MAPT and early-onset autosomal dominant Alzheimer disease: Alzheimer’s disease (AD) is a progressive neurodegenerative disease with a preclinical/prodromal stage characterized by extracellular accumulation of amyloid-β (Aβ) into senile Aβ plaques and later by intracellular accumulation of hyperphosphorylated tau (hTau) protein into neurofibrillary tangles (NFTs), both of which contribute to neuronal and synaptic loss and clinical manifestations of cognitive dysfunction and memory impairment (Bateman et al., 2012; Jack et al., 2013; Vos et al., 2013).