Of note, amnestic Alzheimer's dementia is a common clinical diagnosis of genetically confirmed FTLD‐TDP in elderly individuals [39, 40], and in an autopsy series from the State of Florida brain bank, late onset patients with C9orf72 mutations often present with Alzheimer type dementia or Lewy body dementia [41]. Here, C9orf72 is linked to Lewy body dementia.