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. The gene discussed is ARID1B; the disease is epilepsy.