[Xeroderma pigmentosum presenting clinical features of spinocerebellar degeneration].

A case of group D xeroderma pigmentosum is reported. This 26-year-old woman was normal delivery, and showed a normal psychomotor development. Her parents noted a patchy brownish pigmentation on her limbs, face and trunk soon after the birth. Gait disturbance appeared at 17 years old and progressed over 9 years. Neurological examination disclosed a severe loss of deep sensation, spastic weakness and mild cerebellar ataxia. Slight involvement of peripheral nerves was revealed by the elecrophysiological investigations. CT and MRI brain scans showed a cerebellar atrophy, however no atrophy was seen in the cerebrum. Adrenocortical hypo-function was noted by decreased 17 KS and 17 OHCS. Unscheduled DNA synthesis of the patient's skin fibroblast was 45% of normal controls, and the result was consistent with group D xeroderma pigmentosum. The neurological findings of this patient are well characterized by the degeneration of the posterior and lateral column of the spinal cord, cerebellum and peripheral nerves. We discussed symptomatological and etiological similarities of the present case to spinocerebellar degeneration. It may be necessary to consider the possibility of xeroderma pigmentosum in the differential diagnosis of spinocerebellar degeneration.