SOD1 and sporadic amyotrophic lateral sclerosis: As opposed to sporadic amyotrophic lateral sclerosis, we found that the share of male and female patients was comparable in C9orf72 which is consistent with previous reports.17-20,24 Likewise, the proportion of approximately two thirds of patients with spinal onset and one third of patients with bulbar onset in C9orf72 is in line with pre-existing data.18-20,25 Therefore, we can conclude that the share of bulbar patients in C9orf72 is higher compared to sporadic amyotrophic lateral sclerosis, and much higher than in SOD1 patients who very rarely feature a bulbar onset.