Most cases of ALS do not have a known cause, and only 5%–10% of cases are inherited with mutations in genes such as SOD1, FUS, C9ORF72, ATAXIN-2, CCNF, GLT8D1, KIF5A, NEK1, C21orf2, DNAJC7, ANXA11 and TIA (Laffita-Mesa et al., 2013; Brown and Al-Chalabi, 2017). The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.