What is Angelman Syndrome?
Angelman Syndrome (AS) is a neurological disorder in which severe learning difficulties are associated with characteristic facial appearance and behaviour. Dr Harry Angelman, a paediatrician working in Warrington, Cheshire UK, first reported three children with this condition in 1965 and it was initially presumed to be rare. In 1987, it was first noted that around half of the children with AS have a piece of Chromosome 15 missing (chromosome 15 deletion). Since this time the condition has been reported more frequently and the Incidence is now thought to be 1 in 25,000 children.
Diagnoses of Angelman Syndrome
The diagnosis of AS is usually made by a paediatrician or clinical geneticist and is based
on :-
- A history of delayed motor milestones and then later a delay in general development, especially speech.
- A happy disposition with frequent laughter
- A deletion in chromosome 15
- Characteristic facial appearance
- A history of epilepsy and abnormal EEG tracing
- Unusual movements including fine tremors, jerky limb movements hand flapping and a wide based, stiff legged gait
What causes Angelman Syndrome?
AS is due to abnormal expression of a group of genes on chromosome 15. It is likely that at least one of these genes controls development of the brain, especially the parts associated with language, movement and pigmentation. It seems also that some genes influence chemical transmission of messages within the brain. All of these hypotheses need further investigation and research.
Behaviour in Angelman Syndrome
The behavioural features of AS are very characteristic. They are first apparent as feeding problems in infancy and a poor sleeping patters. Many AS children require far less sleep than a normal child. The children are typically happy and sociable and laugh with minimum provocation, sometimes inappropriately in situations which others would not find funny.
AS children tend to enjoy similar pastimes. They prefer the ‘ruff and tumble’ games rather than activities that require concentration and they love water.
Problem behaviours which have been noted in AS are hair pulling, biting, mouthing and chewing.
The Clinical Features of Angelman Syndrome
(Not every patient will show every feature)
- Feeding problems
- Delay in sitting and walking
- Poor attention span
- Hyperactivity
- Severe learning disability
- Epilepsy
- Unusual movements, ie fine tremor, hand flapping and jerky movements
- Affectionate nature and frequent laughter
- Absent speech
- Wide-based, stiff-legged gait
- Below average head size, often with flattened back
- Poor sleeping patterns
- Squint
- Subtle but characteristic facial features, ie wide smiling mouth, prominent chin, thin upper lip, deepset eyes, tendency to hold tongue between lips.
* Source : Angelman Syndrome Association of SA Inc
