A thermolabile variant of alpha-L-fucosidase--clinical and laboratory findings.

A family with two sibs affected clinically with the severe infantile form of fucosidosis is described. Biochemical studies revealed a relatively high residual activity (34-60% of normal) with markedly decreased thermostability. The importance of including thin layer chromatography for urinary oligosaccharides in the diagnostic workup for such patients is emphasized.