Genetic linkage analysis of DFNB۲۲ in families with autosomal recessive non-syndromic hearing loss inKhuzestan province

Background and aims: Hearing loss (HL) is the most common sensorineural disorder affecting ۱ in ۱۰۰۰ newborns. Autosomal recessivenon-syndromic hearing loss (ARNSHL), which is the most common cause of severe HL, is caused by mutations in more than ۸۰ loci.The OTOA gene located on DFNB۲۲ is a rare cause of the disease and the gene studied less in Iranian ARNSHL families. Hence, limitedinformation is available on the frequency and type of OTOA mutations in different populations. In this study, we investigated the role ofDFNB۲۲ locus in ARNSHL patients in Khuzestan province, Iran.Materials and Methods: In this descriptive-experimental study, ۲۳ large families with pre-lingual ARNSHL from Khuzestan province wereenrolled. Mutations in GJB۲ were excluded by DNA sequencing followed by linkage analysis. Homozygosity mapping of DFNB۲۲ wasconducted using ۶ short tandem repeat polymorphic markers via touch-down PCR and polyacrylamide gel electrophoresis. Homozygosityby-descent was identified by calculating two-point and multi-point LOD score and haplotype reconstruction.Results: Families were negative for GJB۲ mutations. Genotyping the STRP markers, haplotype reconstruction, and two-point and multiplepointLOD scores did not show homozygosity-by-descent in any of the pedigrees.Conclusion: Our findings suggest that OTOA mutations might not contribute significantly to the molecular pathophysiology of ARNSHL inKhuzestan province. However, extending the sample size can illuminate the role of this gene in Khuzestan province.

کلیدواژه ها:

Genetic linkage analysis ، ARNSHL ، DFNB۲۲ ، OTOA