The exclusion of patients with ALS spectrum disorders, including primary lateral sclerosis, primary spinal muscular atrophy, and other motor neuron disease (N = 7) (Supplementary Table 2) or patients with C9orf72 mutations (N = 10) (Supplementary Table 3) only changed these results marginally. This evidence concerns the gene C9orf72 and amyotrophic lateral sclerosis.