GJB2 (connexin 26) variants and nonsyndromic sensorineural hearing loss: a HuGE review

Genet Med. 2002 Jul-Aug;4(4):258-74. doi: 10.1097/00125817-200207000-00004.


Despite the enormous heterogeneity of genetic hearing loss, variants in one locus, Gap Junction Beta 2 or GJB2 (connexin 26), account for up to 50% of cases of nonsyndromic sensorineural hearing loss in some populations. This article reviews genetic epidemiology studies of the alleles of GJB2, prevalence rates, genotype-phenotype relations, contribution to the incidence of hearing loss, and other issues related to the clinical validity of genetic testing for GJB2. This review focuses primarily on three alleles: 167 Delta T, 35 Delta G, and 235 Delta C. These alleles are recessive for nonsyndromic prelingual sensorineural hearing loss, and the evidence suggests complete penetrance but variable expressivity.

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Age of Onset
  • Alleles
  • Connexin 26
  • Connexins / genetics*
  • Disease Progression
  • Genetic Variation*
  • Hearing Loss / diagnosis
  • Hearing Loss / genetics*
  • Hearing Loss / physiopathology
  • Hearing Loss, High-Frequency / genetics
  • Humans


  • Connexins
  • GJB2 protein, human
  • Connexin 26