CRB2 and Leber congenital amaurosis: Interestingly, a new Crb1Crb2 double knockout mouse model which disrupted both alleles of Crb2 in rods (Δrods) on a genetic background lacking Crb1 (Crb1KOCrb2Δrods) does not have an LCA-like but RP-like phenotype.