Less than 10% of patients with OI have recessive forms of inheritance caused by mutations in genes encoding proteins that are involved in the synthesis, transport, and post-translational modifications of collagen or factors associated with differentiation and mineralization of bone cells (CRTAP, PPIB, BMP1, CCDC134, CREB3L1, FAM46A, FKBP10, P3H1, P4HB, PLOD2, PLS3, SEC24D, SERPINF1, SERPINH1, SP7, SPARC, and TMEM38B) [1,3,6]. The gene discussed is P3H1; the disease is osteogenesis imperfecta.