A large genetic analysis of nearly 100,000 Americans has identified thousands of new variants in genes known to influence how people respond to prescription medicines. The work used data from the All of Us Research Program, an initiative of the National Institutes of Health designed to build a health database that reflects a wider range of people living in the United States than many earlier genomic studies.
The analysis focused on 16 pharmacogenes, a group of genes associated with variation in genetics and drug response. Researchers found that every participant carried at least one variant in the genes under review. The finding underlines how common pharmacogenetic differences are across the population and why they matter for health systems that increasingly rely on genomic information to guide prevention, diagnosis and care.
One of the most significant elements of the study is the ancestry diversity of the participants. Earlier research on pharmacogenes has often drawn heavily from populations of European ancestry, limiting the ability to detect variants that may be more frequent or more visible in other groups. By examining a broader dataset, the All of Us analysis expanded the catalogue of variants that may be relevant to prescribing decisions and exposed gaps left by less representative research cohorts.
The study also found that one in four participants had taken a medication that could be affected by the variants identified in the 16 pharmacogenes. That does not mean all of those patients experienced a different response, nor does it automatically translate into immediate changes in treatment. It does show, however, that pharmacogenomic information is not a niche concern: it intersects with medicines already used by a substantial share of patients.
For precision medicine, the findings reinforce a central challenge. Genetic testing can only support safer and more effective prescribing if the underlying reference data includes the populations clinicians serve. The All of Us results add evidence that more inclusive research can uncover clinically relevant variation that might otherwise remain invisible, helping future studies, laboratories and care providers interpret drug-response genes with greater accuracy.
