RPE65 and Leber congenital amaurosis: Retinal pigment epithelium-specific 65 kDa (RPE65, OMIM 180069) is an enzyme that catalyses a critical step in the visual cycle, within the RPE.23 Biallelic disease-causing variants in RPE65 cause 5%–10% of all LCA/EOSRD cases and these patients show severe, early-onset night blindness.1 Clinical trials targeting replacement of RPE65 have been in development since 2007.24 25