Metachromatic leukodystrophy: diagnosis with samples of venous blood.

Arylsulfatase A and B have been demonstrated in preparations of human leukocytes. The level of activity of arylsulfatase A is markedly decreased in the preparations from patients with metachromatic leukodystrophy. Acid phosphatase and arylsulfatase B activities were normal. The assay of arylsulfatase A in leukocyte preparations can be useful in the diagnosis of metachromatic leukodystrophy while obviating the difficulties of current methods.