SOD1 and amyotrophic lateral sclerosis: Cortical hyperexcitability was also shown to be an early and prominent feature in familial ALS, including phenotypes linked to mutations in the superoxide dismutase-1 [52], fused in sarcoma (FUS) [61] and c9orf72 genes [62], and correlating with peripheral neurodegeneration in the SOD-1 genotypes [63].