SIGMAR1 and amyotrophic lateral sclerosis: Of these 4 variants, rs1056899, rs2296871, and rs882709 were reported by Kim et al, who observed frequencies of 0.781, 0.747, and 0.387, respectively, in Korean controls.[18] Regarding SIGMAR1, the rs4879809 variant has been reported to play a role in the pathogenesis of ALS in a Pakistani family.[19] VAPB is another gene considered to be a gene with minor involvement in ALS.