we present a familial case of a lethal early-onset epileptic encephalopathy, associated with two novel compound heterozygous missense variants on the TBC1D24 gene, which were detected by exome sequencing. The detailed clinical data of the three siblings is summarized in order to support the variability of the phenotype, severity, and progression of this disorder among these family members. Functional studies demonstrated that the identified novel missense mutations result in a loss of expression of the protein, suggesting a correlation between residual expression, and the disease severity. This indicates that protein expression analysis is important for interpreting genetic results when novel variants are found, as well as for complementing clinical assessment by predicting the functional impact. Further analysis is necessary to delineate the clinical presentation of individuals with TBC1D24 pathogenic variants, as well as to develop markers for diagnosis, prognosis, and potential targeted treatments. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

EPO Receptor Gain-of-Function Causes Hereditary Polycythemia, Alters CD34+ Cell Differentiation and Increases Circulating Endothelial Precursors

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Perrotta, Silverio; Cucciolla, Valeria; Ferraro, Marcella; Ronzoni, Luisa; Tramontano, Annunziata; Rossi, Francesca; Scudieri, Anna Chiara; Borriello, Adriana; Roberti, Domenico; Nobili, Bruno; Cappellini, Maria Domenica; Oliva, Adriana; Amendola, Giovanni; Migliaccio, Anna Rita; Mancuso, Patrizia; Martin-Padura, Ines; Bertolini, Francesco; Yoon, Donghoon; Prchal, Josef T.; Della Ragione, Fulvio

2010-01-01

Background Gain-of-function of erythropoietin receptor (EPOR) mutations represent the major cause of primary hereditary polycythemia. EPOR is also found in non-erythroid tissues, although its physiological role is still undefined. Methodology/Principal Findings We describe a family with polycythemia due to a heterozygous mutation of the EPOR gene that causes a G→T change at nucleotide 1251 of exon 8. The novel EPOR G1251T mutation results in the replacement of a glutamate residue by a stop codon at amino acid 393. Differently from polycythemia vera, EPOR G1251T CD34+ cells proliferate and differentiate towards the erythroid phenotype in the presence of minimal amounts of EPO. Moreover, the affected individuals show a 20-fold increase of circulating endothelial precursors. The analysis of erythroid precursor membranes demonstrates a heretofore undescribed accumulation of the truncated EPOR, probably due to the absence of residues involved in the EPO-dependent receptor internalization and degradation. Mutated receptor expression in EPOR-negative cells results in EPOR and Stat5 phosphorylation. Moreover, patient erythroid precursors present an increased activation of EPOR and its effectors, including Stat5 and Erk1/2 pathway. Conclusions/Significance Our data provide an unanticipated mechanism for autosomal dominant inherited polycythemia due to a heterozygous EPOR mutation and suggest a regulatory role of EPO/EPOR pathway in human circulating endothelial precursors homeostasis. PMID:20700488

EnsembleGASVR: A novel ensemble method for classifying missense single nucleotide polymorphisms

KAUST Repository

Rapakoulia, Trisevgeni

2014-04-26

Motivation: Single nucleotide polymorphisms (SNPs) are considered the most frequently occurring DNA sequence variations. Several computational methods have been proposed for the classification of missense SNPs to neutral and disease associated. However, existing computational approaches fail to select relevant features by choosing them arbitrarily without sufficient documentation. Moreover, they are limited to the problem ofmissing values, imbalance between the learning datasets and most of them do not support their predictions with confidence scores. Results: To overcome these limitations, a novel ensemble computational methodology is proposed. EnsembleGASVR facilitates a twostep algorithm, which in its first step applies a novel evolutionary embedded algorithm to locate close to optimal Support Vector Regression models. In its second step, these models are combined to extract a universal predictor, which is less prone to overfitting issues, systematizes the rebalancing of the learning sets and uses an internal approach for solving the missing values problem without loss of information. Confidence scores support all the predictions and the model becomes tunable by modifying the classification thresholds. An extensive study was performed for collecting the most relevant features for the problem of classifying SNPs, and a superset of 88 features was constructed. Experimental results show that the proposed framework outperforms well-known algorithms in terms of classification performance in the examined datasets. Finally, the proposed algorithmic framework was able to uncover the significant role of certain features such as the solvent accessibility feature, and the top-scored predictions were further validated by linking them with disease phenotypes. © The Author 2014.

A novel OPA1 mutation in a Chinese family with autosomal dominant optic atrophy

International Nuclear Information System (INIS)

Zhang, Juanjuan; Yuan, Yimin; Lin, Bing; Feng, Hao; Li, Yan; Dai, Xianning; Zhou, Huihui; Dong, Xujie; Liu, Xiao-Ling; Guan, Min-Xin

2012-01-01

Highlights: ► We report the characterization of a four-generation large Chinese family with ADOA. ► We find a new heterozygous mutation c.C1198G in OPA1 gene which may be a novel pathogenic mutation in this pedigree. ► We do not find any mitochondrial DNA mutations associated with optic atrophy. ► Other factors may also contribute to the phenotypic variability of ADOA in this pedigree. -- Abstract: A large four-generation Chinese family with autosomal dominant optic atrophy (ADOA) was investigated in the present study. Eight of the family members were affected in this pedigree. The affected family members exhibited early-onset and progressive visual impairment, resulting in mild to profound loss of visual acuity. The average age-at-onset was 15.9 years. A new heterozygous mutation c.C1198G was identified by sequence analysis of the 12th exon of the OPA1 gene. This mutation resulted in a proline to alanine substitution at codon 400, which was located in an evolutionarily conserved region. This missense mutation in the GTPase domain was supposed to result in a loss of function for the encoded protein and act through a dominant negative effect. No other mutations associated with optic atrophy were found in our present study. The c.C1198G heterozygous mutation in the OPA1 gene may be a novel key pathogenic mutation in this pedigree with ADOA. Furthermore, additional nuclear modifier genes, environmental factors, and psychological factors may also contribute to the phenotypic variability of ADOA in this pedigree.

Hypomyelinating leukodystrophy-associated missense mutation in HSPD1 blunts mitochondrial dynamics

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

2015-07-03

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

SDS, a structural disruption score for assessment of missense variant deleteriousness

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Thanawadee ePreeprem

2014-04-01

Full Text Available We have developed a novel structure-based evaluation for missense variants that explicitly models protein structure and amino acid properties to predict the likelihood that a variant disrupts protein function. A structural disruption score (SDS is introduced as a measure to depict the likelihood that a case variant is functional. The score is constructed using characteristics that distinguish between causal and neutral variants within a group of proteins. The SDS score is correlated with standard sequence-based deleteriousness, but shows promise for improving discrimination between neutral and causal variants at less conserved sites.The prediction was performed on 3-dimentional structures of 57 gene products whose homozygous SNPs were identified as case-exclusive variants in an exome sequencing study of epilepsy disorders. We contrasted the candidate epilepsy variants with scores for likely benign variants found in the EVS database, and for positive control variants in the same genes that are suspected to promote a range of diseases. To derive a characteristic profile of damaging SNPs, we transformed continuous scores into categorical variables based on the score distribution of each measurement, collected from all possible SNPs in this protein set, where extreme measures were assumed to be deleterious. A second epilepsy dataset was used to replicate the findings. Causal variants tend to receive higher sequence-based deleterious scores, induce larger physico-chemical changes between amino acid pairs, locate in protein domains, buried sites or on conserved protein surface clusters, and cause protein destabilization, relative to negative controls. These measures were agglomerated for each variant. A list of nine high-priority putative functional variants for epilepsy was generated. Our newly developed SDS protocol facilitates SNP prioritization for experimental validation.

Hypomyelinating leukodystrophy-associated missense mutation in HSPD1 blunts mitochondrial dynamics

International Nuclear Information System (INIS)

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

2015-01-01

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

Development and pathology of two undescribed species of microsporidia infecting the predatory mite, Phytoseiulus persimilis Athias-Henriot.

Science.gov (United States)

Bjøornson, S; Keddie, B A

2000-11-01

Two undescribed species of microsporidia were found in mass-reared Phytoseiulus persimilis Athias-Henriot from two commercial sources during a routine examination of these predators for pathogens. Both microsporidian species were described from specimens that had been prepared for transmission electron microscopy; live specimens were unavailable for examination. One microsporidium, identified as Species A, was described from two specimens obtained from a commercial insectary in North America. All observed stages of this microsporidium were uninucleate. Rounded-to-ovoid schizonts appeared to develop in direct contact with the cytoplasm of lyrate organ cells (ovarian tissue). Mature spores of Species A were elongate-ovoid and measured 2.88 x 1.21 microm. A polar filament coiled 7 to 10 times in the posterior half of the spore. Sporoblasts and spores were observed in the cytoplasm of cells of numerous tissues and in developing eggs within gravid females. A second species, identified as Species B, was described from five specimens obtained from a commercial source in Israel. All observed stages of this microsporidium were uninucleate. Schizonts of Species B were observed within the cytoplasm of cecal wall cells and within the nuclei of lyrate organ cells. Mature spores were ovoid and measured 2.65 x 1.21 microm. A polar filament coiled 3 to 4 times in the posterior half of the spore. Densely packed ribosomes often concealed the polar filament and other internal spore characteristics. Spores were observed in the cytoplasm of cells of numerous tissues and occasionally within the nuclei of lyrate organ cells. Numerous spores and presporal stages were observed within the ovary and developing eggs. The development and pathology of Species A and B were compared to those of Microsporidium phytoseiuli Bjøornson, Steiner and Keddie, a microsporidium previously described from P. persimilis obtained from a commercial source in Europe. The occurrence of three species of

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

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Philip W. Brownjohn

2018-04-01

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

CCDC115 Deficiency Causes a Disorder of Golgi Homeostasis with Abnormal Protein Glycosylation.

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Jansen, Jos C; Cirak, Sebahattin; van Scherpenzeel, Monique; Timal, Sharita; Reunert, Janine; Rust, Stephan; Pérez, Belén; Vicogne, Dorothée; Krawitz, Peter; Wada, Yoshinao; Ashikov, Angel; Pérez-Cerdá, Celia; Medrano, Celia; Arnoldy, Andrea; Hoischen, Alexander; Huijben, Karin; Steenbergen, Gerry; Quelhas, Dulce; Diogo, Luisa; Rymen, Daisy; Jaeken, Jaak; Guffon, Nathalie; Cheillan, David; van den Heuvel, Lambertus P; Maeda, Yusuke; Kaiser, Olaf; Schara, Ulrike; Gerner, Patrick; van den Boogert, Marjolein A W; Holleboom, Adriaan G; Nassogne, Marie-Cécile; Sokal, Etienne; Salomon, Jody; van den Bogaart, Geert; Drenth, Joost P H; Huynen, Martijn A; Veltman, Joris A; Wevers, Ron A; Morava, Eva; Matthijs, Gert; Foulquier, François; Marquardt, Thorsten; Lefeber, Dirk J

2016-02-04

Disorders of Golgi homeostasis form an emerging group of genetic defects. The highly heterogeneous clinical spectrum is not explained by our current understanding of the underlying cell-biological processes in the Golgi. Therefore, uncovering genetic defects and annotating gene function are challenging. Exome sequencing in a family with three siblings affected by abnormal Golgi glycosylation revealed a homozygous missense mutation, c.92T>C (p.Leu31Ser), in coiled-coil domain containing 115 (CCDC115), the function of which is unknown. The same mutation was identified in three unrelated families, and in one family it was compound heterozygous in combination with a heterozygous deletion of CCDC115. An additional homozygous missense mutation, c.31G>T (p.Asp11Tyr), was found in a family with two affected siblings. All individuals displayed a storage-disease-like phenotype involving hepatosplenomegaly, which regressed with age, highly elevated bone-derived alkaline phosphatase, elevated aminotransferases, and elevated cholesterol, in combination with abnormal copper metabolism and neurological symptoms. Two individuals died of liver failure, and one individual was successfully treated by liver transplantation. Abnormal N- and mucin type O-glycosylation was found on serum proteins, and reduced metabolic labeling of sialic acids was found in fibroblasts, which was restored after complementation with wild-type CCDC115. PSI-BLAST homology detection revealed reciprocal homology with Vma22p, the yeast V-ATPase assembly factor located in the endoplasmic reticulum (ER). Human CCDC115 mainly localized to the ERGIC and to COPI vesicles, but not to the ER. These data, in combination with the phenotypic spectrum, which is distinct from that associated with defects in V-ATPase core subunits, suggest a more general role for CCDC115 in Golgi trafficking. Our study reveals CCDC115 deficiency as a disorder of Golgi homeostasis that can be readily identified via screening for abnormal

[Hereditary heterozygous factor VII deficiency in patients undergoing surgery : Clinical relevance].

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Woehrle, D; Martinez, M; Bolliger, D

2016-10-01

A hereditary deficiency in coagulation factor VII (FVII) may affect the international normalized ratio (INR) value. However, FVII deficiency is occasionally associated with a tendency to bleed spontaneously. We hypothesized that perioperative substitution with coagulation factor concentrates might not be indicated in most patients. In this retrospective data analysis, we included all patients with hereditary heterozygous FVII deficiency who underwent surgical procedures at the University Hospital Basel between December 2010 and November 2015. In addition, by searching the literature, we identified publications reporting patients with FVII deficiency undergoing surgical procedures without perioperative substitution. We identified 22 patients undergoing 46 surgical procedures, resulting in a prevalence of 1:1500-2000. Coagulation factor concentrates were administered during the perioperative period in 15 procedures (33 %), whereas in the other 31 procedures (66 %), FVII deficiency was not substituted. No postoperative bleeding or thromboembolic events were reported. In addition, we found no differences in pre- and postoperative hemoglobin and coagulation parameters, with the exception of an improved postoperative INR value in the substituted group. In the literature review, we identified five publications, including 125 patients with FVII deficiency, undergoing 213 surgical procedures with no perioperative substitution. Preoperative substitution using coagulation factor concentrates does not seem to be mandatory in patients with an FVII level ≥15 %. For decision-making on preoperative substitution, patient history of an increased tendency to bleed may be more important than the FVII level or increased INR value.

Mutations in LRRC50 predispose zebrafish and humans to seminomas.

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Sander G Basten

2013-04-01

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

Infantile Alexander Disease: Spectrum of GFAP Mutations and Genotype-Phenotype Correlation

Science.gov (United States)

Rodriguez, Diana; Gauthier, Fernande; Bertini, Enrico; Bugiani, Marianna; Brenner, Michael; N'guyen, Sylvie; Goizet, Cyril; Gelot, Antoinette; Surtees, Robert; Pedespan, Jean-Michel; Hernandorena, Xavier; Troncoso, Monica; Uziel, Graziela; Messing, Albee; Ponsot, Gérard; Pham-Dinh, Danielle; Dautigny, André; Boespflug-Tanguy, Odile

2001-01-01

Heterozygous, de novo mutations in the glial fibrillary acidic protein (GFAP) gene have recently been reported in 12 patients affected by neuropathologically proved Alexander disease. We searched for GFAP mutations in a series of patients who had heterogeneous clinical symptoms but were candidates for Alexander disease on the basis of suggestive neuroimaging abnormalities. Missense, heterozygous, de novo GFAP mutations were found in exons 1 or 4 for 14 of the 15 patients analyzed, including patients without macrocephaly. Nine patients carried arginine mutations (four had R79H; four had R239C; and one had R239H) that have been described elsewhere, whereas the other five had one of four novel mutations, of which two affect arginine (2R88C and 1R88S) and two affect nonarginine residues (1L76F and 1N77Y). All mutations were located in the rod domain of GFAP, and there is a correlation between clinical severity and the affected amino acid. These results confirm that GFAP mutations are a reliable molecular marker for the diagnosis of infantile Alexander disease, and they also form a basis for the recommendation of GFAP analysis for prenatal diagnosis to detect potential cases of germinal mosaicism. PMID:11567214

Dupuytren’s and Ledderhose Diseases in a Family with LMNA-Related Cardiomyopathy and a Novel Variant in the ASTE1 Gene

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Michael V. Zaragoza

2017-11-01

Full Text Available Dupuytren’s disease (palmar fibromatosis involves nodules in fascia of the hand that leads to flexion contractures. Ledderhose disease (plantar fibromatosis is similar with nodules of the foot. While clinical aspects are well-described, genetic mechanisms are unknown. We report a family with cardiac disease due to a heterozygous LMNA mutation (c.736C>T, p.Gln246Stop with palmar/plantar fibromatosis and investigate the hypothesis that a second rare DNA variant increases the risk for fibrotic disease in LMNA mutation carriers. The proband and six family members were evaluated for the cardiac and hand/feet phenotypes and tested for the LMNA mutation. Fibroblast RNA studies revealed monoallelic expression of the normal LMNA allele and reduced lamin A/C mRNAs consistent with LMNA haploinsufficiency. A novel, heterozygous missense variant (c.230T>C, p.Val77Ala in the Asteroid Homolog 1 (ASTE1 gene was identified as a potential risk factor in fibrotic disease using exome sequencing and family studies of five family members: four LMNA mutation carriers with fibromatosis and one individual without the LMNA mutation and no fibromatosis. With a possible role in epidermal growth factor receptor signaling, ASTE1 may contribute to the increased risk for palmar/plantar fibromatosis in patients with Lamin A/C haploinsufficiency.

Novel cystathionine β-synthase gene mutations in a Filipino patient with classic homocystinuria.

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Silao, Catherine Lynn T; Fabella, Terence Diane F; Rama, Kahlil Izza D; Estrada, Sylvia C

2015-10-01

Classic homocystinuria due to cystathionine β-synthase (CBS) deficiency is an autosomal recessive disorder of sulfur metabolism. Clinical manifestations include mental retardation, dislocation of the optic lens (ectopia lentis), skeletal abnormalities and a tendency to thromboembolic episodes. We present the first mutational analysis of CBS in a Filipino patient with classic homocystinuria. Genomic DNA was extracted from peripheral blood collected from a diagnosed Filipino patient with classic homocystinuria. The entire coding region of CBS (17 exons) was amplified using polymerase chain reaction and bidirectionally sequenced using standard protocols. The patient was found to be compound heterozygous for two novel mutations, g.13995G>A [c.982G>A; p.D328K] and g.15860-15868dupGCAGGAGCT [c.1083-1091dupGCAGGAGCT; p. Q362-L364dupQEL]. Four known single-nucleotide polymorphisms (rs234706, rs1801181, rs706208 and rs706209) were also detected in the present patient's CBS. The patient was heterozygous for all the identified alleles. This is the first mutational analysis of CBS done in a Filipino patient with classic homocystinuria who presented with a novel duplication mutation and a novel missense mutation. Homocystinuria due to CBS deficiency is a heterogeneous disorder at the molecular level. © 2015 Japan Pediatric Society.

