Voretigene neparvovec (VN) is an AAV2-mediated gene replacement therapy for the treatment of Leber congenital amaurosis (LCA) associated with biallelic mutations in RPE65. It delivers wild-type cDNA of the RPE65 gene, which is critical for the visual cycle and is shown to improve the visual function of patients (Maguire et al., 2008). Here, RPE65 is linked to Leber congenital amaurosis.