Pathologically, tau abnormalities are implicated in various tauopathies, including Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), frontotemporal dementia with parkinsonism-17 (FTDP-17), corticobasal degeneration (CBD), chronic traumatic encephalopathy (CTE), argyrophilic grain disease (AGD), Pick’s disease, and Huntington’s disease. Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.