Centrifugal osteopetrosis: appendicular sclerosis with relative sparing of the vertebrae

A previously unreported pattern of bone involvement in autosomal dominant osteopetrosis is described in three affected members of a Vietnamese kindred. The hands, feet, distal bones, and skull were markedly osteosclerotic on radiologic examination. The vertebrae displayed very minimal thickening of the endplates in two of the cases, and no visible involvement in the third. The vertebral bone density (assessed by dual-energy X-ray absorptiometry) was markedly elevated, suggesting that the spine was not completely spared. This pattern contrasts with the predominantly axial distribution of the recognized variants of osteopetrosis.