Cockayne syndrome: report of two siblings and review of literature in Japan.

Typical Cockayne syndrome was seen in a boy and his younger sister and these two cases are reported here, and reported cases of the syndrome in Japan are summarized. Both cases (an 11-year-old boy and a 7-year-old girl) had dwarfism, a senile face, retinitis pigmentosa, photosensitivity, and mental retardation. Calcium deposition in the basal ganglia was seen by CT scan. In both cases nerve conduction velocities were reduced suggesting peripheral neuropathy, but segmental demyelination on sural nerve biopsy was not demonstrated. Twenty seven cases of the syndrome has now been reported in Japan in 21 families (including the above two cases), consisting of 14 males and 12 females (the sex of one case was unknown): consanguineous marriage was confirmed in 14 families. Eleven cases in five families were siblings. The estimated ages of onset were from 1 month to 3 years, and in most cases photosensitivity was the initial symptom. Clinical manifestations were mental retardation in 25 cases (93%), dwarfism in 24 cases (89%), photosensitivity in 23 cases (85%), articular contracture in 22 cases (81%), sunken eyes in 20 cases (74%), retinitis pigmentosa in 17 cases (63%), deafness in 16 cases (59%), and intracranial calcification in 14 cases (51%). Intracranial calcification will be more often detected in future following the development of CT scanning.