MAPT and early-onset autosomal dominant Alzheimer disease: Alzheimer’s disease (AD) is a severe neurodegenerative brain disorder, characterized by two main pathologies, namely extracellular β-amyloid plaques and intraneuronal neurofibrillary tangles (NFTs) composed of phosphorylated Tau (Braak and del Tredici, 2015; Swerdlow, 2012).