MAPT and frontotemporal dementia: Abnormal intracellular aggregation and accumulation of the microtubule-associated protein tau is a common feature of many neurodegenerative disorders, including Alzheimer disease (AD), frontotemporal lobar degeneration, Pick ́s disease, argyrophilic grain disease, corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) [3].