question: Is TREM2 associated with Alzheimer's disease?
answer: A rare variant of the TREM2 gene, which encodes the triggering receptor encoded in myeloid cells 2 (rs75932628-T) causing a R47H substitution has been associated with both early and late onset Alzheimer's disease in various populations.  Emerging evidence has demonstrated that TREM2 could suppress inflammatory response by repression of microglia-mediated cytokine production and secretion, which may prevent inflammation-induced bystander damage of neurons. Higher levels of TREM2 mRNA (p = 0.002) and protein (p < 0.001) were identified in AD patients which indicates that TREM2 might serve as a novel noninvasive biomarker for AD diagnosis. Based on the potential protective actions of TREM2 in AD pathogenesis, targeting TREM2 might provide new opportunities for AD treatment.