scholarly journals Four Novel Variants in POU4F3 Cause Autosomal Dominant Nonsyndromic Hearing Loss

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Tian-Yi Cui ◽  
Xue Gao ◽  
Sha-Sha Huang ◽  
Yan-Yan Sun ◽  
Si-Qi Zhang ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Autosomal Dominant ◽  
Asian Population ◽  
Nonsyndromic Hearing Loss ◽  
Hereditary Hearing Loss ◽  
Variant Of Uncertain Significance ◽  
Targeted Next Generation Sequencing ◽  
Pathogenic Variants ◽  
Novel Variants ◽  
Uncertain Significance

Hereditary hearing loss is one of the most common sensory disabilities worldwide. Mutation of POU domain class 4 transcription factor 3 (POU4F3) is considered the pathogenic cause of autosomal dominant nonsyndromic hearing loss (ADNSHL), designated as autosomal dominant nonsyndromic deafness 15. In this study, four novel variants in POU4F3, c.696G>T (p.Glu232Asp), c.325C>T (p.His109Tyr), c.635T>C (p.Leu212Pro), and c.183delG (p.Ala62Argfs∗22), were identified in four different Chinese families with ADNSHL by targeted next-generation sequencing and Sanger sequencing. Based on the American College of Medical Genetics and Genomics guidelines, c.183delG (p.Ala62Argfs∗22) is classified as a pathogenic variant, c.696G>T (p.Glu232Asp) and c.635T>C (p.Leu212Pro) are classified as likely pathogenic variants, and c.325C>T (p.His109Tyr) is classified as a variant of uncertain significance. Based on previous reports and the results of this study, we speculated that POU4F3 pathogenic variants are significant contributors to ADNSHL in the East Asian population. Therefore, screening of POU4F3 should be a routine examination for the diagnosis of hereditary hearing loss.

scholarly journals Comprehensive molecular-genetic analysis of mid-frequency sensorineural hearing loss

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zuzana Pavlenkova ◽  
Lukas Varga ◽  
Silvia Borecka ◽  
Miloslav Karhanek ◽  
Miloslava Huckova ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Genetic Disorder ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Sensorineural Hearing ◽  
Variant Of Uncertain Significance ◽  
Pathogenic Variants ◽  
Causal Genes ◽  
Uncertain Significance

AbstractThe genetic heterogeneity of sensorineural hearing loss (SNHL) is a major hurdle to the detection of disease-causing variants. We aimed to identify underlying causal genes associated with mid-frequency hearing loss (HL), which contributes to less than about 1% of SNHL cases, by whole exome sequencing (WES). Thirty families segregating mid-frequency SNHL, in whom biallelic GJB2 mutations had been previously excluded, were selected from among 851 families in our DNA repository of SNHL. DNA samples from the probands were subjected to WES analysis and searched for candidate variants associated with SNHL. We were able to identify the genetic aetiology in six probands (20%). In total, we found three pathogenic and three likely pathogenic variants in four genes (COL4A5, OTOGL, TECTA, TMPRSS3). One more proband was a compound heterozygote for a pathogenic variant and a variant of uncertain significance (VUS) in MYO15A gene. To date, MYO15A and TMPRSS3 have not yet been described in association with mid-frequency SNHL. In eight additional probands, eight candidate VUS variants were detected in five genes (DIAPH1, MYO7A, TECTA, TMC1, TSPEAR). Seven of these 16 variants have not yet been published or mentioned in the available databases. The most prevalent gene was TECTA, identified in 23% of all tested families. Furthermore, we confirmed the hypothesis that a substantive portion of cases with this conspicuous audiogram shape is a consequence of a genetic disorder.

scholarly journals Genomic Observations of a Rare/Pathogenic SMAD3 Variant in Loeys–Dietz Syndrome 3 Confirmed by Protein Informatics and Structural Investigations

Medicina ◽  
2019 ◽  
Vol 55 (5) ◽  
pp. 137
Author(s):  
John E. Richter ◽  
Ayesha Samreen ◽  
Charitha Vadlamudi ◽  
Haytham Helmi ◽  
Ahmed N. Mohammad ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Autosomal Dominant ◽  
Connective Tissue Disorders ◽  
Structural Investigations ◽  
Variant Of Uncertain Significance ◽  
Common Features ◽  
Pathogenic Variants ◽  
Uncertain Significance ◽  
History Of ◽  
Arterial Aneurysms

