TREM2 and frontotemporal dementia: NHD is caused by genetic mutations in the TREM2, a transmembrane receptor of microglia, which plays an important role in neuroinflammation.[1–3] The majority of patients have been reported in Finland and Japan,[4] but there are less than 200 cases in the literature,[5] FTD has a slow and insidious onset and it is typically diagnosed during middle age.