To evaluate poly(GP), a dipeptide repeat protein, and neurofilament light chain (NfL) as biomarkers in presymptomatic <i>C9orf72</i> repeat expansion carriers and patients with <i>C9orf72-</i>associated frontotemporal dementia.
Cerebrospinal fluid (CSF) neurofilament light chain protein (NfL) and Alzheimer's disease (AD) core biomarker levels have been evaluated in cohorts of patients with frontotemporal dementia spectrum (FTD), but the distribution of values across the different clinical syndromes and underlying proteinopathies, and the relative diagnostic accuracy appear discordant among studies.