GRN and behavioral variant of frontotemporal dementia: Though all GRN null mutations cause the disease through this common mechanism, linked to the degradation of RNA through non-sense mediated decay (Baker et al., 2006; Cruts et al., 2006), the spectrum of clinical presentations associated with mutations in GRN is heterogeneous: however, the bvFTD is the most common clinical presentation, characterized by progressive behavioral changes (Gass et al., 2006; Rademakers et al., 2007; Beck et al., 2008; Le Ber et al., 2008; Benussi et al., 2009).