In ALS, 90% of cases are classified as sporadic ALS, and the remaining 10% of cases are familial ALS with dominantly inherited autosomal mutations in SOD1 (superoxide dismutase 1), TDP-43 (TAR DNA-binding protein 43), FUS (fused in sarcoma/translated in liposarcoma), and C9orf72 (chromosome 9 open reading frame 72)83. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.