Background and objectives: Loeys–Dietz syndrome 3, also known as aneurysms-–osteoarthritis syndrome, is an autosomal dominant genetic connective tissue disease caused by pathogenic variants in SMAD3, a transcription factor involved in TGF-β signaling. This disorder is characterized by early-onset osteoarthritis and arterial aneurysms. Common features include scoliosis, uvula abnormalities, striae, and velvety skin. Materials and Methods: The pathogenicity of a variant of uncertain significance in the SMAD3 gene was evaluated (variant c.220C > T) through personalized protein informatics and molecular studies. Results: The case of a 44-year-old male, who was originally presumed to have Marfan syndrome, is presented. An expanded gene panel determined the probable cause to be a variant in SMAD3, c.220C > T (p.R74W). His case was complicated by a history of stroke, but his phenotype was otherwise characteristic for Loeys–Dietz syndrome 3. Conclusion: This case emphasizes the importance of comprehensive genetic testing to evaluate patients for connective tissue disorders, as well as the potential benefit of utilizing a protein informatics platform for the assessment of variant pathogenicity.

scholarly journals Mutation in the Hair Cell Specific Gene POU4F3 Is a Common Cause for Autosomal Dominant Nonsyndromic Hearing Loss in Chinese Hans

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Longxia He ◽  
Xiuhong Pang ◽  
Penghui Chen ◽  
Hao Wu ◽  
Tao Yang
Keyword(s):  
Hearing Loss ◽  
Hair Cell ◽  
Autosomal Dominant ◽  
Specific Gene ◽  
Nonsyndromic Hearing Loss ◽  
Chinese Han ◽  
Common Cause ◽  
Targeted Next Generation Sequencing ◽  
Degrees Of Severity

Autosomal dominant nonsyndromic hearing loss (ADNSHL) is extremely heterogeneous. So far the genetic etiological contribution of the gene POU4F3 associated with ADNSHL has been rarely reported. In our previous study, a c.603_604delGG mutation in the hair cell specific gene POU4F3 has been identified as the pathogenic cause in one of the seven Chinese Han ADNSHL families. In the present study, we performed targeted next-generation sequencing of 144 known deafness genes in another nine Chinese Han ADNSHL families and identified two more novel mutations in POU4F3, p.Leu311Pro and c.120+1G>C, as the pathogenic cause. Clinical characterization of the affected individuals in these three families showed that the three POU4F3 mutations may lead to progressive hearing loss with variable ages of onset and degrees of severity. Our results suggested that mutations in POU4F3 are a relatively common cause (3/16) for ADNSHL in Chinese Hans, which should be routinely screened in such cases during genetic testing.

scholarly journals Comprehensive molecular-genetic analysis of mid-frequency sensorineural hearing loss

2021 ◽  
Author(s):  
Zuzana Pavlenkova ◽  
Lukas Varga ◽  
Silvia Borecka ◽  
Miloslav Karhanek ◽  
Miroslava Huckova ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Sensorineural Hearing Loss ◽  
Genetic Disorder ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Sensorineural Hearing ◽  
Variant Of Uncertain Significance ◽  
Pathogenic Variants ◽  
Causal Genes ◽  
Uncertain Significance

Abstract The genetic heterogeneity of sensorineural hearing loss (SNHL) is a major hurdle to the detection of disease-causing variants. We aimed to identify underlying causal genes associated with mid-frequency hearing loss (HL), which contributes to less than about 1% of SNHL cases, by whole exome sequencing (WES). Thirty families segregating mid-frequency SNHL, in whom biallelic GJB2 mutations had been previously excluded, were selected from among 851 families in our DNA repository of SNHL. DNA samples from the probands were subjected to WES analysis and searched for candidate variants associated with SNHL. We were able to identify the genetic aetiology in six probands (20%). In total, we found three pathogenic and three likely pathogenic variants in four genes COL4A5, OTOGL, TECTA, TMPRSS3). One proband was a compound heterozygote for a pathogenic variant and a variant of uncertain significance (VUS) in MYO15A gene. To date, MYO15A and TMPRSS3 have not yet been described in association with mid-frequency SNHL. In eight additional probands, eight candidate VUS variants were detected in five genes (DIAPH1, MYO7A, TECTA, TMC1, TSPEAR). Seven of these 16 variants have not yet been published or mentioned in the available databases. The most prevalent gene was TECTA, identified in 23% of all tested families. Furthermore, we confirmed the hypothesis that a substantive portion of cases with this conspicuous audiogram shape is a consequence of a genetic disorder.

