Tekin, MustafaAslan, İdil2022-04-152022-04-152008http://hdl.handle.net/20.500.12575/78898Hearing loss is the most common sensoineural disorder. Congenital or prelingualhearing loss occurs approximately in one case per 1000 live births. Genetic causesaccount for 50%of cases. Additional findings are present in 30%of cases, which arereferred to as having syndromic deafness. Autosomal recessive transmission occursin 80%of hereditary deafness. To date, 27 genes, in which mutations are responsiblefor autosomal recessive deafness have been identified.We aimed to identify novel genes for non-syndromic autosomal recessive deafnessby searching four candidate genes (TMHS, TRPA1, GJA7, SLC12A2) in deaffamilies.Ninety-seven families with parental consanguinity segregating autosomal recessiveprofound prelingual deafness were included in this study. Mutations in GJB2 werescreened and found to be negative in all families. Homozygous run flanking the fourstudied genes were evaluated with microsatellite and single nucleoted polymorphism(SNP) genotyping in 66 and 51 families respectively.Microstellite followed by SSCP and no change was found in TMHS gene.Ahomozygous p.Arg3Cys (c.7C>T) change was found in TRPA1 gene. However it wasassensed to be a polymorphism based on previously reported studies.Heterozygous p.Asp297Asn (c.889G>A) was detected in GJA7 gene in two unrelatedfamilies. Although this change has not been reported earlier, it was considered to be apolymorphism because this position is not conserved in different species and theamino acid change was not assensed to be not significant for the alteration of proteinfunction.No DNA sequence change was found in the SLC12A2 gene.In conclusion TMHS, TRPA1, GJA7 and SLC12A2 genes are not a common cause ofautosomal recessive sensorineural hearing losstrTMHSGJA7MİkrodizindoctoralThesis