Angelman Syndrome

6th September 2018

Angelman Syndrome (AS) is a genetic disorder of which epilepsy is a common symptom. Epilepsy affects 7 out of 10 children who are diagnosed with AS. In less enlightened times it was also known as ‘Happy Puppet Syndrome’ as children are often happy and have jerking, puppet-like movements. However, this unofficial term is considered to be upsetting and should only ever be referred to as Angelman Syndrome. It’s caused by an abnormality of chromosome 15.


As previously mentioned, epilepsy is a common symptom of Angelman Syndrome. Children with Angelman Syndrome are also prone to being happy moods and unexpected outbursts of laughter.

Children who have AS will have severe learning difficulties and speech delay, as well as other developmental problems. There are also common facial distinctions in children with AS, such as a pointed chin, thin wide mouth and protruding tongue. AS presents with jerking and thrusting movements and children with AS will often have a fascination with running water.

In addition, a child may become unresponsive or quiet for prolonged periods. This is known as non-compulsive status epilepticus (NCSE). During this time they may drool excessively or be unable to eat. NCSE can last anywhere from minutes to hours or even days. An electroencephalogram (EEG) test is required to detect NCSE.


7 out of 10 children with AS will experience seizures. Myoclonic, atonic or astatic and tonic seizures are the most common (read our blog post on seizures here). Generalised tonic-clonic and focal seizures are much less common. These seizures will normally commence from 18 months to 2 years, and may initially happen alongside a high fever.  


Diagnosis of AS is usually made between the age of 3 – 10, although sometimes earlier. This is because the behavioural and physical features of the syndrome which become more prevalent at an older age. Facial features become more pronounced around ages 3 and 4, which is often what results in a diagnosis. Unexpected burst of happiness and laughter can be common in babies, but in an older child they may be more of a cause for concern.


In children with AS, the epilepsy aspect of the syndrome can often be controlled with antiepileptic drugs (AEDs). Sodium valproate (Epilim), clonazepam (Rivotril), lamotrigine (Lamictal) and levetiracetam (Keppra) are all commonly prescribed for children who have AS.

A ketogenic diet and Vagus Nerve Stimulation (VNS) may also be beneficial in many children who have AS (click the links for more info on both of these). It’s also likely that they will require intervention from a speech therapist, physiotherapist and occupational therapist.

Families who have a child with AS are recommended to consult a genetic specialist who can explain the syndrome and discuss the prognosis of future children potentially having AS.

National Epilepsy Training can help

Our experts are on hand to help the families of children with AS. We have a range of training and care services to help manage the condition as effectively as possible. Call us on 01706 373075 or email