Amongst the known pathogenic mutations, two were also found in AD patients with more than 65 years of onset: the known pathogenic PSEN1 p.C263F, identified in five patients with onset age range of 53–70, and the PSEN1 p.G183V, previously identified in a patient with frontotemporal dementia and Pick-type tauopathy [42] (further discussed later in the text). Here, PSEN1 is linked to frontotemporal dementia.