A connexin 26 mutation causes a syndrome of sensorineural hearing loss andpalmoplantar hyperkeratosis (MIM 148350)

We report a missense mutation in the connexin 26 gene (GJB2) in a family wi th an autosomal dominant syndrome of hearing loss and hyperkeratosis. The a ffected family members have high frequency, slowly progressive, bilateral, sensorineural hearing loss and palmoplantar hyperkeratosis. The mutation ca uses arm amino acid substitution (G59A), which may disrupt a reverse turn i n the first extracellular loop of connexin 26. Connexin 26 mutations have b een reported in syndromes of deafness and palmoplantar keratoderma. These d ata provide additional evidence for the pole of connexin 26 in syndromes of this type.