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

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Gianluigi Laccetta

2017-11-01

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

Cognitive assessment of mice strains heterozygous for cell-adhesion genes reveals strain-specific alterations in timing.

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Gallistel, C R; Tucci, Valter; Nolan, Patrick M; Schachner, Melitta; Jakovcevski, Igor; Kheifets, Aaron; Barboza, Luendro

2014-03-05

We used a fully automated system for the behavioural measurement of physiologically meaningful properties of basic mechanisms of cognition to test two strains of heterozygous mutant mice, Bfc (batface) and L1, and their wild-type littermate controls. Both of the target genes are involved in the establishment and maintenance of synapses. We find that the Bfc heterozygotes show reduced precision in their representation of interval duration, whereas the L1 heterozygotes show increased precision. These effects are functionally specific, because many other measures made on the same mice are unaffected, namely: the accuracy of matching temporal investment ratios to income ratios in a matching protocol, the rate of instrumental and classical conditioning, the latency to initiate a cued instrumental response, the trials on task and the impulsivity in a switch paradigm, the accuracy with which mice adjust timed switches to changes in the temporal constraints, the days to acquisition, and mean onset time and onset variability in the circadian anticipation of food availability.

Generalized pustular psoriasis in infant with heterozygous mutation in the IL36RN gene successfully treated with infliximab

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Glerup, Mia; Veirum, Jens Erik; Iversen, L

2014-01-01

started on intravenous antibiotics and topical corticosteroids. During the following week the dermal changes presented with scaly sharply demarcated psoriasiform plaques. Infection was cleared and treatment with topical betamethasone gave a partial improvement. Cardiac surgery was performed at the age...... during the cardiac procedures, but the extracorporeal membrane oxygenation (ECMO) system had been primed with methyl-prednisolone and a rebound effect of steroid was suspected. Methotrexate treatment was initiated and topical corticosteroids and parenteral antibiotics were added. On suspection for DIRA......L IL36Ra mutation along with heterozygous Q705K NLRP3 mutation, phenotypically expressed as DITRA with severe generalized pustular psoriasis. Reduction of the IL36Ra function will lead to excessive activity of cytokines belonging to the IL-1 family, furthermore the gain-of-function mutation in NLRP3...

Aberrant methylation of Polo-like kinase CpG islands in Plk4 heterozygous mice

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Ward, Alejandra; Morettin, Alan; Shum, David; Hudson, John W

2011-01-01

Hepatocellular carcinoma (HCC), one of the most common cancers world-wide occurs twice as often in men compared to women. Predisposing conditions such as alcoholism, chronic viral hepatitis, aflatoxin B1 ingestion, and cirrhosis all contribute to the development of HCC. We used a combination of methylation specific PCR and bisulfite sequencing, qReal-Time PCR (qPCR), and Western blot analysis to examine epigenetic changes for the Polo-like kinases (Plks) during the development of hepatocellular carcinoma (HCC) in Plk4 heterozygous mice and murine embryonic fibroblasts (MEFs). Here we report that the promoter methylation of Plk4 CpG islands increases with age, was more prevalent in males and that Plk4 epigenetic modification and subsequent downregulation of expression was associated with the development of HCC in Plk4 mutant mice. Interestingly, the opposite occurs with another Plk family member, Plk1 which was typically hypermethylated in normal liver tissue but became hypomethylated and upregulated in liver tumours. Furthermore, upon alcohol exposure murine embryonic fibroblasts exhibited increased Plk4 hypermethylation and downregulation along with increased centrosome numbers and multinucleation. These results suggest that aberrant Plk methylation is correlated with the development of HCC in mice

Gain-of-function mutations in the phosphatidylserine synthase 1 (PTDSS1) gene cause Lenz-Majewski syndrome.

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Sousa, Sérgio B; Jenkins, Dagan; Chanudet, Estelle; Tasseva, Guergana; Ishida, Miho; Anderson, Glenn; Docker, James; Ryten, Mina; Sa, Joaquim; Saraiva, Jorge M; Barnicoat, Angela; Scott, Richard; Calder, Alistair; Wattanasirichaigoon, Duangrurdee; Chrzanowska, Krystyna; Simandlová, Martina; Van Maldergem, Lionel; Stanier, Philip; Beales, Philip L; Vance, Jean E; Moore, Gudrun E

2014-01-01

Lenz-Majewski syndrome (LMS) is a syndrome of intellectual disability and multiple congenital anomalies that features generalized craniotubular hyperostosis. By using whole-exome sequencing and selecting variants consistent with the predicted dominant de novo etiology of LMS, we identified causative heterozygous missense mutations in PTDSS1, which encodes phosphatidylserine synthase 1 (PSS1). PSS1 is one of two enzymes involved in the production of phosphatidylserine. Phosphatidylserine synthesis was increased in intact fibroblasts from affected individuals, and end-product inhibition of PSS1 by phosphatidylserine was markedly reduced. Therefore, these mutations cause a gain-of-function effect associated with regulatory dysfunction of PSS1. We have identified LMS as the first human disease, to our knowledge, caused by disrupted phosphatidylserine metabolism. Our results point to an unexplored link between phosphatidylserine synthesis and bone metabolism.

Waardenburg syndrome: a rare cause of inherited neuropathy due to SOX10 mutation.

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Bogdanova-Mihaylova, Petya; Alexander, Michael D; Murphy, Raymond P J; Murphy, Sinéad M

2017-09-01

Waardenburg syndrome (WS) is a rare disorder comprising sensorineural deafness and pigmentation abnormalities. Four distinct subtypes are defined based on the presence or absence of additional symptoms. Mutations in six genes have been described in WS. SOX10 mutations are usually associated with a more severe phenotype of WS with peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, and Hirschsprung disease. Here we report a 32-year-old man with a novel heterozygous missense variant in SOX10 gene, who presented with congenital deafness, Hirschsprung disease, iris heterochromia, foot deformity, and intermediate conduction velocity length-dependent sensorimotor neuropathy. This case highlights that the presence of other non-neuropathic features in a patient with presumed hereditary neuropathy should alert the clinician to possible atypical rare causes. © 2017 Peripheral Nerve Society.

Identification of a Novel Mutation in a Pseudohypoparathyroidism Family

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Zhi-Min Miao

2011-01-01

Full Text Available Pseudohypoparathyroidism type Ia (PHP Ia is defined as a series of disorders characterized by multihormone resistance in end-organs and Albright hereditary osteodystrophy (AHO phenotype. PHP Ia is caused by heterozygous inactivating mutations in GNAS, which encodes the stimulatory G-protein alpha subunit (Gsa. A patient with typical clinical manifestations of pseudohypoparathyroidism (PHP (round face, short stature, centripetal obesity, brachydactyly, and multi-hormone resistance: parathyroid hormone (PTH, thyroid-stimulating hormone (TSH, and gonadotropins presented at our center. The sequence of the GNAS gene from the patient and her families revealed a novel missense mutation (Y318H in the proband and her mother. An in vitro Gsa functional study showed that Gsa function was significantly impaired. These results stress the importance of GNAS gene investigation.

R353Q polymorphism in the factor VII gene and cardiovascular risk in Heterozygous Familial Hypercholesterolemia: a case-control study.

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Criado-García, Juan; Fuentes, Francisco; Cruz-Teno, Cristina; García-Rios, Antonio; Jiménez-Morales, Anabel; Delgado-Lista, Javier; Mata, Pedro; Alonso, Rodrigo; López-Miranda, José; Pérez-Jiménez, Francisco

2011-04-09

Heterozygous Familial Hypercholesterolemia (FH) is a genetic disorder characterized by a high risk of cardiovascular disease. Certain polymorphisms of the factor VII gene have been associated with the development of coronary artery disease and there is a known association between factor VII levels and polymorphic variants in this gene. To date, no study has evaluated the association between factor VII and coronary artery disease in patients with FH. This case-control study comprised 720 patients (546 with FH and 174 controls). We determined the prevalence and allele frequencies of the R353Q polymorphism of factor VII, the plasma levels of factor VII antigen (FVII Ag) and whether they could be predictive factors for cardiovascular risk. 75% (410) of the patients with FH were RR, 23% (127) RQ and 1.6% (9) QQ; in the control group 75.3% (131) were RR, 21.3% (37) RQ and 3.4% (6) QQ (p = 0.32). No statistically significant associations were observed in the distribution of genotypes and allele frequencies between case (FH) and control groups. Nor did we find differences when we evaluated the relationship between the R353Q polymorphism and cardiovascular risk (including coronary disease, ischemic stroke and peripheral arterial disease), either in the univariate analysis or after adjustment for sex, age, arterial hypertension, body mass index, xanthomas, diabetes, smoking, HDLc and LDLc and lipid-lowering treatment. The FVII Ag concentrations behaved in a similar fashion, with no differences for the interaction between controls and those with FH (RR vs. RQ/QQ; p = 0.96). In the subgroup of patients with FH no association was found among cardiovascular disease, genotype and FVII Ag levels (RR vs. RQ/QQ; p = 0.97). Our study did not find a direct relationship between cardiovascular risk in patients with Heterozygous Familial Hypercholesterolemia, the R353Q polymorphism of factor VII and FVII Ag levels.

Novel root-fungus symbiosis in Ericaceae: sheathed ericoid mycorrhiza formed by a hitherto undescribed basidiomycete with affinities to Trechisporales.

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Martin Vohník

Full Text Available Ericaceae (the heath family are widely distributed calcifuges inhabiting soils with inherently poor nutrient status. Ericaceae overcome nutrient limitation through symbiosis with ericoid mycorrhizal (ErM fungi that mobilize nutrients complexed in recalcitrant organic matter. At present, recognized ErM fungi include a narrow taxonomic range within the Ascomycota, and the Sebacinales, basal Hymenomycetes with unclamped hyphae and imperforate parenthesomes. Here we describe a novel type of basidiomycetous ErM symbiosis, termed 'sheathed ericoid mycorrhiza', discovered in two habitats in mid-Norway as a co-dominant mycorrhizal symbiosis in Vaccinium spp. The basidiomycete forming sheathed ErM possesses clamped hyphae with perforate parenthesomes, produces 1- to 3-layer sheaths around terminal parts of hair roots and colonizes their rhizodermis intracellularly forming hyphal coils typical for ErM symbiosis. Two basidiomycetous isolates were obtained from sheathed ErM and molecular and phylogenetic tools were used to determine their identity; they were also examined for the ability to form sheathed ErM and lignocellulolytic potential. Surprisingly, ITS rDNA of both conspecific isolates failed to amplify with the most commonly used primer pairs, including ITS1 and ITS1F + ITS4. Phylogenetic analysis of nuclear LSU, SSU and 5.8S rDNA indicates that the basidiomycete occupies a long branch residing in the proximity of Trechisporales and Hymenochaetales, but lacks a clear sequence relationship (>90% similarity to fungi currently placed in these orders. The basidiomycete formed the characteristic sheathed ErM symbiosis and enhanced growth of Vaccinium spp. in vitro, and degraded a recalcitrant aromatic substrate that was left unaltered by common ErM ascomycetes. Our findings provide coherent evidence that this hitherto undescribed basidiomycete forms a morphologically distinct ErM symbiosis that may occur at significant levels under natural conditions, yet

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

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

2012-12-15

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

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

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

2014-01-01

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

Novel rare missense variations and risk of autism spectrum disorder: whole-exome sequencing in two families with affected siblings and a two-stage follow-up study in a Japanese population.

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Jun Egawa

Full Text Available Rare inherited variations in multiplex families with autism spectrum disorder (ASD are suggested to play a major role in the genetic etiology of ASD. To further investigate the role of rare inherited variations, we performed whole-exome sequencing (WES in two families, each with three affected siblings. We also performed a two-stage follow-up case-control study in a Japanese population. WES of the six affected siblings identified six novel rare missense variations. Among these variations, CLN8 R24H was inherited in one family by three affected siblings from an affected father and thus co-segregated with ASD. In the first stage of the follow-up study, we genotyped the six novel rare missense variations identified by WES in 241 patients and 667 controls (the Niigata sample. Only CLN8 R24H had higher mutant allele frequencies in patients (1/482 compared with controls (1/1334. In the second stage, this variation was further genotyped, yet was not detected in a sample of 309 patients and 350 controls (the Nagoya sample. In the combined Niigata and Nagoya samples, there was no significant association (odds ratio = 1.8, 95% confidence interval = 0.1-29.6. These results suggest that CLN8 R24H plays a role in the genetic etiology of ASD, at least in a subset of ASD patients.

Double heterozygous mutations Gln100Leu and His348Gln of the F7 gene in a patient with factor VII deficiency.

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Li, Min; Zheng, Fangxiu; Jin, Yanhui; Wang, Mingshan; Zhu, Liqing; Yang, Lihong

2013-03-01

A 25-year-old Chinese woman who had a history of easy bruising was admitted to hospital due to uncontrolled epistaxis. She showed factor VII activity level of 2% and factor VII antigen level of 4% of the normal value. We detected a novel missense mutation g.8355 A>T (p.Gln100Leu) in the second epidermal growth factor-like (EGF) domain and a g.11482 T>G (p.His348Gln) in the catalytic domain. Although the Gln100 residue is close to the junction of EGF-2 domain with the serine protease domain, we infer that the substitution of polar negatively charged Gln residue at the position 100 with introduction of nonpolar Leu residue may be likely to perturb proper folding, resulting in decreasing factor VII activity.

Ultrasonic vocalizations of adult male Foxp2-mutant mice: behavioral contexts of arousal and emotion.

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Gaub, S; Fisher, S E; Ehret, G

2016-02-01

Adult mouse ultrasonic vocalizations (USVs) occur in multiple behavioral and stimulus contexts associated with various levels of arousal, emotion and social interaction. Here, in three experiments of increasing stimulus intensity (water; female urine; male interacting with adult female), we tested the hypothesis that USVs of adult males express the strength of arousal and emotion via different USV parameters (18 parameters analyzed). Furthermore, we analyzed two mouse lines with heterozygous Foxp2 mutations (R552H missense, S321X nonsense), known to produce severe speech and language disorders in humans. These experiments allowed us to test whether intact Foxp2 function is necessary for developing full adult USV repertoires, and whether mutations of this gene influence instinctive vocal expressions based on arousal and emotion. The results suggest that USV calling rate characterizes the arousal level, while sound pressure and spectrotemporal call complexity (overtones/harmonics, type of frequency jumps) may provide indices of levels of positive emotion. The presence of Foxp2 mutations did not qualitatively affect the USVs; all USV types that were found in wild-type animals also occurred in heterozygous mutants. However, mice with Foxp2 mutations displayed quantitative differences in USVs as compared to wild-types, and these changes were context dependent. Compared to wild-type animals, heterozygous mutants emitted mainly longer and louder USVs at higher minimum frequencies with a higher occurrence rate of overtones/harmonics and complex frequency jump types. We discuss possible hypotheses about Foxp2 influence on emotional vocal expressions, which can be investigated in future experiments using selective knockdown of Foxp2 in specific brain circuits. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

A novel OPA1 mutation in a Chinese family with autosomal dominant optic atrophy

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Zhang, Juanjuan; Yuan, Yimin; Lin, Bing; Feng, Hao; Li, Yan [School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang (China); Dai, Xianning; Zhou, Huihui [Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou 325035, Zhejiang (China); Dong, Xujie [School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang (China); Liu, Xiao-Ling, E-mail: lxl@mail.eye.ac.cn [School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou 325027, Zhejiang (China); Guan, Min-Xin, E-mail: min-xin.guan@cchmc.org [Attardi Institute of Mitochondrial Biomedicine and Zhejiang Provincial Key Laboratory of Medical Genetics, School of Life Sciences, Wenzhou Medical College, Wenzhou 325035, Zhejiang (China); Institute of Genetics, Zhejiang University, Hangzhou, Zhejiang 310012 (China); Division of Human Genetics, Cincinnati Children' s Hospital Medical Center, OH 45229 (United States)

2012-03-23

Highlights: Black-Right-Pointing-Pointer We report the characterization of a four-generation large Chinese family with ADOA. Black-Right-Pointing-Pointer We find a new heterozygous mutation c.C1198G in OPA1 gene which may be a novel pathogenic mutation in this pedigree. Black-Right-Pointing-Pointer We do not find any mitochondrial DNA mutations associated with optic atrophy. Black-Right-Pointing-Pointer Other factors may also contribute to the phenotypic variability of ADOA in this pedigree. -- Abstract: A large four-generation Chinese family with autosomal dominant optic atrophy (ADOA) was investigated in the present study. Eight of the family members were affected in this pedigree. The affected family members exhibited early-onset and progressive visual impairment, resulting in mild to profound loss of visual acuity. The average age-at-onset was 15.9 years. A new heterozygous mutation c.C1198G was identified by sequence analysis of the 12th exon of the OPA1 gene. This mutation resulted in a proline to alanine substitution at codon 400, which was located in an evolutionarily conserved region. This missense mutation in the GTPase domain was supposed to result in a loss of function for the encoded protein and act through a dominant negative effect. No other mutations associated with optic atrophy were found in our present study. The c.C1198G heterozygous mutation in the OPA1 gene may be a novel key pathogenic mutation in this pedigree with ADOA. Furthermore, additional nuclear modifier genes, environmental factors, and psychological factors may also contribute to the phenotypic variability of ADOA in this pedigree.

A case report of novel mutation in PRF1 gene, which causes familial autosomal recessive hemophagocytic lymphohistiocytosis.

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Bordbar, Mohammad Reza; Modarresi, Farzaneh; Farazi Fard, Mohammad Ali; Dastsooz, Hassan; Shakib Azad, Nader; Faghihi, Mohammad Ali

2017-05-03

Hemophagocytic Lymphohistiocytosis (HLH) is a life-threatening immunodeficiency and multi-organ disease that affects people of all ages and ethnic groups. Common symptoms and signs of this disease are high fever, hepatosplenomegaly, and cytopenias. Familial form of HLH disease, which is an autosomal recessive hematological disorder is due to disease-causing mutations in several genes essential for NK and T-cell granule-mediated cytotoxic function. For an effective cytotoxic response from cytotoxic T lymphocyte or NK cell encountering an infected cell or tumor cell, different processes are required, including trafficking, docking, priming, membrane fusion, and entry of cytotoxic granules into the target cell leading to apoptosis. Therefore, genes involved in these steps play important roles in the pathogenesis of HLH disease which include PRF1, UNC13D (MUNC13-4), STX11, and STXBP2 (MUNC18-2). Here, we report a novel missense mutation in an 8-year-old boy suffered from hepatosplenomegaly, hepatitis, epilepsy and pancytopenia. The patient was born to a first-cousin parents with no previous documented disease in his parents. To identify mutated gene in the proband, Whole Exome Sequencing (WES) utilizing next generation sequencing was used on an Illumina HiSeq 2000 platform on DNA sample from the patient. Results showed a novel deleterious homozygous missense mutation in PRF1 gene (NM_001083116: exon3: c. 1120 T > G, p.W374G) in the patient and then using Sanger sequencing it was confirmed in the proband and his parents. Since his parents were heterozygous for the identified mutation, autosomal recessive pattern of inheritance was confirmed in the family. Our study identified a rare new pathogenic missense mutation in PRF1 gene in patient with HLH disease and it is the first report of mutation in PRF1 in Iranian patients with this disease.

