Autosomal dominant collagen disease resulting from defective biosynthesis of collagen type i and characterized by brittle, osteoporotic, and easily fractured bones; may also present with blue sclerae, loose joints, and imperfect dentin formation.

Osteogenesis imperfecta (IPA: ; OI), colloquially known as brittle bone disease, is a group of genetic disorders that all result in bones that break easily.: 85  The range of symptoms—on the skeleton as well as on the body's other organs—may be mild to severe.: 1512  Symptoms found in various types of OI include whites of the eye (sclerae) that are blue instead, short stature, loose joints, hearing loss, breathing problems and problems with the teeth (dentinogenesis imperfecta). Potentially life-threatening complications, all of which become more common in more severe OI, include: tearing (dissection) of the major arteries, such as the aorta;: 333  pulmonary valve insufficiency secondary to distortion of the ribcage;: 335–341  and basilar invagination.: 106–107  The underlying mechanism is usually a problem with connective tissue due to a lack of, or poorly formed, type I collagen.: 1513  In more than 90% of cases, OI occurs due to mutations in the COL1A1 or COL1A2 genes...