SPRINGDALE : Geneticist finds variety improves research
Posted on Saturday, April 12, 2008
SPRINGDALE — Researchers have learned over the years that expanding clinical trials to subjects from both sexes, multiple minority groups, and adults and children has improved treatments, a scientist told health workers and educators Friday.
Georgia M. Dunston believes the disparities among patients better serve science when they are used to determine how genetics reacts with behavior, environmental and social factors — not when used to design drugs or treatments targeted to a particular group.
“I like to think of differences as tools for discovery,” Dunston, a geneticist and professor of microbiology at Howard University College of Medicine in Washington, told the 2008 Arkansas Minority Health Conference at the Northwest Arkansas Convention Center in Springdale. “The key to understanding disease is understanding the differences in biology.” When the federal Food and Drug Administration approved for the first time a heart drug marketed to blacks, that represented a failure to look at the cause of disease and not just the disease itself, said Dunston, founding director of Howard’s National Human Genome Center.
Genomics, the study of the DNA contained within an organism, pushes science to treat patients as individuals, taking into account their ancestry but also lifestyle and other factors, so that unwanted drug side effects can be reduced.
Since scientists around the globe have mapped the human genome, researchers have come to recognize that humans are 99. 9 percent the same, she said. Yet the small remaining differences represent a vast, as-yet-unexplored territory in biomedical research.
Based on her genetic studies, which focus on common diseases such as cancer, diabetes and heart disease, Dunston said she has come to believe that race among humans is a social concept and not a biological one, adding that the notion is debated in scientific circles.
“We’ve found there is no sequence of genes that is found in people that you can equate to a particular so-called race,” she said, adding that researchers have found such sequences that define breeds — or the equivalent of races — among animals such as dogs, horses and cattle.
Discounting outward appearance, she said, that means: “I could be more different from another black person than I am from someone in another, what we call, race.” Where minority-group disparities do make a big difference is in areas such as tissue typing for organ transplants, Dunston said.
But that’s because the continents that have been home to humans longer, such as Africa, have produced more tissue types over time. More tissue types make it more difficult to get an exact match for organ donations, said Dunston, whose early work included collecting samples from black women to expand scientists’ spectrum of tissues and their understanding of those differences.
People of African descent have roughly 10 times more genetic variation than those of either European or Asian descent because of this, she said.
“Health disparities are a tool of inquiry,” Dunston said. “It’s a way of asking questions about the body and helping us understand the biology of the disease.”
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