PSEN1 and behavioral variant of frontotemporal dementia: PSEN1 pathogenic variant carriers have been reported (tough much less frequently than early onset DAT) to also present as behavioral variant frontotemporal dementia (bvFTD), Parkinson ́s disease, spastic paraparesis, corticobasal syndrome, dementia with Lewy bodies (DLB), non-fluent variant PPA, and cerebral amyloid angiopathy.