Angelman syndrome (AS) is a neurobehavioral and genetically determined condition, which affects approximately 1 in 15,000 individuals. It is caused by various genetic mutations and deletions of the maternally-inherited UBE3A gene, on the 15q11-13 chromosomal region. The UBE3A gene, which encodes E3 ubiquitin ligase, shows tissue-specific imprinting, being expressed entirely from the maternal allele.The diagnosis of AS is confirmed either by methylation test or by mutation analysis. A more severe clinical picture is linked with the deletion phenotype.Patients with AS have a behavioral and motor pattern defined as "happy puppet" because it is characterized by puppet-like ataxic jerky movements; a happy, sociable disposition; and paroxysms of laughter. There is currently no cure for AS, and management is mainly symptomatic. Novel therapeutic options are directed toward the possibility of activating the silenced paternal copy of the UBE3A gene.