The degree of thalamic atrophy is more marked in familial FTD compared with sporadic FTD (Spinelli et al., 2021), particularly C9orf72 mutation carriers (Bocchetta et al., 2018, 2021; Bocchetta et al., 2020; Panman et al., 2019). This evidence concerns the gene C9orf72 and frontotemporal dementia.