A genetic disorder, also known as osteogenesis imperfecta, that is characterized by bones that break easily, often with a minimum or total absence of physical trauma. The range in severity of this disorder is extreme; some affected individuals have a few broken bones, and others have experienced as many as several hundred fractures over the course of a lifetime. Brittle bones are caused by a genetic defect affecting the amount or quality of the person’s collagen. The defective amount or type or collagen results in weak bones that break easily. When there is insufficient collagen, the person may experience fractures before puberty and have a tendency toward spinal curvature and brittle teeth. In the most severe form of osteogenesis imperfecta in which collagen is not properly formed in a newborn, the infant could die because the condition causes severe respiratory problems. Other types of osteogenesis imperfecta related to improper collagen formation may produce symptoms present at birth, including a blue or gray tint to the whites of the eyes, bone deformity, loose joints, poor muscle development in arms and legs, spinal curvature, a barrel-shaped rib cage, triangular face, and hearing loss.