Mutations in the BAF-Complex Subunit DPF2 Are Associated with Coffin-Siris Syndrome.

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Vasileiou, Georgia; Vergarajauregui, Silvia; Endele, Sabine; Popp, Bernt; Büttner, Christian; Ekici, Arif B; Gerard, Marion; Bramswig, Nuria C; Albrecht, Beate; Clayton-Smith, Jill; Morton, Jenny; Tomkins, Susan; Low, Karen; Weber, Astrid; Wenzel, Maren; Altmüller, Janine; Li, Yun; Wollnik, Bernd; Hoganson, George; Plona, Maria-Renée; Cho, Megan T; Thiel, Christian T; Lüdecke, Hermann-Josef; Strom, Tim M; Calpena, Eduardo; Wilkie, Andrew O M; Wieczorek, Dagmar; Engel, Felix B; Reis, André

2018-03-01

Variants affecting the function of different subunits of the BAF chromatin-remodelling complex lead to various neurodevelopmental syndromes, including Coffin-Siris syndrome. Furthermore, variants in proteins containing PHD fingers, motifs recognizing specific histone tail modifications, have been associated with several neurological and developmental-delay disorders. Here, we report eight heterozygous de novo variants (one frameshift, two splice site, and five missense) in the gene encoding the BAF complex subunit double plant homeodomain finger 2 (DPF2). Affected individuals share common clinical features described in individuals with Coffin-Siris syndrome, including coarse facial features, global developmental delay, intellectual disability, speech impairment, and hypoplasia of fingernails and toenails. All variants occur within the highly conserved PHD1 and PHD2 motifs. Moreover, missense variants are situated close to zinc binding sites and are predicted to disrupt these sites. Pull-down assays of recombinant proteins and histone peptides revealed that a subset of the identified missense variants abolish or impaire DPF2 binding to unmodified and modified H3 histone tails. These results suggest an impairment of PHD finger structural integrity and cohesion and most likely an aberrant recognition of histone modifications. Furthermore, the overexpression of these variants in HEK293 and COS7 cell lines was associated with the formation of nuclear aggregates and the recruitment of both wild-type DPF2 and BRG1 to these aggregates. Expression analysis of truncating variants found in the affected individuals indicated that the aberrant transcripts escape nonsense-mediated decay. Altogether, we provide compelling evidence that de novo variants in DPF2 cause Coffin-Siris syndrome and propose a dominant-negative mechanism of pathogenicity. Copyright © 2018 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

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

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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.

Genetic interactions between planar cell polarity genes cause diverse neural tube defects in mice

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Jennifer N. Murdoch

2014-10-01

Full Text Available Neural tube defects (NTDs are among the commonest and most severe forms of developmental defect, characterized by disruption of the early embryonic events of central nervous system formation. NTDs have long been known to exhibit a strong genetic dependence, yet the identity of the genetic determinants remains largely undiscovered. Initiation of neural tube closure is disrupted in mice homozygous for mutations in planar cell polarity (PCP pathway genes, providing a strong link between NTDs and PCP signaling. Recently, missense gene variants have been identified in PCP genes in humans with NTDs, although the range of phenotypes is greater than in the mouse mutants. In addition, the sequence variants detected in affected humans are heterozygous, and can often be detected in unaffected individuals. It has been suggested that interactions between multiple heterozygous gene mutations cause the NTDs in humans. To determine the phenotypes produced in double heterozygotes, we bred mice with all three pairwise combinations of Vangl2Lp, ScribCrc and Celsr1Crsh mutations, the most intensively studied PCP mutants. The majority of double-mutant embryos had open NTDs, with the range of phenotypes including anencephaly and spina bifida, therefore reflecting the defects observed in humans. Strikingly, even on a uniform genetic background, variability in the penetrance and severity of the mutant phenotypes was observed between the different double-heterozygote combinations. Phenotypically, Celsr1Crsh;Vangl2Lp;ScribCrc triply heterozygous mutants were no more severe than doubly heterozygous or singly homozygous mutants. We propose that some of the variation between double-mutant phenotypes could be attributed to the nature of the protein disruption in each allele: whereas ScribCrc is a null mutant and produces no Scrib protein, Celsr1Crsh and Vangl2Lp homozygotes both express mutant proteins, consistent with dominant effects. The variable outcomes of these genetic

CBS mutations and MTFHR SNPs causative of hyperhomocysteinemia in Pakistani children.

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Ibrahim, Shahnaz; Maqbool, Saadia; Azam, Maleeha; Iqbal, Mohammad Perwaiz; Qamar, Raheel

2018-03-29

Three index patients with hyperhomocysteinemia and ocular anomalies were screened for cystathionine beta synthase (CBS) and methylenetetrahydrofolate reductase (MTHFR) polymorphisms. Genotyping of hyperhomocysteinemia associated MTHFR polymorphisms C677T (rs1801133) and A1298C (rs1801131) was done by PCR-restriction fragment length polymorphism. Sanger sequencing was performed for CBS exonic sequences along with consensus splice sites. In the case of MTHFR polymorphisms, all the patients were heterozygous CT for the single nucleotide polymorphism (SNP) C677T and were therefore carriers of the risk allele (T), while the patients were homozygous CC for the risk genotype of the SNP A1298C. CBS sequencing resulted in the identification of two novel mutations, a missense change (c.467T>C; p.Leu156Pro) in exon 7 and an in-frame deletion (c.808_810del; p.Glu270del) in exon 10. In addition, a recurrent missense mutation (c.770C>T; p.Thr257Met) in exon 10 of the gene was also identified. The mutations were present homozygously in the patients and were inherited from the carrier parents. This is the first report from Pakistan where novel as well as recurrent CBS mutations causing hyperhomocysteinemia and lens dislocation in three patients from different families are being reported with the predicted effect of the risk allele of the MTHFR SNP in causing hyperhomocysteinemia.

Two Patients with Severe Short Stature due to a FBN1 Mutation (p.Ala1728Val) with a Mild Form of Acromicric Dysplasia.

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de Bruin, Christiaan; Finlayson, Courtney; Funari, Mariana F A; Vasques, Gabriela A; Lucheze Freire, Bruna; Lerario, Antonio M; Andrew, Melissa; Hwa, Vivian; Dauber, Andrew; Jorge, Alexander A L

2016-01-01

Acromicric dysplasia (AD) and geleophysic dysplasia 2 (GD2) belong to the category of acromelic dysplasia syndromes, consisting of severe short stature, short hands and feet and skin thickening. Both can result from missense mutations in the transforming growth factor beta 5 domain of the fibrillin-1 gene (FBN1). Two patients (P1 age 10, and P2 age 7) from unrelated families presented to their endocrinologist with severe short stature (approx. -4 SDS). They were otherwise asymptomatic and only had mild facial dysmorphisms. Extensive endocrine work-up did not reveal an underlying etiology. Exome sequencing was performed in each family. Exome sequencing identified the presence of the same heterozygous missense variant c.C5183T (p.Ala1728Val) in the FBN1 gene in both P1 and P2. This variant was previously reported in a patient with GD2 and associated cardiac valvulopathy and hepatomegaly. Detailed clinical re-examination, cardiac and skeletal imaging did not reveal any abnormalities in P1 or P2 other than mild hip dysplasia. This report broadens the phenotypic spectrum of growth disorders associated with FBN1 mutations. Identical mutations give rise to a wide phenotypic spectrum, ranging from isolated short stature to a more classic picture of GD2 with cardiac involvement, distinct facial dysmorphisms and various skeletal anomalies. © 2016 S. Karger AG, Basel.

A novel mutation in the WFS1 gene identified in a Taiwanese family with low-frequency hearing impairment

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Chung Shing-Fang

2007-05-01

Full Text Available Abstract Background Wolfram syndrome gene 1 (WFS1 accounts for most of the familial nonsyndromic low-frequency sensorineural hearing loss (LFSNHL which is characterized by sensorineural hearing losses equal to and below 2000 Hz. The current study aimed to contribute to our understanding of the molecular basis of LFSNHL in an affected Taiwanese family. Methods The Taiwanese family with LFSNHL was phenotypically characterized using audiologic examination and pedigree analysis. Genetic characterization was performed by direct sequencing of WFS1 and mutation analysis. Results Pure tone audiometry confirmed that the family members affected with LFSNHL had a bilateral sensorineural hearing loss equal to or below 2000 Hz. The hearing loss threshold of the affected members showed no progression, a characteristic that was consistent with a mutation in the WFS1 gene located in the DFNA6/14/38 locus. Pedigree analysis showed a hereditarily autosomal dominant pattern characterized by a full penetrance. Among several polymorphisms, a missense mutation Y669H (2005T>C in exon 8 of WFS1 was identified in members of a Taiwanese family diagnosed with LFSNHL but not in any of the control subjects. Conclusion We discovered a novel heterozygous missense mutation in exon 8 of WFS1 (i.e., Y669H which is likely responsible for the LFSNHL phenotype in this particular Taiwanese family.

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

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Abitbol, M; Legrand, R; Tiret, L

2014-12-01

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

Poly(ADP-ribose) synthesis following DNA damage in cells heterozygous or homozygous for the xeroderma pigmentosum genotype

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McCurry, L.S.; Jacobson, M.K.

1981-01-01

Treatment of normal human cells with DNA-damaging agents such as uv light or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stimulates the conversion of NAD to the chromosomal polymer poly(ADP-ribose) which in turn results in a rapid depletion of the cellular NAD pool. The effect of uv light or MNNG on the NAD pools of seven cell lines of human fibroblasts either homozygous or heterozygous for the xeroderma pigmentosum genotype has been studied. Xeroderma pigmentosum cells of genetic complementation groups A, C, and D are deficient in the excision repair of DNA damage caused by uv light. Following uv treatment, the NAD content of these cells was unchanged or only slightly reduced. All of the cell lines are able to excise DNA damage caused by MNNG and all of the cell lines had a greatly reduced content of NAD following MNNG treatment. The results demonstrate a close relationship between the conversion of NAD to poly(ADP-ribose) and DNA excision repair in human cells

Novel compound heterozygous MYO7A mutations in Moroccan families with autosomal recessive non-syndromic hearing loss.

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Amina Bakhchane

Full Text Available The MYO7A gene encodes a protein belonging to the unconventional myosin super family. Mutations within MYO7A can lead to either non syndromic hearing loss or to the Usher syndrome type 1B (USH1B. Here, we report the results of genetic analyses performed on Moroccan families with autosomal recessive non syndromic hearing loss that identified two families with compound heterozygous MYO7A mutations. Five mutations (c.6025delG, c.6229T>A, c.3500T>A, c.5617C>T and c.4487C>A were identified in these families, the latter presenting two differently affected branches. Multiple bioinformatics programs and molecular modelling predicted the pathogenic effect of these mutations. In conclusion, the absence of vestibular and retinal symptom in the affected patients suggests that these families have the isolated non-syndromic hearing loss DFNB2 (nonsyndromic autosomal recessive hearing loss presentation, instead of USH1B.

Normal X-inactivation mosaicism in corneas of heterozygous FlnaDilp2/+ female mice--a model of human Filamin A (FLNA diseases

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Douvaras Panagiotis

2012-02-01

Full Text Available Abstract Background Some abnormalities of mouse corneal epithelial maintenance can be identified by the atypical mosaic patterns they produce in X-chromosome inactivation mosaics and chimeras. Human FLNA/+ females, heterozygous for X-linked, filamin A gene (FLNA mutations, display a range of disorders and X-inactivation mosaicism is sometimes quantitatively unbalanced. FlnaDilp2/+ mice, heterozygous for an X-linked filamin A (Flna nonsense mutation have variable eye, skeletal and other abnormalities, but X-inactivation mosaicism has not been investigated. The aim of this study was to determine whether X-inactivation mosaicism in the corneal epithelia of FlnaDilp2/+ mice was affected in any way that might predict abnormal corneal epithelial maintenance. Results X-chromosome inactivation mosaicism was studied in the corneal epithelium and a control tissue (liver of FlnaDilp2/+ and wild-type (WT female X-inactivation mosaics, hemizygous for the X-linked, LacZ reporter H253 transgene, using β-galactosidase histochemical staining. The corneal epithelia of FlnaDilp2/+ and WT X-inactivation mosaics showed similar radial, striped patterns, implying epithelial cell movement was not disrupted in FlnaDilp2/+ corneas. Corrected stripe numbers declined with age overall (but not significantly for either genotype individually, consistent with previous reports suggesting an age-related reduction in stem cell function. Corrected stripe numbers were not reduced in FlnaDilp2/+ compared with WT X-inactivation mosaics and mosaicism was not significantly more unbalanced in the corneal epithelia or livers of FlnaDilp2/+ than wild-type Flna+/+ X-inactivation mosaics. Conclusions Mosaic analysis identified no major effect of the mouse FlnaDilp2 mutation on corneal epithelial maintenance or the balance of X-inactivation mosaicism in the corneal epithelium or liver.

A novel heterozygous mutation of the WFS1 gene leading to constitutive endoplasmic reticulum stress is the cause of Wolfram syndrome.

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Morikawa, Shuntaro; Tajima, Toshihiro; Nakamura, Akie; Ishizu, Katsura; Ariga, Tadashi

2017-12-01

Wolfram syndrome (WS) is a disorder characterized by the association of insulin-dependent diabetes mellitus (DM), diabetes insipidus, deafness, and optic nerve atrophy. WS is caused by WFS1 mutations encoding WFS1 protein expressed in endoplasmic reticulum (ER). During ER protein synthesis, misfolded and unfolded proteins accumulate, known as "ER stress". This is attenuated by the unfolded protein response (UPR), which recovers and maintains ER functions. Because WFS1 is a UPR component, mutant WFS1 might cause unresolvable ER stress conditions and cell apoptosis, the major causes underlying WS symptoms. We encountered an 11-month-old Japanese female WS patient with insulin-dependent DM, congenital cataract and severe bilateral hearing loss. Analyze the WFS1 and functional consequence of the patient WFS1 in vitro. The patient WFS1 contained a heterozygous 4 amino acid in-frame deletion (p.N325_I328del). Her mutant WFS1 increased GRP78 and ATF6α promoter activities in the absence of thapsigargin, indicating constitutive ER stress and nuclear factor of activated T-cell reporter activity, reflecting elevated cytosolic Ca 2+ signals. Mutant transfection into cells reduced mRNA expression levels of sarcoplasmic/endoplasmic reticulum Ca 2+ transport ATPase 2b (SERCA2b) compared with wild type. Because SERCA2b is required for ER and cytoplasmic Ca 2+ homeostasis, decreased SERCA2b expression might affect ER Ca 2+ efflux, causing cell apoptosis. A novel heterozygous mutation of WFS1 induced constitutive ER stress through ATF6α activation and ER Ca 2+ efflux, resulting in cell apoptosis. These results provide new insights into the roles of WFS1 in UPR and mechanism of monogenic DM. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Heterozygous Disruption of Autism susceptibility candidate 2 Causes Impaired Emotional Control and Cognitive Memory.

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Kei Hori

Full Text Available Mutations in the Autism susceptibility candidate 2 gene (AUTS2 have been associated with a broad range of psychiatric illnesses including autism spectrum disorders, intellectual disability and schizophrenia. We previously demonstrated that the cytoplasmic AUTS2 acts as an upstream factor for the Rho family small GTPase Rac1 and Cdc42 that regulate the cytoskeletal rearrangements in neural cells. Moreover, genetic ablation of the Auts2 gene in mice has resulted in defects in neuronal migration and neuritogenesis in the developing cerebral cortex caused by inactivation of Rac1-signaling pathway, suggesting that AUTS2 is required for neural development. In this study, we conducted a battery of behavioral analyses on Auts2 heterozygous mutant mice to examine the involvement of Auts2 in adult cognitive brain functions. Auts2-deficient mice displayed a decrease in exploratory behavior as well as lower anxiety-like behaviors in the absence of any motor dysfunction. Furthermore, the capability for novel object recognition and cued associative memory were impaired in Auts2 mutant mice. Social behavior and sensory motor gating functions were, however, normal in the mutant mice as assessed by the three-chamber test and prepulse inhibition test, respectively. Together, our findings indicate that AUTS2 is critical for the acquisition of neurocognitive function.

Recombination and synaptic adjustment in oocytes of mice heterozygous for a large paracentric inversion.

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Torgasheva, Anna A; Rubtsov, Nikolai B; Borodin, Pavel M

2013-03-01

Homologous chromosome synapsis in inversion heterozygotes results in the formation of inversion loops. These loops might be transformed into straight, non-homologously paired bivalents via synaptic adjustment. Synaptic adjustment was discovered 30 years ago; however, its relationship with recombination has remained unclear. We analysed this relationship in female mouse embryos heterozygous for large paracentric inversion In(1)1Rk using immunolocalisation of the synaptonemal complex (SYCP3) and mature recombination nodules (MLH1) proteins. The frequency of cells containing bivalents with inversion loops decreased from 69 % to 28 % during pachytene. If an MLH1 focus was present in the non-homologously paired inverted region of the straight bivalent, it was always located in the middle of the inversion. Most of the small, incompletely adjusted loops contained MLH1 foci near the points at which pairing partners were switched. This observation indicates that the degree of synaptic adjustment depended on the crossover position. Complete synaptic adjustment was only possible if a crossover (CO) was located exactly in the middle of the inversion. If a CO was located at any other site, this interrupted synaptic adjustment and resulted in inversion loops of different sizes with an MLH1 focus at or near the edge of the remaining loop.

