The finding of a high incidence of recorded non-FTD dementia in C9orf72 HRE carriers adds to the debate surrounding the spectrum of C9orf72 HRE-associated disease.24 These cases may represent misdiagnosis or mis-recording of FTD.25 Alternatively, they may suggest an association between C9orf72 HRE and amnestic dementias, such as limbic-predominant age-related TDP-43 encephalopathy (LATE) or Alzheimer’s disease, hitherto under-detected due to the skewed selection of individuals for genetic testing. Here, C9orf72 is linked to early-onset autosomal dominant Alzheimer disease.