SOD1 and amyotrophic lateral sclerosis: The frequency of SOD1 mutations is even higher among Iranian FALS cases (38.5%).        12  Whereas SOD1 was identified as an ALS gene in 1993 and was the first gene to be identified, C9orf72 was identified only in 2011.17,19,25 Worldwide, more than 170 ALS causing mutations in SOD1 are reported in Human Gene Mutation Database (HGMD 2014.2; http://www.hgmd.org/).