High-throughput SNP genotyping in the highly heterozygous genome of Eucalyptus: assay success, polymorphism and transferability across species

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2011-01-01

Background High-throughput SNP genotyping has become an essential requirement for molecular breeding and population genomics studies in plant species. Large scale SNP developments have been reported for several mainstream crops. A growing interest now exists to expand the speed and resolution of genetic analysis to outbred species with highly heterozygous genomes. When nucleotide diversity is high, a refined diagnosis of the target SNP sequence context is needed to convert queried SNPs into high-quality genotypes using the Golden Gate Genotyping Technology (GGGT). This issue becomes exacerbated when attempting to transfer SNPs across species, a scarcely explored topic in plants, and likely to become significant for population genomics and inter specific breeding applications in less domesticated and less funded plant genera. Results We have successfully developed the first set of 768 SNPs assayed by the GGGT for the highly heterozygous genome of Eucalyptus from a mixed Sanger/454 database with 1,164,695 ESTs and the preliminary 4.5X draft genome sequence for E. grandis. A systematic assessment of in silico SNP filtering requirements showed that stringent constraints on the SNP surrounding sequences have a significant impact on SNP genotyping performance and polymorphism. SNP assay success was high for the 288 SNPs selected with more rigorous in silico constraints; 93% of them provided high quality genotype calls and 71% of them were polymorphic in a diverse panel of 96 individuals of five different species. SNP reliability was high across nine Eucalyptus species belonging to three sections within subgenus Symphomyrtus and still satisfactory across species of two additional subgenera, although polymorphism declined as phylogenetic distance increased. Conclusions This study indicates that the GGGT performs well both within and across species of Eucalyptus notwithstanding its nucleotide diversity ≥2%. The development of a much larger array of informative SNPs across

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

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

2007-05-01

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

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

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

2017-01-01

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

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

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Caitlin J Rinz

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

Mutation in TWINKLE in a Large Iranian Family with Progressive External Ophthalmoplegia, Myopathy, Dysphagia and Dysphonia, and Behavior Change.

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Tafakhori, Abbas; Yu Jin Ng, Alvin; Tohari, Sumanty; Venkatesh, Byrappa; Lee, Hane; Eskin, Ascia; Nelson, Stanley F; Bonnard, Carine; Reversade, Bruno; Kariminejad, Ariana

2016-02-01

TWINKLE (c10orf2) gene is responsible for autosomal dominant progressive external ophthalmoplegia (PEO). In rare cases, additional features such as muscle weakness, peripheral neuropathy, ataxia, cardiomyopathy, dysphagia, dysphonia, cataracts, depression, dementia, parkinsonism, and hearing loss have been reported in association with heterozygous mutations of the TWINKLE gene. We have studied a large Iranian family with myopathy, dysphonia, dysphagia, and behavior change in addition to PEO in affected members. We identified a missense mutation c.1121G > A in the c10orf2 gene in all affected members. Early death is a novel feature seen in affected members of this family that has not been reported to date. The association of PEO, myopathy, dysphonia, dysphagia, behavior change and early death has not been previously reported in the literature or other patients with this mutation.

Autosomal-dominant non-autoimmune hyperthyroidism presenting with neuromuscular symptoms.

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Elgadi, Aziz; Arvidsson, C-G; Janson, Annika; Marcus, Claude; Costagliola, Sabine; Norgren, Svante

2005-08-01

Neuromuscular presentations are common in thyroid disease, although the mechanism is unclear. In the present study, we investigated the pathogenesis in a boy with autosomal-dominant hyperthyroidism presenting with neuromuscular symptoms. The TSHr gene was investigated by direct sequencing. Functional properties of the mutant TSHr were investigated during transient expression in COS-7 cells. Family members were investigated by clinical and biochemical examinations. Sequence analysis revealed a previously reported heterozygous missense mutation Glycine 431 for Serine in the first transmembrane segment, leading to an increased specific constitutive activity. Three additional affected family members carried the same mutation. There was no indication of autoimmune disorder. All symptoms disappeared upon treatment with thacapzol and L-thyroxine and subsequent subtotal thyroidectomy. The data imply that neuromuscular symptoms can be caused by excessive thyroid hormone levels rather than by autoimmunity.

Functional recovery of regenerating motor axons is delayed in mice heterozygously deficient for the myelin protein P(0) gene

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Rosberg, Mette Romer; Alvarez, Susana; Krarup, Christian

2013-01-01

Mice with a heterozygous knock-out of the myelin protein P0 gene (P0+/-) develop a neuropathy similar to human Charcot-Marie-Tooth disease. They are indistinguishable from wild-types (WT) at birth and develop a slowly progressing demyelinating neuropathy. The aim of this study was to investigate...... whether the regeneration capacity of early symptomatic P0+/- is impaired as compared to age matched WT. Right sciatic nerves were lesioned at the thigh in 7-8 months old mice. Tibial motor axons at ankle were investigated by conventional motor conduction studies and axon excitability studies using...... threshold tracking. To evaluate regeneration we monitored the recovery of motor function after crush, and then compared the fiber distribution by histology. The overall motor performance was investigated using Rotor-Rod. P0+/- had reduced compound motor action potential amplitudes and thinner myelinated...

Changes in 5-HT4 receptor and 5-HT transporter binding in olfactory bulbectomized and glucocorticoid receptor heterozygous mice

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Licht, Cecilie L; Kirkegaard, Lisbeth; Zueger, Maha

2010-01-01

. The olfactory bulbectomized mice displayed increased activity in the open field test, a characteristic depression-like feature of this model. After bulbectomy, 5-HT(4) receptor binding was increased in the ventral hippocampus (12%) but unchanged in the dorsal hippocampus, frontal and caudal caudate putamen......]citalopram in two murine models of depression-related states, olfactory bulbectomy and glucocorticoid receptor heterozygous (GR(+/-)) mice. The olfactory bulbectomy model is characterized by 5-HT system changes, while the GR(+/-) mice have a deficit in hypothalamic-pituitary-adrenal (HPA) system control....... Among post hoc analyzed regions, there was a 14% decrease in 5-HT(4) receptor binding in the olfactory tubercles. The 5-HTT binding was unchanged in the hippocampus and caudate putamen of bulbectomized mice but post hoc analysis showed small decreases in lateral septum and lateral globus pallidus...

R353Q polymorphism in the factor VII gene and cardiovascular risk in Heterozygous Familial Hypercholesterolemia: a case-control study

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Pérez-Jiménez Francisco

2011-04-01

Full Text Available Abstract Background Heterozygous Familial Hypercholesterolemia (FH is a genetic disorder characterized by a high risk of cardiovascular disease. Certain polymorphisms of the factor VII gene have been associated with the development of coronary artery disease and there is a known association between factor VII levels and polymorphic variants in this gene. To date, no study has evaluated the association between factor VII and coronary artery disease in patients with FH. Results This case-control study comprised 720 patients (546 with FH and 174 controls. We determined the prevalence and allele frequencies of the R353Q polymorphism of factor VII, the plasma levels of factor VII antigen (FVII Ag and whether they could be predictive factors for cardiovascular risk. 75% (410 of the patients with FH were RR, 23% (127 RQ and 1.6% (9 QQ; in the control group 75.3% (131 were RR, 21.3% (37 RQ and 3.4% (6 QQ (p = 0.32. No statistically significant associations were observed in the distribution of genotypes and allele frequencies between case (FH and control groups. Nor did we find differences when we evaluated the relationship between the R353Q polymorphism and cardiovascular risk (including coronary disease, ischemic stroke and peripheral arterial disease, either in the univariate analysis or after adjustment for sex, age, arterial hypertension, body mass index, xanthomas, diabetes, smoking, HDLc and LDLc and lipid-lowering treatment. The FVII Ag concentrations behaved in a similar fashion, with no differences for the interaction between controls and those with FH (RR vs. RQ/QQ; p = 0.96. In the subgroup of patients with FH no association was found among cardiovascular disease, genotype and FVII Ag levels (RR vs. RQ/QQ; p = 0.97. Conclusions Our study did not find a direct relationship between cardiovascular risk in patients with Heterozygous Familial Hypercholesterolemia, the R353Q polymorphism of factor VII and FVII Ag levels.

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

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Abhisek Swaika

2016-01-01

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

Autosomal recessive Noonan syndrome associated with biallelic LZTR1 variants.

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Johnston, Jennifer J; van der Smagt, Jasper J; Rosenfeld, Jill A; Pagnamenta, Alistair T; Alswaid, Abdulrahman; Baker, Eva H; Blair, Edward; Borck, Guntram; Brinkmann, Julia; Craigen, William; Dung, Vu Chi; Emrick, Lisa; Everman, David B; van Gassen, Koen L; Gulsuner, Suleyman; Harr, Margaret H; Jain, Mahim; Kuechler, Alma; Leppig, Kathleen A; McDonald-McGinn, Donna M; Can, Ngoc Thi Bich; Peleg, Amir; Roeder, Elizabeth R; Rogers, R Curtis; Sagi-Dain, Lena; Sapp, Julie C; Schäffer, Alejandro A; Schanze, Denny; Stewart, Helen; Taylor, Jenny C; Verbeek, Nienke E; Walkiewicz, Magdalena A; Zackai, Elaine H; Zweier, Christiane; Zenker, Martin; Lee, Brendan; Biesecker, Leslie G

2018-02-22

PurposeTo characterize the molecular genetics of autosomal recessive Noonan syndrome.MethodsFamilies underwent phenotyping for features of Noonan syndrome in children and their parents. Two multiplex families underwent linkage analysis. Exome, genome, or multigene panel sequencing was used to identify variants. The molecular consequences of observed splice variants were evaluated by reverse-transcription polymerase chain reaction.ResultsTwelve families with a total of 23 affected children with features of Noonan syndrome were evaluated. The phenotypic range included mildly affected patients, but it was lethal in some, with cardiac disease and leukemia. All of the parents were unaffected. Linkage analysis using a recessive model supported a candidate region in chromosome 22q11, which includes LZTR1, previously shown to harbor mutations in patients with Noonan syndrome inherited in a dominant pattern. Sequencing analyses of 21 live-born patients and a stillbirth identified biallelic pathogenic variants in LZTR1, including putative loss-of-function, missense, and canonical and noncanonical splicing variants in the affected children, with heterozygous, clinically unaffected parents and heterozygous or normal genotypes in unaffected siblings.ConclusionThese clinical and genetic data confirm the existence of a form of Noonan syndrome that is inherited in an autosomal recessive pattern and identify biallelic mutations in LZTR1.Genet Med advance online publication, 22 February 2018; doi:10.1038/gim.2017.249.

Identification of a homozygous PSTPIP1 mutation in a patient with a PAPA-like syndrome responding to canakinumab treatment.

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Geusau, Alexandra; Mothes-Luksch, Nadine; Nahavandi, Hesam; Pickl, Winfried F; Wise, Carol A; Pourpak, Zahra; Ponweiser, Elisabeth; Eckhart, Leopold; Sunder-Plassmann, Raute

2013-02-01

Pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome (OMIM 604416) is a rare autosomal dominant inherited autoinflammatory syndrome characterized by pyogenic sterile arthritis and less frequently accompanied by pyoderma gangrenosum and acne. It is associated with dominant missense mutations in the proline-serine-threonine phosphatase-interacting protein 1 gene (PSTPIP1) located on chromosome 15. The patient was diagnosed as having features of a PAPA-like syndrome in which cutaneous manifestations, such as pyoderma gangrenosum and acne fulminans, predominated. Sequencing of the PSTPIP1 gene was performed in the patient and his extended family. The patient's DNA analysis revealed a homozygous nucleotide exchange c.773G>C in the PSTPIP1 gene, leading to the substitution of glycine 258 by alanine (p.Gly258Ala), a previously reported heterozygous polymorphism. Heterozygous changes were identified in both of the patient's parents and in 7 other family members, all of whom were asymptomatic. The patient was treated with canakinumab, a human anti-interleukin 1β monoclonal antibody, which led to rapid remission of the symptoms. To our knowledge, this is the first reported case of the resolution of dermatological symptoms associated with a PAPA-like syndrome using canakinumab treatment. Further study of the p.Gly258Ala variant is warranted to determine whether this mutation has a role in causing an apparently recessive cutaneous syndrome resembling PAPA syndrome.

Mutation analysis of genes that control the G1/S cell cycle in melanoma: TP53, CDKN1A, CDKN2A, and CDKN2B

International Nuclear Information System (INIS)

Soto, José Luis; Cabrera, Carmen M; Serrano, Salvio; López-Nevot, Miguel Ángel

2005-01-01

The role of genes involved in the control of progression from the G1 to the S phase of the cell cycle in melanoma tumors in not fully known. The aim of our study was to analyse mutations in TP53, CDKN1A, CDKN2A, and CDKN2B genes in melanoma tumors and melanoma cell lines We analysed 39 primary and metastatic melanomas and 9 melanoma cell lines by single-stranded conformational polymorphism (SSCP). The single-stranded technique showed heterozygous defects in the TP53 gene in 8 of 39 (20.5%) melanoma tumors: three new single point mutations in intronic sequences (introns 1 and 2) and exon 10, and three new single nucleotide polymorphisms located in introns 1 and 2 (C to T transition at position 11701 in intron 1; C insertion at position 11818 in intron 2; and C insertion at position 11875 in intron 2). One melanoma tumor exhibited two heterozygous alterations in the CDKN2A exon 1 one of which was novel (stop codon, and missense mutation). No defects were found in the remaining genes. These results suggest that these genes are involved in melanoma tumorigenesis, although they may be not the major targets. Other suppressor genes that may be informative of the mechanism of tumorigenesis in skin melanomas should be studied

Genetic analysis of PAX3 for diagnosis of Waardenburg syndrome type I.

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Matsunaga, Tatsuo; Mutai, Hideki; Namba, Kazunori; Morita, Noriko; Masuda, Sawako

2013-04-01

PAX3 genetic analysis increased the diagnostic accuracy for Waardenburg syndrome type I (WS1). Analysis of the three-dimensional (3D) structure of PAX3 helped verify the pathogenicity of a missense mutation, and multiple ligation-dependent probe amplification (MLPA) analysis of PAX3 increased the sensitivity of genetic diagnosis in patients with WS1. Clinical diagnosis of WS1 is often difficult in individual patients with isolated, mild, or non-specific symptoms. The objective of the present study was to facilitate the accurate diagnosis of WS1 through genetic analysis of PAX3 and to expand the spectrum of known PAX3 mutations. In two Japanese families with WS1, we conducted a clinical evaluation of symptoms and genetic analysis, which involved direct sequencing, MLPA analysis, quantitative PCR of PAX3, and analysis of the predicted 3D structure of PAX3. The normal-hearing control group comprised 92 subjects who had normal hearing according to pure tone audiometry. In one family, direct sequencing of PAX3 identified a heterozygous mutation, p.I59F. Analysis of PAX3 3D structures indicated that this mutation distorted the DNA-binding site of PAX3. In the other family, MLPA analysis and subsequent quantitative PCR detected a large, heterozygous deletion spanning 1759-2554 kb that eliminated 12-18 genes including a whole PAX3 gene.

Explosive mutation accumulation triggered by heterozygous human Pol ε proofreading-deficiency is driven by suppression of mismatch repair

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Campbell, Brittany B; Ungerleider, Nathan; Light, Nicholas; Wu, Tong; LeCompte, Kimberly G; Goksenin, A Yasemin; Bunnell, Bruce A; Tabori, Uri; Shlien, Adam

2018-01-01

Tumors defective for DNA polymerase (Pol) ε proofreading have the highest tumor mutation burden identified. A major unanswered question is whether loss of Pol ε proofreading by itself is sufficient to drive this mutagenesis, or whether additional factors are necessary. To address this, we used a combination of next generation sequencing and in vitro biochemistry on human cell lines engineered to have defects in Pol ε proofreading and mismatch repair. Absent mismatch repair, monoallelic Pol ε proofreading deficiency caused a rapid increase in a unique mutation signature, similar to that observed in tumors from patients with biallelic mismatch repair deficiency and heterozygous Pol ε mutations. Restoring mismatch repair was sufficient to suppress the explosive mutation accumulation. These results strongly suggest that concomitant suppression of mismatch repair, a hallmark of colorectal and other aggressive cancers, is a critical force for driving the explosive mutagenesis seen in tumors expressing exonuclease-deficient Pol ε. PMID:29488881

Generation of human iPSC line from a patient with laterality defects and associated congenital heart anomalies carrying a DAND5 missense alteration

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Fernando Cristo

2017-12-01

Full Text Available A human iPSC line was generated from exfoliated renal epithelial (ERE cells of a patient affected with Congenital Heart Disease (CHD and Laterality Defects carrying tshe variant p.R152H in the DAND5 gene. The transgene-free iPSCs were generated with the human OSKM transcription factor using the Sendai-virus reprogramming system. The established iPSC line had the specific heterozygous alteration, a stable karyotype, expressed pluripotency markers and generated embryoid bodies that can differentiate towards the three germ layers in vitro. This iPSC line offers a useful resource to study the molecular mechanisms of cardiomyocyte proliferation, as well as for drug testing.

Screening of Missense SNPs in Coding Regions of COX-2 as a Key Enzyme Involved in Cancer

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Sodabeh Jahanbakhsh-Godehkahriz

2013-09-01

Full Text Available Background & Objectives: Non-synonymous single nucleotide polymorphism (nsSNPs which results in disruption of protein function are used as markers in linkage and association of human proteins that might be involved in diseases and cancers .   Methods: To study the functional effect of nsSNP in cyclooxygenase-2 (COX2 amino acids, the nucleotide sequences encoding COX-2 gene in cancers were extracted from the NCBI (gi|223941909 data bank (283 cases and analyzed by SIFT, I-Mutant 2.0, SNP and GO, PANTHER and FASTSNP servers. These servers involve programs that predict the effects of amino acid substitution on protein function, stability and missense .   Results: COX-2 is an essential enzyme for the production of pro-inflammatory prostaglandins which are relevant to cancer development and progression. The substitutions in some positions such as R228H and S428A of COX-2 in most of cancers linked to reformed protein function through disruption in enzyme active site.   Conclusion: Amino acid substitutions as a consequence of COX-2 nsSNPs have important role in human disease. Substitutions which are located in catalytic domain are important for the enzymatic function of COX-2 and associated with higher expression of COX-2.

Effects of LSD on grooming behavior in serotonin transporter heterozygous (Sert⁺/⁻) mice.

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Kyzar, Evan J; Stewart, Adam Michael; Kalueff, Allan V

2016-01-01

Serotonin (5-HT) plays a crucial role in the brain, modulating mood, cognition and reward. The serotonin transporter (SERT) is responsible for the reuptake of 5-HT from the synaptic cleft and regulates serotonin signaling in the brain. In humans, SERT genetic variance is linked to the pathogenesis of various psychiatric disorders, including anxiety, autism spectrum disorders (ASD) and obsessive-compulsive disorder (OCD). Rodent self-grooming is a complex, evolutionarily conserved patterned behavior relevant to stress, ASD and OCD. Genetic ablation of mouse Sert causes various behavioral deficits, including increased anxiety and grooming behavior. The hallucinogenic drug lysergic acid diethylamide (LSD) is a potent serotonergic agonist known to modulate human and animal behavior. Here, we examined heterozygous Sert(+/-) mouse behavior following acute administration of LSD (0.32 mg/kg). Overall, Sert(+/-) mice displayed a longer duration of self-grooming behavior regardless of LSD treatment. In contrast, LSD increased serotonin-sensitive behaviors, such as head twitching, tremors and backwards gait behaviors in both Sert(+/+) and Sert(+/-) mice. There were no significant interactions between LSD treatment and Sert gene dosage in any of the behavioral domains measured. These results suggest that Sert(+/-) mice may respond to the behavioral effects of LSD in a similar manner to wild-type mice. Copyright © 2015 Elsevier B.V. All rights reserved.

