CRX and Leber congenital amaurosis: Because CRX appears to interact with many retinal genes, mutations in the CRX gene are responsible for a wide phenotypic spectrum of retinal dystrophies, including cone–rod dystrophy type 2 (CORD2), Leber congenital amaurosis (LCA), pattern dystrophy (PD), macular degeneration, and RP [4,6].