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U.S. Department of Health and Human Services


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Polymorphic Distribution

This graph demonstrates a population drug metabolism distribution for CYP2D6. On the graph, PM means poor metabolizer, EM means extensive metabolizer, which is the normal or usual phenotype, and URM means ultra-rapid metabolizer. Approximately 7% of the U.S. population has a genetic defect in CYP2D6 that results in a poor metabolizer phenotype. 


  • A trait that has differential expression less than 1% of the population


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