Angelman syndrome is a genetic disorder that causes developmental disabilities and neurological problems, such as difficulty speaking, balancing and walking and, in some cases, seizures. Frequent smiles and outbursts of laughter are common for people with Angelman syndrome, and many have happy, excitable personalities.
Angelman syndrome usually isn't detected until parents begin to notice developmental delays when a baby is about 6 to 12 months old. Seizures often begin when a child is between 2 and 3 years old.
People with Angelman syndrome tend to live a normal life span, but they may become less excitable with age. Other signs and symptoms remain. Treatment for Angelman syndrome focuses on managing the child's medical and developmental problems.
Characteristic Angelman syndrome signs and symptoms include:
People who have Angelman syndrome may also have other signs and symptoms, including:
When to see a doctor
If your child seems to have developmental delays, or if your child has other signs or symptoms of Angelman syndrome, make an appointment to talk with your child's doctor.
Angelman syndrome is a genetic disorder. It's most often caused by problems with a gene located on chromosome 15 called the ubiquitin-protein ligase E3A (UBE3A) gene.
Genes are segments of DNA that provide the blueprints for all of your characteristics. You receive your genes, which occur in pairs, from your parents. One copy comes from your mother (maternal copy), and the other copy comes from your father (paternal copy).
A missing or defective gene
Normally, only the maternal copy of the UBE3A gene is active in the brain, caused by what's known as genomic imprinting. Most cases of Angelman syndrome occur when part of the maternal chromosome 15, which contains this gene, is missing or damaged. In a small number of cases, Angelman syndrome is caused when two paternal copies of the gene are inherited, instead of one paternal and one maternal copy (paternal uniparental disomy).
Angelman syndrome is rare. In most cases, researchers don't know what causes the genetic changes that result in Angelman syndrome. Most people with Angelman syndrome don't have a family history of the disease. In a small percentage of cases, however, Angelman syndrome may be inherited from a parent, so a family history of the disease may increase a baby's risk of developing Angelman syndrome.
Complications associated with Angelman syndrome include:
Preparing for your appointment
Call your doctor if your baby or child isn't reaching expected developmental milestones or has any other signs or symptoms common to Angelman syndrome. After your initial appointment, you may be referred to a doctor who specializes in the diagnosis and treatment of conditions that affect the brain and nervous system (neurologist).
Here's some information to help you get ready for your appointment and to know what to expect from your doctor.
What you can do
Questions to ask your child's doctor at the initial appointment include:
Questions to ask if you're referred to a specialist include:
Don't hesitate to ask any other questions that occur to you.
What to expect from your doctor
A doctor who sees your child for possible Angelman syndrome is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to talk about in-depth. The doctor may ask:
Tests and diagnosis
Your child's doctor may suspect Angelman syndrome if your child has developmental delays and other signs and symptoms of the disorder, such as problems with movement and balance, small head size, and flatness in the back of the head, along with frequent laughter.
Confirming a diagnosis of Angelman syndrome requires taking a blood sample from your child for genetic studies. A combination of genetic tests can reveal the chromosome defects related to Angelman syndrome. These tests may look at:
Treatments and drugs
Because there isn't a way to repair chromosome defects, there's no cure for Angelman syndrome. Treatment focuses on managing the medical and developmental problems that the chromosome defects cause.
A team of health care professionals will likely work with you to manage your child's condition. Depending on your child's signs and symptoms, treatment for Angelman syndrome may involve the following:
Coping and support
Finding out your child has Angelman syndrome can be overwhelming. You may not know what to expect, and you may worry about your ability to care for a child with medical concerns and developmental disabilities. There are resources that can help.
Work with a team
Consider a support group
In rare cases, Angelman syndrome may be passed from affected parent to child through defective genes. If you're concerned about a family history of Angelman syndrome, or if you already have a child with Angelman syndrome, you may wish to talk to your doctor or a genetic counselor for help planning future pregnancies.
Last Updated: 2012-01-17
© 1998-2014 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.
Terms and conditions of use