title: Mutation analysis of the Cx26, Cx30, and Cx31 genes in autosomal recessive nonsyndromic hearing impairment.
abstract: CONCLUSIONS
  Biallelic Cx26 mutations are the most common cause of autosomal recessive nonsyndromic hearing impairment (ARNHI) in Switzerland. Mutations in Cx30 and 31, digenic mutations as well as large deletions/duplications, are unlikely to be a major cause of hearing loss in Swiss patients with ARNHI. Multiplex ligation-dependent probe amplification (MLPA) is a highly accurate screening method for detection of c.del(GJB6-D13S1830).
  
  
  OBJECTIVE
  The intent of this study was to investigate the prevalence of the point and digenic mutations including large deletions and duplications in the Cx26, 30, and 31 genes in a Swiss patient cohort with ARNHI and cochlear implant.
  
  
  METHODS
  The coding regions of Cx26, 30, and 31 were sequenced in 32 patients. Large deletions/duplications were assessed by MLPA.
  
  
  RESULTS
  In one patient digenic heterozygous mutations involving Cx26 (c.35delG) and Cx30 (c.del(GJB6-D13S1830)) were identified. Biallelic Cx26 mutations were detected in 31%. One putative mutation (c.94C>T) was found in Cx31. MLPA analysis did not reveal any additional deletion or duplication in all three Cx genes, except for the heterozygous c.del(GJB6-D13S1830) deletion.
authors.affiliation: Hals-Nasen-Ohren-Klinik, Kantonsspital, Aarau, Switzerland. nicolas.guertler@ksa.ch
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gürtler
authors.forename: Carole
authors.initials: C
authors.lastname: Egenter
authors.forename: Nemya
authors.initials: N
authors.lastname: Bösch
authors.forename: Martina
authors.initials: M
authors.lastname: Plasilova
mesh_terms: D016022:Case-Control Studies; D003054:Cochlear Implants; D015331:Cohort Studies; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D003638:Deafness / Q000235:genetics* / Q000601:surgery; D017353:Gene Deletion; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D009154:Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012680:Sensitivity and Specificity
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26