genetic linkage analysis of dfnb22 in families with autosomal recessive nonsyndromic hearing loss in khuzestan province

Background and aims: hearing loss (hl) is the most common sensorineural disorder affecting 1 in 1000 newborns. autosomal recessive nonsyndromic hearing loss (arnshl), which is the most common cause of severe hl, is caused by mutations in more than 80 loci. the otoa gene located on dfnb22 is a rare cause of the disease and the gene studied less in iranian arnshl families. hence, limited information is available on the frequency and type of otoa mutations in different populations. in this study, we investigated the role of dfnb22 locus in arnshl patients in khuzestan province, iran. materials and methods: in this descriptiveexperimental study, 23 large families with prelingual arnshl from khuzestan province were enrolled. mutations in gjb2 were excluded by dna sequencing followed by linkage analysis. homozygosity mapping of dfnb22 was conducted using 6 short tandem repeat polymorphic markers via touchdown pcr and polyacrylamide gel electrophoresis. homozygositybydescent was identified by calculating twopoint and multipoint lod score and haplotype reconstruction. results: families were negative for gjb2 mutations. genotyping the strp markers, haplotype reconstruction, and twopoint and multiplepoint lod scores did not show homozygositybydescent in any of the pedigrees. conclusion: our findings suggest that otoa mutations might not contribute significantly to the molecular pathophysiology of arnshl in khuzestan province. however, extending the sample size can illuminate the role of this gene in khuzestan province.