MAPT and early-onset autosomal dominant Alzheimer disease: The microtubule-associated protein Tau, encoded by the MAPT gene, has been associated with multiple neurodegenerative disorders, including Alzheimer’s disease (AD), fronto-temporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), Pick’s disease (PiD), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP).