SOD1 and amyotrophic lateral sclerosis: When we meta-analysed per-gene case-control counts of rare functional mutations in our Chinese sample with those from the largest WES study of European ancestry [9] (Additional file 1: Table S6), three genes surpassed genome-wide significance for association with ALS with smaller p values than in the European ancestry samples alone: TBK1; NEK1;and SOD1 (Table 1; Fig. 1).