Lysosome storage disease due to alpha-L-fucosidase (E.C. 18.104.22.168) deficiency in leukocytes manifested by abnormal accumulation in tissues and urinary excretion of partially catabolized oligosaccharides, glycoasparagines, and glycolipids with alpha-linked fucose at the nonreducing end of the glycogen chain. The phenotype is variable and may include delayed growth and mental development, progressive neurological deterioration, Hurler-like (mucopolysaccharidosis I-H) coarse facies, recurrent infections, visceromegaly, skeletal abnormalities, joint contractures, deafness, and angiokeratoma corporis diffusum. Several types are recognized by different researchers. The form exhibiting a longer survival, mild neurological manifestations, and angiokeratoma is sometimes referred to as fucosidosis type II. In a different scheme, three different types are recognized according to their age of onset. Types I and II are the most severe and have their onsets at 10 and 18 months, respectively with life expectancy of 6 years. Type III represents a juvenile form which is marked by a milder form of psychomotor retardation and a slower deterioration of neurological activities. Hurler-like (gargyloid) facies occur mainly in types I and II and is less commonly in type III.