Angelman syndrome

Angelman syndrome is a rare condition which used to be called the "happy puppet" syndrome because the children behave as though they are a "puppet-on-a-string". However, Angelman syndrome is the name used today.

Children have learning difficulties and speech delay that are usually severe. They also have jerking movements, tongue-thrusting, a characteristic (typical) facial appearance, and a happy mood with sudden bursts of laughter and epilepsy. Many children also have a fascination for water, and usually running water.

The condition is due to an abnormality on chromosome 15. The condition is usually diagnosed between four and 10 years of age, but sometimes earlier.

Symptoms

Although children with AS may show delay in development goals in the first one or two years of life, the diagnosis may not be made until the age of two or three years when the behavioural features (cheerful mood and bursts of sudden and unexplained laughter) become more obvious. The facial appearance also becomes more noticeable in the second year of life, with the development of a pointed chin, thin wide mouth and protruding tongue.

Epilepsy usually starts between 18 months and two years of age and may initially happen with high temperatures (febrile convulsions). However, most of the seizures happen without a fever. Eventually seizures will happen in seven or eight out of every 10 children who have Angelman syndrome.

The types of seizures include myoclonic ("jerks"), atonic or astatic ("drops") and tonic ("stiffening") seizures. Generalised tonic-clonic seizures are less common. Children may also have very prolonged periods of absences that last many minutes or even hours and this is called ‘non-convulsive status epilepticus’.

Children with AS do usually learn to walk, but this is late (between the ages of two and five years) and their walking is unsteady.

Speech delay is very common and is usually quite severe. They usually have problems understanding what is said to them (this is called ‘receptive dysphasia’) and also in expressing their thoughts (this is called ‘expressive dysphasia’). Some children only have two or three words of speech (at most) and, therefore communicate by facial expression or, rarely, by signs or gestures. Most children are also doubly incontinent.

Diagnosis

The diagnosis of AS is usually made on the basis of the facial appearance, behaviour and epileptic seizure types of the children. The electroencephalogram (EEG) may also be useful in helping to confirm the condition.

Brain scans are not helpful in diagnosing Angelman syndrome, because they are usually normal. If the child is found to have the abnormality on chromosome 15, then this confirms the diagnosis of AS. The abnormality is not found in every child with AS; it is found in just over two-thirds of children with AS. The chromosome abnormality can be looked for in a blood test.

Treatment

In most children with AS, the epilepsy can be controlled with anti-epileptic medications. Medications that are commonly prescribed include sodium valproate (Epilim), clonazepam (Rivotril), lamotrigine (Lamictal), carbamazepine (Tegretol). The new antiepileptic drug, levetiracetam (Keppra) may also be helpful, particularly in treating the myoclonic seizures. Another medication called piracetam (Nootropil) may also be effective in controlling the jerky movements.

Children also need intensive help with communication. This is given by speech and language therapists. Children are usually also seen by a physiotherapist. Many children have poor sleep patterns and either find it difficult to fall asleep or wake frequently throughout the night. There is a medication called melatonin that may help improve sleep.

It is important that all families who have a child with AS are seen by a specialist in genetics (called a ‘clinical geneticist’) as well as their epilepsy consultant because AS is a genetic condition.

Prognosis (outlook)

The general health of children with AS is good and there are no major life-threatening events. The epileptic seizures are frequent and may be difficult to treat with anti-epileptic drugs for the first few years. The epilepsy usually improves with time, usually after the age of 10 years. In fact, in a number of children, the epileptic seizures disappear completely after the age of 10 or 12 years.

Many children with AS also develop behaviour problems in mid- to late childhood and these may be very difficult to manage.
Support organisations

ASSERT

Contact a Family
209-211 City Road
London
EC1V 1JN
telephone 0808 808 3555
http://www.cafamily.org.uk/

If you would like any more information about epilepsy, then please contact Epilepsy Action via the Email Helpline or, if you live in the UK, by phoning the Freephone Helpline on 0808 800 5050.

Epilepsy Action is indebted to Dr Richard Appleton, a Consultant Paediatric Neurologist who specialises in children’s epilepsy, and to Dr Rachel Kneen, Consultant Paediatric Neurologist and Dr Stewart Macleod, Specialist Registrar in paediatric neurology, at Alder Hey at Alder Hey Children’s Hospital, Liverpool, who have kindly prepared the information on this page.

Because this page is written by an epilepsy healthcare professional and not by Epilepsy Action, it falls outside the requirements of the Information Standard. This is why the Information Standard logo is not shown on this page.