bone, joint, and muscle disorders
Paget Disease of Bone
Causes of Paget Disease of Bone
Normally, cells that break down old bone (osteoclasts) and cells that form new bone (osteoblasts) work in balance to maintain bone structure and integrity. In Paget disease, both osteoclasts and osteoblasts become overactive in some areas of bone, and the rate at which bone is broken down and rebuilt (called bone Bones ) in these areas increases tremendously. The overactive areas enlarge but, despite being large, are structurally abnormal and weak. The cause of Paget disease is unknown in most people. The disorder tends to run in families. Specific, identified gene abnormalities contribute in about 10% of people who have Paget disease, and other genetic abnormalities probably contribute in others. Also, some evidence suggests that a virus may be involved. However, there is no evidence that the disorder is contagious. 