More clinical phenotype-genotype studies are needed to clarify the prognostic role of repeat lengths over 5, which usually represent more than 50% of sporadic ALS patients without C9orf72 HRE in Asia [this study, 56%; another study in China, 64% (23); and Korea, 50.3% (24)]. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.