Cartilage of I-cell disease.

Biochemical analysis and morphologic observation of the iliac crest cartilage from 8-year-old girl with I-cell disease were performed. Instead of hypertrophic change of chondrocytes in the zone of cartilage-bone junction, there were small atrophic cells having many inclusion bodies accumulated with lamellar materials. Another characteristic finding in this zone was numerous cellular debris in the cartilage matrix. Significantly, a large amount of unsulfated chondroitin (21%) occurred in the cartilage with I-cell disease, and compensatory decrease of chondroitin 4-sulfate (14%) was observed. The percentage of chondroitin and chondroitin 4-sulfate on the control averaged 8.5 and 43%, respectively. The sedimentation profile of the proteoglycans closely resembled that of the normal cartilage.