GRN and frontotemporal dementia: Unfortunately, our sample did not have genetic status information available, limiting our ability to investigate whether the FTD patients were carriers of specific mutations (e.g. progranulin gene), previously linked to increased WMH burden in genetic forms of FTD (Caroppo et al., 2014, Desmarais et al., 2021, Sudre et al., 2019, Woollacott et al., 2018).