MAPT and early-onset autosomal dominant Alzheimer disease: Cerebral accumulation of amyloidogenic proteins is a hallmark of neurodegenerative diseases; Aβ and tau accumulate in Alzheimer’s disease (AD), tau accumulates in frontotemporal dementia (FTD), and α-synuclein accumulates in Parkinson’s disease (PD) and dementia with Lewy bodies (DLB).