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At a glance

The Happy Puppet Syndrome (Angelman’s Syndrome) is a genetic disorder that mainly affects the nervous system. The clinical features include microcephaly, happy facial appearance, severe mental retardation, developmental disability, speech problems (absence of speech), balance and movement problems, seizures, and sleep problems and social disposition. Children are usually happy in nature and have a particular interest in water. The symptoms generally become noticeable by 1 year of age.


Angelman Syndrome; Puppet Children; Puppet-Like Syndrome; Syndrome du Pantin Hilare (French).


Genetic or sporadic disease that was first described in 1965 by Harry Angelman (13 August 1915-8 August 1996), a British consultant pediatrician. An American Angelman Syndrome Support Group was started in Waterlooville, Hampshire, in 1986. His original 1965 paper described what he called “happy puppet children” and which was not immediately recognized as scientifically important. Because the name was considered pejorative, it was later renamed Angelman Syndrome. During a visit to the United States of America to discuss his work, his contribution to medicine was acclaimed by President Bill Clinton.


1:12,000 to 20,000 live births. Males and females are equally frequently affected.

Genetic inheritance

Some cases are transmitted as an autosomal dominant trait.


Caused by a gene encoding ubiquitin-protein ligase (UBE3A) located on 15q11-13.


Onset between 3 and 7 years of age. The affected children have a happy disposition and laugh frequently for almost any reason. Movements are jerky, like those of a marionette or puppet. Seizures are present in 96% of cases with a characteristic EEG.

Clinical aspects

Features include neurologic disorders (jerky movements caused by ataxia associated with hypertonia, brisk tendon reflexes, hyperreflexia, hyperkinesia, hypsarrhythmia, epilepsy, cerebral atrophy/myelin abnormality at MRI), craniofacial malformations (brachycephaly with occipital flattening, microcephaly, prognathism, macrostomia, oligodontia, protruding tongue, open mouth, widely spaced teeth, deficient pigmentation of the choroid with optic pallor and characteristic blue irides, and Brushfield spots), and skin (hypopigmentation, blond hair). Associated with happy disposition, children present with hyperactivity, restlessness, absent speech, sleeping disorders, feeding problems, and drooling. Thoracic scoliosis can be observed.

Precautions before anesthesia

Evaluate tracheal intubation because of skull anomalies (clinical, radiographs). Evaluate neurologic function (clinical, CT, MRI, EEG, epileptic treatment efficiency).

Anesthetic considerations

Cooperation is impossible to obtain and often makes anesthetic induction difficult. Tracheal intubation can be difficult and may require adapted anesthetic management.

Pharmacological implications

Consider interaction between antiepileptic treatment and anesthetic drugs. Muscle relaxants should be avoided until airway is secure.

Other conditions to be ...

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