Genetic research has a serious diversity problem, new study from UNC finds

Almost 90% of the thousands of federally funded “epigenetic” studies conducted over the last decade relied exclusively on gene samples from white people, UNC researchers have found.

That means any medical treatments that grow out of that research will mostly benefit white people.

“It’s not just European-origin individuals who have better access to health care,” said Charles Breeze, an author of the paper and a researcher associated with the University of North Carolina-Chapel Hill. “They also have better access to the underlying science behind the health care.”

The problem appears to be getting worse, not better. From 2009 to 2021, the UNC researchers found, the cumulative number of experiments on European samples increased, far outpacing experiments on other races. Many other studies could not be included in the paper because they didn’t report race or ethnicity information at all.

Epigenetic research, a burgeoning subset of genetics research, has drawn large investments from pharmaceutical companies that are eager to apply it to treating genetic diseases. Breeze said the the lack of diversity in the genetic samples could mean fewer treatments for diseases that disproportionately affect people of color, like kidney disease.

“This is a very deep disparity and it will take years to remediate it,” Breeze said.

The researchers analyzed more than 5,000 experiments that had been conducted as part of a federally funded effort to map certain parts of the human genome. About 87% of the experiments exclusively used samples labeled “European” while about 9% reported used samples labeled “Black” and about 4% studied samples from a different ancestry.

To the layperson, genetic research often conjures the image of a double-helix DNA strand that lays straight like a ladder.

The reality is much more complex. In human cells, DNA is coiled around proteins, folded into densely packed structures and surrounded by chemical marks that influence how genes are expressed.

Epigenetics researchers study those peripheral proteins and chemicals to see how they affect genes and what impact they may have on genetic diseases.

While these complicated structures and interactions are well mapped in people of European-ancestry, little has been done for people of other races.

Breeze doesn’t think researchers are intentionally excluding certain ancestries from their research. The disparity is a product of years of not paying attention, he said.

Epigenetic research hubs are often based in affluent areas, where researchers collect genetic samples that tend to skew white from local hospitals.

These samples are then uploaded to a database, where other researchers can use them in their own research.

“I know a lot of these people working in epigenetics are not heavily prejudiced individuals,” he said. “These are just people who have sort of sleepwalked into the situation in which they’ve just been sourcing the local samples because it’s easier.”

For epigeneticists who are interested in studying nonwhite populations, the small number of diverse samples can be limiting.

Dr. Nora Franceschini, a researcher at the UNC-Chapel Hill Gillings School of Global Public health and leading author on the paper, studies kidney disease that gets its genetic origin from Africa. It’s difficult to study the epigenetics of this disease because the widely available European samples don’t have the variant she’s interested in studying.

“The problem is when you are interested in doing this kind of research and then you don’t have the data to it,” she said.

Breeze said prestigious scientific journals are more likely to accept studies that used large sample sizes, so there’s also an incentive for scientists to focus their research on the vastly available European samples, instead of a far more limited pool of samples from other ancestries.

“They get published in the best journals, they get the best funding,” he said.

Teddy Rosenbluth covers science for The News & Observer in a position funded by Duke Health and the Burroughs Wellcome Fund. The N&O maintains full editorial control of the work