SOD1 and amyotrophic lateral sclerosis: There were significant differences in survival between spinal onset ALS and bulbar onset ALS patients (p < 0.0001) (Fig. 3B) and among ALS patient genotype groups (p < 0.0001 for overall comparisons, p < 0.01 for ALS patients with SOD1 mutations versus C9orf72HRE mutations) (Fig. 3D).