Point mutations in various genes, for instance the Cu/Zn superoxide dismutase 1 (SOD1) and the more recently described C9orf72 genes (Rosen et al., 1993; DeJesus-Hernandez et al., 2011; Renton et al., 2011), lead to familial forms of ALS. The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.