Since the identification of rhodopsin (RHO [MIM: 180380]) in 1990 as the first gene involved in the development of AD-RP5, 270 genes have been additionally described as causative of IRDs (RetNet, Retinal Information Network; https://sph.uth.edu/retnet/; accessed on March 2020). The gene discussed is RHO; the disease is Alzheimer disease.