A skin biopsy often is done. This involves removing a tiny piece of skin, usually from the back of the arm. The skin cells are grown in culture and the collagen is studied. It is inherited in an autosomal dominant pattern but may occur as a result of a spontaneous mutation. People with OI type I have an average of 20 to 40 fractures before puberty.
Fewer fractures occur after puberty.
Prenatal diagnosis often is possible. OI type II results from a new mutation. Infants with this form of OI have fractures before birth, have extremely fragile bones, and usually die shortly after birth. Prenatal diagnosis is possible. It usually results from a new dominant mutation.