Fibrogenesis imperfecta ossium (clinical, biochemical and ultrastructural investigations).

The authors report a case of fibrogenesis imperfecta ossium (FIO). Only four cases diagnosed during life have previously been described in the literature. This is an extremely rare disease of entirely unknown aetiology. Clinical, biochemical and ultrastructural investigations were carried out. The most significant finding was the abnormal structure of the bone tissue, which was studied both by optical and electron microscopy on three successive biopsies of the iliac crest. In addition to deficient synthesis of the collagen fibrils, important anomalies related to the proteoglycans and the cellular elements were demonstrated. These have not been reported in previous cases. Some significant analogies with experimental lathyrism are also discussed.