Pathogenic variants of PRPH2 were found to be causative of a broad spectrum of both rod- and cone-dominant forms of retinal degeneration, with significant inter- and intrafamilial phenotypic variability, ranging from RP to variable forms of MD; this is consistent with reports on the distinct roles and methods of rod and cone maintenance found in both in vivo and in vitro experiments [22]. Here, PRPH2 is linked to Menkes disease.