Phenotype of Usher syndrome type II assosiated with compound missense mutations of c.721 C>T and c.1969 C>T in MYO7A in a Chinese Usher syndrome family.

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Zhai, Wei; Jin, Xin; Gong, Yan; Qu, Ling-Hui; Zhao, Chen; Li, Zhao-Hui

2015-01-01

To identify the pathogenic mutations in a Chinese pedigree affected with Usher syndrome type II (USH2). The ophthalmic examinations and audiometric tests were performed to ascertain the phenotype of the family. To detect the genetic defect, exons of 103 known RDs -associated genes including 12 Usher syndrome (USH) genes of the proband were captured and sequencing analysis was performed to exclude known genetic defects and find potential pathogenic mutations. Subsequently, candidate mutations were validated in his pedigree and 100 normal controls using polymerase chain reaction (PCR) and Sanger sequencing. The patient in the family occurred hearing loss (HL) and retinitis pigmentosa (RP) without vestibular dysfunction, which were consistent with standards of classification for USH2. He carried the compound heterozygous mutations, c.721 C>T and c.1969 C>T, in the MYO7A gene and the unaffected members carried only one of the two mutations. The mutations were not present in the 100 normal controls. We suggested that the compound heterozygous mutations of the MYO7A could lead to USH2, which had revealed distinguished clinical phenotypes associated with MYO7A and expanded the spectrum of clinical phenotypes of the MYO7A mutations.

Mapping of the human cone transducin {alpha} subunit (GNAT2) gene to 1p13 and mutation analysis in patients with Stargardt`s disease

Energy Technology Data Exchange (ETDEWEB)

Magovcevic, I.; Weremowicz, S.; Morton, C.C. [Harvard Medical School, Boston, MA (United States)] [and others

1994-09-01

Transducin {alpha} subunits are members of a large family of G-proteins and play an important role in phototransduction in rod and cone photoreceptors. We report the localization of the human cone {alpha} transducin (GNAT2) gene using fluorescence in situ hybridization (FISH) on chromosome 1 in band p13. The recent assignment of a gene for Stargardt`s disease to the same chromosomal region by linkage analysis prompted us to investigate the possible role of GNAT2 in the pathogenesis of this disease. Stargardt`s disease is characterized by degeneration in late childhood or early adulthood of the macula of the retina, a region rich in cones. We screened patients with Stargardt`s disease, with or without peripheral cone involvement as monitored by the full-field ERG, for mutations in this gene. We investigated 66 unrelated patients including 22 with peripheral cone dysfunction for mutations in the coding region of the GNAT2 gene using polymerase chain reaction-single strand conformation polymorphism analysis (SSCP) and direct sequencing. One patient (034-16) was heterozygous for a silent change in exon VI, Asp238Asp (GAT to GAC). Two patients, one (035-005) with peripheral cone involvement and one (071-001) without peripheral cone involvement, were heterozygous for the missense change Val124Met (GTG to ATG) in exon IV. A subsequent screen of 96 unrelated, unaffected controls revealed one individual (N10) who was also heterozygous for the Val124Met alteration. We concluded that Asp238Asp and Val124Met are rare variants not causing Stargardt`s disease. Hence, no disease-specific mutations were found indicating that GNAT2 is probably not involved in the pathogenesis of most cases of Stargardt`s disease.

A dominant-negative mutation of mouse Lmx1b causes glaucoma and is semi-lethal via LDB1-mediated dimerization [corrected].

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Sally H Cross

2014-05-01

Full Text Available Mutations in the LIM-homeodomain transcription factor LMX1B cause nail-patella syndrome, an autosomal dominant pleiotrophic human disorder in which nail, patella and elbow dysplasia is associated with other skeletal abnormalities and variably nephropathy and glaucoma. It is thought to be a haploinsufficient disorder. Studies in the mouse have shown that during development Lmx1b controls limb dorsal-ventral patterning and is also required for kidney and eye development, midbrain-hindbrain boundary establishment and the specification of specific neuronal subtypes. Mice completely deficient for Lmx1b die at birth. In contrast to the situation in humans, heterozygous null mice do not have a mutant phenotype. Here we report a novel mouse mutant Icst, an N-ethyl-N-nitrosourea-induced missense substitution, V265D, in the homeodomain of LMX1B that abolishes DNA binding and thereby the ability to transactivate other genes. Although the homozygous phenotypic consequences of Icst and the null allele of Lmx1b are the same, heterozygous Icst elicits a phenotype whilst the null allele does not. Heterozygous Icst causes glaucomatous eye defects and is semi-lethal, probably due to kidney failure. We show that the null phenotype is rescued more effectively by an Lmx1b transgene than is Icst. Co-immunoprecipitation experiments show that both wild-type and Icst LMX1B are found in complexes with LIM domain binding protein 1 (LDB1, resulting in lower levels of functional LMX1B in Icst heterozygotes than null heterozygotes. We conclude that Icst is a dominant-negative allele of Lmx1b. These findings indicate a reassessment of whether nail-patella syndrome is always haploinsufficient. Furthermore, Icst is a rare example of a model of human glaucoma caused by mutation of the same gene in humans and mice.

A novel loss-of-function heterozygous BRCA2 c.8946_8947delAG mutation found in a Chinese woman with family history of breast cancer.

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Ma, Jing; Yang, Jichun; Jian, Wenjing; Wang, Xianming; Xiao, Deyong; Xia, Wenjun; Xiong, Likuan; Ma, Duan

2017-04-01

Breast cancer is the most frequent female malignancy worldwide. Among them, some cases have hereditary susceptibility in two leading genes, BRCA1 and BRCA2. Heterozygous germ line mutations in them are related with increased risk of breast, ovarian and other cancer, following autosomal dominant inheritance mode. For purpose of early finding, early diagnosis and early treatment, mutation detecting of BRCA1/2 genes was performed in unselected 300 breast or ovarian patients and unaffected women using next-generation sequencing and then confirmed by Sanger sequencing. A non-previously reported heterozygous mutation c.8946_8947delAG (p.D2983FfsX34) of BRCA2 gene was identified in an unaffected Chinese woman with family history of breast cancer (her breast cancer mother, also carrying this mutation). The BRCA2-truncated protein resulted from the frame shift mutation was found to lose two putative nuclear localization signals and a Rad51-binding motif in the extreme C-terminal region by bioinformatic prediction. And then in vitro experiments showed that nearly all the mutant protein was unable to translocate to the nucleus to perform DNA repair activity. This novel mutant BRCA2 protein is dysfunction. We classify the mutation into disease causing and conclude that it is the risk factor for breast cancer in this family. So, conducting the same mutation test and providing genetic counseling for this family is practically meaningful and significant. Meanwhile, the identification of this new mutation enriches the Breast Cancer Information Core database, especially in China.

Two novel mutations in exon 3 and 4 of low density lipoprotein (LDL) receptor gene in patients with heterozygous familial hypercholesterolemia

International Nuclear Information System (INIS)

Khan, S.P.

2011-01-01

Objective: To determine the common mutation of low density lipoprotein receptor in hypercholesterolemia patients requiring screening for heterozygous familial hypercholesterolemia (HeFH) in Karachi. Study Design: Case-series. Place and Duration of Study: Dr. Ziauddin Hospital Laboratory and Dr. Rubina Ghani's Pathological and Molecular Laboratories, Karachi, for the PCR bench work from June 2008 to October 2009. Methodology: All the patients selected for this study were from Dr. Ziauddin Hospital and National Institute of Cardiovascular Diseases. All the patients having high total cholesterol and LDL-cholesterol were included in this study with premature coronary artery diseases or a family history of hypercholesterolemia. Exclusion criteria included Diabetes mellitus, hypertension, renal disease, hypothyroidism and steroid therapy. After lipid profile with overnight fasting, DNA was extracted from whole blood collected in EDTA (ethylenediamine tetra acetic acid) tube and multiplex PCR (polymerase chain reaction) using forward and reverse primers of exons 3, 4, 9 and 14 of base pairs 162, 431, 550 and 496 respectively. Results: Out of total of 120 hypercholesterolemia cases, 42 patients were classical cases of HeFH (heterozygous familial hypercholesterolemia) with xanthomas, xanthelasmas and LDL-C > 160 mg/dl. The total cholesterol (260 +- 57 mg/dL) and LDL-C (192 +- 39 mg/dL ) of cases was significantly high as compared to, controls having total cholesterol (184 9 +- 27 mg/dL) and LDL-C (105 +- 22 mg/dL), p > 0.001. Two novel point mutations were noted in exon 3 and exon 4. The other 78 cases were probable with raised LDL-C (low density lipoprotein cholesterol) and family history of premature coronary heart diseases. Conclusion: The frequency of HeFH was 35% classical and 65% probable cases out of total 120 hypercholesterolemia patients from two tertiary care hospitals in Karachi. The point mutation on exon 3 and exon 4 of LDLR gene was the most common. PCR is

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

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

2015-01-01

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

A kinase-dead knock-in mutation in mTOR leads to early embryonic lethality and is dispensable for the immune system in heterozygous mice

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Cavender Druie

2009-05-01

Full Text Available Abstract Background The mammalian target of rapamycin protein (mTOR is an evolutionarily conserved kinase that regulates protein synthesis, cell cycle progression and proliferation in response to various environmental cues. As a critical downstream mediator of PI3K signaling, mTOR is important for lymphocyte development and function of mature T and B-cells. Most studies of mTOR in immune responses have relied on the use of pharmacological inhibitors, such as rapamycin. Rapamycin-FKBP12 complex exerts its immunosuppressive and anti-proliferative effect by binding outside the kinase domain of mTOR, and subsequently inhibiting downstream mTOR signaling. Results To determine the requirement for mTOR kinase activity in the immune system function, we generated knock-in mice carrying a mutation (D2338 in the catalytic domain of mTOR. While homozygous mTOR kd/kd embryos died before embryonic day 6.5, heterozygous mTOR+/kd mice appeared entirely normal and are fertile. mTOR +/kd mice exhibited normal T and B cell development and unaltered proliferative responses of splenocytes to IL-2 and TCR/CD28. In addition, heterozygousity for the mTOR kinase-dead allele did not sensitize T cells to rapamycin in a CD3-mediated proliferation assay. Unexpectedly, mTOR kinase activity towards its substrate 4E-BP1 was not decreased in hearts and livers from heterozygous animals. Conclusion Altogether, our findings indicate that mTOR kinase activity is indispensable for the early development of mouse embryos. Moreover, a single wild type mTOR allele is sufficient to maintain normal postnatal growth and lymphocyte development and proliferation.

Heterozygous Null Bone Morphogenetic Protein Receptor Type 2 Mutations Promote SRC Kinase-dependent Caveolar Trafficking Defects and Endothelial Dysfunction in Pulmonary Arterial Hypertension*

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Prewitt, Allison R.; Ghose, Sampa; Frump, Andrea L.; Datta, Arumima; Austin, Eric D.; Kenworthy, Anne K.; de Caestecker, Mark P.

2015-01-01

Hereditary pulmonary arterial hypertension (HPAH) is a rare, fatal disease of the pulmonary vasculature. The majority of HPAH patients inherit mutations in the bone morphogenetic protein type 2 receptor gene (BMPR2), but how these promote pulmonary vascular disease is unclear. HPAH patients have features of pulmonary endothelial cell (PEC) dysfunction including increased vascular permeability and perivascular inflammation associated with decreased PEC barrier function. Recently, frameshift mutations in the caveolar structural protein gene Caveolin-1 (CAV-1) were identified in two patients with non-BMPR2-associated HPAH. Because caveolae regulate endothelial function and vascular permeability, we hypothesized that defects in caveolar function might be a common mechanism by which BMPR2 mutations promote pulmonary vascular disease. To explore this, we isolated PECs from mice carrying heterozygous null Bmpr2 mutations (Bmpr2+/−) similar to those found in the majority of HPAH patients. We show that Bmpr2+/− PECs have increased numbers and intracellular localization of caveolae and caveolar structural proteins CAV-1 and Cavin-1 and that these defects are reversed after blocking endocytosis with dynasore. SRC kinase is also constitutively activated in Bmpr2+/− PECs, and localization of CAV-1 to the plasma membrane is restored after treating Bmpr2+/− PECs with the SRC kinase inhibitor 3-(4-chlorophenyl)-1-(1,1-dimethylethyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine (PP2). Late outgrowth endothelial progenitor cells isolated from HPAH patients show similar increased activation of SRC kinase. Moreover, Bmpr2+/− PECs have impaired endothelial barrier function, and barrier function is restored after treatment with PP2. These data suggest that heterozygous null BMPR2 mutations promote SRC-dependent caveolar trafficking defects in PECs and that this may contribute to pulmonary endothelial barrier dysfunction in HPAH patients. PMID:25411245

The refractive state of the eye in Icelandic horses with the Silver mutation.

Science.gov (United States)

Johansson, Maria K; Jäderkvist Fegraeus, Kim; Lindgren, Gabriella; Ekesten, Björn

2017-06-02

The syndrome Multiple Congenital Ocular Anomalies (MCOA) is a congenital eye disorder in horses. Both the MCOA syndrome and the Silver coat colour in horses are caused by the same missense mutation in the premelanosome protein (PMEL) gene. Horses homozygous for the Silver mutation (TT) are affected by multiple ocular defects causing visual impairment or blindness. Horses heterozygous for the Silver mutation (CT) have less severe clinical signs, usually cysts arising from the ciliary body iris or retina temporally. It is still unknown if the vision is impaired in horses heterozygous for the Silver mutation. A recent study reported that Comtois horses carrying the Silver mutation had significantly deeper anterior chambers of the eye compared to wild-type horses. This could potentially cause refractive errors. The purpose of the present study was to investigate if Icelandic horses with the Silver mutation have refractive errors compared to wild-type horses. One hundred and fifty-two Icelandic horses were included in the study, 71 CT horses and five TT horses. All horses were genotyped for the missense mutation in PMEL. Each CT and TT horse was matched by a wild-type (CC) horse of the same age ± 1 year. Skiascopy and a brief ophthalmic examination were performed in all horses. Association between refraction and age, eye, genotype and sex was tested by linear mixed-effect model analysis. TT horses with controls were not included in the statistical analyses as they were too few. The interaction between age and genotype had a significant impact on the refractive state (P = 0.0001). CT horses older than 16 years were on average more myopic than wild-type horses of the same age. No difference in the refractive state could be observed between genotypes (CT and CC) in horses younger than 16 years. TT horses were myopic (-2 D or more) in one or both eyes regardless of age. Our results indicate that an elderly Icelandic horse (older than 16 years) carrying the Silver

Hot-spot KIF5A mutations cause familial ALS

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Yilmaz, Rüstem; Müller, Kathrin; Grehl, Torsten; Petri, Susanne; Meyer, Thomas; Grosskreutz, Julian; Weydt, Patrick; Ruf, Wolfgang; Neuwirth, Christoph; Weber, Markus; Pinto, Susana; Claeys, Kristl G; Schrank, Berthold; Jordan, Berit; Knehr, Antje; Günther, Kornelia; Hübers, Annemarie; Zeller, Daniel; Kubisch, Christian; Jablonka, Sibylle; Klopstock, Thomas; de Carvalho, Mamede; Sperfeld, Anne; Borck, Guntram; Volk, Alexander E; Dorst, Johannes; Weis, Joachim; Otto, Markus; Schuster, Joachim; Del Tredici, Kelly; Braak, Heiko; Danzer, Karin M; Freischmidt, Axel; Meitinger, Thomas; Strom, Tim M; Ludolph, Albert C; Andersen, Peter M; Weishaupt, Jochen H; Weyen, Ute; Hermann, Andreas; Hagenacker, Tim; Koch, Jan Christoph; Lingor, Paul; Göricke, Bettina; Zierz, Stephan; Baum, Petra; Wolf, Joachim; Winkler, Andrea; Young, Peter; Bogdahn, Ulrich; Prudlo, Johannes; Kassubek., Jan

2018-01-01

Abstract Heterozygous missense mutations in the N-terminal motor or coiled-coil domains of the kinesin family member 5A (KIF5A) gene cause monogenic spastic paraplegia (HSP10) and Charcot-Marie-Tooth disease type 2 (CMT2). Moreover, heterozygous de novo frame-shift mutations in the C-terminal domain of KIF5A are associated with neonatal intractable myoclonus, a neurodevelopmental syndrome. These findings, together with the observation that many of the disease genes associated with amyotrophic lateral sclerosis disrupt cytoskeletal function and intracellular transport, led us to hypothesize that mutations in KIF5A are also a cause of amyotrophic lateral sclerosis. Using whole exome sequencing followed by rare variant analysis of 426 patients with familial amyotrophic lateral sclerosis and 6137 control subjects, we detected an enrichment of KIF5A splice-site mutations in amyotrophic lateral sclerosis (2/426 compared to 0/6137 in controls; P = 4.2 × 10−3), both located in a hot-spot in the C-terminus of the protein and predicted to affect splicing exon 27. We additionally show co-segregation with amyotrophic lateral sclerosis of two canonical splice-site mutations in two families. Investigation of lymphoblast cell lines from patients with KIF5A splice-site mutations revealed the loss of mutant RNA expression and suggested haploinsufficiency as the most probable underlying molecular mechanism. Furthermore, mRNA sequencing of a rare non-synonymous missense mutation (predicting p.Arg1007Gly) located in the C-terminus of the protein shortly upstream of the splice donor of exon 27 revealed defective KIF5A pre-mRNA splicing in respective patient-derived cell lines owing to abrogation of the donor site. Finally, the non-synonymous single nucleotide variant rs113247976 (minor allele frequency = 1.00% in controls, n = 6137), also located in the C-terminal region [p.(Pro986Leu) in exon 26], was significantly enriched in familial amyotrophic lateral sclerosis patients (minor

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

Science.gov (United States)

2011-01-01

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

Mutations of the aminoacyl-tRNA-synthetases SARS and WARS2 are implicated in the etiology of autosomal recessive intellectual disability.

