FIBROGENESIS IMPERFECTA OSSIUM

The clinical features, investigation, treatment and outcome of two adu lts with fibrogenesis imperfecta ossium are described. In this rare ac quired disorder of bone, normal lamellar collagen is replaced by struc turally unsound collagen-deficient tissue, which leads to extreme bone fragility and ununited fractures. Transmission microscopy and SEM sho wed striking ultrastructural changes in bone structure and mineralisat ion. Both patients had monoclonal IgG paraproteins in the plasma and o ne excreted monoclonal lambda light chains in the urine, No abnormal p lasma cells were found in the bone marrow and there was no evidence of amyloid deposition in the tissues. In both patients initial treatment with 1 alpha-hydroxycholecalciferol appeared to be ineffective, but i n one, repeated courses of melphalan and corticosteroids over three ye ars together with 1 alpha-hydroxycholecalciferol produced striking cli nical and histological improvement, The findings in these and other pa tients strongly suggest that paraproteinaemia is an integral feature o f fibrogenesis imperfecta ossium, and this needs further investigation .