GJB2 غربالگري ناشنوايان غيرسندرومي اتوزومال مغلوب براي جهش ژن

Screening of autosomal recessive onsyndromic hearing loss for GJB2 mutations

Introduction:Hereditary Hearing loss (HHL) affects one in 1000-2000 new-borns and more than 50% of these cases, the loss has a genetic basis. About 70% of HHL is non-syndromic with autosomal recessive forms accounting for~85%of the genetic load. To date, more than 100 locus estimated for this kind of deafness. Different genes have been reported to be involved, but mutations in the connexin 26 gene (Cx26) have been established as the basisofautosomal recessive non-syndromic hear- ing loss. Materials & Methods: The aim ofthis project is to study the prevalence ofconnexin 26 mutations by using Amplification Refractory Mutation System ARMS/ PCR for detection of 35delG andthen we analyzed all samples excluding 35delG homozygote byDHPLC and Direct Sequencing. Finding: We screened 76 chromosomes (3 8 patient) forGJB2mutations . Thirty two(42%) carry GJB2 mutations including 35de1Cs W 24X,R32H, R127H,-3 170G>A.Among them, 35delG has the highest frequency(84%). Polymorphism V 1531 was found in three chromosomes. Conclusion: According to our results, other loci and genes may be the majorresponsible for nonsyndromic deafness in this population.