MAPT and Alzheimer disease: However, in tauopathies, including Alzheimer's disease (AD) and frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), tau is hyperphosphorylated, leading to the aggregation of tau and MT destabilization, and finally resulting in neuronal death and a reduction in brain weight and volume (Ballatore et al., 2007; Gomez-Isla et al., 1996; Huang and Mucke, 2012).