UBE3A and neurodevelopmental disorder: As mentionedbefore, deletion or inactivation of the maternally inherited UBE3A gene results in the absence of the functional UBE3Aprotein in the brain, causing Angelman syndrome,54,55 which is a neurodevelopmental disorder characterized by delayeddevelopment, lack of speech, intellectual disability, seizure, andother symptoms.56,57 It was also reported that obesityis common with Angelman syndrome.58,59 The cohabitationof obesity with Angelman syndrome suggests that a loss-of-functionmutation in UBE3A potentially causes dysregulation of metabolic pathwaysand energy metabolism.