scholarly journals Comprehensive simulation and interpretation of single nucleotide substitutions in GJB2 reveals the genetic and phenotypic landscape of GJB2-related hearing loss

2021 ◽  
Author(s):  
Jiale Xiang ◽  
Xiangzhong Sun ◽  
Nana Song ◽  
Lisha Chen ◽  
Sathishkumar Ramaswamy ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Transmembrane Domain ◽  
Phenotypic Heterogeneity ◽  
Nonsyndromic Hearing Loss ◽  
Coding Region ◽  
Nucleotide Substitutions ◽  
Single Nucleotide ◽  
Variant Of Uncertain Significance ◽  
Missense Variants ◽  
Pathogenic Variants

AbstractGenetic variants in the GJB2 gene are the most frequent causes of congenital and childhood hearing loss worldwide. In addition to nonsyndromic hearing loss, GJB2 pathogenic variants are also correlated with syndromic phenotypes, showing high genetic and phenotypic heterogeneity. To comprehensively delineate the genetic and phenotypic landscape of GJB2 variants, we interpreted and manually curated all the 2043 possible single-nucleotide substitution (SNS) coding variants in this gene following the hearing loss-specific ACMG/AMP guidelines. As a result, 61 (3.0%), 188 (9.2%), 1487 (72.8%), 301 (14.7%) and 6 (0.3%) variants were classified as pathogenic, likely pathogenic, variant of uncertain significance, likely benign and benign, respectively. Interestingly, 54% (84/156) of pathogenic/likely pathogenic missense variants were not recorded in ClinVar. Further analysis showed that the second transmembrane domain (TM2) and the 310 helix are highly enriched for pathogenic missense variants. The N-terminal tail and the extracellular loop (E1) showed a high density of variants that are associated with syndromic or dominant nonsyndromic hearing loss. On the other hand, the intracellular loops (CL and CT) were extremely tolerant to variation. Based on this new information, we propose refinements of the guidelines for variant interpretation in GJB2. In summary, our study interpreted all possible SNS variants in the coding region of the GJB2 gene, characterized novel clinically significant (N = 249) and benign or likely benign (N = 307) in this gene, and revealed significant genotype-phenotype correlations at this common hearing loss locus. The interpretation of GJB2 SNS variants in the coding region provides a prototype for genes with similarly high genetic and phenotypic heterogeneity.

scholarly journals Janus-faced EPHB4-associated disorders: novel pathogenic variants and unreported intrafamilial overlapping phenotypes

2021 ◽  
Author(s):  
Silvia Martin-Almedina ◽  
Kazim Ogmen ◽  
Ege Sackey ◽  
Dionysios Grigoriadis ◽  
Christina Karapouliou ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Fetal Hydrops ◽  
Clinical Phenotypes ◽  
Functional Studies ◽  
Pathogenic Variants ◽  
Disease Mechanisms ◽  
Novel Variants ◽  
Uncertain Significance ◽  
Clinical Phenotyping

Abstract Purpose Several clinical phenotypes including fetal hydrops, central conducting lymphatic anomaly or capillary malformations with arteriovenous malformations 2 (CM-AVM2) have been associated with EPHB4 (Ephrin type B receptor 4) variants, demanding new approaches for deciphering pathogenesis of novel variants of uncertain significance (VUS) identified in EPHB4, and for the identification of differentiated disease mechanisms at the molecular level. Methods Ten index cases with various phenotypes, either fetal hydrops, CM-AVM2, or peripheral lower limb lymphedema, whose distinct clinical phenotypes are described in detail in this study, presented with a variant in EPHB4. In vitro functional studies were performed to confirm pathogenicity. Results Pathogenicity was demonstrated for six of the seven novel EPHB4 VUS investigated. A heterogeneity of molecular disease mechanisms was identified, from loss of protein production or aberrant subcellular localization to total reduction of the phosphorylation capability of the receptor. There was some phenotype–genotype correlation; however, previously unreported intrafamilial overlapping phenotypes such as lymphatic-related fetal hydrops (LRFH) and CM-AVM2 in the same family were observed. Conclusion This study highlights the usefulness of protein expression and subcellular localization studies to predict EPHB4 variant pathogenesis. Our accurate clinical phenotyping expands our interpretation of the Janus-faced spectrum of EPHB4-related disorders, introducing the discovery of cases with overlapping phenotypes.

