RPGR and Cone rod dystrophy: Male patients with pathogenic variants in this gene usually have RP (electrophysiologically a rod-cone dystrophy), but affected individuals can display a cone or cone-rod dystrophy.8 Female carriers can show a tapetal reflex or disease phenotypes of varying severity, including a phenotype as severe as that seen in affected males.9 Screening of the ORF15 exon, where many pathogenic variants lie,6 can be challenging owing to a repetitive nucleotide sequence; hence, variants can be missed, even in the context of whole-genome sequencing.