PITPNM1 and macular degeneration: Although there have been no reports of lipid accumulation in the retinal pigment epithelium (RPE) in animal models or patients with RPGR mutations, macular degeneration has been observed in some RPGRORF15 patients, and altered RPE integrity has also been noted in rd9 mice (Charng et al., 2016; Falasconi et al., 2019).