title: [Detection with restriction enzyme for mutation 233delC of the connexin26 gene].
abstract: BACKGROUND
  Connexin26, a gap junction protein that spreads in the inner ear, is thought to be mainly responsible for nonsyndromic hereditary deafness. In the Caucasian population, 30delG is the most frequent mutation. 233delC is the most frequent, however, in the Japanese population. We studied 233delC mutations with restriction enzyme Apa I.
  
  
  METHODS
  Subjects were 61 patients visiting the hospital between March 1997 and October 1999 suspected of hereditary deafness. All gave written informed consent for participation.
  
  
  METHODS
  Genomic DNA was extracted from peripheral blood cells and amplified by polymerase chain reaction (PCR) using 1 set of primers targeting the connexin26 gene (nucleotide--36 to 256). After ethanol precipitation, the PCR product was digested by restriction enzyme Apa I and analyzed through agarose gel electrophoresis. The wild gene is digested by Apa I and appeared to be shorter than the original PCR product, i.e., judged to be normal.
  
  
  RESULTS
  Three patients had 233delC mutations--1 homozygous and 2 heterozygous. These mutant alleles were confirmed to have 233delC mutations by direct sequence.
  
  
  CONCLUSIONS
  In targeting the mutation 233delC of the connexin 26 gene, restriction enzyme Apa I appears to be the most useful and economic method.
authors.affiliation: Department of Otolaryngology, Shiga University of Medical Science, Otsu.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Hanamitsu
authors.forename: Mikio
authors.initials: M
authors.lastname: Suzuki
authors.forename: Hiroya
authors.initials: H
authors.lastname: Kitano
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kitanishi
mesh_terms: D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000379:methods*; D003638:Deafness / Q000151:congenital / Q000235:genetics*; D015252:Deoxyribonucleases, Type II Site-Specific; D005260:Female; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26; D015252:Deoxyribonucleases, Type II Site-Specific; C038485:GGGCCC-specific type II deoxyribonucleases