What is AS?
Angelman Syndrome (AS) is a rare neuro-genetic disorder named after an English paediatrician, Dr. Harry Angelman, who first described the syndrome in 1965. A syndrome is number of features which occur together as a group and indicate a particular condition. AS is characterised by severe intellectual disability, speech impediment, sleep disturbance, unstable jerky gait, seizures and usually a happy demeanour.
Is it difficult to diagnose?
Yes, but with increasing public awareness of the condition and more accurate diagnostic tests, more children are being diagnosed. It is estimated that Angelman Syndrome occurs about one in 20,000 births. Assessing the physical and behavioural features of AS helps in a more accurate diagnosis.
Always Seen/Consistent (100%)
Severe intellectual disability and developmental delay (failure to match developmental milestones of other children), eg. delays in sitting and walking, delay in fine motor skills development and delay in toilet training;
Profound speech impairment: no speech or minimal use of words; receptive and non-verbal communication skills higher than verbal ones;
Movement for balance disorder (tremulous movement of limbs, stiffness and jerkiness in limbs) and ataxia of gait (lack of muscular co-ordination when walking);
Behavioural uniqueness: any combination of frequent laughter/smiling; Happy demeanour; easily excitable personality, often with hand flapping movements; short attention span and hyperactivity.
Usually Seen/Frequent (More than 80%)
Small head size - often by age two years; *Seizures - onset usually before three years of age; *Abnormal EEG (brain wave pattern irregularity).
Sometimes Seen/Associated (20% to 80%)
Flat occiput (flattened back of head);
Tongue thrusting; suck/swallowing disorders;
Feeding problems during infancy;
Wide mouth, widely spaced teeth;
Excessive chewing/mouthing behaviours;
Scoliosis (curvature of the spine);
Strabismus (crossed eye);
Hypo pigmented skin, light hair and eye colour (compared to family), a feature in deletion cases;
Wide based gait (feet far apart with flat, out turned feet);
Tendency to hold arms up and flexed while walking;
Increased sensitivity to heat;
Attraction to/fascination with water.
Not all features may be present. A diagnosis of Angelman Syndrome is based on a combination of the clinical features as above, together with genetic diagnostic tests.
Com a colaboração:Angelman Syndrome Association Australia