ELEVATED SULFATIDE EXCRETION IN COMPOUND HETEROZYGOTES OF METACHROMATIC LEUKODYSTROPHY AND ASA-PSEUDODEFICIENCY ALLELE

Objective: Use of sulfatide excretion in differentiating MLD/PD-hetero zygotes from MLD-patients and PD/PD-homozygotes. Design and Methods: S ulfatide was extracted from urine sediment with chloroform/methanol (2 :1, v/v). The quantity of sulfatide was measured densitometrically (la mbda = 580 nm) after thin-layer chromatography. ASA and beta-galactosi dase activities were assayed enzymatically. Results: MLD/PD-heterozygo tes excreted sulfatide in the range of 4.8-36.3 nmol/mg lipid (mean +/ - SD = 17.8 +/- 10.7), whereas sulfatide in MLD-patients ranged from 7 4.3-411.6 nmol/mg lipid (mean +/- SD = 184.5 +/- 130.8) and in PD/PD-h omozygotes sulfatide excretion remained in normal range of 0.0-5.9 nmo l/mg lipid (mean +/- SD = 1.64 +/- 2.12). ASA activities in these grou ps were very low or lowered. Conclusions: The quantitative measurement of sulfatide in urine allows differentiation between MLD/PD-heterozyg otes and MLD-heterozygotes, as well as between MLD/PD-heterozygotes wi th very low ASA activity and MLD-patients or PD/PD-homozygotes. The qu antitative measurement of sulfatide in urine differs between MLD-carri ers and controls.