Most cases of Alzheimer’s disease (AD), and ones of frontotemporal lobar degeneration associated with tauopathy (FTLD-tau), including cases with Pick bodies (PiD), corticobasal degeneration (CBD), progressive supranuclear palsy (PSP) and argyrophilic grain disease (AGD), are sporadic. The gene discussed is MAPT; the disease is argyrophilic grain disease.