Although there was some regional variation in the gene panel tested by respondents, there was a general consensus in the choice of testing for 4 main ALS genes (figure 3A): SOD1 (68.3% of respondents test), C9orf72 (63.5%), TARDBP (43.1%), and FUS (43.7%). The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.