MAPT and early-onset autosomal dominant Alzheimer disease: Aggregation of misfolded amyloid structured proteins such as tau and α-synuclein can lead to the formation of amyloid fibrils and deposition of toxic insoluble cellular aggregates, which are one of the pathological hallmarks associated with neurodegenerative disorders including Alzheimer’s disease (AD) and Parkinson’s disease [30, 33].