The fact that the atrophy pattern in our C9orf72 mutation carrier study group goes beyond the expected atrophy in the frontal and temporal subregion of the thalamus is an indicator that atrophy in mutation carriers may exceed the SN and is in keeping with the described cortical pattern of atrophy detected in mutation carriers that also goes beyond the sporadic FTD-associated atrophy pattern. This evidence concerns the gene C9orf72 and frontotemporal dementia.