COL1A2 and osteogenesis imperfecta: Ninety percent of OI patients are caused by two mutations of COL1A1 (MIM 120150) and COL1A2 (MIM 120160) encoding α1 chain and α2 chain of type 1 collagen (Orioli et al., 1986; Sykes et al., 1986; Primorac et al., 2001; Marini et al., 2017; Moosa et al., 2019).