The intronic hexanucleotide repeat expansion GGGGCC (G4C2) in the chromosome 9 open reading frame 72 (C9orf72) gene is the most common genetic cause of ALS, accounting for ~40% of fALS and ~10% of sALS (DeJesus‐Hernandez et al., 2011; Renton et al., 2011). This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.