Late-onset globoid cell leukodystrophy: unusual ultrastructural pathology and subtotal beta-galactocerebrosidase deficiency.

An 11-year-old girl was found to have severely reduced beta-galactocerebrosidase activity as evidence of late-onset globoid cell leukodystrophy, while her mother had almost normal enzyme activity in circulating white blood cells. Clinically, the patient showed a remitting course marked by seizures, ataxia, white-matter disease on computed tomographic scan, and reduced conduction velocities of peripheral nerves. Symptoms improved somewhat around the age of 10 years. Two sural nerve biopsies, performed 6 years apart, disclosed a demyelinating neuropathy. By electron microscopy, membrane-bound vacuolar lysosomes in Schwann cells of myelinated axons, unlike the typical needlelike inclusions seen in classic infantile globoid cell leukodystrophy, were present in both specimens. Thus, clinical, morphologic, and biochemical data in this patient--and her mother--emphasize, compared with past reports on late-onset globoid cell leukodystrophy, considerable variation in the nosologic spectrum of late-onset globoid cell leukodystrophy and conspicuous differences from classic infantile globoid cell leukodystrophy.