MAPT and early-onset autosomal dominant Alzheimer disease: In particular, tau aggregation is a neuropathological hallmark of several neurodegenerative disorders classified as tauopathies, including frontotemporal dementia and Alzheimer’s disease, and changes in splicing of the tau gene leading to an imbalance in MAPT3R and MAPT4R isoforms have been implicated in neurodegeneration (35–37).