Gap junction beta-2 protein (connexin 26) is a member of the gap junction protein family which is also known as connexins. Gap junctions are reponsible for intercellular communication and they control diffusion of nutrients, ions and metabolites between cells. Several findings support the importance of connexin 26 in auditory transduction. Although the exact involvement of GJB2 in cochlear cells is not known, research has shown that connexin 26 may be involved in the maintenance of potassium ion equilibrium within the cochlear cells, a process important for the conversion of sound waves to electrical impulses. Studies also suggests that connexin 26 may play a role in the maturation and development of cochlear cells.
Mutations in the GJB2 gene have been implicated in nonsyndromic deafness (autosomal dominant and autosomal recessive), Vohwinkel syndrome, palmoplantar keratoderma with deafness, Bart-Pumphrey syndrome, and keratitis-ichthyosis-deafness (KID) syndrome. Connexin 26 mutations account for 10-30% of sporadic non-syndromic deafness.
In two separate studies reported by Simsek et al. (2001a and 2001b), 35delG mutation in GJB2 gene wasn't detected among Omani patients with nonsyndromic autosomal recessive deafness (NARD) or control subjects. Simsek et al. (2001a) concluded that 35delG may not be associated with NARD in Oman.