TREM2 and Alzheimer disease: One of the first reports of AD associated rare variants utilizing the recent advances in sequencing technologies was Jonsson et al.’s (2013) study, which found that the rare missense variant in TREM2, rs75932628 [predicted to encode the protein change, R47H, with NHLBI Exome Sequencing Project (ESP, http://evs.gs.washington.edu/EVS/) MAF of 0.26% in European–Americans (EA) and 0.02% in African–Americans (AA)] conveyed an increased risk of AD in the Icelandic population (Jonsson et al., 2013).