Osteopetrosisis a rare genetic disorder in which BONE remodeling is defective. Though the body builds new bone (osteoblastic activity), it does not adequately clear away old bone (osteoclastic activity). Consequently the bones become very dense though are also very brittle and vulnerable to FRACTURE. When symptoms are present early in childhood (infantile osteopetrosis), the outcome is very poor because the excessive bone structure crowds out the BONE MARROW. BONE MARROW TRANSPLANTATION is at present the only successful treatment for infantile osteopetrosis but itself carries significant risk.
Adult-onset osteopetrosis is present from birth but does not cause symptoms until adulthood when the abnormalities of bone structure are advanced enough to become apparent. Many adults who have osteopetrosis do not have overt symptoms and discover they have the disorder when receiving treatment for another condition for which the doctor requests an X-RAY. X-ray provides definitive diagnosis as osteopetrosis has a distinct, characteristic presentation. There are no treatments for adult-onset osteopetrosis other than efforts to reduce the risk for fracture. Adultonset osteopetrosis increases the risk for OSTEOMYELITIS (INFECTION of the bone), which is one of the common reasons people initially seek medical care.