title: Connexin 26 mutations in cases of sensorineural deafness in eastern Austria.
abstract: Mutations in the connexin 26 (Cx26) gene (GJB2) are associated with autosomal nonsyndromic sensorineural hearing loss. This study describes mutations in the Cx26 gene in cases of familial and sporadic hearing loss (HL) by gene sequencing and identifies the allelic frequency of the most common mutation leading to HL (35delG) in the population of eastern Austria. For this purpose we have developed and applied a molecular beacon based real-time mutation detection assay. Mutation frequencies in the Cx26 gene of individuals from affected families (14 out of 46) and sporadic cases (11 out of 40) were 30.4% and 27.5%, respectively. In addition to known disease related alterations, a novel mutation 262 G-->T (A88S) was also identified. 35delG accounted for almost 77% of all Cx26 mutations detected and displayed an allelic frequency in the normal hearing population of 1.7% (2 out of 120). The high prevalence of the 35delG mutation in eastern Austria would therefore allow screening of individuals and family members with Cx26 dependent deafness by a highly specific and semi-automated method.
authors.affiliation: Department of Otorhinolaryngology, AKH-8J, Währinger Gürtel 18-20, Vienna, Austria, A-1090. klemens.frei@akh-wien.ac.at
authors.forename: Klemens
authors.initials: K
authors.lastname: Frei
authors.forename: Károly
authors.initials: K
authors.lastname: Szuhai
authors.forename: Trevor
authors.initials: T
authors.lastname: Lucas
authors.forename: Klara
authors.initials: K
authors.lastname: Weipoltshammer
authors.forename: Christian
authors.initials: C
authors.lastname: Schöfer
authors.forename: Reinhard
authors.initials: R
authors.lastname: Ramsebner
authors.forename: Wolf-Dieter
authors.initials: WD
authors.lastname: Baumgartner
authors.forename: Anton K
authors.initials: AK
authors.lastname: Raap
authors.forename: Reginald
authors.initials: R
authors.lastname: Bittner
authors.forename: Franz J
authors.initials: FJ
authors.lastname: Wachtler
authors.forename: Karin
authors.initials: K
authors.lastname: Kirschhofer
mesh_terms: D000293:Adolescent; D000328:Adult; D001317:Austria; D002648:Child; D002675:Child, Preschool; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D005787:Gene Frequency; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D009154:Mutation; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26