None of the MFN2-amyotrophic lateral sclerosis patients tested positive for the pathogenic C9orf72 gene expansion, nor did they exhibit mutations in the SOD1 gene or the known mutational hotspots of the TARDBP (exon 6) and FUS (exons 13-14-15) genes. This evidence concerns the gene MFN2 and amyotrophic lateral sclerosis.