C9orf72 and amyotrophic lateral sclerosis: A total of 65 patients with SALS, 22 ALS patients with SOD1/C9orf72 mutations, and 64 HCs participated in this study, of which 3 patients with SOD1-mutated ALS, 3 patients with C9orf72-mutated ALS, and 3 HCs were in the initial screening phase and 8 patients with SOD1-mutated ALS, 8 patients with C9orf72-mutated ALS, 65 patients with SALS, and 61 HCs were in the validation stage.