While 15 of 121 (12.4%) subjects were thus explained by mutations in one of these assumed as common FTD genes that are frequently sequenced in clinical routine (C9orf72, GRN, MAPT, and TBK1), 8 (6.6%) of the FTD subjects could be explained by mutations in other genes. This evidence concerns the gene C9orf72 and frontotemporal dementia.