Increased Urinary Excretion of Keratan Sulfate in Fucosidosis

Abstract

In 2 children exhibiting the clinical symptoms of fucosidosis, the diagnosis was biochemically ascertained by the demonstration of a profound .alpha.-L-fucosidase deficiency in cultured skin fibroblasts. The non-dialyzed urines of these fucosidosis patients were separated into 2 fractions by chromatography on Biogel P-2. The 1st fraction containing the glycosaminoglycans was further fractionated on Dowex 1 .times. 2 by stepwise elution with increasing NaCl concentrations. Keratan sulfate-chondroitin sulfates attached to the same peptide core were assayed and characterized mainly in the fractions eluted with 1.25, 1.5, 2.0 and 3.0 mol/l NaCl. Whereas the excretion of normal children of the same age was found to be 0.77 .mu.mol glucosamine equivalents/day in the 2 mol/l and 3 mol/l NaCl fraction, the 2 patients excreted 6.7 and 3.5 .mu.mol glucosamine equivalents per day, respectively. Since keratan sulfate contains .alpha.-fucose at the non-reducing terminal, this increase in excretion of long chain keratan sulfate in fucosidosis could result from impaired degradation of keratan sulfate, due to the .alpha.-fucosidase deficiency.