What is it?

Angelman syndrome is a complex genetic disorder that primarily affects the nervous system.1

What causes it?

Typically, people inherit a working copy of the UBE3A gene from each parent (so they have two copies). In certain parts of the brain, only the copy inherited from a person’s mother (the maternal copy) is active. Angelman syndrome occurs when there is a mutation (change) or deletion in a person’s maternal UBE3A gene, so they have no working copies of the gene in those areas of the brain.1

What are some of the common symptoms?1

  • Developmental delay
  • Behavioral problems
  • Intellectual disability
  • Severe speech impairment
  • Movement and balance problems (ataxia)
  • Recurrent seizures (epilepsy)
  • Small head size (microcephaly)

How many people have it?

Angelman syndrome affects an estimated 1 in 12,000 to 20,000 people globally.1

Common names for Angelman Syndrome

  • AS1

1Angelman Syndrome. Nation Institutes of Health: Genetics Home Reference Website. https://ghr.nlm.nih.gov/condition/angelman-syndrome#. Published October 29, 2019. Accessed December 5, 2019.