Angelman SyndromeSymptoms, Doctors, Treatments, Advances & More
Angelman Syndrome Overview
Learn About Angelman Syndrome
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.
AS most often occurs because the UBE3A gene passed on from the mother doesn't work the way it should. In some cases, AS is caused when two copies of the 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:
- 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 age 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.
There is no cure for AS. 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
Jessica Duis is a Medical Genetics specialist and a Pediatrics provider practicing medicine in Aurora, Colorado. Dr. Duis is rated as an Elite provider by MediFind in the treatment of Angelman Syndrome. She is also highly rated in 4 other conditions, according to our data. Her clinical expertise encompasses Angelman Syndrome, Prader-Willi Syndrome, 3-Hydroxy-3-Methylglutaryl-CoA Lyase Deficiency, Chondrodystrophy, and Gastrostomy.
Lynne Bird is a Medical Genetics specialist and a Pediatrics provider practicing medicine in San Diego, California. Dr. Bird is rated as an Elite provider by MediFind in the treatment of Angelman Syndrome. She is also highly rated in 29 other conditions, according to our data. Her clinical expertise encompasses Angelman Syndrome, Prader-Willi Syndrome, VACTERL Association, and Mucolipidosis Type 4.
Erasmus MC
Ype Elgersma practices practicing medicine in Rotterdam, Netherlands. Elgersma is rated as an Elite expert by MediFind in the treatment of Angelman Syndrome. They are also highly rated in 14 other conditions, according to our data. Their clinical expertise encompasses Angelman Syndrome, Neurofibromatosis Type 1 (NF1), Neurofibromatosis, and Legius Syndrome.
More information and support for people with AS and their families can be found at:
- 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 setting.
Complications may include:
- Severe seizures
- Gastroesophageal reflux (heartburn)
- Scoliosis (curved spine)
- Accidental injury due to uncontrolled movements
Contact your health care provider if your child has symptoms of this condition.
There is no way to prevent AS. If you have a child with AS or a family history of the condition, you may want to talk with your provider or genetic counselor before becoming pregnant.
Summary: The main goal of the study is to evaluate the safety and efficacy of GTX-102 in participants with Angelman syndrome.
Summary: The goal of this observational study is to learn about the natural progression of Angelman syndrome (AS) in children and adults with a confirmed genetic diagnosis of AS. The main questions it aims to answer are: * How do developmental skills, such as communication, motor abilities, and adaptive behaviors, change over a 1-year period in people with AS? * Are there specific patterns in brain activit...
Published Date: July 28, 2025
Published By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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O'Neill ME, Shapiro BK. Developmental delay and intellectual disability. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 56.
Yimaz F, Beck CR, Lee C. The chromosomal and genomic basis of disease: disorders of the autosomes and sex chromosomes. In: Cohn RD, Scherer SW, Hamosh A, eds. Thompson & Thompson Genetics and Genomics in Medicine. 9th ed. Philadelphia, PA: Elsevier; 2024:chap 6.