scholarly journals Revealing the Mutational Spectrum in Southern Africans With Amyotrophic Lateral Sclerosis

2022 ◽  
Vol 8 (1) ◽  
pp. e654
Author(s):  
Melissa Nel ◽  
Amokelani C. Mahungu ◽  
Nomakhosazana Monnakgotla ◽  
Gerrit R. Botha ◽  
Nicola J. Mulder ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Population Group ◽  
Genetic Ancestry ◽  
Familial Case ◽  
Data Sets ◽  
Variant Of Uncertain Significance ◽  
Pathogenic Variants ◽  
Sporadic Als ◽  
Uncertain Significance ◽  
Lateral Sclerosis

Background and ObjectivesTo perform the first screen of 44 amyotrophic lateral sclerosis (ALS) genes in a cohort of African genetic ancestry individuals with ALS using whole-genome sequencing (WGS) data.MethodsOne hundred three consecutive cases with probable/definite ALS (using the revised El Escorial criteria), and self-categorized as African genetic ancestry, underwent WGS using various Illumina platforms. As population controls, 238 samples from various African WGS data sets were included. Our analysis was restricted to 44 ALS genes, which were curated for rare sequence variants and classified according to the American College of Medical Genetics guidelines as likely benign, uncertain significance, likely pathogenic, or pathogenic variants.ResultsThirteen percent of 103 ALS cases harbored pathogenic variants; 5 different SOD1 variants (N87S, G94D, I114T, L145S, and L145F) in 5 individuals (5%, 1 familial case), pathogenic C9orf72 repeat expansions in 7 individuals (7%, 1 familial case) and a likely pathogenic ANXA11 (G38R) variant in 1 individual. Thirty individuals (29%) harbored ≥1 variant of uncertain significance; 10 of these variants had limited pathogenic evidence, although this was insufficient to permit confident classification as pathogenic.DiscussionOur findings show that known ALS genes can be expected to identify a genetic cause of disease in >11% of sporadic ALS cases of African genetic ancestry. Similar to European cohorts, the 2 most frequent genes harboring pathogenic variants in this population group are C9orf72 and SOD1.

Genetic Characterization of Hereditary Cancer Syndromes Based on Targeted Next-Generation Sequencing

2021 ◽  
pp. 1-9
Author(s):  
Pelin Ercoskun ◽  
Cigdem Yuce Kahraman ◽  
Guller Ozkan ◽  
Abdulgani Tatar
Keyword(s):  
Hereditary Cancer ◽  
Hereditary Cancer Syndrome ◽  
Cancer Syndrome ◽  
Targeted Next Generation Sequencing ◽  
Pathogenic Variants ◽  
Novel Variants ◽  
Genetics And Genomics ◽  
Cancer Syndromes ◽  
Generation Sequencing

A hereditary cancer syndrome is a genetic predisposition to cancer caused by a germline mutation in cancer-related genes. Identifying the disease-causing variant is important for both the patient and relatives at risk in cancer families because this could be a guide in treatment and secondary cancer prevention. In this study, hereditary cancer panel harboring cancer-related genes was performed on MiSeq Illumina NGS system from peripheral blood samples. Sequencing files were fed into a cloud-based data analysis pipeline. Reportable variants were classified according to the American College of Medical Genetics and Genomics guidelines. Three hundred five individuals were included in the study. Different pathogenic/likely pathogenic variants were detected in 75 individuals. The majority of these variants were in the <i>MUTYH</i>, <i>BRCA2</i>, and <i>CHEK2</i> genes. Nine novel pathogenic/likely pathogenic variants were identified in <i>BRCA1</i>, <i>BRCA2</i>, <i>GALNT12</i>, <i>ATM</i>, <i>MLH1</i>, <i>MSH2</i>, <i>APC</i>, and <i>KIT</i> genes. We obtained interesting and novel variants which could be related to hereditary cancer, and this study confirmed that NGS is an indispensable method for the risk assessment in cancer families.

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