We identified seven amyotrophic lateral sclerosis patients (1.7%) carrying ≥29 repeats (29, 29, 30, 30, 31, 33 and 34) in ATXN2 (Fig. 1) compared to three (0.4%) in the control group (31, 31 and 34 repeats) (OR 4.8, 95% CI 1.1–21.2, P = 0.04) (Table 1). This evidence concerns the gene ATXN2 and amyotrophic lateral sclerosis.