Sanfilippo B syndrome. A case report.

An autopsy case of a 9 years and 5 months old gargoyle girl diagnosed as Sanfilippo B syndrome by the biochemical demonstration of a large amount of heparan sulfate in urine and some organs and of deficiency of alpha-N-acetyl-D-glucosaminidase in the liver and brain was reported. The morphological changes characterized by cytoplasmic swelling and vacuolization were more generalized than those which had been described in previously reported cases. Histochemically, accumulation of variable amounts of acidic glycosaminoglycans and compound lipids, presumably gangliosides and phospholipids, was substantiated in the vacuolated cells of various visceral organs and in the ballooned neuronal cells. Ultrastructurally, numerous inclusions found in these cells were largely divided into two types; flocculent reticulogranular and osmiophilic, mostly laminated materials, many of which were bound by a single unit membrane. Enzyme cytochemistry proved acid phosphatase activity in the majority of the inclusions in fibroblasts and fibrocytes biopsied from the skin. Rough endoplasmic reticulum in these cells was markedly dilated with reticulogranular materials. The morphological changes of the present case and their pathogenesis were discussed.