C9 and frontotemporal dementia: Up to 30% of patients present with a genetic autosomal dominant inheritance pattern, in majority evoked by a repeat expansion in the C9ORF72 gene (FTD-C9), or mutations in the progranulin gene (FTD-GRN) or the microtubule-associated protein tau gene (FTD-MAPT) [27, 61, 64].