[Juvenile Sandhoff disease with local panatrophy--a case report].

A case of juvenile Sandhoff disease with Gowers' local panatrophy was reported. A mentally retarded 39 year-old man had been noticed to have localized skin atrophy on the right leg since 7 years of age, and was also aware of the atrophy of his right leg since his junior high school age. His parents were first cousins. He had multiple localized atrophic skin lesions on the right side of his nape, the right side of lower back, and the right thigh. These skin lesions did not show any signs of sclerosis. Although he was mentally retarded (IQ=44), the neurological examination was normal including funduscopy. Histological examination of the atrophic skin le led that the epidermal basal layer was hyperpigmented and that the dermis and subcutaneous fatty tissue were extremely atrophic. The nerves meandered across the dermis and subcutaneous tissue, and had membranous lipid storage cytosomes in the axon and Schwann cells. Biochemical studies revealed marked deficiency fo leukocyte hexosaminidase activity. Total hexosaminidase activity was decreased to 18% of normal controls, and hexosaminidase B activity was completely deficient. Other lysosomal enzymes in leukocytes were normal in activities. Both parent showed intermediate levels of leukocyte hexosaminidase A and B activities. Electron microscopy analysis of a rectal biopsy specimen showed neuronal accumulation of dense osmophilic deposits, as well as membranous cytoplasmic bodies in Meissner's plexus. On the basis of the patient's age at onset and the above findings, the patient was diagnosed to have juvenile Sandhoff disease. The local panatrophy observed in the present case could be the result of the accumulation of GM2-ganglioside in autonomic nervous system, and may well be a new clinical feature of GM2-gangliosidosis.