New to Angelman Syndrome

Angelman Syndome Explained

Angelman Syndome Explained

Angelman Syndrome is a genetic disorder of chromosome 15   characterised by severe intellectual disability, lack of speech, sleep disturbance, and yet, usually a happy demeanor. As part of our DNA, we each have 23 pairs of chromosomes, with one of each pair coming from the mother and the other from the father. Angelman Syndrome (or AS) is a disorder of Chromosome 15. There are several ways in which Chromosome 15 may be affected. Your medical professional will explain which one applies to your child.

Why did it happen?

The chromosome disorder was there when your child was conceived and there is nothing you or your partner could have done to have caused or prevented it from happening.

How common is it?

Angelman Syndrome affects about 1 in 20,000 – 25,000 individuals. That means based on our population there are roughly   250-350 people in Ireland with AS. It affects males & females equally and is present across all races and nationalities.

In about 95% of cases the cause is a random occurrence with no family history. For subsequent pregnancies the risk of recurrence is very little different to the general population.

In about 5% of cases the disorder is inherited. The genetic situation is different for each family and if planning further children then you should discuss your own individual situation with your local geneticist.

AS the characteristics

AS the characteristics.

What are the features?

Below are a collection of symptoms seen in individuals with Angelman Syndrome. AS is a disorder, not a disease and that means affected individuals can live healthy, happy lives. This disorder does, however, have symptoms that should be monitored and managed. Not all of the problems listed below occur in all people. It is not possible to know how many of these features your child might have or to what extent they will be affected by them. There may be many problems or there may only be a few and these problems may be very mild or may be more severe.


  • Developmental delay, functionally severe
  • Speech impairment, no or minimal use of words
  • Movement or balance disorder
  • Apparent happy demeanor; easily excitable personality, often with hand flapping movements; short attention span


  • Seizures, onset usually before 3 years of age
  • Tongue thrusting or protruding;
  • Suck or swallowing disorder; drooling
  • Feeding problems during infancy
  • Wide mouth, wide-spaced teeth
  • Excessive chewing/mouthing behaviours
  • Light skin, hair and eye colour (compared to family)
  • Increased sensitivity to heat
  • Sleep disturbance
  • Attraction to or fascination with water

What happens now?

What happens now?

It is likely that your child’s blood has been taken to test for Angelman Syndrome and confirm the diagnosis. You will have to wait several weeks for the results. At some point you may be offered Genetic counseling.

To ensure your child has the chance to reach their full potential, you will be referred to the local health provider’s “Early Intervention Team”. This is a group of professionals who can help your child with advice on Physiotherapy, Occupational Therapy, Epilepsy, Communication skills and other aspects important to your child’s development. There may be a waiting list before your child can be seen.

What treatments are available?

In addition to developmental interventions there are medical treatments available to help your child with epilepsy, nutrition, sleep and many other aspects. Your medical professional will assess your child’s needs and make appropriate recommendations.

There is an ongoing programme of research and clinical trials around the world to identify a treatment for AS to assist with cognitive skills, motor function and epileptic activity. Some promising advances have been made.

What help is available?

Your medical professional can help you with questions you have about the diagnosis or can direct you to health professionals with specific expertise.

At ASI  we have a wide network of parents all over the country and can put you in touch with a parent in your area if you wish to talk about the diagnosis. We have an active online forum for parent-to-parent discussions and support and we also host family information days and other events. You may also find it helpful to use our parent information leaflet to share with other family members or carers. This can be downloaded and printed (insert link)

This community may be able to help you identify strategies and techniques such as communication, behavioural or occupational therapies which help with the day to day living with Angelman Syndrome for both the person and family members.