C9orf72 and Atrophy: Using an average of the best performing direct measure, the current study reports a similar pattern of results, with annual atrophy rates of 1.8 (0.9)% in MAPT, 1.6 (1.1)% for C9orf72 and 3.1 (2.0)% for GRN patients, who conclusively exhibit the highest rate of change across subgroups.