TCF4 and Intellectual disability: Cross-ancestry meta-analyses revealed additional novel associations: TCF4 had a significant effect on Cocaine LU; this gene is associated with Pitt–Hopkins syndrome, a disorder of severe developmental delay and intellectual disability (Sweatt, 2013), and also with PTSD reexperiencing (Gelernter et al., 2019), corneal endothelial dystrophy, schizophrenia (Forrest et al., 2014), and depression (Mossakowska-Wojcik et al., 2018).