Studies in osteopetrosis

Abstract

A child with the severe congenital form of osteopetrosis (Albers-Schonberg disease) has been studied from 3 months to 5 years of age. The anaemia was controlled by adequate corticosteroid treatment but only at dosages that slowed or inhibited growth in stature. Attempts were made to deplete the child of calcium by dietary means. Only partial control of bone density, as seen on radiographs, could at first be achieved. Calcium balances confirmed the suspected gross overpositivity. Excessive calcium absorption seems to be an important feature of th:a disease. More severe calcium restriction did- not produce negative balance. Addition of cellulose phosphate to the very low calcium diet made the balance zero, the child first going through a state of severe hypocalcaemic tetany as if parathyroid function had been previously suppressed. It may be that some of the disease manifestations can be explained on the basis of diminished action of parathyroid hormone on the bones. Red cell studies showed that most of the active marrow was in the liver and spleen and most of the red cell destruction in the spleen. After splenectomy the red cell life-span markedly increased and it was possible to reduce and soon abandon corticosteroid therapy. During the last months of the child's follow-up he continued on the strict calcium-depleting rdgime without corticosteroid therapy. He showed a large spurt in growth, became more lively and active, and laid down less dense bone:which showed signs of remodelling.