Angelman syndrome (AS) is a neurological genetic disorder characterized by developmental delay, intellectual disability, significant speech impairment or absence, and/or balance problems (ataxia). Most affected individuals experience recurrent seizures (epilepsy) and a small head size (microcephaly). In some cases, affected children may have lighter skin, blonde hair, and light-colored eyes compared to other family members. Angelman syndrome is not a condition that can be immediately diagnosed at birth. Typically, developmental delays begin to be noticed between 6 and 12 months of age. Other common signs and symptoms of the syndrome usually become evident during early childhood.