However, there were no significant differences in duration of illness between C9ORF72 associated FTD, non-mutational FTD or GRN associated FTD (F2,37 = 1.6, p = 0.215), or between C9ORF72 associated FTD + MND and non-mutational FTD + MND (p = 0.900), or between C9ORF72 associated MND and non-mutational MND (p = 0.605). Here, GRN is linked to frontotemporal dementia.