Genetic frontotemporal dementia cases represent a privileged scenario to study the earliest phases of the disease in presymptomatic individuals and assess the changes in defined neuropathological subtypes, such as FTLD-tau, associated with MAPT mutations, or FTLD-TDP, due to GRN or C9orf72 genetic variations.7 Here, C9orf72 is linked to frontotemporal dementia.