Study Suggests Most People May Have Gene Variants That Impact Drugs’ Effectiveness

Image of a collection of prescription capsules and tablets in the shape of DNA. (Shutterstock)

January 26, 2024

Variations in people’s genes can affect how well medications work for them. Some variants can increase the risk of an adverse drug event, while other variants may reduce the effectiveness of certain drugs or even change how they work. New research supported by the Clinical and Translational Science Awards (CTSA) Program found that at some point in their lives, four out of five people had taken drugs that could have been affected by their genes. The findings point to potential clinical benefits of testing people to help predict whether their genes might alter a medication’s effectiveness.

The U.S. Food and Drug Administration has identified more than 60 genes with variants that can affect more than 190 drugs. In a recent study in the journal Frontiers in Medicine, researchers at the Marshfield Clinic Research Institute sequenced the entire genomes, or all the genes, of 300 deceased people who participated in a precision medicine project. The investigators also had access to the lifetime medical records from those 300 people. The scientists identified 17 variants in nine genes known to impact medications. They found that 93% (279) of the study’s 300 participants had at least one of the pharmacologically significant gene variants.

Using the participants’ lifetime health records and prescription drug histories, the research team discovered that 80% (241 of 300) were prescribed at least one of 43 medications that could have been affected by the patients’ gene variants.

That gene-medication overlap may have had clinical impact. For example, four patients took simvastatin despite having genetic variants that put them at high risk of a muscle injury called myopathy when given the drug. Of those four, three had documented drug complications from simvastatin, including two who had myopathy.

The researchers estimated that about 80% of the study participants could have benefited until age 50 from genomic testing to identify potential pharmacological problems. Although the potential benefit from testing declines with age, the scientists said about 70% of 70-year-olds could still have better outcomes from such testing. Studies like this highlight the potential benefits over a person’s lifetime of using genomic information to personalize medical treatments.

Learn more about the researchers’ findings.