Considering that elevated plasma p181-tau levels are specifically observed in MCI due to AD and the early phase of AD, but not in other types of neurodegenerative diseases such as vascular dementia or frontotemporal dementia [21, 33], these results validate our assumption that plasma p-tau concentrations can be used as a marker for detecting the development of DS-AD. The gene discussed is MAPT; the disease is frontotemporal dementia.