Deficiency of alpha-L-fucosidase.

A new form of alpha-L-fucosidase deficiency has been found in a 20-year-old severely retarded male. Additional signs include angiokeratoma corporis diffusum and anhydrosis. The skin lesion is due to an accumulation of residual bodies, presumably containing oligosaccharides and glycoproteins, in endothelial cells and fibrocytes. The enzyme activity in blood relatives indicates that the disease is inherited as a simple autosomal recessive trait that segregates according to Mendelian principles. Because the enzyme activity in the heterozygotes was consistently below that of normal controls, the carriers of the trait in this family could be ascertained.