We and others have shown that mice (Kato et al., 2002; Holmen et al., 2004; Clément-Lacroix et al., 2005; Cong and Zhang, 2015) or rats (Ubels et al., 2022, 2020) lacking LRP5 develop skeletal and retinal defects similar to those seen in human OPPG patients. The gene discussed is LRP5; the disease is osteoporosis-pseudoglioma syndrome.