DDX3X and epilepsy: Eight of those (SCN1A, IQSEC2, STXBP1, CACNA1E, ARID1B, DDX3X, WHSC1, PHF21A) have been known to be responsible for NDDs associated with IDs or epilepsies.9, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29