Two patients with an unusual form of type II fucosidosis

Two brothers with an unusual form of fucosidosis are presented, providing further evidence for the clinical heterogeneity of the disease. The patients have several characteristics of type II, but from the point of view of progression rate and survival, they resemble more type III. However, the characteristic skin lesions of type III are not seen. In contrast to all other subtypes, a dry, thin skin is observed. The authors tend to classify these patients as a "slow motion" type II variant. Both in leukocyte lysates and plasma, severe alpha-L-fucosidase deficiency was established. In the parents, intermediate alpha-L-fucosidase activities were observed in leukocytes, but normal values in plasma, indicating that plasma is not suitable for carrier detection in this family. It is felt that no conclusions regarding clinical subtypes of fucosidosis can be drawn without careful characterization of the mutant enzyme in the primarily affected tissues.