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 and develop sleep problems that may improve with age. Treatment focuses on managing medical and developmental issues.
Characteristic Angelman syndrome signs and symptoms include:
People who have Angelman syndrome may also have other signs and symptoms, including:
Most babies with Angelman syndrome don't show signs or symptoms of the disorder when they're born. The first signs of Angelman syndrome are usually developmental delays, such as lack of crawling or babbling, between 6 and 12 months.
If your child seems to have developmental delays or if your child has other signs or symptoms of Angelman syndrome, make an appointment with your child's doctor.
Angelman syndrome is a genetic disorder, most often caused by problems with a gene located on chromosome 15 called the ubiquitin protein ligase E3A (UBE3A) gene.
You receive your genes, which occur in pairs, from your parents — one copy from your mother (maternal copy) and the other from your father (paternal copy). Your cells typically use information from both copies, but in a small number of genes, only one copy is active.
Normally, only the maternal copy of the UBE3A gene is active in the brain. Most cases of Angelman syndrome occur when part of the maternal copy is missing or damaged. In a few cases, Angelman syndrome is caused when two paternal copies of the gene are inherited, instead of one from each parent.
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, flatness in the back of the head, and 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:
Complications associated with Angelman syndrome include:
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, consider talking to your doctor or a genetic counselor for help planning future pregnancies.
Finding out that 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.
Find a team of doctors and therapists you trust to help you with important decisions about your child's care and treatment. These professionals can also help identify and evaluate appropriate resources in your area.
Connecting with other families facing similar challenges may help you feel less alone. Ask your child's doctor for information about support groups and other helpful organizations in your area.
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.