KCNV2 and night blindness: To conclude, compound heterozygous variations (c.731G>C and c.280dup) were revealed in the KCNV2 gene of a male with CDSRR, which presented nystagmus, photophobia, dyschromatopsia, and night blindness at an early age, but had uncharacteristic FFERG changes compared to generalized CDSRR patients.