MAPT and early-onset autosomal dominant Alzheimer disease: The formation of neurofibrillary tangles due to aggregation of the microtubule associated protein tau is at the center of multiple neurodegenerative disorders, including progressive supranuclear palsy (PSP), frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), corticobasal degeneration, Pick’s disease, Alzheimer’s disease (AD) and others [1].