Angelman syndrome (AS) is a behavioural disorder characterised by seizures, severe developmental delay, absent speech and ataxia.
- Incidence: 1 in 12 000-40 000
- All ethnic groups
- Male = Female
- Severe developmental delay
- Profound speech delay. Many children do not speak more than 3-4 words.
- Specific behaviour with excitability and inappropriate laughter.
- Movement and balance problems
- Wide based ataxic gait.
- Sleep disorder.
- Less commonly there is hypopigmentation
- Jerky gait
- Increased muscle tone
- Down-turned corners of the mouth
- Wide mouth
- Deep set eyes
- Prominent chin
- Happy and sociable affect
- Almost all patients develop seizures. Usual onset is by the second year.
- Scoliosis occurs in 40% of adults
- Loss of mobility and contractures