Investigation of D7S496 marker characteristics in five Iranian ethnic groups for linkage analysis of autosomal recessive non syndromic hearing loss

The most important currently identifiable genetic cause of autosomal recessive non syndromic hearing loss (ARNSHL) after GJB2 mutations are the SLC26A4 gene mutations. In this investigation, the characteristics and informativeness of D7S496 CA repeat STR marker in SLC26A4 gene region was examined in five ethnic groups of the Iranian population.
The locus were genotyped in 165 individuals of five different ethnic groups including Fars, Azari, Turkmen, Gilaki and Arabs using PCR followed by PAGE and fluorescent capillary electrophoresis. In this study, the results were analyzed by GeneMarker HID Human STR Identity software, GenePop program and Microsatellite Tools software.
Analysis of the allelic frequency revealed the presence of 10 alleles for D7S496 marker in the Iranian population, which allele 137bp at the D7S496 locus with 41.52% allele frequency was the most frequent. The observed heterozygosity of all ethnic groups was approximately above 70%, which Turkmen ethnic had the highest heterozygosity among all. Finally, analysis of PIC value represents D7S496 marker as a highly informative marker in Iranian population (PIC value above 0.7).
Our data introduce D7S496 as a highly informative marker in diagnosis of SLC26A4 based ARNSHL by Linkage analysis.