APOE and frontotemporal dementia: Increased frequency of the ApoE4 allele in patients with FTLD has also been reported previously,[32,34] and it has also been found to increase the penetrance of dementia, since valosin-containing protein (VCP) is associated with FTD,[35] and to impair long-term memory functions and reduce parahippocampal perfusion in FTLD patients.[36]