Recently, mice that exhibit NFT-like lesions and plaques have been produced by combining FAD mutations with mutant forms of tau found in a distinct form of dementia known as frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17).61 FTDP-17 is part of the spectrum of frontotemporal dementias (FTDs) that include Pick’s disease, progressive supranuclear palsy, and corticobasal degeneration.61 In these disorders, hyperphosphorylated forms of tau accumulate in NFTs in the absence of neuritic plaques. FTD cases present clinically with often prominent behavioral disturbances or isolated language defects and relatively preserved memory initially. Like AD, most FTD occurs sporadically. However, in some families with FTDP, the disease is caused by mutations in the tau gene on chromosome 17 (FTDP-17). Mutations, including exonic point mutations, which alter the protein coding sequence, and intronic mutations, which affect splicing or the level of tau expression, have all been identified.
