Lrp5 knockout mice recapitulate the bone phenotypes seen in human OPPG patients (Kato et al., 2002; Holmen et al., 2004; Clément-Lacroix et al., 2005; Cui et al., 2011; Sawakami et al., 2006). This evidence concerns the gene LRP5 and osteoporosis-pseudoglioma syndrome.