C9orf72 and amyotrophic lateral sclerosis: Subgroup analyses by ethnicity indicated that C9orf72 repeat expansions were risk factors for both Caucasian and Asian ALS patients (OR = 80.41, 95% CI = 45.32–142.67, and p < 0.00001; OR = 8.51, 95% CI = 1.61–44.91, and p = 0.01) (details were shown in Figure 2).