Osteogenesis imperfecta is a genetic disorder. It is commonly called brittle bone disease. It is usually an autosomal dominant disease, which means a person can get it if only one of their parents has the abnormal gene. OI affects the part of the bones called the collagen rod, which provides bone strength. The abnormal gene weakens or even destroys the collagen rod. This disease was first identified by Vrolik in 1849.