The behavioral phenotype of the Angelman syndrome.

The Angelman syndrome is clinically delineated by the combination of seizures, absent speech, hypermotoric and ataxic movements and certain remarkable behaviors. Those with the syndrome have a predisposition toward apparent happiness and paroxysms of laughter, and this finding helps distinguish Angelman syndrome from other ones involving severe developmental handicap. In this review the core neurological features of the syndrome are discussed with a focus on those behaviors that make Angelman syndrome a prototypical genetic disorder expressing a behavioral phenotype.