C9orf72 and frontotemporal dementia: When calculated separately in groups of C9orf72 and GRN mutation carriers and in patients with presumed TDP‐43 (including GRN mutation carriers, C9orf72 mutation carriers, and FTD‐MND phenotype) vs. tau pathologies (MAPT mutation carriers, CBD, and PSP patients), no statistically significant differences were found.