A 47-year old woman was referred for bone pain and abnormal findings on radiography. The patient repoed that for the past 17 years, she has habitually consumed water from that area. She repoed a 5-years history ofpain in the lower back, arms, legs and hips, Because of brittleness, all her teeth had been extracted. Radiography ofthe forearm revealed interosseous membrane calcification and radiography ofthe spine revealed a rugger-jersey appearance (striated pattern of increased density in the upper and lower zones of the veebrae). The probable diagnosis is