Relative frequency of GJB2 gene mutations in autosomal recessive non-syndromic hearing loss [ARNSHL] patients in lurastan population

ABSTRACT

Congenital hearing loss with many genetic and environmental causes affecting 1 in 1000 newborns. Mutations in the GJB2 [Gap Junction Beta-2] gene encoding the gap junction protein connexin 26 have been established as the main cause of autosomal recessive non-syndromic hearing loss. The aim of this study was to study the frequency of GJB2 mutations in Lurastan non-syndromic deaf population using ARMS/PCR, DHPLC and direct sequencing. For this purpose, 106 chromosomes from 53 patients were studied. Eighteen chromosomes [17%] carry GJB2 mutations including 35delG, 314dell4, 512insAACG, -3170G>A, W24X, V95M and 510insCGAA. The last mutation is a novel GJB2 mutation, 35delG mutation was diagnosed in 10 chromosomes [9/4%]; 4 patients were homozygote and 2 patients were heterozygote. Also polymorphism VI531 were found in 3 families. This frequency is significantly higher compared to that of the whole population of Iran