  WS is a rare genetic disorder with a complex phenotype. Physically,  WS individuals display dismorphic facial features, abnormal growth  patterns, gastrointestinal problems, early puberty, neurological  abnormalities (including hypotonia, hyperreflexia, hyperacuisis and  cerebellar dysfunction), defective vision and eye development, bad  teeth, connective tissue abnormalities, and heart problems.  Psychologically, in addition to their low non-verbal IQ and  comparatively spared language abilities, they display relatively good audiovisual memory but very impaired visual-spatial abilities,  leading to difficulties in daily life (e.g., getting dressed). They  have outgoing personalities and are highly sociable to the point of  overfriendliness, but also display numerous behavioral and emotional  problems (especially hyperactivity and difficulty concentrating in  childhood, and anxiety in later life). (Morris and Mervis 2000;  Mervis et al. 2000.)