Sulfatide excreting heterozygous carrier of juvenile metachromatic leukodystrophy or asymptomatic patient of adult metachromatic leukodystrophy.

In a family with juvenile metachromatic leukodystrophy (sulfatide lipidosis) 2 patients showed residual arysulfatase A activities of 5--6%. The patients' healthy father was characterized biochemically by a 39% normal activity of leukocyte plus plasma arylsulfatase A. The father was further characterized by a high sulfatide excretion (0.2--0.5 mg/I urine) and, paradoxically, by a normal sulfatide degrading enzyme activity in vitro. This special carrier is suspected to be heterozygous for a) arylsulfatase A deficiency and b) arylsulfatase A (sulfatidase) lability. This presumed additional genetic defect could be the cause of the sulfatide excretion which, in turn, would be a sign of the preclinical stage of an exceptional form of adult metachromatic leukodystrophy. The normal sulfatidase activity seems to be due to an in vitro effect.