While there are no known mutations in tau that are associated with AD, tau mutations are associated with FTD with parkinsonism (FTPD-17), another form of dementia (Hutton et al., 1998; Poorkaj et al., 1998; Spillantini et al., 1998; see Section “Frontotemporal Dementia”). The gene discussed is MAPT; the disease is frontotemporal dementia.