Angelman Syndrome


Here you’ll find answers to some of the questions that parents often have about this condition. Additional resources are listed at the bottom of the page. Diagnosis and management information can be found in the Angelman Syndrome module, which is written for primary care clinicians but also may be of help to parents and family members.

What is Angelman syndrome and what causes it?

Angelman syndrome (AS) is a genetic disorder that causes severe developmental delay/intellectual disability (DD/ID) and a distinctive and recognizable pattern of behaviors that include frequent smiling, laughing, hyperactivity, and decreased communication skills. Individuals with AS are missing a functional copy of the UBE3A gene from their mother. The exact manner in which this causes the syndrome is not well understood.

What are the symptoms of Angelman syndrome?

Symptoms of AS include a clinical pattern of developmental delay, distinctive features, a happy demeanor, and is typically complicated by seizures. Full criteria can be found in our Angelman Syndromemoudle in the Diagnostic Criteria section.

How is it diagnosed?

The diagnosis of AS is based on clinical features and genetic testing, which confirms the diagnosis in approximately 90% of individuals with the typical phenotype. Because AS is a clinical diagnosis, individuals who meet clinical criteria but whose genetic testing is negative continue to carry the diagnosis.

What is the prognosis?

Most children with AS will have clinically significant seizures and will need antiepileptic therapy. Children with AS do not show developmental regression and, with good proactive care, should have normal life expectancies. They are, however, at risk for early death due to seizures, aspiration pneumonia, and chronic and restrictive lung diseases.

What is the risk for other family members or future babies?

The risk to siblings of a child with AS (proband) depends on the genetic mechanism leading to the loss of UBE3A function: typically less than 1% risk for children with AS with a deletion or UPD, and as high as 50% for children with AS with an intellectual disability or a mutation of UBE3A.

What treatments/therapies/medications are recommended or available?

There is no treatment for the underlying condition. Children with AS have developmental delays and should receive speech/language, occupational, and physical therapy to help maximize functioning. Seizures are treated with antiepileptic medication.

How will my child and our family be impacted?

The diagnosis of AS in one of your children will have an important impact on your family. Children with AS will most likely have intellectual disability and delays in other areas such as physical and social abilities. They will most likely have seizures and require therapies and special education to develop to their full potential. This may be devastating to families at first, but you will most likely find that you can rise to meet the challenges ahead and that there will be benefits you can't imagine right when you receive the diagnosis. The Medical Home Portal is designed to help and to answer some of your questions, not just now but as your child grows older. We recommend strongly that you contact the Angelman Syndrome Foundation for help and support.

My child's teacher says that my child is having seizures at school but her neurologist is unimpressed and does not yet want to start medication. Why?

It is sometimes difficult to tell seizures from unusual movements in children with Angelman syndrome. Your child's neurologist may want to avoid over-medicating for movements that are not known to be seizures. He/she is likely considering your child's history, EEG results, etc. Raise this question at your next neurology visit or with your child's primary care clinician.

We don't have insurance and our child needs a second, very expensive medication for his seizures. What can we do?

Some prescription assistance programs for epilepsy medications may be able to help, depending on family income. See Prescription Assistance Programs (American Epilepsy Society).


Information & Support

Where can I go for further information?

For Parents and Patients


Support Resources (Angelman Syndrome Foundation)
Educational and community resources for those caring for children with Angelman syndrome.

Epilepsy Foundation
A national organization that provides information about epilepsy; programs to improve epilepsy treatment; materials to assist in helping people with epilepsy find jobs; activities in schools to educate the public; activities to educate policymakers; funds for research; links to find local and state resources; and news about conferences and other items of interest.


Angelman Syndrome Foundation
Information, resources, and discussion forums for individuals with AS and their families. This organization also raises money for research on AS.

Foundation for Angelman Syndrome Therapeutics (FAST)
Established in 2008, FAST aims to assist individuals living with Angelman syndrome to realize their full potential and quality of life and to bring practical treatment into current medical practice as quickly as possible. The website offers educational material, ways to connect with the founder (a parent of a child with Angelman syndrome) and with other parents, and other resources.

Angelman Syndrome (Genetics Home Reference)
Excellent, detailed review of condition for patients and families; U.S. National Library of Medicine.

Prescription Assistance Programs (American Epilepsy Society)
Information and links to various prescription assistance programs, which may help reduce the cost of medications significantly.

Angelman Syndrome (Orphanet)
Information and links about AS.

Angelman Syndrome (Mayo Clinic)
Information about symptoms, causes, risk factors, complications, tests, treatment, and coping strategies.

American Epilepsy Society
Information and resources to understand epilepsy, especially for those who are not familiar with the condition.

Genetics in Primary Care Institute (AAP)
Contains health supervision guidelines and other useful resources for the care of children with genetic disorders; American Academy of Pediatrics.

Services in Rhode Island

Select services for a different state: ID, MT, NM, NV, UT

Developmental - Behavioral Pediatrics

See all Developmental - Behavioral Pediatrics services providers (12) in our database.

Early Childhood Education/Preschool

See all Early Childhood Education/Preschool services providers (3) in our database.

Early Intervention for Children with Disabilities/Delays

See all Early Intervention for Children with Disabilities/Delays services providers (12) in our database.

Occupational Therapy, Pediatric

See all Occupational Therapy, Pediatric services providers (11) in our database.

Pediatric Gastroenterology

See all Pediatric Gastroenterology services providers (18) in our database.

Pediatric Neurology

See all Pediatric Neurology services providers (11) in our database.

Pediatric Ophthalmology

See all Pediatric Ophthalmology services providers (7) in our database.

Pediatric Orthopedics

See all Pediatric Orthopedics services providers (10) in our database.

Pediatric Sleep Medicine

See all Pediatric Sleep Medicine services providers (1) in our database.

Physical Therapy

See all Physical Therapy services providers (3) in our database.

Psychologist, Child-18 (PhD, PsyD)

See all Psychologist, Child-18 (PhD, PsyD) services providers (17) in our database.

School Districts

See all School Districts services providers (34) in our database.

Speech - Language Pathologists

See all Speech - Language Pathologists services providers (19) in our database.

For other services related to this condition, browse our Services categories or search our database.


Families can join the Patient Contact Registry (Rare Diseases Clinical Research Network) for the Angelman, Rett & Prader-Willi Syndromes Consortium.

Angelman Syndrome Studies (

Authors & Reviewers

Initial publication: March 2012; last update/revision: October 2015
Current Authors and Reviewers:
Reviewer: Alan F. Rope, MD
Funding: The Medical Home Portal thanks the 2011-2012 URLEND Medical Home Portal trainees group for their contribution to this page.