GUCY2D and Leber congenital amaurosis: To date, we have conducted studies with this goal in LCA caused by mutations in CEP290 (Centrosomal protein, 290 kDa), CRB1 (Crumbs homolog-1), CRX (Cone-rod homeobox-containing gene), GUCY2D (Guanylate cyclase 2D, retinal), RDH12 (Retinol dehydrogenase 12), RPE65, RPGRIP1 (Retinitis pigmentosa GTPase regulator-interacting protein), or TULP1 (Tubby-like protein 1) [6,11-19].