Until this report, the implication of RD3 in retinal dystrophies was based on the following three studies: homozygosity for truncating mutations in two consanguineous LCA families [2/59; 21,35], two naturally occurring models of autosomal recessive EOSRD, the retinal degeneration 3 (rd3) mouse [21], [38] and the rod-cone dystrophy 2 (rcd2) collie [39]–[40]. This evidence concerns the gene GUCY2D and cone dystrophy.