Osteogenesis Imperfecta Type I

Osteogenesis imperfecta (OI) is a group of genetic disorders that mainly affect the bones. Osteogenesis imperfecta type 1 is the mildest form of OI and is 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. Most of the mutations that cause osteogenesis imperfecta type 1 occur in the COL1A1 gene. These genetic changes reduce the amount of type I collagen produced in the body, which causes bones to be brittle and to fracture easily. OI type 1 exhibits an autosomal dominant pattern of inheritance.