title: Sequence Variations and Haplotypes of the GJB2 Gene Revealed by Resequencing of 192 Chromosomes from the General Population in Korea.
abstract: OBJECTIVE
  Hearing impairment (HI) is the most common sensory deficit in human. The Gap Junction Protein, Beta-2 (GJB2) gene encodes the protein connexin 26, and this gene accounts for up to half of the cases of autosomal recessive nonsyndromic HI. This study was conducted to obtain a set of sequence variations (SVs) of the GJB2 gene among Koreans from the general population for making molecular genetic diagnoses and performing genetic counseling.
  
  
  METHODS
  We resequenced the GJB2 gene in 192 chromosomes from 96 adult individuals of Korean descent and who were without a history of hearing difficulty. The data of the SVs was obtained and the haplotypes were reconstructed from the data.
  
  
  RESULTS
  Five SVs were observed, including a novel one (c.558G>A; p.T186T), with the allele frequencies ranging from 0.5% (1/192) to 41% (79/192). The linkage disequilibrium study and haplotype construction showed that some of the SVs are in tight linkage, resulting in a limited number of haplotypes.
  
  
  CONCLUSIONS
  We observed SVs of the GJB2 gene with different allele frequencies, and a limited number of haplotypes were constructed. The data from this study can be used as reference data for GJB2-related hearing genetic studies, including studies on the founder effect and population genetics, and this data is particularly relevant to people of East Asian decent.
authors.affiliation: Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hee-Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Chang-Hun
authors.initials: CH
authors.lastname: Park
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Ki-O
authors.initials: KO
authors.lastname: Lee
authors.forename: Hong-Hee
authors.initials: HH
authors.lastname: Won
authors.forename: Moon-Hee
authors.initials: MH
authors.lastname: Ko
authors.forename: Hosuk
authors.initials: H
authors.lastname: Chu
authors.forename: Yang-Sun
authors.initials: YS
authors.lastname: Cho
authors.forename: Won-Ho
authors.initials: WH
authors.lastname: Chung
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Sung Hwa
authors.initials: SH
authors.lastname: Hong