In control group girls, ACE2 levels were higher than in OI group girls {[2.37 ± 1.39 vs. 1.16 (1.46) pg/ml]} (z = −3.10, P = 0.002); Ang(1-7) levels in control group girls {[40.40 ± 22.45 vs. 14.12 (21.94) ng/ml]} were also higher than in OI group girls (z = −4.20, P < 0.001). This evidence concerns the gene ACE2 and osteogenesis imperfecta.