Chondroitin 4- and 6-sulfate mucopolysaccharidosis--a morphological study.

A 17-year-old patient clinically manifesting gargoyle face, dwarfism, skeletal bone deformity, mild mental retardation and benign course was presented. Biochemically, increased urinary excretion of acidic glycosaminoglycans was confirmed and chondroitin 4-sulfate and chondroitin 6-sulfate were substantiated to be the major components of the acid mucopolysacchariduria. Light microscopically, variable numbers of foam cells were observed in the biopsy materials of the lymph nodes, liver and skin, as well as in the smears of bone marrow aspirates. In the liver, the parenchymal cells appeared vacuolated. Histochemically, accumulation of sulfated acid glycosaminoglycans was demonstrated in the cytoplasm of the foam cells proliferating in these tissues, as well as in the liver cells. Electron microscopically, all of these storage cells were found to contain numerous, membrane-bound, vacuolar inclusions filled with flocculent, finely reticulogranular materials of low electron density similar to those seen in the storage cells of Hurler, Hunter or Sanfilippo's syndrome. Empty vacuoles were often coexistent. Accordingly, this case should be termed "chondroitin 4- and 6-sulfate mucopolysaccharidosis", with emphasis on the possibility of a new type of genetic mucopolysaccharidosis.