MAPT and early-onset autosomal dominant Alzheimer disease: The microtubule-associated protein Tau is a major component of the neurofibrillary tangles (Grundke-Iqbal et al., 1986) that are a hallmark of Alzheimer’s disease (AD) and a number of other neurodegenerative diseases, together called Tauopathies (Lee et al., 2001; Lee and Leugers, 2012).