While the vast majority of ALS cases are described as sporadic (sALS), 10% of ALS patients have a family history (fALS) linked to mutations in increasingly recognized genes, the most important of which being C9ORF72 [1,2]; superoxide dismutase 1 (SOD1) [3,4,5,6,7,8]; and TARDBP and FUS [9,10,11,12,13,14]. The gene discussed is C9orf72; the disease is amyotrophic lateral sclerosis.