Fucosidosis. II. Ultrastructure.

The ultrastructural changes of a sural nerve biopsy, liver biopsy and the autopsy of a case (I) of fucosidosis are described. Light microscopy revealed the presence of foam cells in various organs. The contents of the vacuoles stained positive with P.A.S. and Sudan. Electron microscopical examination showed inclusions in hepatocytes, Schwann cells and neurons. These inclusions had a single limiting membrane and contained heterogeneous structures, vesicular, multivesicular and membrane like structures, forming concentric lamellae. In another patient (case III) with a different clinical presentation and a different enzyme pattern (a reduced alpha-L-fucosidase activity, in combination with a reduced arylsulfatase A activity) similar abnormalities as in case I were found in a sural nerve and liver biopsy. It is suggested that the combined reduction of enzyme activity is responsible for the disease.