Osteogenesis imperfecta (OI), also known as brittle-bone disease, is an inherited disorder characterized by bones that break easily without a specific cause. An estimated 20,000 to 50,000 people in the United States have this disease, which can affect men and women of all races.
OI is believed to be due to a genetic defect that causes imperfectly formed or an inadequate amount of bone collagen, a protein found in the connective tissue.
There are four types of the disorder, with varying degrees of severity in the symptoms. Type I, mild cases, can usually be traced through the family.
Its symptoms can include:
Type II is the most severe form and it affects newborns. It is sometimes fatal, although patients have lived to adulthood with it. Type II includes severe bone deformities with fractures and short stature.
Type III and Type IV have similar symptoms that are less severe than Type II.