SYNGAP1 and epilepsy: SYNGAP1 is a recently discovered NDD gene (Hoischen et al., 2014; Zhu et al., 2014; Hamdan et al., 2009), causally-linked to a range of sporadic disorders, including ID (Deciphering Developmental Disorders Study, 2015; Deciphering Developmental Disorders Study, 2017; Hamdan et al., 2009; Rauch et al., 2012), ASD (Kyle Satterstrom et al., 2018; O'Roak et al., 2014; Hamdan et al., 2011), severe epilepsy (Vlaskamp et al., 2019; Carvill et al., 2013; von Stülpnagel et al., 2015) and schizophrenia (Purcell et al., 2014).