Fibrogenesis imperfecta ossium with early onset: observations after 20 years of illness.

Fibrogenesis imperfecta ossium is a rare, acquired disorder of bone mineralization characterized by a morphologic abnormality of bone collagen that presents with bone pain and tenderness and usually results in the patient becoming bedridden. Onset of symptoms in the six previously reported cases of this disorder occurred in patients over 50 years of age. We report a case of fibrogenesis imperfecta ossium with symptoms starting at age 39 where the diagnosis was not made even after three bone biopsies because of the failure to recognize the characteristic morphologic abnormality of collagen. Elevated serum alkaline phosphatase, increased urinary hydroxyproline, and numerous osteoclasts on a bone biopsy are compatible with increased bone turnover. There was no apparent abnormality of vitamin D metabolism contributing to this disorder. Treatment with sodium fluoride, synthetic salmon calcitonin, and 24,25-dihydroxyvitamin D did not result in any apparent benefit.