MAPT and early-onset autosomal dominant Alzheimer disease: Intracytoplasmic hyperphosphorylated tau (hp-tau) aggregates are pathognomonic in tauopathies such as Alzheimer’s disease (AD), frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17), and progressive supranuclear palsy (PSP), while phosphorylated α-synuclein (p-αSyn) aggregates are involved in α-synucleinopathies including Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA) [50].