Clinical presentation among C9orf72, MAPT, and GRN mutation carriers. Although the majority of carriers were asymptomatic at baseline assessment, bvFTD was the most common phenotypic presentation among C9orf72 and MAPT mutation carriers, whereas the clinical spectrum was more heterogeneous among GRN carriers. Numbers of individuals with gene mutations are listed under each diagnostic category. (AD, Alzheimer’s disease dementia; ALS, amyotrophic lateral sclerosis; bvFTD, behavioral variant frontotemporal dementia (FTD); CBS, corticobasal syndrome; lvPPA, logopenic variant PPA; MCI, mild cognitive impairment; nfvPPA, non-fluent variant PPA; PPA, primary progressive aphasia; svPPA, semantic variant PPA)