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Musante, Luciana; Püttmann, Lucia; Kahrizi, Kimia; Garshasbi, Masoud; Hu, Hao; Stehr, Henning; Lipkowitz, Bettina; Otto, Sabine; Jensen, Lars R; Tzschach, Andreas; Jamali, Payman; Wienker, Thomas; Najmabadi, Hossein; Ropers, Hans Hilger; Kuss, Andreas W

2017-06-01

Intellectual disability (ID) is the hallmark of an extremely heterogeneous group of disorders that comprises a wide variety of syndromic and non-syndromic phenotypes. Here, we report on mutations in two aminoacyl-tRNA synthetases that are associated with ID in two unrelated Iranian families. In the first family, we identified a homozygous missense mutation (c.514G>A, p.Asp172Asn) in the cytoplasmic seryl-tRNA synthetase (SARS) gene. The mutation affects the enzymatic core domain of the protein and impairs its enzymatic activity, probably leading to reduced cytoplasmic tRNA Ser concentrations. The mutant protein was predicted to be unstable, which could be substantiated by investigating ectopic mutant SARS in transfected HEK293T cells. In the second family, we found a compound heterozygous genotype of the mitochondrial tryptophanyl-tRNA synthetase (WARS2) gene, comprising a nonsense mutation (c.325delA, p.Ser109Alafs*15), which very likely entails nonsense-mediated mRNA decay and a missense mutation (c.37T>G, p.Trp13Gly). The latter affects the mitochondrial localization signal of WARS2, causing protein mislocalization. Including AIMP1, which we have recently implicated in the etiology of ID, three genes with a role in tRNA-aminoacylation are now associated with this condition. We therefore suggest that the functional integrity of tRNAs in general is an important factor in the development and maintenance of human cognitive functions. © 2017 Wiley Periodicals, Inc.

Inherited Anti-Thrombin Deficiency in A Malay-Malaysian Family: A Missense Mutation at Nucleotide g.13267C>A aka anti-thrombin Budapest 5 (p.Pro439Thr) of the SERPINC 1 gene.

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Norlelawati, A T; Rusmawati, I; Naznin, M; Nur Nadia, O; Rizqan Aizzani, R; Noraziana, A W

2014-02-01

Inherited anti-thrombin deficiency is an autosomal dominant disorder which is associated with increased risk for venous thromboembolism (VTE). This condition is very rare in Malaysia and there has been no documented report. Thus, the aim of the present study is to investigate the type of an inherited anti-thrombin deficiency mutation in a 25-year-old Malay woman who presented with deep vein thrombosis in her first pregnancy. DNA was extracted from the patient's blood sample and buccal mucosal swabs from family members. Polymerase chain reaction(PCR) assays were designed to cover all seven exons of the serpin peptidase inhibitor, clade C (antithrombin), member 1 (SERPINC1) gene; and the products were subjected to DNA sequencing. Sequences were referred to NCBI Reference Sequence: NG_012462.1. A heterozygous substitution mutation at nucleotide position 13267 (CCT->ACT) was identified in the patient and two other family members, giving a possible change of codon 439 (Pro→Thr) also known as anti-thrombin Budapest 5. The genotype was absent in 90 healthy controls. The study revealed a heterozygous antithrombin Budapest 5 mutation in SERPINC 1 giving rise to a possible anti-thrombin deficiency in a Malay-Malaysian family.

Amino-terminal residues of ΔNp63, mutated in ectodermal dysplasia, are required for its transcriptional activity.

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Lena, Anna Maria; Duca, Sara; Novelli, Flavia; Melino, Sonia; Annicchiarico-Petruzzelli, Margherita; Melino, Gerry; Candi, Eleonora

2015-11-13

p63, a member of the p53 family, is a crucial transcription factor for epithelial development and skin homeostasis. Heterozygous mutations in TP63 gene have been associated with human ectodermal dysplasia disorders. Most of these TP63 mutations are missense mutations causing amino acidic substitutions at p63 DNA binding or SAM domains that reduce or abolish the transcriptional activity of mutants p63. A significant number of mutants, however, resides in part of the p63 protein that apparently do not affect DNA binding and/or transcriptional activity, such as the N-terminal domain. Here, we characterize five p63 mutations at the 5' end of TP63 gene aiming to understand the pathogenesis of the diseases and to uncover the role of ΔNp63α N-terminus residues in determining its transactivation potential. Copyright © 2015 Elsevier Inc. All rights reserved.

Coffin-Siris syndrome: phenotypic evolution of a novel SMARCA4 mutation.

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Tzeng, Michael; du Souich, Christèle; Cheung, Helen Wing-Hong; Boerkoel, Cornelius F

2014-07-01

Coffin-Siris Syndrome (CSS) is an intellectual disability disorder caused by mutation of components of the SWI/SNF chromatin-remodeling complex. We describe the evolution of the phenotypic features for a male patient with CSS from birth to age 7 years and 9 months and by review of reported CSS patients, we expand the phenotype to include neonatal and infantile hypertonia and upper airway obstruction. The propositus had a novel de novo heterozygous missense mutation in exon 17 of SMARCA4 (NM_001128849.1:c.2434C>T (NP_001122321.1:p.Leu812Phe)). This is the first reported mutation within motif Ia of the SMARCA4 SNF2 domain. In summary, SMARCA4-associated CSS is a pleiotropic disorder in which the pathognomic clinical features evolve and for which the few reported individuals do not demonstrate a clear genotype-phenotype correlation. © 2014 Wiley Periodicals, Inc.

Nonhomologous Synapsis and Reduced Crossing over in a Heterozygous Paracentric Inversion in Saccharomyces Cerevisiae

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Dresser, M. E.; Ewing, D. J.; Harwell, S. N.; Coody, D.; Conrad, M. N.

1994-01-01

Homologous chromosome synapsis (``homosynapsis'') and crossing over are well-conserved aspects of meiotic chromosome behavior. The long-standing assumption that these two processes are causally related has been challenged recently by observations in Saccharomyces cerevisiae of significant levels of crossing over (1) between small sequences at nonhomologous locations and (2) in mutants where synapsis is abnormal or absent. In order to avoid problems of local sequence effects and of mutation pleiotropy, we have perturbed synapsis by making a set of isogenic strains that are heterozygous and homozygous for a large chromosomal paracentric inversion covering a well marked genetic interval and then measured recombination. We find that reciprocal recombination in the marked interval in heterozygotes is reduced variably across the interval, on average to ~55% of that in the homozygotes, and that positive interference still modulates crossing over. Cytologically, stable synapsis across the interval is apparently heterologous rather than homologous, consistent with the interpretation that stable homosynapsis is required to initiate or consummate a large fraction of the crossing over observed in wild-type strains. When crossing over does occur in heterozygotes, dicentric and acentric chromosomes are formed and can be visualized and quantitated on blots though not demonstrated in viable spores. We find that there is no loss of dicentric chromosomes during the two meiotic divisions and that the acentric chromosome is recovered at only 1/3 to 1/2 of the expected level. PMID:7851761

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

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

2017-03-01

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

Whole-exome sequencing identifies novel compound heterozygous mutations in USH2A in Spanish patients with autosomal recessive retinitis pigmentosa.

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Méndez-Vidal, Cristina; González-Del Pozo, María; Vela-Boza, Alicia; Santoyo-López, Javier; López-Domingo, Francisco J; Vázquez-Marouschek, Carmen; Dopazo, Joaquin; Borrego, Salud; Antiñolo, Guillermo

2013-01-01

Retinitis pigmentosa (RP) is an inherited retinal dystrophy characterized by extreme genetic and clinical heterogeneity. Thus, the diagnosis is not always easily performed due to phenotypic and genetic overlap. Current clinical practices have focused on the systematic evaluation of a set of known genes for each phenotype, but this approach may fail in patients with inaccurate diagnosis or infrequent genetic cause. In the present study, we investigated the genetic cause of autosomal recessive RP (arRP) in a Spanish family in which the causal mutation has not yet been identified with primer extension technology and resequencing. We designed a whole-exome sequencing (WES)-based approach using NimbleGen SeqCap EZ Exome V3 sample preparation kit and the SOLiD 5500×l next-generation sequencing platform. We sequenced the exomes of both unaffected parents and two affected siblings. Exome analysis resulted in the identification of 43,204 variants in the index patient. All variants passing filter criteria were validated with Sanger sequencing to confirm familial segregation and absence in the control population. In silico prediction tools were used to determine mutational impact on protein function and the structure of the identified variants. Novel Usher syndrome type 2A (USH2A) compound heterozygous mutations, c.4325T>C (p.F1442S) and c.15188T>G (p.L5063R), located in exons 20 and 70, respectively, were identified as probable causative mutations for RP in this family. Family segregation of the variants showed the presence of both mutations in all affected members and in two siblings who were apparently asymptomatic at the time of family ascertainment. Clinical reassessment confirmed the diagnosis of RP in these patients. Using WES, we identified two heterozygous novel mutations in USH2A as the most likely disease-causing variants in a Spanish family diagnosed with arRP in which the cause of the disease had not yet been identified with commonly used techniques. Our data

Paternal uniparental heterodisomy with partial isodisomy of chromosome 1 in a patient with retinitis pigmentosa without hearing loss and a missense mutation in the Usher syndrome type II gene USH2A.

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Rivolta, Carlo; Berson, Eliot L; Dryja, Thaddeus P

2002-11-01

To evaluate a form of nonmendelian inheritance in a patient with retinitis pigmentosa (RP). Direct DNA sequencing of the USH2A coding region and microsatellite analysis of polymorphic markers from chromosome 1 and other chromosomes. A patient with RP without hearing loss caused by the homozygous mutation Cys759Phe in the USH2A gene on chromosome 1q was found to be the daughter of a noncarrier mother and a father who was heterozygous for this change. Further evaluation with microsatellite markers revealed that the patient had inherited 2 copies of chromosome 1 from her father and none from her mother. The paternally derived chromosome 1's were heteroallelic from the centromere of chromosome 1 to the proximal short and long arms. The distal regions of the short and long arms of chromosome 1 were homoallelic, including the region of 1q with the mutant USH2A allele. This genetic pattern is compatible with a phenomenon of uniparental primary heterodisomy with regions of homozygosity arising through a nondisjunction event during paternal meiosis I and subsequent trisomy rescue or gamete complementation. A paternal second cousin of the patient also had RP and also had an identical heterozygous mutation in the USH2A gene in the same codon. However, the analysis of an isocoding polymorphism 20 base pairs away and closely linked microsatellite markers in the patient and family members indicated that the 2 mutant alleles are unlikely to be identical by descent and that the 2 relatives fortuitously had RP and a mutation in the same codon of the USH2A gene. This family illustrates that recessive RP without hearing loss can rarely be inherited from only 1 unaffected carrier parent in a nonmendelian manner. The genetic counseling of families with recessively inherited eye diseases must take into consideration the possibility that an unaffected heterozygous carrier can have an affected offspring homozygous for the same mutation, even if the carrier's spouse has wild-type alleles

Hearing dysfunction in heterozygous Mitf(Mi-wh) /+ mice, a model for Waardenburg syndrome type 2 and Tietz syndrome.

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Ni, Christina; Zhang, Deming; Beyer, Lisa A; Halsey, Karin E; Fukui, Hideto; Raphael, Yehoash; Dolan, David F; Hornyak, Thomas J

2013-01-01

The human deafness-pigmentation syndromes, Waardenburg syndrome (WS) type 2a, and Tietz syndrome are characterized by profound deafness but only partial cutaneous pigmentary abnormalities. Both syndromes are caused by mutations in MITF. To illuminate differences between cutaneous and otic melanocytes in these syndromes, their development and survival in heterozygous Microphthalmia-White (Mitf(Mi-wh) /+) mice were studied and hearing function of these mice characterized. Mitf(Mi-wh) /+ mice have a profound hearing deficit, characterized by elevated auditory brainstem response thresholds, reduced distortion product otoacoustic emissions, absent endocochlear potential, loss of outer hair cells, and stria vascularis abnormalities. Mitf(Mi-wh) /+ embryos have fewer melanoblasts during embryonic development than their wild-type littermates. Although cochlear melanocytes are present at birth, they disappear from the Mitf(Mi-wh) /+ cochlea between P1 and P7. These findings may provide insight into the mechanism of melanocyte and hearing loss in human deafness-pigmentation syndromes such as WS and Tietz syndrome and illustrate differences between otic and follicular melanocytes. © 2012 John Wiley & Sons A/S.

Pregnancy-associated osteoporosis with a heterozygous deactivating LDL receptor-related protein 5 (LRP5) mutation and a homozygous methylenetetrahydrofolate reductase (MTHFR) polymorphism.

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Cook, Fiona J; Mumm, Steven; Whyte, Michael P; Wenkert, Deborah

2014-04-01

Pregnancy-associated osteoporosis (PAO) is a rare, idiopathic disorder that usually presents with vertebral compression fractures (VCFs) within 6 months of a first pregnancy and delivery. Spontaneous improvement is typical. There is no known genetic basis for PAO. A 26-year-old primagravida with a neonatal history of unilateral blindness attributable to hyperplastic primary vitreous sustained postpartum VCFs consistent with PAO. Her low bone mineral density (BMD) seemed to respond to vitamin D and calcium therapy, with no fractures after her next successful pregnancy. Investigation of subsequent fetal losses revealed homozygosity for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism associated both with fetal loss and with osteoporosis (OP). Because her neonatal unilateral blindness and OP were suggestive of loss-of-function mutation(s) in the gene that encodes LDL receptor-related protein 5 (LRP5), LRP5 exon and splice site sequencing was also performed. This revealed a unique heterozygous 12-bp deletion in exon 21 (c.4454_4465del, p.1485_1488del SSSS) in the patient, her mother and sons, but not her father or brother. Her mother had a normal BMD, no history of fractures, PAO, ophthalmopathy, or fetal loss. Her two sons had no ophthalmopathy and no skeletal issues. Her osteoporotic father (with a family history of blindness) and brother had low BMDs first documented at ages ∼40 and 32 years, respectively. Serum biochemical and bone turnover studies were unremarkable in all subjects. We postulate that our patient's heterozygous LRP5 mutation together with her homozygous MTHFR polymorphism likely predisposed her to low peak BMD. However, OP did not cosegregate in her family with the LRP5 mutation, the homozygous MTHFR polymorphism, or even the combination of the two, implicating additional genetic or nongenetic factors in her PAO. Nevertheless, exploration for potential genetic contributions to PAO may explain part of the pathogenesis of this

Identification of FASTKD2 compound heterozygous mutations as the underlying cause of autosomal recessive MELAS-like syndrome.

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Yoo, Da Hye; Choi, Young-Chul; Nam, Da Eun; Choi, Sun Seong; Kim, Ji Won; Choi, Byung-Ok; Chung, Ki Wha

2017-07-01

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a condition that affects many parts of the body, particularly the brain and muscles. This study examined a Korean MELAS-like syndrome patient with seizure, stroke-like episode, and optic atrophy. Target sequencing of whole mtDNA and 73 nuclear genes identified compound heterozygous mutations p.R205X and p.L255P in the FASTKD2. Each of his unaffected parents has one of the two mutations, and both mutations were not found in 302 controls. FASTKD2 encodes a FAS-activated serine-threonine (FAST) kinase domain 2 which locates in the mitochondrial inner compartment. A FASTKD2 nonsense mutation was once reported as the cause of a recessive infantile mitochondrial encephalomyopathy. The present case showed relatively mild symptoms with a late onset age, compared to a previous patient with FASTKD2 mutation, implicating an inter-allelic clinical heterogeneity. Because this study is the second report of an autosomal recessive mitochondrial encephalomyopathy patient with a FASTKD2 mutation, it will extend the phenotypic spectrum of the FASTKD2 mutation. Copyright © 2017. Published by Elsevier B.V.

Clonal evolution following chemotherapy-induced stem cell depletion in cats heterozygous for glucose-6-phosphate dehydrogenase

International Nuclear Information System (INIS)

Abkowitz, J.L.; Ott, R.M.; Holly, R.D.; Adamson, J.W.

1988-01-01

The number of hematopoietic stem cells necessary to support normal hematopoiesis is not known but may be small. If so, the depletion or damage of such cells could result in apparent clonal dominance. To test this hypothesis, dimethylbusulfan [2 to 4 mg/kg intravenously (IV) x 3] was given to cats heterozygous for the X-linked enzyme glucose-6-phosphate dehydrogenase (G-6-PD). These cats were the daughters of domestic X Geoffroy parents. After the initial drug-induced cytopenias (2 to 4 weeks), peripheral blood counts and the numbers of marrow progenitors detected in culture remained normal, although the percentages of erythroid burst-forming cells (BFU-E) and granulocyte/macrophage colony-forming cells (CFU-GM) in DNA synthesis increased, as determined by the tritiated thymidine suicide technique. In three of six cats treated, a dominance of Geoffroy-type G-6-PD emerged among the progenitor cells, granulocytes, and RBCs. These skewed ratios of domestic to Geoffroy-type G-6-PD have persisted greater than 3 years. No changes in cell cycle kinetics or G-6-PD phenotypes were noted in similar studies in six control cats. These data suggest that clonal evolution may reflect the depletion or damage of normal stem cells and not only the preferential growth and dominance of neoplastic cells

Thiamine responsive megaloblastic anemia: a novel SLC19A2 compound heterozygous mutation in two siblings.

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Mozzillo, Enza; Melis, Daniela; Falco, Mariateresa; Fattorusso, Valentina; Taurisano, Roberta; Flanagan, Sarah E; Ellard, Sian; Franzese, Adriana

2013-08-01

Thiamine responsive megaloblastic anemia (TRMA) is an autosomal recessive disease caused by loss of function mutations in the SLC19A2 gene. TRMA is characterized by anemia, deafness, and diabetes. In some cases, optic atrophy or more rarely retinitis pigmentosa is noted. We now report two sisters, the eldest of which presented to a different hospital during childhood with sensorineural deafness, which was treated with a hearing prosthesis, insulin requiring diabetes, retinitis pigmentosa, optic atrophy, and macrocytic anemia. These features initially suggested a clinical diagnosis of Wolfram syndrome (WS). Therapy with thiamine was initiated which resulted in the resolution of the anemia. The younger sister, who was affected with sensorineural deafness, was referred to our hospital for non-autoimmune diabetes. She was found to have macrocytosis and ocular abnormalities. Because a diagnosis of TRMA was suspected, therapy with insulin and thiamine was started. Sequencing analysis of the SLC19A2 gene identified a compound heterozygous mutation p.Y81X/p.L457X (c.242insA/c.1370delT) in both sisters. Non-autoimmune diabetes associated with deafness and macrocytosis, without anemia, suggests a diagnosis of TRMA. Patients clinically diagnosed with WS with anemia and/or macrocytosis should be reevaluated for TRMA. © 2012 John Wiley & Sons A/S.

