The results indicate that individuals with WS were significantly more likely to have an anxiety disorder [risk ratio (RR) 4.00 (95 % CI 2.27–7.06); p < 0.0001], and in particular, to have a specific phobia [RR 5.57 (95 % CI 2.62–11.86); p < 0.0001] or GAD [RR 10.00 (95 % CI 1.30–76.67); p < 0.05], than individuals with heterogeneous ID (for full table of results, see Online Resource F). Here, GAD1 is linked to anxiety disorder.