Frontotemporal dementia is the second most common form of presenile dementia and autosomal dominant inheritance is present in 20-30% of cases, with mutations in granulin (GRN) as a major cause. The exact pathophysiological mechanism by which GRN mutations lead to neurodegeneration is poorly understood. We aimed to identify novel cerebrospinal fluid (CSF) biomarkers in GRN-associated frontotemporal dementia using shotgun proteomics. We included CSF from presymptomatic and symptomatic GRN mutation carriers and healthy non-carriers (controls). We validated our discovery proteomics results in a large international cohort of GRN-mutation carriers and other forms of genetic FTD (C9orf72- and MAPT-mutation carriers) by parallel reaction monitoring.