The Hurler syndrome: A biochemical and clinical study

Abstract

Five patients with the Hurler syndrome, and their parents, have been studied. Urinary mucopolysaccharides from the patients, their parents, and normal subjects were compared after concentration by ultrafiltration and fractionation by zone electrophoresis. Three patients excreted increased amounts of both chondroitin sulfate B and heparitin sulfate, whereas two had an increased excretion of heparitin sulfate only. In addition, at least four patients excreted chondroitin sulfate A and/or C, which is the main mucopolysaccharide fraction of normal urine. Observations on the mucopolysaccharides of two pairs of brothers suggested that biochemical findings in sibs with the Hurler syndrome may be similar. Examination of the urinary mucopolysaccharides of the parents did not give conclusive evidence for the occurrence of chemical abnormalities in carriers of the disease trait. The two patients who excreted heparitin sulfate only had rather small and uncharacteristic bone changes whereas the skeletal changes in the three patients who excreted chondroitin sulfate B, in addition to heparitin sulfate, were advanced and typical of the Hurler syndrome.