Osteopetrorickets : the paradox of plenty, pathophysiology and treatment : Osteopetrosis

Rickets is a common and paradoxical feature of infantile malignant osteopetrosis and results from the inability of osteoclasts to maintain a normal calcium-phosphorus balance in the extracellular fluid. Despite a markedly positive total body calcium balance, rickets arises when the serum calcium X phosphorus product is insufficient to mineralize newly formed chondroid and osteoid. In five children with malignant infantile osteopetrosis, there were clinical, radiographic, biochemical, and histologic findings of rickets. Characteristic biochemical abnormalities included hypocalcemia, hypophosphatemia, and elevated levels of serum acid phosphatase, alkaline phosphatase, c-terminal parathyroid hormone, and 1,25-dihydroxyvitamin D