Common conditions

Angelman syndrome

Angelman syndrome (AS) is a behavioural disorder characterised by seizures, severe developmental delay, absent speech and ataxia.

Epidemiology

Incidence: 1 in 12 000-40 000
All ethnic groups
Male = Female

Clinical Presentation

Severe developmental delay
Profound speech delay. Many children do not speak more than 3-4 words.
Seizures
Specific behaviour with excitability and inappropriate laughter.
Movement and balance problems
Wide based ataxic gait.
Sleep disorder.
Less commonly there is hypopigmentation

Physical Signs

Microcephaly
Jerky gait
Increased muscle tone
Down-turned corners of the mouth
Wide mouth
Deep set eyes
Prominent chin
Hypotonia
Happy and sociable affect

Complications

Almost all patients develop seizures. Usual onset is by the second year.
Scoliosis occurs in 40% of adults
Loss of mobility and contractures