SYNGAP1 and Cognitive impairment: Syngap1 heterozygous KO mice offer both construct and face validity for a form of ID with epilepsy, termed MRD5, with a 50% reduction in SynGAP protein resulting in cognitive deficits, spontaneous interictal activity and decreased seizure threshold (Clement et al., 2012; Ozkan et al., 2014).