MAPT and Alzheimer disease: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) plaques and abnormal hyperphosphorylation of tau protein, ultimately leading to synaptic dysfunction, brain atrophy, and cognitive decline (Bondi et al., 2017; De Wilde et al., 2016; Double et al., 1996).