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We report the allele frequency of common mutations for each gene in our patient cohort and the exonic distribution of coding sequence alterations in the IDS , SGSH and NAGLU genes , which reveals several potential " hot - spots " .
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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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