Skip to main content

Health Encyclopedia

Search the Health Encyclopedia

Angelman syndrome

Definition

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.

Causes

This condition involves the gene UBE3A.

Most genes come in pairs. Children 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.

Symptoms

In newborns and infants:

  • Loss of muscle tone (floppiness)
  • Trouble feeding
  • Heartburn (acid reflux)
  • Trembling arm and leg movements

In toddlers and older children:

  • Unstable or jerky walking
  • Little or no speech
  • Happy, excitable personality
  • Laughing and smiling often
  • Light hair, skin, and eye color compared to rest of family
  • Small head size compared to body, flattened back of head
  • Severe intellectual disability
  • Seizures
  • Excessive movement of the hands and limbs
  • Sleep problems
  • Tongue thrusting, drooling
  • Unusual chewing and mouthing movements
  • Crossed eyes
  • Walking with arms uplifted and hands waving

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 two and five 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:

  • Missing pieces of chromosomes
  • DNA test to see if copies of the gene from both parents are in an inactive or active state
  • Gene mutation in the mother's copy of the gene

Other tests may include:

Treatment

There is no cure for Angelman syndrome. Treatment helps to manage health and development problems caused by the condition.

  • Anticonvulsant medicines help control seizures
  • Behavior therapy helps manage hyperactivity, sleep problems, and development problems
  • Occupational and speech therapy manage speech problems and teach living skills
  • Physical therapy helps with walking and movement problems

Support Groups

Angelman Syndrome Foundation: www.angelman.org

ASSERT: www.angelmanuk.org

Outlook (Prognosis)

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.

Possible Complications

Complications may include:

  • Severe seizures
  • Gastroesophageal reflux (heartburn)
  • Scoliosis (curved spine)
  • Accidental injury due to uncontrolled movements

When to Contact a Medical Professional

Call your health care provider if your child has symptoms of this condition.

Prevention

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 health care provider before becoming pregnant.

References

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, 2015. 

Review Date:8/1/2015
Reviewed By:Chad Haldeman-Englert, MD, FACMG, Fullerton Genetics Center, Asheville, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

adam.com

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.

Health
Outcome Data

No data available for this condition/procedure.

Health Encyclopedia

More Features

We Appreciate Your Feedback!
1. Did you find this information useful?
         Yes
         No
2. Would you recommend this website to family and friends?
         Yes
         No