RD3 is a 23-kDa retinal protein that is essential for proper photoreceptor function, and the deletion of RD3 causes retinal degeneration and blindness in human patients that possess recessive Leber Congenital Amaurosis 12 (LCA) (Friedman et al., 2006). This evidence concerns the gene RD3 and Leber congenital amaurosis 12.