Fortunately, in KCNV2-associated retinopathy, electroretinography is pathognomonic for disease associated with this gene, facilitating judgements of pathogenicity of rare variants.39 On the other hand, variants in RP1L1 give rise to a dominantly inherited occult maculopathy or a recessively inherited rod-cone dystrophy. This evidence concerns the gene KCNV2 and Cone rod dystrophy.