MAPT and Alzheimer disease: Alzheimer’s disease (AD) is the most common progressive age-associated neurodegenerative disorder, characterised by abnormal accumulation of protein aggregates in the form of β-amyloid (Aβ)-containing plaques, and neurofibrillary tangles composed of hyperphosphorylated tau (Blennow et al., 2006; De Strooper and Karran, 2016).