UBE3A and Global developmental delay: Angelman syndrome (AS) is a neurogenetic disease caused by methylation of or microdeletion at maternally inherited 15q11–q13 or UBE3A variants (16), and is characterized by epileptic seizures, developmental delay, happy demeanor, motor deficits, etc. A case report of VNS efficacy in AS showed that all three patients under study had a decrease in seizure frequency and one became seizure-free following VNS treatment (16).