COL1A1 and osteogenesis imperfecta: This cohort included 78% of OI type I, 13% of type III, 5% of type IV, and 3% with type V. Molecular diagnosis of OI genes was confirmed in 30/50 (60%) patients: COL1A1 (70% of molecular diagnoses, COL1A2 22%, IFITM5 4%, FKBP10 4%).