The M34T allele variant of Connexin 26

GJB2 encodes the protein Connexin 26, one of the building blocks of gap jun ctions. Each Connexin 26 molecule can oligomerize with five other connexins to form a connexon; two connexons, in turn, can form a gap junction. Becau se mutations in GJB2 are the most common cause of congenital severe-to-prof ound autosomal recessive nonsyndromic hearing loss, the effect of the Conne xin 26 allele variants on this dynamic 'construction' process and the funct ion of any gap junctions that do form is particularly germane. One of the m ore controversial allele variants, M34T, has been hypothesized to cause aut osomal dominant nonsyndromic hearing loss. In this paper, we present clinic al and genotypic data that refutes this hypothesis and suggests that the ef fect of the M34T allele variant may be dependent on the mutations segregati ng in the opposing allele.