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 mild neurocognitive disorder.