Scarcity despite wealth: osteopetrorickets.

Infantile malignant osteopetrosis is a rare and genetically autosomal recessive disease characterized by osteoclast malfunction. Decreased osteoclast-mediated bone resorption may be inadequate to maintain a normal serum calcium-phosphorus balance in the extracellular fluid. Consequently, despite markedly positive total body calcium balance, patients with osteopetrosis paradoxically could develop rickets. The concurrence of osteopetrosis and rickets has been termed "osteopetrorickets". We report here a 3-month-old boy who was diagnosed with osteopetrorickets with clinical features. Although osteopetrorickets is defined as a rare paradoxical feature of infantile malignant osteopetrosis in some studies, it seems to be more common than was previously known. Coexistence of rickets and osteopetrosis may have adverse effects on clinical response to stem cell transplantation. Therefore, a diagnosis of rickets must be considered in patients with osteopetrosis and then for better results, prior to the SCT, the rickets should be completely treated.