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.