There has been strong evidence to support the pathogenic role for mutations in Cu/Zn superoxide dismutase 1 (SOD1), Fused in sarcoma (FUS), TAR DNA-binding protein (TARDBP), and C9ORF72. However, mutations in other genes are not common or even rarely seen in ALS cases. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.