This aligns with evidence suggesting that C9orf72 HRE carriers are more represented among bvFTD – with or without comorbid MND – than PPA patients (Le Ber et al., 2013; Costa et al., 2020), as well as that this genetic form accounts mostly accounts for PNFA (Saracino et al., 2021). This evidence concerns the gene C9orf72 and behavioral variant of frontotemporal dementia.