SOD1 and amyotrophic lateral sclerosis: The most common genetic alterations in ALS are the GGGGCC (G4C2) hexanucleotide repeat expansion in C9ORF72, nonsynonymous mutations in the genes encoding superoxide dismutase 1 (SOD1), trans-active response (TAR) DNA-binding protein 43 (TDP-43), and fused in sarcoma (FUS) [2, 3].