SYNGAP1 and epilepsy: To date, more than 200 patients with SYNGAP1 mutations associated with various phenotypes, such as ID, DD, epilepsy, ASD, and schizophrenia, have been reported in the Human Gene Mutation Database (HGMD) (Jimenez-Gomez et al., 2019; Gamache et al., 2020; Zhang H et al., 2020).