Phenotype of Usher syndrome type II assosiated with compound missense mutations of c.721 C>T and c.1969 C>T in MYO7A in a Chinese Usher syndrome family

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Wei Zhai

2015-08-01

Full Text Available AIM:To identify the pathogenic mutations in a Chinese pedigree affected with Usher syndrome type II (USH2.METHODS:The ophthalmic examinations and audiometric tests were performed to ascertain the phenotype of the family. To detect the genetic defect, exons of 103 known RDs -associated genes including 12 Usher syndrome (USH genes of the proband were captured and sequencing analysis was performed to exclude known genetic defects and find potential pathogenic mutations. Subsequently, candidate mutations were validated in his pedigree and 100 normal controls using polymerase chain reaction (PCR and Sanger sequencing.RESULTS:The patient in the family occurred hearing loss (HL and retinitis pigmentosa (RP without vestibular dysfunction, which were consistent with standards of classification for USH2. He carried the compound heterozygous mutations, c.721 C>T and c.1969 C>T, in the MYO7A gene and the unaffected members carried only one of the two mutations. The mutations were not present in the 100 normal controls.CONCLUSION:We suggested that the compound heterozygous mutations of the MYO7A could lead to USH2, which had revealed distinguished clinical phenotypes associated with MYO7A and expanded the spectrum of clinical phenotypes of the MYO7A mutations.

Adenosine kinase deficiency disrupts the methionine cycle and causes hypermethioninemia, encephalopathy, and abnormal liver function.

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Bjursell, Magnus K; Blom, Henk J; Cayuela, Jordi Asin; Engvall, Martin L; Lesko, Nicole; Balasubramaniam, Shanti; Brandberg, Göran; Halldin, Maria; Falkenberg, Maria; Jakobs, Cornelis; Smith, Desiree; Struys, Eduard; von Döbeln, Ulrika; Gustafsson, Claes M; Lundeberg, Joakim; Wedell, Anna

2011-10-07

Four inborn errors of metabolism (IEMs) are known to cause hypermethioninemia by directly interfering with the methionine cycle. Hypermethioninemia is occasionally discovered incidentally, but it is often disregarded as an unspecific finding, particularly if liver disease is involved. In many individuals the hypermethioninemia resolves without further deterioration, but it can also represent an early sign of a severe, progressive neurodevelopmental disorder. Further investigation of unclear hypermethioninemia is therefore important. We studied two siblings affected by severe developmental delay and liver dysfunction. Biochemical analysis revealed increased plasma levels of methionine, S-adenosylmethionine (AdoMet), and S-adenosylhomocysteine (AdoHcy) but normal or mildly elevated homocysteine (Hcy) levels, indicating a block in the methionine cycle. We excluded S-adenosylhomocysteine hydrolase (SAHH) deficiency, which causes a similar biochemical phenotype, by using genetic and biochemical techniques and hypothesized that there was a functional block in the SAHH enzyme as a result of a recessive mutation in a different gene. Using exome sequencing, we identified a homozygous c.902C>A (p.Ala301Glu) missense mutation in the adenosine kinase gene (ADK), the function of which fits perfectly with this hypothesis. Increased urinary adenosine excretion confirmed ADK deficiency in the siblings. Four additional individuals from two unrelated families with a similar presentation were identified and shown to have a homozygous c.653A>C (p.Asp218Ala) and c.38G>A (p.Gly13Glu) mutation, respectively, in the same gene. All three missense mutations were deleterious, as shown by activity measurements on recombinant enzymes. ADK deficiency is a previously undescribed, severe IEM shedding light on a functional link between the methionine cycle and adenosine metabolism. Copyright © 2011 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Mutation analysis of the ERCC4/FANCQ gene in hereditary breast cancer.

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Sandra Kohlhase

Full Text Available The ERCC4 protein forms a structure-specific endonuclease involved in the DNA damage response. Different cancer syndromes such as a subtype of Xeroderma pigmentosum, XPF, and recently a subtype of Fanconi Anemia, FA-Q, have been attributed to biallelic ERCC4 gene mutations. To investigate whether monoallelic ERCC4 gene defects play some role in the inherited component of breast cancer susceptibility, we sequenced the whole ERCC4 coding region and flanking untranslated portions in a series of 101 Byelorussian and German breast cancer patients selected for familial disease (set 1, n = 63 or for the presence of the rs1800067 risk haplotype (set 2, n = 38. This study confirmed six known and one novel exonic variants, including four missense substitutions but no truncating mutation. Missense substitution p.R415Q (rs1800067, a previously postulated breast cancer susceptibility allele, was subsequently screened for in a total of 3,698 breast cancer cases and 2,868 controls from Germany, Belarus or Russia. The Gln415 allele appeared protective against breast cancer in the German series, with the strongest effect for ductal histology (OR 0.67; 95%CI 0.49; 0.92; p = 0.003, but this association was not confirmed in the other two series, with the combined analysis yielding an overall Mantel-Haenszel OR of 0.94 (95% CI 0.81; 1.08. There was no significant effect of p.R415Q on breast cancer survival in the German patient series. The other three detected ERCC4 missense mutations included two known rare variants as well as a novel substitution, p.E17V, that we identified on a p.R415Q haplotype background. The p.E17V mutation is predicted to be probably damaging but was present in just one heterozygous patient. We conclude that the contribution of ERCC4/FANCQ coding mutations to hereditary breast cancer in Central and Eastern Europe is likely to be small.

Identification and functional characterisation of novel glucokinase mutations causing maturity-onset diabetes of the young in Slovakia.

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Lucia Valentínová

Full Text Available Heterozygous glucokinase (GCK mutations cause a subtype of maturity-onset diabetes of the young (GCK-MODY. Over 600 GCK mutations have been reported of which ∼65% are missense. In many cases co-segregation has not been established and despite the importance of functional studies in ascribing pathogenicity for missense variants these have only been performed for C, c.1113-1114delGC were novel. Parental DNA was available for 22 probands (covering 14/22 mutations and co-segregation established in all cases. Bioinformatic analysis predicted all missense mutations to be damaging. Nine (I110N, V200A, N204D, G223S, G258R, F419S, V244G, L315H, I436N mutations were functionally evaluated. Basic kinetic analysis explained pathogenicity for 7 mutants which showed reduced glucokinase activity with relative activity indices (RAI between 0.6 to <0.001 compared to wild-type GCK (1.0. For the remaining 2 mutants additional molecular mechanisms were investigated. Differences in glucokinase regulatory protein (GKRP -mediated-inhibition of GCK were observed for both L315H & I436N when compared to wild type (IC(50 14.6±0.1 mM & 20.3±1.6 mM vs.13.3±0.1 mM respectively [p<0.03]. Protein instability as assessed by thermal lability studies demonstrated that both L315H and I436N show marked thermal instability compared to wild-type GCK (RAI at 55°C 8.8±0.8% & 3.1±0.4% vs. 42.5±3.9% respectively [p<0.001]. The minimum prevalence of GCK-MODY amongst Slovakian patients with diabetes was 0.03%. In conclusion, we have identified 22 GCK mutations in 36 Slovakian probands and demonstrate that combining family, bioinformatic and functional studies can aid the interpretation of variants identified by molecular diagnostic screening.

[Rapid prenatal genetic diagnosis of a fetus with a high risk for Morquio A syndrome].

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Guo, Yi-bin; Ai, Yang; Zhao, Yan; Tang, Jia; Jiang, Wei-ying; Du, Min-lian; Ma, Hua-mei; Zhong, Yan-fang

2012-04-01

To provide rapid and accurate prenatal genetic diagnosis for a fetus with high risk of Morquio A syndrome. Based on ascertained etiology of the proband and genotypes of the parents, particular mutations of the GALNS gene were screened at 10th gestational week with amplification refractory mutation system (ARMS), denaturing high performance liquid chromatography (DHPLC), and direct DNA sequencing. DHPLC screening has identified abnormal double peaks in the PCR products of exons 1 and 10, whilst only a single peak was detected in normal controls. Amplification of ARMS specific primers derived a specific product for the fetus's gene, whilst no similar product was detected in normal controls. Sequencing of PCR products confirmed that exons 1 and 10 of the GALNS gene from the fetus contained a heterozygous paternal c.106-111 del (p.L36-L37 del) deletion and a heterozygous maternal c.1097 T>C (p.L366P) missense mutation, which resulted in a compound heterozygote status. The fetus was diagnosed with Morquio A syndrome and a genotype similar to the proband. Termination of the pregnancy was recommended. Combined ARMS, DHPLC and DNA sequencing are effective for rapid and accurate prenatal diagnosis for fetus with a high risk for Morquio A syndrome. Such methods are particularly suitable for early diagnosis when pathogenesis is clear. Furthermore, combined ARMS and DHPLC are suitable for rapid processing of large numbers of samples for the identification of new mutations.

A Tandem Duplicate of Anti-Müllerian Hormone with a Missense SNP on the Y Chromosome Is Essential for Male Sex Determination in Nile Tilapia, Oreochromis niloticus

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Li, Minghui; Sun, Yunlv; Zhao, Jiue; Shi, Hongjuan; Zeng, Sheng; Ye, Kai; Jiang, Dongneng; Zhou, Linyan; Sun, Lina; Tao, Wenjing; Nagahama, Yoshitaka; Kocher, Thomas D.; Wang, Deshou

2015-01-01

Variation in the TGF-β signaling pathway is emerging as an important mechanism by which gonadal sex determination is controlled in teleosts. Here we show that amhy, a Y-specific duplicate of the anti-Müllerian hormone (amh) gene, induces male sex determination in Nile tilapia. amhy is a tandem duplicate located immediately downstream of amhΔ-y on the Y chromosome. The coding sequence of amhy was identical to the X-linked amh (amh) except a missense SNP (C/T) which changes an amino acid (Ser/Leu92) in the N-terminal region. amhy lacks 5608 bp of promoter sequence that is found in the X-linked amh homolog. The amhΔ-y contains several insertions and deletions in the promoter region, and even a 5 bp insertion in exonVI that results in a premature stop codon and thus a truncated protein product lacking the TGF-β binding domain. Both amhy and amhΔ-y expression is restricted to XY gonads from 5 days after hatching (dah) onwards. CRISPR/Cas9 knockout of amhy in XY fish resulted in male to female sex reversal, while mutation of amhΔ-y alone could not. In contrast, overexpression of Amhy in XX fish, using a fosmid transgene that carries the amhy/amhΔ-y haplotype or a vector containing amhy ORF under the control of CMV promoter, resulted in female to male sex reversal, while overexpression of AmhΔ-y alone in XX fish could not. Knockout of the anti-Müllerian hormone receptor type II (amhrII) in XY fish also resulted in 100% complete male to female sex reversal. Taken together, these results strongly suggest that the duplicated amhy with a missense SNP is the candidate sex determining gene and amhy/amhrII signal is essential for male sex determination in Nile tilapia. These findings highlight the conserved roles of TGF-β signaling pathway in fish sex determination. PMID:26588702

A high incidence of meiotic silencing of unsynapsed chromatin is not associated with substantial pachytene loss in heterozygous male mice carrying multiple simple robertsonian translocations.

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Marcia Manterola

2009-08-01

Full Text Available Meiosis is a complex type of cell division that involves homologous chromosome pairing, synapsis, recombination, and segregation. When any of these processes is altered, cellular checkpoints arrest meiosis progression and induce cell elimination. Meiotic impairment is particularly frequent in organisms bearing chromosomal translocations. When chromosomal translocations appear in heterozygosis, the chromosomes involved may not correctly complete synapsis, recombination, and/or segregation, thus promoting the activation of checkpoints that lead to the death of the meiocytes. In mammals and other organisms, the unsynapsed chromosomal regions are subject to a process called meiotic silencing of unsynapsed chromatin (MSUC. Different degrees of asynapsis could contribute to disturb the normal loading of MSUC proteins, interfering with autosome and sex chromosome gene expression and triggering a massive pachytene cell death. We report that in mice that are heterozygous for eight multiple simple Robertsonian translocations, most pachytene spermatocytes bear trivalents with unsynapsed regions that incorporate, in a stage-dependent manner, proteins involved in MSUC (e.g., gammaH2AX, ATR, ubiquitinated-H2A, SUMO-1, and XMR. These spermatocytes have a correct MSUC response and are not eliminated during pachytene and most of them proceed into diplotene. However, we found a high incidence of apoptotic spermatocytes at the metaphase stage. These results suggest that in Robertsonian heterozygous mice synapsis defects on most pachytene cells do not trigger a prophase-I checkpoint. Instead, meiotic impairment seems to mainly rely on the action of a checkpoint acting at the metaphase stage. We propose that a low stringency of the pachytene checkpoint could help to increase the chances that spermatocytes with synaptic defects will complete meiotic divisions and differentiate into viable gametes. This scenario, despite a reduction of fertility, allows the spreading

A heterozygous microdeletion of 20p12.2-3 encompassing PROKR2 and BMP2 in a patient with congenital hypopituitarism and growth hormone deficiency.

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Parsons, Samuel J H; Wright, Neville B; Burkitt-Wright, Emma; Skae, Mars S; Murray, Phillip G

2017-08-01

Congenital growth hormone deficiency is a rare disorder with an incidence of approximately 1 in 4,000 live births. Pituitary development is under the control of a multitude of spatiotemporally regulated signaling molecules and transcription factors. Mutations in the genes encoding these molecules can result in hypopituitarism but for the majority of children with congenital hypopituitarism, the aetiology of their disease remains unknown. The proband is a 5-year-old girl who presented with neonatal hypoglycaemia and prolonged jaundice. No definitive endocrine cause of hypoglycaemia was identified in the neonatal period. She was born of normal size at 42 weeks but demonstrated growth failure with a progressive reduction in height to -3.2 SD by age 4.5 years and failed a growth hormone stimulation test with a peak growth hormone of 4.2 mcg/L. MRI of the pituitary gland demonstrated a hypoplastic anterior lobe and ectopic posterior lobe. Array CGH demonstrated an inherited 0.2 Mb gain at 1q21.1 and a de novo 4.8 Mb heterozygous deletion at 20p12.2-3. The deletion contained 17 protein coding genes including PROKR2 and BMP2, both of which are expressed during embryological development of the pituitary gland. PROKR2 mutations have been associated with hypopituitarism but a heterozygous deletion of this gene with hypopituitarism is a novel observation. In conclusion, congenital hypopituitarism can be present in individuals with a 20p12.3 deletion, observed with incomplete penetrance. Array CGH may be a useful investigation in select cases of early onset growth hormone deficiency, and patients with deletions within this region should be evaluated for pituitary hormone deficiencies. © 2017 Wiley Periodicals, Inc.

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

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

2016-08-25

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

Non-alcoholic fatty liver disease in mice with heterozygous mutation in TMED2.

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Wenyang Hou

Full Text Available The transmembrane emp24 domain/p24 (TMED family are essential components of the vesicular transport machinery. Members of the TMED family serve as cargo receptors implicated in selection and packaging of endoplasmic reticulum (ER luminal proteins into coatomer (COP II coated vesicles for anterograde transport to the Golgi. Deletion or mutations of Tmed genes in yeast and Drosophila results in ER-stress and activation of the unfolded protein response (UPR. The UPR leads to expression of genes and proteins important for expanding the folding capacity of the ER, degrading misfolded proteins, and reducing the load of new proteins entering the ER. The UPR is activated in non-alcoholic fatty liver disease (NAFLD in human and mouse and may contribute to the development and the progression of NAFLD. Tmed2, the sole member of the vertebrate Tmed β subfamily, exhibits tissue and temporal specific patterns of expression in embryos and developing placenta but is ubiquitously expressed in all adult organs. We previously identified a single point mutation, the 99J mutation, in the signal sequence of Tmed2 in an N-ethyl-N-nitrosourea (ENU mutagenesis screen. Histological and molecular analysis of livers from heterozygous mice carrying the 99J mutation, Tmed299J/+, revealed a requirement for TMED2 in liver health. We show that Tmed299J/+ mice had decreased levels of TMED2 and TMED10, dilated endoplasmic reticulum membrane, and increased phosphorylation of eIF2α, indicating ER-stress and activation of the UPR. Increased expression of Srebp1a and 2 at the newborn stage and increased incidence of NAFLD were also found in Tmed299J/+ mice. Our data establishes Tmed299J/+ mice as a novel mouse model for NAFLD and supports a role for TMED2 in liver health.

Biallelic PMS2 Mutation and Heterozygous DICER1 Mutation Presenting as Constitutional Mismatch Repair Deficiency With Corpus Callosum Agenesis: Case Report and Review of Literature.

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Cheyuo, Cletus; Radwan, Walid; Ahn, Janice; Gyure, Kymberly; Qaiser, Rabia; Tomboc, Patrick

2017-10-01

Constitutional mismatch repair deficiency syndrome is a cancer predisposition syndrome caused by autosomal recessive biallelic (homozygous) germline mutations in the mismatch repair genes (MLH1, MSH2, MSH6, and PMS2). The clinical spectrum includes neoplastic and non-neoplastic manifestations. We present the case of a 7-year-old boy who presented with T-lymphoblastic lymphoma and glioblastoma, together with non-neoplastic manifestations including corpus callosum agenesis, arachnoid cyst, developmental venous anomaly, and hydrocephalus. Gene mutation analysis revealed pathogenic biallelic mutations of PMS2 and heterozygous DICER1 variant predicted to be pathogenic. This report is the first to allude to a possible interaction of the mismatch repair system with DICER1 to cause corpus callosum agenesis.

A novel missense mutation pattern of the GCH1 gene in dopa-responsive dystonia Novo padrão de mutação missense no gene GCH1 na distonia dopa-responsiva

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Rosana H. Scola

2007-12-01

Full Text Available Dopa-responsive dystonia (DRD is an inherited metabolic disorder now classified as DYT5 with two different biochemical defects: autosomal dominant GTP cyclohydrolase 1 (GCH1 deficiency or autosomal recessive tyrosine hydroxylase deficiency. We report the case of a 10-years-old girl with progressive generalized dystonia and gait disorder who presented dramatic response to levodopa. The phenylalanine to tyrosine ratio was significantly higher after phenylalanine loading test. This condition had two different heterozygous mutations in the GCH1 gene: the previously reported P23L mutation and a new Q182E mutation. The characteristics of the DRD and the molecular genetic findings are discussed.Distonia dopa-responsiva (DRD, classificada como DYT5, é um erro inato do metabolismo que pode ser causado por dois diferentes tipos de defeito bioquímico: deficiência de GTP ciclo-hidrolase 1 (GCH1 (autossômica dominante ou de tirosina hidroxilase (autossômica recessiva. Descrevemos o caso de menina de 10 anos com distonia generalizada progressiva e alteração da marcha com importante melhora após uso de levodopa. A relação fenilalanina/tirosina estava aumentada após teste de sobrecarga com fenilalanina. O estudo molecular mostrou que o paciente apresenta uma combinação hererozigótica de mutação no gene GCH1: a já conhecida mutação P23L e uma nova mutação Q182E. Discutem-se as características da DRD e as alterações genéticas possíveis.

