Osteogenesis imperfecta (OI) is a genetic disorder linked to mutations in the genes that encode the components of type 1 collagen. The disorder is primarily characterized by individuals having bones that fracture easily. However, it also includes other features, such as blue sclera, a condition in which the whites of the eye (the sclera) are blue, and early-onset hearing loss. These characteristics of OI indicate that the genes involved exhibit