Also called: Brittle bone disease, OI

Osteogenesis imperfecta (OI) is a genetic disorder in which bones break easily. Sometimes the bones break for no known reason. OI can also cause weak muscles, brittle teeth, a curved spine and hearing loss. The cause is a gene defect that affects how you make collagen, a protein that helps make bones strong. Usually you inherit the faulty gene from a parent. Sometimes, it is due to a mutation, a random gene change. OI can range from mild to severe and symptoms vary from person to person. A person may have just a few or as many as several hundred fractures in a lifetime. There is no cure, but you can manage symptoms. Treatments include exercise, pain medicine, physical therapy, wheelchairs, braces and surgery.