MAPT and early-onset autosomal dominant Alzheimer disease: Alzheimer’s disease (AD), the most common form of dementia, is characterized by the deposition of two main protein aggregates in the brain: senile plaques consisting of amyloid-β (Aβ) and neurofibrillary tangles (NFTs) composed mainly of the microtubule-associated protein tau and found as intraneuronal inclusion.1