We have previously reported in a largely overlapping data set that two copies of the C9orf72 intermediate-length alleles, especially when the longer allele is ≥ 17 repeats—and homozygosity for the minor allele of rs3849942 (in LD with rs2814707)—associate with ALS risk after exclusion of HRE carriers (Kaivola et al., 2020). Here, C9orf72 is linked to amyotrophic lateral sclerosis.