By admin 
A landmark study involving nearly 100,000 Americans has identified thousands of previously unknown genetic variants in a specific set of genes that dictate how the human body responds to prescription medications. This breakthrough, made possible by the inclusion of a more diverse array of ancestral backgrounds than any prior research of its kind, marks a significant leap forward in the field of pharmacogenomics—the study of how genes affect a person’s response to drugs. By utilizing data from the National Institutes of Health’s (NIH) ambitious All of Us Research Program, researchers have demonstrated that genetic diversity is not just a matter of equity, but a fundamental requirement for the future of safe and effective medicine.
The findings, published on Wednesday in the journal Science Translational Medicine, reveal a startling prevalence of these genetic markers. According to the research team, every single one of the nearly 100,000 participants carried at least one variant in the 16 "pharmacogenes" analyzed in the study. Perhaps more significantly, the data showed that one in four participants was already taking a medication whose efficacy or safety could be directly impacted by their specific genetic profile. This high frequency suggests that the current "one-size-fits-all" approach to prescribing medicine may be failing a substantial portion of the population, often leading to ineffective treatments or dangerous side effects that could, in theory, be predicted and avoided.
Pharmacogenomics is a cornerstone of the broader "precision medicine" movement, which seeks to move away from standardized treatment protocols in favor of care tailored to an individual’s unique biological makeup. Pharmacogenes are responsible for producing the enzymes and proteins that metabolize drugs, transport them through the bloodstream, or serve as targets for the medication’s active ingredients. When a person carries a variant in one of these genes, their body may process a drug too quickly, rendering it ineffective, or too slowly, causing the drug to build up to toxic levels. In other cases, these variants can trigger idiosyncratic immune responses or cause the drug to interact with the body in unintended ways, leading to severe adverse drug reactions (ADRs).
The 16 genes highlighted in the study are among the most clinically relevant in modern medicine. They influence the body’s reaction to a wide spectrum of common treatments, including selective serotonin reuptake inhibitors (SSRIs) used for depression and anxiety, statins for high cholesterol, various forms of chemotherapy, and the widely prescribed blood thinner clopidogrel (Plavix). For example, a patient with a specific variant in the CYP2C19 gene might be a "poor metabolizer" of Plavix, meaning the drug cannot be converted into its active form in their body. For such a patient, taking the standard dose provides no protection against heart attacks or strokes, yet without genetic testing, a physician would have no way of knowing the treatment is failing until a medical emergency occurs.
Loren Saulsberry, a health policy researcher who focuses on equity and pharmacogenomics and was not involved in the study, noted that the paper provides critical evidence for the utility of genetically guided care. "This really furthers the emerging evidence of how genetically guided clinical care adds benefit across a diverse population," Saulsberry said. Historically, genomic research has been criticized for its heavy reliance on datasets derived from populations of European descent, such as the U.K. Biobank. This Eurocentric bias has created a "genomic gap," where medical breakthroughs and diagnostic tools are often less accurate or even entirely inapplicable to people of African, Hispanic, Asian, or Indigenous descent. By leveraging the All of Us dataset—which intentionally recruits from historically underrepresented communities—this new study helps bridge that gap, ensuring that the benefits of precision medicine are accessible to all Americans.
Philip Empey, the senior author of the paper and director of the Center for Clinical Pharmaceutical Sciences at the University of Pittsburgh, emphasized that while genetics is not the only factor in drug response, its role is increasingly undeniable. "If you have a prior experience with a medicine that did not work for you, or had a side effect, we can’t say it’s absolutely because of genetics, but we are appreciating more and more that people are different, and genetics is one reason that may suggest where there may be differences," Empey explained. He added that the study highlights an urgent need to integrate genetic data more seamlessly into clinical practice.
However, the path from a research paper to a patient’s bedside is fraught with systemic obstacles. Currently, the vast majority of Americans have not had their genomes sequenced, and even for those who have, the data is rarely integrated into the electronic health records (EHRs) that doctors use daily. Furthermore, many clinicians are not trained to interpret pharmacogenetic data or may be unaware of which drugs are affected by specific variants. There is also the challenge of the "long tail" of genetic variation; while some variants are common, many are rare, and a single patient might possess a unique constellation of variants that requires sophisticated computational analysis to interpret.
The All of Us Research Program was launched with the goal of enrolling at least one million participants to create the most diverse health database in history. This diversity was the engine behind the new study’s success, allowing researchers to identify thousands of variants that simply do not appear in more homogenous datasets. However, the future of this vital resource is currently under threat due to shifting political and financial priorities. The program has historically relied on two primary funding streams: the 21st Century Cures Act, passed in 2016, and annual appropriations from Congress. The funding from the Cures Act is set to expire in the 2027 fiscal year, leaving a massive hole in the program’s budget.
The financial strain is already being felt. While the program expects to receive approximately $122 million once a final federal budget is approved, this represents a staggering 80% decrease from its peak funding level in 2023. Joshua Denny, who served as the CEO of All of Us until late 2024 and now holds a leadership position at the University of Chicago, warned that these cuts have already forced the program to scale back its ambitions. "The engagement activities, the brick and mortar that we had enrolling at academic medical centers and FQHCs [Federally Qualified Health Centers] and mobile units… these kinds of things were cut back dramatically," Denny said. Perhaps most significantly for the participants themselves, the program has had to halt its initiative to return genetic health-related results to those who donated their DNA, a move that undermines the "partnership" model the program was built upon.
The impact of these budget cuts extends to the next generation of precision medicine: pediatrics. All of Us began enrolling children in 2023, but the initiative has been hampered by the lack of resources. Currently, only about 5,000 children are enrolled, and that data has not yet been made available to the broader research community. Sara Van Driest, the director of pediatrics for All of Us, stressed that pediatric research is essential because drug metabolism changes significantly as children grow and develop. "In order to really enroll children at scale and build a dataset that’s going to fuel the future of precision health, we’re going to need stable funding in the years ahead," Van Driest said. "I should say, increased and stable funding in the years ahead."
The stakes are high. Adverse drug reactions are estimated to be the fourth leading cause of death in the United States, ahead of pulmonary disease, diabetes, and automobile accidents. They also place a massive economic burden on the healthcare system, costing billions of dollars annually in hospitalizations and emergency room visits. By identifying the genetic markers that predispose individuals to these reactions, pharmacogenomics offers a rare opportunity to improve patient outcomes while simultaneously reducing healthcare costs.
As the scientific community continues to digest the findings from the All of Us study, the conversation is shifting toward implementation. Experts argue that pharmacogenetic testing should eventually become a standard part of preventative care, performed once in a lifetime and stored in a patient’s medical record to be consulted every time a new prescription is written. For this vision to become a reality, however, the infrastructure for large-scale genomic research must be preserved. The discovery of thousands of new variants is a testament to what is possible when science embraces diversity, but it is also a reminder of how much remains unknown. Without continued investment in programs like All of Us, the promise of truly personalized medicine may remain out of reach for the very populations that stand to benefit from it the most.
