The first case of hypophosphatasia in adults reported in Italy (20th in the world) is described with remarks on the epidemiology, pathogenesis and therapeutic possibilities. The formation of renal and cholecystic calculi after long-term, intensive vitamin D and Calcium therapy indicates the limited capacity of pyrophosphate (PPi), even in large doses, to prevent the precipitation in man of calcium and phosphorus and the subsequent formation of ectopic calcifications
