For germline mutations in AD risk genes, we examined base substitutions and small indels in six AD risk genes, including APOE, APP, MAPT, PSEN1, PSEN2, and TREM2, and 290 known pathogenic SNPs therein from the AlzGene mutation database44 (Supplementary Data 11 and Methods). This evidence concerns the gene TREM2 and Alzheimer disease.