اولين مورد گزارش شده از جهش در COL 11A2 با ناشنوايي ارثي اتوزومال مغلوب غيرسندرمي در يك خانواده ايراني

First report of mutation in COL 11A2 gene in an Iranian family with Autosomal recessive non-syndromic hearing loss

Introduction: Hereditary Hearing loss( HHL) affeetsone in 2000 newborns and more than 50% of these cases, the loss has a genetic basis. A bout 70% of HHL is non-syndromic with autosomal recessive mode of inheritance accounting for~S5% of the genetic load and more than hundred loci have been estimated for this kind ofdeafness. Materials and Methods:A 4-year-old boy and her sixteen-year- old sister, both suffering from congenital deafness without any others l i nical symptoms were referred to Genetics Research Center to be screened for molecular basis of their phenotype. Bases on clinical observation, autosomal recessive non-syndromic hearing loss was dignosed for both of them. Using linkage analysis their phenotype localized to 6p2l-3 chromosome in which COL11 A2 has been located Several mutations have been reported in this gene associated with sticklersyndrome type 3 and non-syndromic hearing loss, both with autosomal dominant form of inheritance. Findings: In this study linkage between coL11A2 gene in DFNA13 locus, causative forautosomal dominant hearing loss, and phenotype of autosomal recessive non-syndromic hearing loss in and Iranian family was analyzed and Pro621 Thr mutation was found in this family. Conclusion:Pro 621 Thr mutation found in this study is the first report of COLT11A2 mutation associated with autosomal recessive non-syndromie hearing loss.