COL1A2 and osteogenesis imperfecta: Heterozygous mutations in the human COL1A1 and COL1A2 genes have been identified in patients with Ehlers–Danlos syndrome arthrochalasia type I (Online Mendelian Inheritance in Man [OMIM] #130060) and II (OMIM #617821), osteogenesis imperfecta (OMIM #166200, #166210, #259420, #166220), and Caffey disease (OMIM #114000).