Of note, reduced verbal fluency, non-verbal memory and executive functions were also found in presymptomatic C9orf72 gene carriers.34 Behavioural abnormalities suspicious for FTD were found in 15.2% of rated C9orf72 cases which is not surprising as C9orf72 mutations can cause both amyotrophic lateral sclerosis and FTD.3,9 Our results are in line with the findings of Mandrioli et al. who reported with 10.7% a higher share of FTD in C9orf72 amyotrophic lateral sclerosis patients compared to amyotrophic lateral sclerosis patients without genetic mutations.21 This evidence concerns the gene C9orf72 and frontotemporal dementia.