title: Identification of an ancestral haplotype of the 35delG mutation in the GJB2 (connexin 26) gene responsible for autosomal recessive non-syndromic hearing loss in families from the Eastern Black Sea Region in Turkey.
abstract: Mutations in the GJB2 gene have been shown to be the major cause of autosomal recessively inherited, prelingual, non-syndromic hearing loss. 35delG was found to be the most frequent mutation among Caucasians. In this study, we performed haplotype analysis of two large families with autosomal recessive non-syndromic hearing loss (totally 33 affected, 37 unaffected) from Trabzon (a city from the Eastern Black Sea region) by using polymorphic markers close to the 35delG mutation region, and identified a common haplotype, "2-6-4". The frequency of the mutant chromosomes having the 2-6-4 haplotype was compared between the Eastern Black Sea region and the other regions of Turkey and the difference was found to be significant (chi squared = 5.13/df = 1/p = 0.023). Also, when the frequency of mutant and wild type chromosomes having the 2-6-4 haplotype was compared in the Eastern Black Sea region, a statistically significant difference was observed in the mutant chromosomes (chi squared = 7.46/df = 1/p < or = 0.01). The results of this study demonstrate that the ancestral haplotype of the chromosomes bearing 35delG mutation in the Eastern Black Sea region is "2-6-4".
authors.affiliation: Department of Medical Biology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Balci
authors.forename: Filiz Ozbaş
authors.initials: FO
authors.lastname: Gerçeker
authors.forename: Songül
authors.initials: S
authors.lastname: Aksoy
authors.forename: Gonca
authors.initials: G
authors.lastname: Sennaroğlu
authors.forename: Ersan
authors.initials: E
authors.lastname: Kalay
authors.forename: Levent
authors.initials: L
authors.lastname: Sennaroğlu
authors.forename: Pervin
authors.initials: P
authors.lastname: Dinçer
mesh_terms: D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D006239:Haplotypes; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D009154:Mutation; D014421:Turkey
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26