Individuals with CNTNAP2 loss-of-function mutations typically display four core phenotypes: (1) ID (Lu et al., 2021), (2) ASD (O’Roak et al., 2011), (3) SLI (Centanni et al., 2015), and (4) epilepsy (Friedman et al., 2008). Here, CNTNAP2 is linked to epilepsy.