Additionally, rare FTD-causing mutations have been found in: the Valosin gene (VCP), that was first reported to be mutated in families with hereditary inclusion body myopathy with Paget disease of the bone and FTD; the Charged multivesicular body protein 2B (CHMP2B), with only one proven pathogenic mutation described in 2005 and segregating with FTD; the TAR DNA binding protein (TARDP) and the Fused in Sarcoma (FUS) genes, two well established ALS-associated genes, playing a minor role also in FTD (Pottier et al., 2015). This evidence concerns the gene FUS and bone Paget disease.