 Slow delta activity (~3 Hz) is greatly increased in AS relative to typically developing children, yet more pronounced in children with partial 15q deletions as opposed to those with etiologies principally affecting "UBE3A".Theta activity (~5 Hz) is much greater in children with partial 15q deletions.Thus, delta activity appears to be chiefly reflective of "UBE3A" dysfunction with some modulation from other 15q genes, whereas theta activity may be an electrophysiological readout of genes beyond "UBE3A" such as "GABRA5", "GABRB3", and "GABRG3."