Type 2 GM1 gangliosidosis with long survival and neuronal ceroid lipofuscinosis

Neurologic deterioration began in a girl before age 2 years. By 4 she was spastic and decerebrate. GM 1 gangliosidosis was diagnosed by absence of β-galactosidase activity in leukocytes and fibroblasts. She died at 17 years. Her small brain contained only 2.61 μmole glycolipid N-acetylneuraminic acid per gram, and was filled with autofluorescent material. GM 1 gangliosidosis was confirmed by the presence of membranous cytoplasmic bodies, by the absence of β-galactosidase, and by failure of complementation when the patient9s fibroblasts were fused with cells from other forms of GM 1 gangliosidosis. The autofluorescent material probably accumulated because of the long survival rather than the primary enzyme defect.