C9orf72 and frontotemporal dementia: Twenty-nine people with genetic FTD were recruited (12 C9orf72, 11 MAPT, 6 PGRN), 70 unaffected relatives carrying the same mutation we will refer to as “gene carriers” (17 C9orf72, 13 MAPT, 40 PGRN) and 86 relatives without the mutation referred to as “gene negative.” During image processing, 13 subjects were removed because of excessive motion, 5 with FTD (1 C9orf72, 2 MAPT, 2 PGRN), 2 gene carriers (2 PGRN), and 6 gene negative.