Angelman syndrome (AS) is a genetic condition that causes problems with the way a child's body and brain develop. The syndrome is present from birth (congenital). However, it often isn't diagnosed until about 6 to 12 months of age. This is when development problems are first noticed in most cases.
This condition involves the gene UBE3A.
Most genes come in pairs. Children receive one from each parent. In most cases, both genes are active. This means information from both genes is used by the cells. With the UBE3A gene, both parents pass it on, but only the gene passed on from the mother is active.
Angelman syndrome most often occurs because UBE3A passed on from the mother doesn't work the way it should. In some cases, AS is caused when two copies of UBE3A gene come from the father, and none come from the mother. This means neither gene is active, because they both come from the father.
In newborns and infants:
In toddlers and older children:
Most children with this disorder don't show symptoms until about 6 to 12 months. This is when parents may notice a delay in their child's development, such as not crawling or starting to talk.
Children between 2 and 5 years of age start to show symptoms such as jerky walking, happy personality, laughing often, no speech, and intellectual problems.
Exams and Tests
Genetic tests may diagnose Angelman syndrome. These tests look for:
Other tests may include:
There is no cure for Angelman syndrome. Treatment helps to manage health and development problems caused by the condition.
Angelman Syndrome Foundation: www.angelman.org
People with AS live close to a normal lifespan. Many have friendships and interact socially. Treatment helps improve function. People with AS can't live on their own. However, they may be able to learn certain tasks and live with others in a supervised group home.
Complications may include:
When to Contact a Medical Professional
Call your health care provider if your child has symptoms of this condition.
There is no way to prevent Angelman syndrome. If you have a child with AS or a family history of the condition, you may want to talk with your provider before becoming pregnant.
Dagli AI, Mueller J, Williams CA. Angelman syndrome. GeneReviews. Seattle, WA: University of Washington; 2015:5. PMID: 20301323 www.ncbi.nlm.nih.gov/pubmed/20301323. Accessed August 1, 2017.
Nussbaum RL, McInnes RR, Willard HF. The chromosomal and genomic basis of disease: disorders of the autosomes and sex chromosomes. In: Nussbaum RL, McInnes RR, Willard HF, eds. Thompson & Thompson Genetics in Medicine. 8th ed. Philadelphia, PA: Elsevier; 2016:chap 6.
Review Date: 8/6/2017
Reviewed By: Anna C. Edens Hurst, MD, MS, Assistant Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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