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Fragile X syndrome ( FXS ) is one of the most prevalent and well - studied monogenetic causes of intellectual disability and autism and , although rare , its high penetrance makes it a desirable model for the study of neurodevelopmental disorders more generally .
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Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
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