Osteopetrosis in South Africa. The benign, lethal and intermediate forms.

Osteopetrosis is an unusual bone disorder in which the skeleton is radiographically dense. The condition is conventionally subclassified into a benign autosomal dominant adult form and a malignant autosomal recessive variety. Among 14 affected individuals whom we have studied, 4 adults had an intermediate type of osteopetrosis in which serious complications included osteomyelitis, pathological fractures and dyshaemopoiesis. The fundamental biochemical relationship of this disorder with the classic forms of osteopetrosis is uncertain. The osteopetroses must be distinguished from other sclerosing bone conditions which have a different course and prognosis. Sclerosteosis and craniometaphyseal dysplasia, both of which occur in South Africa, are of practical importance in this context.