COL1A1 and osteogenesis imperfecta: Osteogenesis imperfecta (OI) is a rare inherited connective tissue disease affecting collagen production, with a prevalence around 6–7:100,000, commonly caused by mutations in the COL1A1 and COL1A2 genes, which encode α1 and α2 chains of type I collagen respectively, with a predominantly autosomal dominant inheritance pattern [1].