The great majority of people with OI, even those who are the only affected person in a family, have dominantly inherited forms of the disorder.  Click here for the genetics or possible inheritance of this disorder.

Osteogenesis imperfecta (OI) is a genetic disorder characterized by fragile bones that break easily. It is also known as “brittle bone disease.” A person is born with this disorder and is affected throughout his or her life time.

In addition to fractures people with OI often have muscle weakness, hearing loss, fatigue, joint laxity, curved bones, scoliosis, blue sclerae, dentinogenesis imperfecta (brittle teeth), and short stature. Restrictive pulmonary disease occurs in more severely affected people.

• OI is caused by an error called a mutation on a gene that affects the body’s production of the collagen found in bones, and other tissues. It is not caused by too little calcium or poor nutrition.
• OI is variable with 8 different types described in medical literature.
• The types range in severity from a lethal form to a milder form with few visible symptoms.
• The specific medical problems a person will encounter will depend on the degree of severity.
• A person with mild OI may experience a few fractures while those with the severe forms may have hundreds in a lifetime.
• The number of Americans affected with OI is thought to be 25,000-50,000. 
• The range is so wide because mild OI often goes undiagnosed.