SOX2 and Encephalopathy: For example, among seizure-free individuals (n = 6), cognitive outcomes varied: two had normal EEG and mild ID (SCN1A and SOX2-related DEEs), three had encephalopathy (background slowing) without epileptiform activity and moderate or severe ID (SCN1A, DNMT3A and KCNQ2-related DEEs), and one had encephalopathy with ongoing interictal epileptiform activity and moderate ID (CAMK2A-related DEE).