C9orf72 and amyotrophic lateral sclerosis: On the other hand, around 10% of ALS patients have a family history, involving mutations in a number of genes, such as Cu2+/Zn2+ superoxide dismutase 1 (SOD1), TAR DNA binding protein 43 (TDP-43), fused in sarcoma (FUS) and chromosome 9 open reading frame 72 (C9ORF72) repeat expansions [1].