In this study, only taking into account patients diagnosed with FTD (n = 28), the frequency of clearly pathogenic MAPT, GRN and C9ORF72 mutations was found to be 17.8% (5/28) showing that the frequency of both MAPT and GRN mutations is lower compared to previous findings suggesting that mutations in these genes account only for a small subset of patients in Turkey. This evidence concerns the gene C9orf72 and frontotemporal dementia.