The autism-associated gene DSCAM (Down syndrome cell adhesion molecule) showed significant association with left-handedness after Bonferroni correction for 43 tests (strict set, beta = 0.17, P = 3.6 × 10−4 uncorrected: broad set, beta = 0.15, P = 5.5 × 10−4 uncorrected) (Supplementary Table 7). Here, DSCAM is linked to autism.