MAPT and semantic dementia: FTD with parkinsonism related to chromosome 17 (FTDP-17) is an early-onset autosomal dominant form of FTD clinically characterized by parkinsonism, behavioral changes and dysfunction of personality [102,103] caused by mutations in either the GRN (FTDP-17U form) or MAPT gene (FTDP-17T form) [92,104,105,106].