What is Angelman syndrome?

Angelman syndrome is a complex genetic disorder that causes developmental and neurological problems, such as severe speech impairment and trouble walking and balancing (ataxia).

Affects about 1 in 10,000 people
People with Angelman syndrome are usually happy and affectionate and may laugh often and at inappropriate times
Affected people may also have epilepsy
Is often associated with low levels of pigment in skin, hair, and eyes
Treatment focuses on the behaviors associated with the disorder

What are the risk factors for Angelman syndrome?

There are no known risk factors for Angelman syndrome. In some cases a family history may increase the chances of a baby having the disorder, but the disease is rare. If you already have a child with Angelman syndrome or are concerned about a family history, talking with your doctor or a genetic counselor may be helpful.

Are there medical complications associated with the disorder?

Children with Angelman syndrome may have feeding difficulties, sleep problems, and hyperactivity.

Feeding difficulties, such as problems sucking and swallowing, may occur during the first few months of life.
Sleep disorders, such as frequent waking, may need to be treated with medication or behavior therapy.
Hyperactivity tends to decrease as children get older, but many young children with Angelman syndrome may have short attention spans and move quickly from one activity to the next.

Symptoms & Causes

What are the symptoms of Angelman syndrome?

Hand flapping or walking with arms in the air
Jerky body movements
Stiffed-leg walk
Little or no speech
Attention deficits and hyperactivity
Feeding problems, especially in infancy
Sleep problems and a need for less sleep than their peers
Delays in motor development
Frequent laughter that may occur at inappropriate times
Excitable personality
Tongue thrusting
Strabismus (crossing of the eyes)
Small head size with flatness in the back of the head
A lower jaw that juts out
Light pigmentation in the hair skin and eyes

What causes Angelman syndrome?

Angelman syndrome is caused by a genetic mutation on chromosome 15. The name of this gene is UBE3A. Normally, people inherit one copy of the gene from each parent, and both copies become active in many areas in the body. Angelman syndrome occurs when only one copy of the gene is active in certain areas of the brain.

Diagnosis & Treatments

How do we diagnose Angelman syndrome?

There are no signs of Angelman syndrome at birth. The disorder is typically diagnosed at ages 6 to 12 months, when parents begin to notice developmental days such as a lack of crawling or babbling. Seizures may begin at ages 2 to 3. A doctor may suspect the disorder in children who have some of these symptoms in addition to others, such as difficulty with movement and balance, a small head size with flatness in the back, and frequent laughter.

To confirm a diagnosis of Angelman syndrome, your child's doctor will perform a combination of genetic tests that can include the following:

Chromosome analysis to examine the size, shape, and number of chromosomes in a cell
Fluorescent in situ hybridization (FISH) to see if any chromosomes are missing
DNA methylation test to see if both copies of a gene — one from the mother and one from the father — are active
Sequencing of the ubiquitin-protein ligase E3A (UBE3A): to look for a mutation in the maternal mutation of this gene, which is a rare cause of Angelman syndrome

How do we treat Angelman syndrome?

Treatment for Angelman syndrome focuses on managing the child's medical problems and developmental delays since there is no cure to repair chromosomes. Treatment may include the following:

Anticonvulsant medication for seizures
Physical therapy to help with joint mobility and movement
Speech therapy
Occupational therapy
Behavior therapy

What is the long-term prognosis for a child with Angelman syndrome?

People with Angelman syndrome have almost normal life spans. Adults are not usually able to live on their own but can learn basic household tasks and can live in group homes. Some individuals can have jobs in which they are supervised directly.

Research & Innovation