Skin punch biopsy in the diagnosis of juvenile neuronal ceroid-lipofuscinosis. A comparison with leukocyte peroxidase assay.

Electron microscopical examination of skin punch biopsy specimens was compared with the leukocyte peroxidase assay in establishing the diagnosis of juvenile neuronal ceroid-lipofuscinosis in three families with at least one affected child. Although the leukocyte peroxidase assay failed to distinguish between the patients, heterozygotes, and normal subjects, skin biopsy specimens containing characteristic cytosomes were found only in the children with this disease. In fact, in two families, the three affected members were identified by this method after the biopsy specimens had been randomized. Although only one to four cells containing such cytosomes were identified in each patient, not only cytosomes with curvilinear bodies but also those with rectilinear as well as "fingerprint" profiles were found. Thus, the skin punch biopsy appears to be a useful diagnostic aid the juvenile as well as the late infantile forms of neuronal ceroid-lipofuscinosis.