GJB2

About GJB2

GJB2 on chromosome 13q12.11 encodes connexin 26, a protein that assembles into gap junction channels connecting neighboring cells. In the cochlea, gap junctions formed by connexin 26 and connexin 30 are thought to help recycle potassium ions away from hair cells and maintain the ionic environment of the inner ear fluids. Pathogenic variants in GJB2 are the most common cause of inherited non syndromic hearing loss in many populations, accounting for a large share of autosomal recessive congenital deafness. The 35delG variant is the most frequent in people of European ancestry, while other variants such as 235delC predominate in East Asia and 167delT in Ashkenazi Jewish populations. GJB2 related hearing loss is usually present at birth, bilateral, non progressive, and ranges from mild to profound. A smaller number of dominant GJB2 variants cause syndromes combining hearing loss with skin disorders, such as keratitis ichthyosis deafness syndrome and Vohwinkel syndrome. The link between GJB2 and deafness was reported in 1997. Newborn hearing screening programs identify congenital hearing loss early, and GJB2 testing is commonly one of the first genetic tests performed. Hearing aids and cochlear implants support language development, and cochlear implants generally work well in GJB2 related deafness.