The dominant-negative mutation R75W in GJB2, which arises de novo during early embryogenesis, underlies syndromic hearing loss as well as deafness with palmoplantar keratoderma and is detected in 0.09% of probands with sensorineural hearing loss in Han Chinese populations (16). The gene discussed is GJB2; the disease is epidermolytic palmoplantar keratoderma, 1.