C9orf72 and amyotrophic lateral sclerosis: The most common genetic causes of ALS are the hexanucleotide repeat expansion (HRE) in Chromosome 9 open reading frame 72 (C9orf72) gene [3, 4] and mutations in superoxide dismutase 1 (SOD1) [5], TAR DNA binding protein 43 (TARDBP) [6] or Fused in sarcoma (FUS) [7, 8].