C9orf72 and Cerebellar atrophy: Although abundant DPR pathology within granule cell layer of the cerebellum seems to be a consistent finding in C9orf72 mutation carriers (Al-Sarraj et al., 2011; Irwin et al., 2013) and a number of studies have reported more prominent cerebellar atrophy in C9orf72 mutation carriers compared to sporadic patients (Mahoney et al., 2012; Whitwell et al., 2012; Irwin et al., 2013), we were not able to detect significant group differences with respect to cerebellar volume.