WNT1 and osteogenesis imperfecta: Subgroup analysis based on the type of the underlying mutation in OI mice showed significantly increased osteoclast numbers in OI mice with Co1a1 mutations, with an effect size of 1.70 (CI: 0.34, 3.06), and with Wnt1 mutations, with an effect size of 0.63 (CI: 0.05, 1.21) (Figure 6A).