I-cell disease. A case report and review of the literature.

I-cell disease has been reported by many authors but the electron microscopic findings have been reported only rarely. The patient under study was a female infant with a normal delivery after 38 weeks' normal intrauterine life. She showed the physical findings characteristic of I-cell disease, and the diagnosis was made by the analyses of lysosomal enzymes. The child died at the age of 2 years and 3 months due to respiratory insufficiency. By electron microscopy, various-shaped membrane-bound vacuoles were observed in the cytoplasm of various cells such as hepatocytes, myocardial muscle cells, epithelial cells of the renal glomeruli, proximal renal tubular cells, fibroblasts, and chondrocytes. By histochemical analyses we found that these intracytoplasmic storage vacuoles contained glycosaminoglycan and proteoglycan.