Fibrogenesis imperfecta ossium; a generalised disease of bone characterised by defective formation of the collagen fibres of the bone matrix.

Abstract

1. A description is given of the pathology of a generalised skeletal disease characterised by a defect in the formation of the collagen fibres of the bone matrix—"fibrogenesis imperfecta ossium." 2. Material from two cases, a woman of fifty-six and a man of sixty-four, was examined. All the samples of bone from both patients showed the same defect, which was severe in most of the specimens, and there was radiographic evidence of similar widespread bone changes in both cases. 3. The defect is clear-cut and striking histologically, provided that sections are examined with a polarising microscope, and/or by reticulin methods. 4. As a result of the defect in the bone matrix this fails to calcify, or calcifies imperfectly, showing wide osteoid borders as in severe osteomalacia. But the fibre defect separates it quite clearly from osteomalacia, in which the fibre structure of the osteoid tissue is normal. Moreover neither the biochemical findings (Case 2) nor the radiographic appearances correspond with those of osteomalacia. 5. The collagen fibre defect is confined to the bone matrix; no defect was found in the soft tissue collagen, and even the periosteum shows a normal fibre structure. 6. Both the clinical and the histological evidence indicate that the disease is not congenital, but was, in these two patients, apparently acquired during middle age. There was no family history of bone disease. 7. The cause of the condition is quite obscure. It is not inflammatory or neoplastic, nor is there histological or clinical evidence of a toxic origin. If it is a deficiency disease it is unlike any known vitamin or other chemical deficiency.