The proportion of Aβ positivity and topographical distribution of Aβ in frontotemporal dementia (FTD) cases with and without a genetic mutation. The proportion of patients that demonstrate no Aβ deposition (A0), Aβ in the frontal-temporal cortices (A1), additional Aβ in the basal ganglia (A2), and additional Aβ in the substantia nigra (A3) is shown in FTD cases without a mutation (n = 55), a MAPT mutation (n = 4), a C9ORF72 expansion (n = 10), and a GRN mutation (n = 7) is shown. As only one FTD case without a mutation had an A3 distribution (1%, 1/73), this has been combined with the A2 group.