SOD1 and amyotrophic lateral sclerosis: Optimized sequence kernel association test (SKAT-O)55 identified a significant excess of deleterious minor alleles in the ALS genes NEK1 (127 individuals with ALS and 19 healthy individuals (3.21% and 1.04%): P = 8 × 10−7; Pcorrected = 2.3 × 10−4), comparable with a reported prevalence of 3% (ref. 59), and SOD1 (36 individuals with ALS (0.91%) and 0 healthy individuals: P = 2.6 × 10−4 and Pcorrected = 3.73 × 10−2)60, which is below the reported 2% prevalence3,61 (Fig. 1b, Extended Data Fig. 2a and Supplementary Table 5).