CRB1 and Leber congenital amaurosis: At least 14 genes are associated with LCA and involve various pathways including: retinal development (CRB1 and CRX), phototransduction, (GUCY2D and AIPL1), vitamin A metabolism (RPE65, LRAT, and RDH12), protein transport (TULP1, RPGRIP1, and CEP290), and RPE phagocytosis (MERTK) [8].