ENCEPHALONEUROPATHY WITH LYSOSOMAL ZEBRA BODIES AND GM2 GANGLIOSIDE STORAGE

An 11-year-old girl died of a neuronal storage disorder that clinicall y was characterized by failure to thrive and muscular hypotonia from b irth, with the subsequent evolution of motor neuron disease, epilepsy, and dementia. A wide range of metabolic disorders, including all form s of GM2 gangliosidosis, could be excluded. Electron microscopy demons trated neuronal zebra body inclusions, and immunohistochemistry demons trated that GM2 ganglioside was a major constituent of the storage mat erial. We suggest that the patient died of a lysosomal storage disease that is clinically and biochemically different from Tay-Sachs disease , Sandhoff disease, and other GM2 gangliosidoses described previously. This case also further demonstrates that significant accumulation of GM2 ganglioside, which is crucial for dendritic formation, may occur i n neuronal storage diseases lacking known defects in ganglioside catab olism. (C) 1997 by Elsevier Science Inc.