NM_000329.3(RPE65):c.1543C>T is a missense variant predicted to replace arginine with tryptophan at position 515. This variant is present in gnomAD v.2.1.1 at a GrpMax allele frequency of 0.000002980, with 2 alleles / 126782 total alleles in the European (non-Finnish population), which is lower than the ClinGen LCA / eoRD VCEP PM2_Supporting threshold of <0.0002 (PM2_Supporting). This variant has been reported in at least 1 proband with early-onset severe retinal dystrophy who was homozygous for the variant (0.5 pts, PMID: 25495949). This variant has also been reported in at least 4 probands with early-onset severe retinal dystrophy who were compound heterozygous with either the NM_000329.3(RPE65):c.1022T>C (p.Leu341Ser) (PMID: 34492281)), NM_000329.3(RPE65):c.1102T>C (p.Tyr368His) (PMID: 32032261), NM_000329.3(RPE65):c.1067dup (p.Asn356fs) (PMID: 35129589), or NM_000329.3(RPE65):c.130C>T (p.Arg44Ter) variant (PMID: 30025081) variants suspected in trans (2 pts), which were all previously classified pathogenic by the ClinGen LCA / eoRD VCEP (2.5 total points, PM3_Strong). At least one proband harboring this variant exhibits a phenotype including diagnosis of Leber congenital amaurosis (0.5 pts) based on exome sequencing-based genotyping that did not provide an alternative explanation for visual impairment (2 pts), night blindness (0.5 pts) with onset during the first year of life (1 pt), attenuated retinal vessels (0.5 pts), macular atrophy (0.5 pts), bone spicule pigmentation (0.5 pts), non-recordable electroretinogram pattern in rod (0.5 pts) and cone (1 pt) responses, and decreased central visual acuity (1 pt), which together are highly specific for RPE65-related recessive retinopathy (8 total pts, PMID: 25495949, PP4_Moderate). The computational predictor REVEL gives a score of 0.935, which is above the ClinGen LCA / eoRD VCEP threshold of ≥0.773 and predicts a damaging effect on RPE65 function (PP3_Moderate). The variant exhibited less than 10% enzymatic activity in a retinoid isomerase assay relative to the wild-type control, which is lower than the ClinGen LCA / eoRD PS3_Supporting threshold of <10% activity, indicating that it triggers a severe defect in protein function (PMID: 25752820, PS3_Supporting). In summary, this variant meets the criteria to be classified as pathogenic for RPE65-related recessive retinopathy based on the ACMG/AMP criteria applied, as specified by the ClinGen LCA / eoRD VCEP: PS3_Supporting, PM2_Supporting, PM3_Strong, PP3_Moderate, and PP4_Moderate. (VCEP specifications version 1.0.0; date of approval 09/21/2023).