MAPT and early-onset autosomal dominant Alzheimer disease: Co-occurrence between tau and Aβ pathology has been described to take place within neuronal processes and nerve ending compartments at early stages of Alzheimer’s disease (Takahashi et al., 2010; Amadoro et al., 2012; Spires-Jones and Hyman, 2014; Rajmohan and Reddy, 2017).