MAPT and early-onset autosomal dominant Alzheimer disease: Extracellular senile plaques and intracellular tau protein tangles resulting from the accumulation of β-amyloid (Aβ) are key histopathological hallmarks of Alzheimer’s disease (AD), and the neurotoxicity of Aβ may play a central role in the pathogenesis of AD (Viola and Klein, 2015).