C9orf72 and amyotrophic lateral sclerosis: About 5%–10% of ALS patients are the familial form of ALS that could be caused by various mutations of genetic loci, including TAR DNA-binding protein 43 (TDP-43), superoxide dismutase 1 (SOD1), fused in sarcoma (FUS), and C9ORF72 (Neumann et al., 2006; Turner et al., 2013).