A growing body of evidence has already demonstrated the presence of an overlap between hereditary neuropathy and MND at a genetic level, with several genes (i.e. CHCHD10, GARS, FIG4, KIF5A, NEFH, VCP and SPG11) associated with both amyotrophic lateral sclerosis and Charcot–Marie–Tooth disease type 2.7 These considerations notwithstanding, the significance of MFN2 variants in the context of amyotrophic lateral sclerosis pathogenesis is still unknown and requires further investigations. This evidence concerns the gene FIG4 and amyotrophic lateral sclerosis.