In summary, based on 2 siblings with rod-cone dystrophy with homozygous SLC66A1 whole-gene deletions and further 3 rod-cone dystrophy cases with homozygous predicted LoF variants in SLC66A1, we suggest SLC66A1 may be a novel gene for AR adult-onset rod-cone dystrophy. The gene discussed is SLC66A1; the disease is Cone rod dystrophy.