Osteogenesis imperfecta—Osteogenesis Imperfecta

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. OI is caused by one of several genes that aren’t working properly. When these genes don’t work, it affects how you make collagen, a protein that helps make bones strong.

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.

No single test can identify OI. Your doctor uses your medical and family history, physical exam, and imaging and lab tests to diagnose it. Your doctor may also test your collagen (from skin) or genes (from blood). There is no cure, but you can manage symptoms. Treatments include exercise, pain medicine, physical therapy, wheelchairs, braces, and surgery.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

• Osteogenesis imperfecta (Medical Encyclopedia)

Osteogenesis imperfecta (OI) is a group of genetic disorders that mainly affect the bones. The term “osteogenesis imperfecta” means imperfect bone formation. People with this condition have bones that break easily, often from mild trauma or with no apparent cause. Multiple fractures are common, and in severe cases, can occur even before birth. Milder cases may involve only a few fractures over a person’s lifetime.There are at least eight recognized forms of osteogenesis imperfecta, designated type I through type VIII. The types can be distinguished by their signs and symptoms, although their characteristic features overlap. Type I is the mildest form of osteogenesis imperfecta and type II is the most severe; other types of this condition have signs and symptoms that fall somewhere between these two extremes. Increasingly, genetic factors are used to define the different forms of osteogenesis imperfecta.The milder forms of osteogenesis imperfecta, including type I, are characterized by bone fractures during childhood and adolescence that often result from minor trauma. Fractures occur less frequently in adulthood. People with mild forms of the condition typically have a blue or grey tint to the part of the eye that is usually white (the sclera), and may develop hearing loss in adulthood. Affected individuals are usually of normal or near normal height.Other types of osteogenesis imperfecta are more severe, causing frequent bone fractures that may begin before birth and result from little or no trauma. Additional features of these conditions can include blue sclerae, short stature, hearing loss, respiratory problems, and a disorder of tooth development called dentinogenesis imperfecta. The most severe forms of osteogenesis imperfecta, particularly type II, can include an abnormally small, fragile rib cage and underdeveloped lungs. Infants with these abnormalities have life-threatening problems with breathing and often die shortly after birth.