The Human Genome Project first revealed a rough copy of our genetic instruction book two decades ago.
Doctors will soon be able to look at a person’s DNA and prescribe the right medicines for their illness or even avoid such diseases, according to the promise of that medical moonshot.
Precision medicine, as it is called, has yet to be realized on a broad scale. Real, scientists are discovering more about certain genetic variations linked to particular diseases and others that influence how drugs function in the body. However, many of these advancements have benefited only one group: people with European ancestors. To put it another way, white people.
Instead of a truly human genome that represents everyone, “what we have is essentially a European genome,” says Constance Hilliard, an evolutionary historian at the University of North Texas in Denton. “That data doesn’t work for anybody apart from people of European ancestry.”
She’s referring to more than just the reference genome of the Human Genome Project. Researchers are using a variety of databases to establish precision medicine techniques, including this one. Those genetic databases also use data mostly from white people. The problem, however, is not one of race.
The issue is that these data add up to a list of genetic variants that does not represent the full spectrum of human genetic diversity.
When people of African, Asian, Native American, or Pacific Island descent get a DNA test to see whether they inherited a cancer-causing variant or whether a medicine would work for them, they sometimes come away with more questions than answers.
The findings often show “variants of uncertain significance,” leaving doctors with insufficient knowledge to make decisions. People of European descent are less likely to experience this. Researchers believe that this difference could be reduced if biology comprised a more diverse community of participants.
One approach, according to Hilliard, is to create personalized reference genomes for populations whose members, for example, die at higher rates from cancer or heart disease than other groups, or who have other negative health outcomes.
The more descriptive you can be, the better. African Americans born from enslaved people, for example, have different geographic, ecological, evolutionary, and social backgrounds than recent African immigrants to the United States. Those backgrounds have left imprints in people’s DNA that can influence their health today.
Indigenous peoples from all over the world, as well as Latinos from Mexico versus the Caribbean, Central or South America, face similar challenges.
While attempts have been made to increase diversity among genetic study participants, there is still a long way to go.
How to incorporate more people from diverse backgrounds in genetic research — which goes beyond race and ethnicity to include cultural, social, and economic diversity — is fraught with ethical dilemmas. Respondents to our unscientific poll consistently claimed that genetic research is vital for improving medical treatment.
However, our mostly white respondents were divided on whether personalized projects like Hilliard’s or a more generic attempt to add variants to the current human reference genome was the better option. Many people were worried that highlighting genetic differences would perpetuate erroneous notions of racial inferiority and superiority, leading to increased discrimination.