Localization of Nonsyndromic Hearing Impairment Genes Non-syndromic hearing impairment (NSHI) is the most heterogeneous trait known, with >140 mapped loci and >50 identified genes. However, the vast majority of NSHI genes have neither been localized nor identified. The extreme genetic heterogeneity of NSHI is due to the different processes which can malfunction within the inner ear and cause the hearing impairment (HI) phenotype. Identification of genes involved in HI is the first step in improving knowledge of the auditory process which in turn will aid in the development of diagnostic modalities and therapeutic interventions, and additionally aid in early diagnosis through genetic screening. In order to map and refine the interval for novel NSHI loci and NSHI loci with unknown genes, pedigrees segregating NSHI are being ascertained from throughout Pakistan. These pedigrees are usually both consanguineous and can independently establish linkage. Due to extreme locus heterogeneity of NSHI it is important that loci be mapped using families which can individually establish linkage. Consanguineous pedigrees are ideal for mapping autosomal recessive (AR) NSHI since homozygosity mapping can be performed, and unlike pedigrees without consanguineous matings, they can be sufficiently informative to establish linkage. Using DNA samples from the ascertained pedigrees, whole genome genotyping will be carried out using the Illumina Infinium HumanLinkage-12 panel. Linkage and haplotype analysis, and for consanguineous ARNSHI families homozygosity mapping, will be used to localize NSHI loci to the smallest possible genetic intervals. Information from multiple families with established linkage to the same genetic region will be used to refine the interval whenever possible. The study will provide a rich resource of families to carry out NSHI gene identification using next generation sequencing. Goal: To map NSHI loci and refine them to the smallest possible region using a large resource of well characterized families with NSHI.

Public Health Relevance

Large consanguineous families with nonsyndromic hearing impairment (NSHI) will be ascertained from Pakistan. In order to map NSHI loci, linkage analysis will be carried using genotype data generated from SNP arrays. Completion of the aims of this proposal will provide a resource to identify genes for novel loci as well as for known NSHI loci for which the gene is unknown.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC011651-04
Application #
8642638
Study Section
Special Emphasis Panel (ZRG1-GGG-N (02))
Program Officer
Watson, Bracie
Project Start
2011-04-01
Project End
2016-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
4
Fiscal Year
2014
Total Cost
$272,922
Indirect Cost
$77,320
Name
Baylor College of Medicine
Department
Genetics
Type
Schools of Medicine
DUNS #
051113330
City
Houston
State
TX
Country
United States
Zip Code
77030
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Rehman, Atteeq U; Santos-Cortez, Regie Lyn P; Morell, Robert J et al. (2014) Mutations in TBC1D24, a gene associated with epilepsy, also cause nonsyndromic deafness DFNB86. Am J Hum Genet 94:144-52
Santos-Cortez, Regie Lyn P; Lee, Kwanghyuk; Azeem, Zahid et al. (2013) Mutations in KARS, encoding lysyl-tRNA synthetase, cause autosomal-recessive nonsyndromic hearing impairment DFNB89. Am J Hum Genet 93:132-40
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Lee, Kwanghyuk; Ansar, Muhammad; Andrade, Paula B et al. (2012) Novel CLDN14 mutations in Pakistani families with autosomal recessive non-syndromic hearing loss. Am J Med Genet A 158A:315-21
Ansar, Muhammad; Lee, Kwanghyuk; Naqvi, Syed Kamran-Ul-Hassan et al. (2011) A new autosomal recessive nonsyndromic hearing impairment locus DFNB96 on chromosome 1p36.31-p36.13. J Hum Genet 56:866-8