MUTILATING HAND SYNDROME IN AN INFANT WITH FAMILIAL CARPAL-TUNNEL SYNDROME

A 7-month-old infant, son of consanguinous Indian parents, presented w ith recurrent chewing of his digits in a median nerve distribution as the primary manifestation of carpal tunnel syndrome, in conjunction wi th features consistent with congenital insensitivity to pain. Electrom yography (EMG) demonstrated severe median nerve entrapment at the wris t bilaterally, but other nerves were normal. In spite of clinical evid ence of diffuse pain insensitivity, sural nerve and skin biopsies were normal, and he had no evidence of autonomic dysfunction. Hand finding s evolved with scarring and infection of median innervated digits and loss of fine motor skills. Carpal tunnel release resulted in complete clinical resolution and significant EMG improvement. Milder symptoms a nd EMG evidence of median nerve entrapment were demonstrated in both p arents, paternal grandparents, and several of his father's siblings, W e hypothesize this child may be homozygous for a mutant allele that in its heterozygous state predisposes to familial autosomal dominant car pal tunnel syndrome. Homozygosity for this or another mutant allele ma y be responsible for his congenital insensitivity to pain. (C) 1998 Jo hn Wiley & Sons, Inc.