COL1A2 and osteogenesis imperfecta: Osteogenesis imperfecta (OMIM #166200) is a genetic disorder primarily affecting connective tissues due to mutations in the Collagen Type I Alpha 1 Chain (COL1A1) and Collagen Type I Alpha 2 Chain (COL1A2) genes, which code for the α1 and α2 chains of type 1 collagen.