As in GRN and MAPT mutations, deficits in episodic memory at onset, mimicking AD have been reported also in patients with C9orf72 mutations (Wojtas et al., 2012; Cacace et al., 2013; Harms et al., 2013; Murray et al., 2013; Pletnikova et al., 2014). This evidence concerns the gene MAPT and Alzheimer disease.