COL1A1 and osteogenesis imperfecta: In this report, we present 4 OI probands with substitutions of glycine residue including p.G815S from COL1A1 and p.G601S, p.G391V, and p.G322S from COL1A2. The phenotypes of these probands are consistent with the previous reports that these variants of substitutions are associated with severe OI.