• Participant has provided informed consent/assent prior to initiation of any study specific activities/procedures. OR - Participant's legally authorized representative has provided informed consent when the participant is legally too young to provide informed consent and the participant has provided written assent based on local regulations and/or guidelines prior to any study-specific activities/procedures being initiated. - Ambulatory male and female children and adolescents, age 5 to <18 years, including ambulatory with assistance as defined in the pediatric osteogenesis imperfecta (OI) population. - Clinical diagnosis of OI, defined as clinical history consistent with type I, III, or IV OI as determined by presence of expected phenotype (examples include: facial shape, voice, blue sclera, dentinogenesis imperfecta, typical radiographic features, fracture pattern) and lack of additional features unrelated to type I, III, or IV OI (eg, blindness, mental retardation, neuropathy, and craniosynostosis). o If familial, also must be autosomal dominant. - Meets at least one of the following: - 3 or more fractures within the previous 2 years, or - 1 or more nonvertebral fracture(s) within the previous 2 years and at least 1 prevalent vertebral fracture, or - 2 or more prevalent vertebral fractures.

Disease Related - History of an electrophoresis pattern inconsistent with type I, III or IV OI. - History of known mutation in a gene other than collagen type I alpha 1/collagen type I alpha 2 (COL1A1/COL1A2) causing OI or other metabolic bone disease. - History of congenital dislocation of the radial head, interosseous membrane calcification, or exuberant callus formation.