NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

National Center for Biotechnology Information (US). Genes and Disease [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 1998-.

Cover of Genes and Disease

Genes and Disease [Internet].

Show details

Deafness

Last Update: January 31, 2011.

Hearing loss is extremely common and can present at any time from infancy to old age. About 1 in 1000 infants has profound hearing impairment, with half thought to be of genetic origin. Many deafness genes exist, but the most common cause of hearing loss in American and European populations is a mutation in the connexin 26 (Cx26) gene. Cx26 has a carrier rate of 3%, similar to that for cystic fibrosis, and it causes about 20% of childhood deafness.

Mutations in Cx26 cause congenital syndromic and nonsyndromic deafness—that is, the deafness is not accompanied by other symptoms, such as blindness. Cx26 is located on chromosome 13q11-12 and codes for a gap junction protein called connexin 26. Gap junctions are plasma membrane channels that allow the movement of small molecules and ions between adjacent cells. Gap junctions of the inner ear may play a role in maintaining potassium homeostasis, which is important for inner-ear function and, thus, hearing. It has been proposed that mutations in Cx26 may disrupt potassium circulation and result in deafness.

Connexin 26. Connexin 26 (GJB2) is one of the main proteins involved in potassium (K+) homeostasis in the cochlea of the inner ear.

Connexin 26

Connexin 26 (GJB2) is one of the main proteins involved in potassium (K+) homeostasis in the cochlea of the inner ear. It is found in the supporting cells, fibrocytes of the spiral ligament and in cells of the spiral limbus Adapted from Steel, K.P. (1999) (more...)

The discovery that Cx26 mutations are a cause of congenital hearing loss can help in the early diagnosis of hearing impairment. Early identification and management of deafness is important for the development of language and social skills.

Views

The Genes

The Diseases

Websites

  • NIDCD National Institute on Deafness and Other Communication Disorders
  • Info to Go from Gallaudet University
  • MEDLINEplus from the National Library of Medicine

Related information

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...