Osteopetrosis.

The clinical histories of nine children with osteopetrosis are reported. Two of them had the malignant infantile variety of the disease: one died within 3 months of birth and the other has survived 20 months on a regimen of a low calcium intake, cellulose phosphate, and steroids. The beneficial effect of a low calcium intake, in early infancy, is supported by the clinical course in the infant with the malignant variety and in another child with the more benign form of the disease. No calcium balance studies were performed. This study suggests that the active measures outlined may favourably influence the haematological and osteosclerotic course of the disease, pending further knowledge of its aetiological basis, and more specific therapy.