Nearly two decades after researchers assembled the first genetic blueprint for human life, our understanding of our instruction manual has a dramatic and problematic bias: It’s based primarily on white people.
The overwhelming majority of genetic data is from people of European ancestry. As of early January, nearly 96 percent of participants across more than 5,500 studies looking for genetic variants associated with disease or other traits were of European descent, according to the GWAS Diversity Monitor, a real-time online tracker developed and maintained by the Leverhulme Centre for Demographic Science at the University of Oxford. Those with African American or Afro-Caribbean ancestry amount to just 0.18 percent of participants; Hispanic or Latino populations just 0.23 percent. That means efforts aspiring to use DNA to identify the best treatments for any individual patient, what’s commonly known as precision medicine, are heavily skewed toward white people.
There are many reasons behind the stark disparity. A big one, says geneticist Tshaka Cunningham, is distrust of the medical community, born from decades of exploitation and abuse: The Tuskegee Study, where white researchers for decades didn’t treat Black men with syphilis, even after penicillin proved effective against the disease. The case of Henrietta Lacks, whose cervical cancer biopsy gave rise to cells that today serve as a crucial resource for scientific studies even though she never gave consent. The forced sterilization of Black, Latina and Indigenous women that was driven by the eugenics movement — the damaging effects of which persist today.
To celebrate our 100th anniversary, we’re highlighting some of the biggest advances in science over the last century. To see more from the series, visit Century of Science.
READ MORE
What happened to Lacks, for example, “left a scar on many a minority person,” Cunningham says. “It’s like, ‘Am I gonna get Henrietta Lacks-ed or Tuskegee-ed?’”
Cunningham is working with others to build trust and overcome the damage of the past. He is chief scientific officer of Polaris Genomics, a company studying the genetic underpinnings that put some people at increased risk of certain behavioral health conditions, including post-traumatic stress disorder. He is also executive director of the Faith Based Genetic Research Institute, a nonprofit that aims to educate people, primarily people of color, about the value of engaging with the medical community and genetics research.
Science News’ Erin Garcia de Jesús spoke with Cunningham about the need for diverse data in genetics and the challenges researchers face in reaching minority groups.
Garcia de Jesús: Why is it important to have diverse participants in genetics research?
Cunningham: One is the societal imperative for equity — and having research, and products [such as genetic tests and treatments] be broadly available for people. You don’t want to have health disparities between communities. And when it comes to genetics, genomics and precision medicine, you already see this growing divide pushed by one-sided research. Mostly Caucasian groups have been included in genomic research to date, yet the results are meant to be applied to all others too.
There are genetic tests, for example, that have been developed based on research in specific communities. Like for BRCA1. [Mutations in the gene have been linked to a higher risk of breast cancer and are commonly considered in deciding on treatment approach.] You may have a set of BRCA1 mutations that have been defined from studies in Caucasian female populations, but those variants might not be the same variants present in minority female populations, particularly people of African descent or African Americans. So how good is the BRCA1 test for a community of African American patients? Probably not so good.
Then there’s the scientific imperative. Even if you don’t feel strongly about equality for equality’s sake, you can appreciate that for scientific reasons, we want to have as diverse a dataset as we can. That’s how we can really understand the universe of potential genetic variation and what it means.
Polaris Genomics
Garcia de Jesús: What prevents that kind of diversity in current studies?
Cunningham: I think in the United States — and I can really speak only from my experience in the United States — it’s because of the history of racial and ethnic division in our country, and some of the crimes that have been perpetrated on specific groups, even in medical science. African Americans have lived through slavery. They’ve lived through Jim Crow. They’ve lived through Tuskegee. They’ve lived through Henrietta Lacks. And they’ve lived through, in their own lives, any number of discriminations at the hands of the medical system. It creates systemic distrust for many from the African American community that would make them hesitant to participate in scientific studies.
The Latino population may have different reasons. If you’re in the United States and you’re a recent immigrant who is not necessarily documented, you might not trust the establishment with your information. Or even if you are documented, you may not trust the establishment.
The Tuskegee study left a lot of psychological damage in certain communities. It’s created a severe mistrust that can often work counter to people’s overall health — the hesitancy to participate in genetic studies that could greatly benefit the community by driving developments in precision medicine, and even the hesitancy to take the vaccine for COVID-19. That distrust took hundreds of years to develop. We’re only in the last few decades really trying to do anything meaningful to address it.