Studying Development in Williams Syndrome: Progress, Prospects, and Challenges
Williams syndrome (WS) is a genetic disorder caused by a deletion on the long arm of chromosome 7 spanning 1.5 million to 1.8 million base pairs. The disorder has a prevalence of about 1 in 20,000 live births and includes a specific clinical profile, comprising cardiovascular difficulties, idiopathic hypercalcaemia, and dysmorphic facial features amongst others. Behaviourally, individuals with WS have been described as very sociable with high empathy and little fear of strangers. They do, however, show a number of repetitive behaviours and experience anxiety and social difficulties. Cognitively individuals with WS are characterised by mild to moderate intellectual deficits with IQ scores ranging from 40 to 100 and an average Full Scale IQ score of 55 (Martens et al. 2008).
Although both being delayed from infancy onwards, language abilities in WS outperform non-verbal abilities such as visuo-spatial and number abilities (Mervis et al. 2000; Van Herwegen et al. 2011), and the...
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