Paget's disease of bone.

Paget's disease affects approximately 3% of the population over age forty. It may be genetically transmitted (autosomal-dominant), but recent evidence suggests a viral etiology. Effective agents for control of the disorder have been developed over the past decade, but all have significant drawbacks. Calcitonin tends to lose its effectiveness in significant numbers of patients over a few months, mithramycin has significant toxicity, and diphosphonates tend to cause osteomalacia.