We did not replicate any of the other previously reported associations, suggesting that our study gave a false-negative result or that they were population specific or false-positive results (panel, table 3).8, 9, 10, 11, 12 In our joint analysis, which is the largest GWAS of ALS to date, chromosome 9p21.2 and UNC13A were the only significantly associated loci. This evidence concerns the gene UNC13A and amyotrophic lateral sclerosis.