The GRN mutations frequency range from 1 to 11.7% in FTD patients, but the frequency rises to 12–25% in familial FTD (Cruts et al., 2006; Gass et al., 2006; Huey et al., 2006; Bronner et al., 2007; Borroni et al., 2008). This evidence concerns the gene GRN and frontotemporal dementia.