[Neurogenetic dialogue illustrated by the "pantin hilare" of angelman syndrome].

Angelman syndrome is a neurogenetic disorder characterized by developmental delay, absence of speech, motor impairment, exuberant and happy demeanour and epilepsy. It may be caused by various abnormalities of chromosome 15q11-13 affecting the expression ofa gene whose multiple function still need to be clarified. Precise diagnosis carries clinical and genetic counselling implications. However, many clinicians still seem unfamiliar with it, despite the severity and typical aspects of presentation. Beyond individual situations, Angelman syndrome can serve as a paradigm for clinical and basic research into genetic and epigenetic influences in neurology, neurological development, motor control, behavioural phenotypes and epileptic syndromes. Recent advances in molecular biology and animal models of the syndrome provide new data which must be included in our interpretation of Angelman syndrome.