Angelman syndrome is caused by the loss of the normal maternal contribution to a region of chromosome 15, most commonly by deletion of a segment of that chromosome. It is a neuro-genetic disorder characterized by intellectual and developmental disability, sleep disturbance, seizures, jerky movements (especially hand-flapping), frequent laughter or smiling, and usually a happy demeanor.
An older, alternative term for AS, happy puppet syndrome, is generally considered pejorative and stigmatizing so it is no longer the accepted term, though it is sometimes still used as an informal term of diagnosis. People with AS are sometimes known as “angels”, both because of the syndrome’s name and because of their youthful, happy appearance.
Those with the syndrome are generally happy and contented people who like human contact and play. People with AS exhibit a profound desire for personal interaction with others. Communication can be difficult at first, but as a child with AS develops, there is a definite character and ability to make themselves understood. People with AS tend to develop strong non-verbal skills to compensate for their limited use of speech. It is widely accepted that their understanding of communication directed to them is much larger than their ability to return conversation. Most afflicted people will not develop more than 5–10 words, if any at all.
Unfortunately there are no known cure.. Although there are studies being done right now, it is far from human testing.