GRN and frontotemporal dementia: In several previous studies there has been the suspicion for FTD to masquerade clinically as AD [57,83]; therefore it could be argued that the detection of known FTD pathogenic variants (GRN—p.(Arg110*) and GRN- p.(Thr382fs)), or C9ORF72 in the KANL cohort is due to the presence of misclassified FTD cases.