First de novo ANK3 nonsense mutation in a boy with intellectual disability, speech impairment and autistic features.

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Kloth, Katja; Denecke, Jonas; Hempel, Maja; Johannsen, Jessika; Strom, Tim M; Kubisch, Christian; Lessel, Davor

2017-09-01

Ankyrin-G, encoded by ANK3, plays an important role in neurodevelopment and neuronal function. There are multiple isoforms of Ankyrin-G resulting in differential tissue expression and function. Heterozygous missense mutations in ANK3 have been associated with autism spectrum disorder. Further, in three siblings a homozygous frameshift mutation affecting only the longest isoform and a patient with a balanced translocation disrupting all isoforms were documented. The latter four patients were affected by a variable degree of intellectual disability, attention deficit hyperactivity disorder and autism. Here, we report on a boy with speech impairment, intellectual disability, autistic features, macrocephaly, macrosomia, chronic hunger and an altered sleeping pattern. By trio-whole-exome sequencing, we identified the first de novo nonsense mutation affecting all ANK3 transcripts. Thus, our data expand the phenotype of ANK3-associated diseases and suggest an isoform-based, phenotypic continuum between dominant and recessive ANK3-associated pathologies. Copyright © 2017. Published by Elsevier Masson SAS.

A Novel Fibrillin-1 Gene Mutation Leading to Marfan Syndrome in a Korean Girl.

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Nam, Hyo-Kyoung; Nam, Myung-Hyun; Ha, Kee-Soo; Rhie, Young-Jun; Lee, Kee-Hyoung

2017-03-01

Marfan syndrome is an autosomal dominant genetic disorder caused by a connective tissue defect. A nine-year-old girl was referred to our pediatric endocrinology clinic for tall stature. Physical examination revealed a lens dislocation with strabismus, high palate, positive wrist and thumb signs, joint hypermobility, and pes planus. Transthoracic echocardiography revealed dilatation of the aortic root. She was diagnosed with Marfan syndrome based on the revised Ghent diagnostic criteria. Molecular investigation identified a heterozygous c.2810G >A variation in the FBN1 gene in the patient, but not in her parents. To our knowledge, this sequence variant has been reported as a polymorphism (rs113602180), but it is the first report identifying it as the genetic cause of Marfan syndrome. We hypothesize that this de novo novel missense FBN1 mutation disrupts fibrillin-1 function and is probably involved in the development of Marfan syndrome in this patient. © 2017 by the Association of Clinical Scientists, Inc.

Novel variant in the TP63 gene associated to ankyloblepharon-ectodermal dysplasia-cleft lip/palate (AEC) syndrome.

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Gonzalez, Francisco; Loidi, Lourdes; Abalo-Lojo, Jose M

2017-01-01

Ankyloblepharon-ectodermal dysplasia-cleft lip/palate (AEC) syndrome is a disorder resulting from anomalous embryonic development of ectodermal tissues. There is evidence that AEC syndrome is caused by mutations in the TP63 gene, which encodes the p63 protein. This is an important regulatory protein involved in epidermal proliferation and differentiation. Genome sequencing was performed in DNA from peripheral blood leukocytes of a newborn with AEC syndrome and her parents. Variants were searched in all coding exons and intron-exon boundaries of the TP63 gene. A heterozygous missense variant (NM_003722.4:c.1063G>C (p.Asp355His) was found in the newborn patient. No variants were found in either of the parents. We identified a previously unreported variant in TP63 gene which seems to be involved in the somatic malformations found in the AEC syndrome. The absence of this variant in both parents suggests that the variant appeared de novo.

Pulmonary hypoplasia-diaphragmatic hernia-anophthalmia-cardiac defect (PDAC) syndrome due to STRA6 mutations--what are the minimal criteria?

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Segel, Reeval; Levy-Lahad, Ephrat; Pasutto, Francesca; Picard, Elie; Rauch, Anita; Alterescu, Gheona; Schimmel, Michael S

2009-11-01

Microphthalmic syndrome 9 (OMIM601186) is a genetically and phenotypically variable condition, comprising anophthalmia, pulmonary hypoplasia, diaphragmatic hernia, and cardiac malformations (PDAC syndrome). Reported cases have all been associated with fetal/neonatal death or developmental delay. Recessive stimulated by retinoic acid gene 6 homolog (STRA6) mutations have recently been identified as the cause of cases of PDAC in which distinct, "bushy" eyebrows have been observed. We describe a patient with clinical anophthalmia, bushy eyebrows, patent ductus arteriosus, and normal development at age 30 months, who is a compound heterozygote for two novel STRA6 missense mutations. This patient's phenotype is consistent with the multisystemic malformations of PDAC syndrome, but is somewhat milder. This is the first living patient with compound heterozygous STRA6 mutations, which may explain her milder phenotype. We conclude that STRA6 analysis should be considered in all patients with clinical anophthalmia. Genetic counseling should be cautious with respect to long-term developmental outcomes. Copyright 2009 Wiley-Liss, Inc.

A case of hypocholesterolemia and steatosis in a carrier of a PCSK9 loss-of-function mutation and polymorphisms predisposing to nonalcoholic fatty liver disease.

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Di Filippo, Mathilde; Vokaer, Benoit; Seidah, Nabil G

We report a new case of hypobetalipoproteinemia in a 44-year-old man of Peruvian origin exhibiting a heterozygous PCSK9 missense mutation (c.946 G>T, p. Gly316Cys). In vitro functional studies demonstrated that this mutation leads to a loss of function of PCSK9 on low-density lipoprotein receptor degradation. This patient exhibited liver steatosis; he was neither diabetic, nor obese or alcoholic, but is a carrier of 2 polymorphisms, p.Ile148Met (rs738409) and p.Glu167Lys (rs58542926) on PNPLA3 and TM6SF2 gene, respectively, previously shown to be associated with nonalcoholic steatosis and fibrosis evolution. These data suggested that if a resistance to hepatic steatosis mediated by the PCSK9 deficiency exists, as demonstrated in mice, it is not sufficient to prevent hepatic fatty accumulation in the case of genetic factors predisposing to nonalcoholic fatty liver disease. Copyright © 2017 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Next-generation sequencing identifies transportin 3 as the causative gene for LGMD1F.

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Annalaura Torella

Full Text Available Limb-girdle muscular dystrophies (LGMD are genetically and clinically heterogeneous conditions. We investigated a large family with autosomal dominant transmission pattern, previously classified as LGMD1F and mapped to chromosome 7q32. Affected members are characterized by muscle weakness affecting earlier the pelvic girdle and the ileopsoas muscles. We sequenced the whole exome of four family members and identified a shared heterozygous frame-shift variant in the Transportin 3 (TNPO3 gene, encoding a member of the importin-β super-family. The TNPO3 gene is mapped within the LGMD1F critical interval and its 923-amino acid human gene product is also expressed in skeletal muscle. In addition, we identified an isolated case of LGMD with a new missense mutation in the same gene. We localized the mutant TNPO3 around the nucleus, but not inside. The involvement of gene related to the nuclear transport suggests a novel disease mechanism leading to muscular dystrophy.

Systemic vascular phenotypes of Loeys-Dietz syndrome in a child carrying a de novo R381P mutation in TGFBR2: a case report.

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Uike, Kiyoshi; Matsushita, Yuki; Sakai, Yasunari; Togao, Osamu; Nagao, Michinobu; Ishizaki, Yoshito; Nagata, Hazumu; Yamamura, Kenichiro; Torisu, Hiroyuki; Hara, Toshiro

2013-11-12

Loeys-Dietz syndrome, also known as Marfan syndrome type II, is a rare connective tissue disorder caused by dominant mutations in transforming growth factor-beta receptors (TGFBR1 and 2). We report a 7-year-old Japanese boy with Loeys-Dietz syndrome who carried a novel, de novo missense mutation in TGFBR2 (c.1142g > c, R381P). He showed dysmorphic faces and skeletal malformations that were typical in previous cases with Loeys-Dietz syndrome. The cardiac studies disclosed the presence of markedly dilated aortic root and patent ductus aorteriosus. The cranial magnetic resonance imaging (MRI) and angiography (MRA) detected the tortuous appearances of the bilateral middle cerebral and carotid arteries. This study depicts the systemic vascular phenotypes of a child with Loeys-Dietz syndrome that were caused by a novel heterozygous mutation of TGFR2. A large cohort with serial imaging studies for vascular phenotypes will be useful for delineating the genotype-phenotype correlations of Loeys-Dietz syndrome.

A mutation in Ihh that causes digit abnormalities alters its signalling capacity and range.

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Gao, Bo; Hu, Jianxin; Stricker, Sigmar; Cheung, Martin; Ma, Gang; Law, Kit Fong; Witte, Florian; Briscoe, James; Mundlos, Stefan; He, Lin; Cheah, Kathryn S E; Chan, Danny

2009-04-30

Brachydactyly type A1 (BDA1) was the first recorded disorder of the autosomal dominant Mendelian trait in humans, characterized by shortened or absent middle phalanges in digits. It is associated with heterozygous missense mutations in indian hedgehog (IHH). Hedgehog proteins are important morphogens for a wide range of developmental processes. The capacity and range of signalling is thought to be regulated by its interaction with the receptor PTCH1 and antagonist HIP1. Here we show that a BDA1 mutation (E95K) in Ihh impairs the interaction of IHH with PTCH1 and HIP1. This is consistent with a recent paper showing that BDA1 mutations cluster in a calcium-binding site essential for the interaction with its receptor and cell-surface partners. Furthermore, we show that in a mouse model that recapitulates the E95K mutation, there is a change in the potency and range of signalling. The mice have digit abnormalities consistent with the human disorder.

Defects in the CAPN1 Gene Result in Alterations in Cerebellar Development and Cerebellar Ataxia in Mice and Humans

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Yubin Wang

2016-06-01

Full Text Available A CAPN1 missense mutation in Parson Russell Terrier dogs is associated with spinocerebellar ataxia. We now report that homozygous or heterozygous CAPN1-null mutations in humans result in cerebellar ataxia and limb spasticity in four independent pedigrees. Calpain-1 knockout (KO mice also exhibit a mild form of ataxia due to abnormal cerebellar development, including enhanced neuronal apoptosis, decreased number of cerebellar granule cells, and altered synaptic transmission. Enhanced apoptosis is due to absence of calpain-1-mediated cleavage of PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1, which results in inhibition of the Akt pro-survival pathway in developing granule cells. Injection of neonatal mice with the indirect Akt activator, bisperoxovanadium, or crossing calpain-1 KO mice with PHLPP1 KO mice prevented increased postnatal cerebellar granule cell apoptosis and restored granule cell density and motor coordination in adult mice. Thus, mutations in CAPN1 are an additional cause of ataxia in mammals, including humans.

Hb Dartmouth (HBA2: c.200T>C): An α2-Globin Gene Associated with Hb H Disease in One Homozygous Patient.

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Farashi, Samaneh; Faramarzi Garous, Negin; Ashki, Mehri; Vakili, Shadi; Zeinali, Fatemah; Imanian, Hashem; Azarkeivan, Azita; Najmabadi, Hossein

2015-01-01

Hb H (β4) disease is caused by deletion or inactivation of three out of four α-globin genes. A high incidence of Hb H disease has been reported all over the world. There is a wide spectrum of phenotypic presentations, from clinically asymptomatic to having significant hepatosplenomegaly and requiring occasional or even regular blood transfusions, even more severe anemia, Hb Bart's (γ4) hydrops fetalis syndrome that can cause death in the affected fetuses late in gestation. We here present a case who was diagnosed with Hb H disease that represents a new genotype for this hereditary disorder. Hb Dartmouth is a variant caused by a missense mutation at codon 66 of the α2-globin gene (HBA2: c.200T>C), resulting in the substitution of leucine by proline. We here emphasize the importance of this point mutation involving Hb H disease and also the necessity for prenatal diagnosis (PND) for those who carry this point mutation in the heterozygous state.

Exome sequencing links mutations in PARN and RTEL1 with familial pulmonary fibrosis and telomere shortening.

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Stuart, Bridget D; Choi, Jungmin; Zaidi, Samir; Xing, Chao; Holohan, Brody; Chen, Rui; Choi, Mihwa; Dharwadkar, Pooja; Torres, Fernando; Girod, Carlos E; Weissler, Jonathan; Fitzgerald, John; Kershaw, Corey; Klesney-Tait, Julia; Mageto, Yolanda; Shay, Jerry W; Ji, Weizhen; Bilguvar, Kaya; Mane, Shrikant; Lifton, Richard P; Garcia, Christine Kim

2015-05-01

Idiopathic pulmonary fibrosis (IPF) is an age-related disease featuring progressive lung scarring. To elucidate the molecular basis of IPF, we performed exome sequencing of familial kindreds with pulmonary fibrosis. Gene burden analysis comparing 78 European cases and 2,816 controls implicated PARN, an exoribonuclease with no previous connection to telomere biology or disease, with five new heterozygous damaging mutations in unrelated cases and none in controls (P = 1.3 × 10(-8)); mutations were shared by all affected relatives (odds in favor of linkage = 4,096:1). RTEL1, an established locus for dyskeratosis congenita, harbored significantly more new damaging and missense variants at conserved residues in cases than in controls (P = 1.6 × 10(-6)). PARN and RTEL1 mutation carriers had shortened leukocyte telomere lengths, and we observed epigenetic inheritance of short telomeres in family members. Together, these genes explain ~7% of familial pulmonary fibrosis and strengthen the link between lung fibrosis and telomere dysfunction.

Compound heterozygous deletions in pseudoautosomal region 1 in an infant with mild manifestations of langer mesomelic dysplasia.

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Tsuchiya, Takayoshi; Shibata, Minoru; Numabe, Hironao; Jinno, Tomoko; Nakabayashi, Kazuhiko; Nishimura, Gen; Nagai, Toshiro; Ogata, Tsutomu; Fukami, Maki

2014-02-01

Haploinsufficiency of SHOX on the short arm pseudoautosomal region (PAR1) leads to Leri-Weill dyschondrosteosis (LWD), and nullizygosity of SHOX results in Langer mesomelic dysplasia (LMD). Molecular defects of LWD/LMD include various microdeletions in PAR1 that involve exons and/or the putative upstream or downstream enhancer regions of SHOX, as well as several intragenic mutations. Here, we report on a Japanese male infant with mild manifestations of LMD and hitherto unreported microdeletions in PAR1. Clinical analysis revealed mesomelic short stature with various radiological findings indicative of LMD. Molecular analyses identified compound heterozygous deletions, that is, a maternally inherited ∼46 kb deletion involving the upstream region and exons 1-5 of SHOX, and a paternally inherited ∼500 kb deletion started from a position ∼300 kb downstream from SHOX. In silico analysis revealed that the downstream deletion did not affect the known putative enhancer regions of SHOX, although it encompassed several non-coding elements which were well conserved among various species with SHOX orthologs. These results provide the possibility of the presence of a novel enhancer for SHOX in the genomic region ∼300 to ∼800 kb downstream of the start codon. © 2013 Wiley Periodicals, Inc.

The use of high resolution melting analysis to detect Fabry mutations in heterozygous females via dry bloodspots.

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Tai, Chang-Long; Liu, Mei-Ying; Yu, Hsiao-Chi; Chiang, Chiang-Chuan; Chiang, Hung; Suen, Jeng-Hung; Kao, Shu-Min; Huang, Yu-Hsiu; Wu, Tina Jui-Ting; Yang, Chia-Feng; Tsai, Fang-Chih; Lin, Ching-Yuang; Chang, Jan-Gowth; Chen, Hong-Duo; Niu, Dau-Ming

2012-02-18

As an X-linked genetic disorder, Fabry disease was first thought to affect males only, and females were generally considered to be asymptomatic carriers. However, recent research suggests that female carriers of Fabry disease may still develop vital organ damage causing severe morbidity and mortality. In the previous newborn screening, from 299,007 newborns, we identified a total of 20 different Fabry mutations and 121 newborns with Fabry mutations. However, we found that most female carriers are not detected by enzyme assays. A streamlined method for high resolution melting (HRM) analysis was designed to screen for GLA gene mutations using a same PCR and melting program. Primer sets were designed to cover the 7 exons and the Chinese common intronic mutation, IVS4+919G>A of GLA gene. The HRM analysis was successful in identifying heterozygous and hemizygous patients with the 20 surveyed mutations. We were also successful in using this method to test dry blood spots of newborns afflicted with Fabry mutations without having to determine DNA concentration before PCR amplification. The results of this study show that HRM could be a reliable and sensitive method for use in the rapid screening of females for GLA mutations. Copyright © 2011 Elsevier B.V. All rights reserved.

Myosin-binding Protein C Compound Heterozygous Variant Effect on the Phenotypic Expression of Hypertrophic Cardiomyopathy.

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Rafael, Julianny Freitas; Cruz, Fernando Eugênio Dos Santos; Carvalho, Antônio Carlos Campos de; Gottlieb, Ilan; Cazelli, José Guilherme; Siciliano, Ana Paula; Dias, Glauber Monteiro

2017-04-01

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant genetic disease caused by mutations in genes encoding sarcomere proteins. It is the major cause of sudden cardiac death in young high-level athletes. Studies have demonstrated a poorer prognosis when associated with specific mutations. The association between HCM genotype and phenotype has been the subject of several studies since the discovery of the genetic nature of the disease. This study shows the effect of a MYBPC3 compound variant on the phenotypic HCM expression. A family in which a young man had a clinical diagnosis of HCM underwent clinical and genetic investigations. The coding regions of the MYH7, MYBPC3 and TNNT2 genes were sequenced and analyzed. The proband present a malignant manifestation of the disease, and is the only one to express HCM in his family. The genetic analysis through direct sequencing of the three main genes related to this disease identified a compound heterozygous variant (p.E542Q and p.D610H) in MYBPC3. A family analysis indicated that the p.E542Q and p.D610H alleles have paternal and maternal origin, respectively. No family member carrier of one of the variant alleles manifested clinical signs of HCM. We suggest that the MYBPC3-biallelic heterozygous expression of p.E542Q and p.D610H may cause the severe disease phenotype seen in the proband. Resumo A cardiomiopatia hipertrófica (CMH) é uma doença autossômica dominante causada por mutações em genes que codificam as proteínas dos sarcômeros. É a principal causa de morte súbita cardíaca em atletas jovens de alto nível. Estudos têm demonstrado um pior prognóstico associado a mutações específicas. A associação entre genótipo e fenótipo em CMH tem sido objeto de diversos estudos desde a descoberta da origem genética dessa doença. Este trabalho apresenta o efeito de uma mutação composta em MYBPC3 na expressão fenotípica da CMH. Uma família na qual um jovem tem o diagnóstico clínico de CMH foi