Increased urinary excretion of keratan sulfate in fucosidosis

In two children exhibiting the clinical symptoms of fucosidosis, the diagnosis was biochemically ascertained by the demonstration of a profound altpha-L-fucosidase deficiency in cultured skin fibroblasts. The non-dialysed urines of these fucosidosis patients were separated into two fractions by chromatography on Biogel P-2. The first fraction containing the glycosaminoglycans was further fractionated on Dowex 1 X 2 by stepwise elution with increasing NaCl concentrations. Keratan sulfate-chondroitin sulfates attached to the same peptide core were assayed and characterised mainly in the fractions eluted with 1.25, 1.5, 2.0 and 3.0 mol/1 NaCl. Whereas the excretion of normal children of the same age was found to be 0.77 mumol glucosamine equivalents per day in the 2 mol/1 and 3 mol/1 NaCl fraction, the two patients excreted 6.7 (M. C.) and 3.5 (M. S.) mumol 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.