Project description:We analyzed samples from fourteen deaf individuals (Affected 1 through 14), fifteen hearing maternally related family members (Unaffected 1-15), six marry-in controls (Controls 1-6) from extended pedigree from Arab-Israeli village, and nine individuals from another Arab-Israeli village (Controls 7-15). All affected and unaffected maternally-related individuals carry homoplasmic mutation in the 12S rRNA gene of the mitochondrial DNA, associated with both non-syndromic and aminoglycosides-induced deafness. Keywords: Comparison of genome-wide expression in cell lines of maternally-related individuals with mitochondrial mutation and controls carrying wild-type mitochondrial chromosome.
Project description:Background The genetic diversity of loci and mutations underlying hereditary hearing loss is an active area of investigation. To identify loci associated with predominantly non-syndromic sensorineural hearing loss, we performed exome sequencing of families and of single probands, as well as copy number variation (CNV) mapping in a case-control cohort. Results Analysis of three distinct families revealed several candidate loci in two families and a single strong candidate gene, MYH7B, for hearing loss in one family. MYH7B encodes a Type II myosin, consistent with a role for cytoskeletal proteins in hearing. High-resolution genome-wide CNV analysis of 150 cases and 157 controls revealed deletions in genes known to be involved in hearing (e.g. GJB6, OTOA, and STRC, encoding connexin 30, otoancorin, and stereocilin, respectively), supporting CNV contributions to hearing loss phenotypes. Additionally, a novel region on chromosome 16 containing part of the PDXDC1 gene was found to be frequently deleted in hearing loss patients (OR = 3.91, 95% CI: 1.62-9.40, p = 1.45 x 10-7). Conclusions We conclude that many known as well as novel loci and distinct types of mutations not typically tested in clinical settings can contribute to the etiology of hearing loss. Our study also demonstrates the challenges of exome sequencing and genome-wide CNV mapping for direct clinical application, and illustrates the need for functional and clinical follow-up as well as curated open-access databases. Single replicates of 151 non-syndromic hereditary hearing loss cases and 157 controls with normal hearing were analyzed.
Project description:Background The genetic diversity of loci and mutations underlying hereditary hearing loss is an active area of investigation. To identify loci associated with predominantly non-syndromic sensorineural hearing loss, we performed exome sequencing of families and of single probands, as well as copy number variation (CNV) mapping in a case-control cohort. Results Analysis of three distinct families revealed several candidate loci in two families and a single strong candidate gene, MYH7B, for hearing loss in one family. MYH7B encodes a Type II myosin, consistent with a role for cytoskeletal proteins in hearing. High-resolution genome-wide CNV analysis of 150 cases and 157 controls revealed deletions in genes known to be involved in hearing (e.g. GJB6, OTOA, and STRC, encoding connexin 30, otoancorin, and stereocilin, respectively), supporting CNV contributions to hearing loss phenotypes. Additionally, a novel region on chromosome 16 containing part of the PDXDC1 gene was found to be frequently deleted in hearing loss patients (OR = 3.91, 95% CI: 1.62-9.40, p = 1.45 x 10-7). Conclusions We conclude that many known as well as novel loci and distinct types of mutations not typically tested in clinical settings can contribute to the etiology of hearing loss. Our study also demonstrates the challenges of exome sequencing and genome-wide CNV mapping for direct clinical application, and illustrates the need for functional and clinical follow-up as well as curated open-access databases.
Project description:Enlarged vestibular aqueducts (EVA) is one of the most commonly identified inner ear malformations in hearing loss patients including Pendred syndrome. While biallelic mutations of the SLC26A4 gene, encoding pendrin, causes non-syndromic hearing loss with EVA or Pendred syndrome, a considerable number of patients appear to carry mono-allelic mutation. This suggests faulty pendrin regulatory machinery results in hearing loss. Here we identify EPHA2 as another causative gene of Pendred syndrome with SLC26A4. EphA2 forms a protein complex with pendrin controlling pendrin localization, which is disrupted in some pathogenic forms of pendrin. Moreover, point mutations leading to amino acid substitution in the EPHA2 gene are identified from patients bearing mono-allelic mutation of SLC26A4. Ephrin-B2 binds to EphA2 triggering internalization with pendrin inducing EphA2 autophosphorylation weakly. The identified EphA2 mutants attenuate ephrin-B2- but not ephrin-A1-induced EphA2 internalization with pendrin. Our results uncover an unexpected role of the Eph/ephrin system in epithelial function.
Project description:This study demonstrates the baseline data of gradient gene expression in the cochlea. Especially for genes whose mutations cause autosomal dominant non syndromic hearing loss (Pou4f3, Slc17a8, Tmc1, and Crym) as well as genes important for cochlear function (Emilin-2 and Tectb), gradual expression changes help to explain the various pathological conditions.
Project description:<p>Our goal is to find genes responsible for non-syndromic sensorineural hearing loss. Blood samples were collected from the JS6 family affected with hearing loss. The family is of Caribbean Hispanic ethnicity. Family JS6 consisted of two deaf siblings, JS6.001 (Male) and JS6.002 (Female) and healthy parents, JS6.100 (mother) and JS6.200 (father). The siblings had no other medical findings. Audiometry tests and Rinne and Weber tuning fork tests identified sensorineural hearing loss in the two siblings. We performed whole exome sequencing of the four individuals and identified a recessive mutation, p.(Arg186Trp), in the CIB2 gene in the two affected siblings. Both parents were unaffected carriers. </p>
| phs000969 | dbGaP
Project description:Hereditary hearing loss family blood sample sequencing