Angelman syndrome (AS) is a developmental disorder affecting the brain.
AS has been shown in most cases to have a genetic cause. Specifically, it is thought to occur from a problem on a chromosome called 15q11-13 that is passed from a mother to the child. In AS, a part of this chromosome is deleted or not working properly. It can also occur when two copies of the genetic change are inherited from a father (uniparental disomy), there is a change in the UBE3A chromosome or there is a defect in the imprinting center (expression of a gene).
About 1 in 10 people with AS may have symptoms of AS but do not have a clear genetic cause. Epilepsy is present in more than 8 out of 10 affected individuals.
AS occurs in approximately 1 out of 15,000 live births. AS affects boys and girls equally.
AS is generally found when a baby is between 6 and 12 months old and developmental delays become apparent to parents and caregivers.
Treatment focuses on managing medical and developmental issues.