SOD1 and amyotrophic lateral sclerosis: In our study of reported cases of SOD1-associated ALS (Fig. 1a), the United States had prominent contributions to case reporting, particularly in the early stages of research on SOD1 mutations associated with ALS, exhibiting frequencies of 12% to 49.1% in fALS and 0.5% to 1.5% in sALS [14, 15, 39].