C9orf72 and mild neurocognitive disorder: • 398 patients in total (221bvFTD, 66 PNFA, 53 SD/FTD, 68 mixedsyndromes)• 32 C9ORF72- positive (19 FTD, 9 FTD/MND,1 SD/FTD, 3 PNFA)• Neuroimaging available for46 C9ORF72-negativeand 32 C9ORF72- positive