TREM2 and frontotemporal dementia: Interestingly, at the molecular level, genetic variations in TREM2 have also been linked with frontotemporal dementia (FTD) and Nasu-Hakola disease (NHD), the latter of which is characterized by demyelination, early-onset dementia, and bone cyst lipoma and known to be associated with Y38C, W50C, T66M, and V126G mutations in the ectodomains of TREM222–25.