This defective mechanism results in Oguchi disease, a rare form of autosomal recessive congenital stationary night blindness caused by mutations in the genes coding for either SAG or GRK1, as both proteins are involved in terminating the activation of the phototransduction cascade, where SAG plays an important regulatory role while GRK1 functions as the phosphorylating enzyme [23,24]. The gene discussed is GRK1; the disease is Oguchi disease.