Two Cape Coloured siblings with typical features of Hurler's syndrome, but without mucopolysacchariduria or mucopolysaccharide accumulation in tissues, are presented. The clinical features, in conjunction with raised beta-D-galactosidase and alpha-L-fucosidase levels in fibroblast cultures from one of the patients, suggest the diagnosis of a mucolipidosis. Theories relating to the intracellular...