Asset ID: 79333326 / DAJ / Baby girl in angel wings, smiling, rear view

Angelman syndrome (AS) is a neuro-genetic disorder chraacterised by intellectual and developmental delay , sleep disturbance, seizures , jerky movements (especially hand-flapping), frequent laughter or smiling, and usually a happy demeanour.
AS is a classic example of genomic imprinting in that it is usually caused by deletion or inactivation of genes on the maternally inherited chromosome 15 while the paternal copy, which may be of normal sequence, is imprinted and therefore silenced. The sister syndrome, Prader-Willi syndrome , is caused by a similar loss of paternally inherited genes and maternal imprinting. AS is named after a British paediatrician , Dr. Harry Angelman , who first described the syndrome in 1965. An older, alternative term for AS, happy puppet syndrome , is generally considered pejorative and stigmatising 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.

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