C9orf72 and Alzheimer disease: In patients diagnosed with AD we found three C9orf72 expansions, nine DVs in MAPT, five in CSF1R, two in GRN, three in PRNP and one each in SQSTM1, TARDBP and VCP, as well as a homozygous TREM2 DV normally associated with Nasu-Hakola disease.