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As large - scale genome sequencing efforts have revealed the extent of genetic variation at the low end of the frequency range in human populations , the effects of rare variants have been proposed as an explanation of the ' missing genetic variance . ' Improved technologies for genotyping rare variants , including inexpensive whole - genome and whole - exome sequencing and rare - variant genotyping chips , coupled with novel analytical methods , are making genome - wide scans for the effects of rare variants possible , and seem likely to usher in a new era in the genetic analysis of complex traits .
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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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