Osteogenesis imperfecta is an inherited condition in which a person's bones break easily, often for no apparent reason. People with this condition either have less collagen than normal or a poorer quality of collagen. The symptoms of osteogenesis imperfecta vary significantly according to type, and it is difficult to predict which symptoms or complications a person will have.
Osteogenesis imperfecta (OI), also known as brittle bone disease, is a genetic condition characterized by bones that break easily, often for little or no apparent reason. The condition can literally be translated as "imperfectly formed bones."
Collagen is the major protein of the body's connective tissue and is the framework upon which bone and tissue are built. It can be compared to the framework around which a building is constructed. If the collagen framework is defective, the bones fracture easily, the skin is loose and transparent, and the muscles lack tone. People with osteogenesis imperfecta either have less collagen than normal or a poorer quality of collagen.
While the number of people affected with osteogenesis imperfecta in the United States is unknown, the best estimate suggests a minimum of 20,000 and possibly as many as 50,000. This condition also affects people in other countries throughout the world.
The cause of osteogenesis imperfecta, in most cases, is a dominant genetic defect (known as autosomal dominant) in the genes responsible for making collagen. Some children with the condition inherit the disorder from a parent. Other children are born with osteogenesis imperfecta, even though there is no family history of the disorder. In these children, the genetic defect occurred as a spontaneous mutation.