CHM and choroideremia: Unlike these patterns, choroideremia, an X-linked choroidopathy caused by pathogenic variants in the CHM gene,1, 2, 3, 4, 5, 6 is peculiar in that vision loss typically begins with the appearance of multiple peripheral areas of chorioretinal atrophy that spread centripetally and coalesce, usually sparing the foveal center until late in the disease.7