Previous studies have attributed visual deficits in AD patients to degenerative damage in the primary visual cortex (V1) (Mendez et al., 1990; Leuba and Kraftsik, 1994; Armstrong, 1996; Jorge et al., 2020), but several recent studies have shown that visual cortex is relatively unaffected by Aβ and Tau protein pathology (Frisoni et al., 2010; Coppola et al., 2015). The gene discussed is MAPT; the disease is Alzheimer disease.