Sensorineural hearing loss, striate palmoplantar hyperkeratosis, and knuckle pads in a patient with a novel connexin 26 (GJB2) mutation.

M utations in connexin 26 (GJB2, Cx26) cause autosomal recessive and occasionally dominant non-syndromic sensorineural hearing loss (SNHL). Cx26 mutations have also been identified in SNHL with dermatological features of autosomal dominant diffuse palmoplantar hyperkeratosis (DPPK). We describe a girl with bilateral sloping sensorineural hearing loss, striate palmoplantar hyperkeratosis (SPPK), and knuckle pads, who has a novel heterozygous missense mutation (G59R) in the connexin 26 gene (GJB2, Cx26). This mutation resides in the same codon in which a mutation was previously described for a family with dominant sensorineural hearing loss with a diffuse palmoplantar hyperkeratosis (DPPK). Cx26 mutations have not been reported previously with the striate form of palmoplantar hyperkeratosis nor with knuckle pads. Mutations in Cx26 have also been described in a severe condition of congenital deafness, keratopachydermia, and constrictions of fingers and toes (Vohwinkel syndrome; OMIM 124500) 5 as well as in KID syndrome (OMIM 148210) with keratitis, icthyosis, and deafness. 7 To date, mutations in Cx26 have not been associated with a striate subtype of palmoplantar hyperkeratosis (SPPK) or with knuckle pads.