title: GJB2 mutations in Turkish patients with ARNSHL: prevalence and two novel mutations.
abstract: Mutations in the connexin 26 gene (GJB2) cause a significant proportion of prelingual non-syndromic autosomal recessive deafness in all populations studied so far. To determine the percentage of hearing loss attributed to GJB2 in northeast Turkey, 93 unrelated patients with autosomal recessive non-syndromic hearing loss (ARNSHL) were screened. Seven different mutations were found in 29 of the patients with severe to profound hearing loss. The 35delG mutation was the most common mutation, accounting for 76% of all mutant GJB2 alleles. Four already described mutations, W24X, 310del14, delE120 and R184P and two novel mutations, Q80K and P173S, were identified. The allelic Delta(GJB6-D13S1830), which can cause hearing loss in combination with GJB2 mutations, was not present in our patients. Our results are comparable to those reported in other regions in Turkey and indicate that GJB2 mutations account for about 30% of Turkish patients with ARNSHL. Besides 35delG, W24X and delE120 occur more than once in the Turkish ARNSHL population with a frequency of about 5%.
authors.affiliation: Department of Human Genetics, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB, Nijmegen, The Netherlands. e.kalay@antrg.umcn.nl
authors.forename: Ersan
authors.initials: E
authors.lastname: Kalay
authors.forename: Refik
authors.initials: R
authors.lastname: Caylan
authors.forename: Hannie
authors.initials: H
authors.lastname: Kremer
authors.forename: Arjan P M
authors.initials: AP
authors.lastname: de Brouwer
authors.forename: Ahmet
authors.initials: A
authors.lastname: Karaguzel
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005808:Genes, Recessive; D034381:Hearing Loss / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D010375:Pedigree; D014421:Turkey
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26