Precision medicine is a growing field that aims to tailor medicine to an individual patient’s body, including their genetic makeup. But in order for the field to successfully grow, it must first understand the genetic and environmental factors of a disease. Too often, there is not enough genetic, environmental and social diversity in research samples to reap the benefits of precision medicine, argues Elizabeth Cohn, Ph.D., executive director of the Center for Health Innovation at Adelphi University, and the lead author of a new paper published in the journal Nature’s Genetics in Medicine.
Because most genetic samples come from majority populations, people whose genetic backgrounds are not of European descent may not benefit from improvements to precision medicine based on existing genomic databases, says Cohn. This problem of selection is not new—but there are three main challenges in a faced by precision medicine.
The first is deciding which groups to include for a meaningful degree of diversity, says Cohn.
“No single study can be large enough to encompass the full diversity of the U.S., let alone the world,” she says. “But we can oversample groups that have been underrepresented, and groups with higher levels of within group genetic diversity, such as people of African descent.”
Another challenge is selecting appropriate criteria for inclusion—today, most approaches involve self-reported race, but Cohn points out this has problems of its own.
“How you look on the outside is sometimes correlated—and sometimes not—with how you’re genetically made up,” she explains. “When you try to ensure diversity by how you look on the outside, you lose genetic diversity; when you look only at genetic diversity, you lose the effects of living in society within the construct of race.”
The third challenge that Cohn points out is determining—and reaching—target populations.
“Strategies that have been shown to work include early involvement in planning and defining goals of the study, understanding how participants want to see results, and facilitating two-way conversation, even with language barriers,” says Cohn. “Long-term commitment to the well-being of a population is also critical.”
The working group brought together to address this critical area included representatives from the Centers for Disease Control and Prevention, the National Institutes of Health, Universities such as Adelphi, Stanford, Harvard, Columbia, the University of Washington, and faith-based community leaders and local and regional practitioners for a two-day workshop. The paper was published on behalf of that group.
The paper was published online on Aug. 4, 2016, and was co-authored by Gail E. Henderson of UNC Chapel Hill and Paul S. Appelbaum of Columbia University Medical Center.