Several causative genes have been associated with AD-RP, including RHO, PRPF31, PRPH2, RP1, IMPDH1, PRPF8, NR2E3, snRNP200, KLHL7, CRX, PRPF3, TOPORS, ADIPOR1, ARL3, CA4, FSCN2, GUCA1B, HK1, IMPG1, KIF3B, NRL, PRPF4, PRPF6, RDH12, ROM1, RP9, SEMA4A, SPP2, and many others [6]. The gene discussed is CRX; the disease is Alzheimer disease.