ore than a decade after leading geneticists argued that race is not a true biological category, many studies continue to use it, harming scientific understanding and possibly patients, researchers argued in a provocative essay in Science on Thursday.
“We thought that after the Human Genome Project, with [its leaders] saying it’s time to move beyond race as a biological marker, we would have done that,” said Michael Yudell, a professor in the Dornsife School of Public Health at Drexel University and coauthor of the Science paper calling on journals and researchers to stop using race as a category in genetics studies. “Yet here we are, and there is evidence things have actually gotten worse in the genomic age.”
Categorizing someone as “black” can affect medical care, research has shown. Doctors might miss cystic fibrosis in “black” patients because it is considered a “white” disease, a 2015 study suggested. Similarly, because blood disorders called thalassemias are considered a Mediterranean/white disease and sickle-cell anemia a black disease, they are sometimes misdiagnosed when they strike the “wrong” racial group, Yudell and his colleagues wrote.
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Using race as a category has other harmful consequences. The higher rates of hypertension and breast cancer deaths among African Americans, for instance, likely reflect socioeconomic, environmental, and other nongenetic factors. “So many health disparities are not about race but are about social conditions,” such as education, and access to health care, Yudell told STAT, so analyzing health data through the prism of race can blind scientists to factors that contribute more to those disparities.
The reason scientists still use race as a way to group people — asking, for instance, which genetic variants are more common in this or that race — is that many still consider the concept useful if imperfect, said geneticist Neil Risch of the University of California, San Francisco, and president of the American Society of Human Genetics. There are so many racial injustices and more egregious misuses of genetics, he said in an interview, that “there are much bigger fish to fry” than scrubbing race as a biological category. For instance, the genetics society got its first-ever black board member, Charles Rotimi of the National Institutes of Health, only last year.
“Race” means white/Caucasian, black/African, or Asian. That trio is based on easily visible traits, such as skin color and facial features that, biologists once assumed, reflected ancestry and, therefore, shared genes. But these broad categories are both “poorly defined” and “flawed surrogates,” NIH Director Dr. Francis Collins wrote in 2004.
“Surrogate” means that “black,” for instance, is used to stand for “having ancestral roots in Africa.” But the genomes of African-Americans are, on average, 24 percent European (that is, one-quarter of their genetic variants originated in populations in Europe). The average European-American genome is 4 percent African, a 2014 study found. So while race provides a clue to ancestral origins and, therefore, genetic inheritance, it is an imprecise clue because many people have ancestors from many regions of the world: a “black” American often has important “white” gene variants, including ones linked to disease.
Scientists including Collins and his rival in the Human Genome Project, Craig Venter, urged biologists more than a decade ago to move away from the Big Three racial categories and substitute something more accurate. Yet many genetic studies still use race.
Yudell and his colleagues, including an anthropologist and a sociologist, are asking the National Academy of Sciences to convene a panel to recommend ways to categorize people more precisely than by race. Research journals, they say, should discourage use of racial categories in studies that analyze genetic and other biological or medical data, substituting more precise groupings such as ancestry or population — Kurdish or Basque, for example, or Filipino, or Japanese, or Ito.
“It’s time to move on” from race, Yudell said.
A fair-size contingent of biologists disagree. They agree that race is imperfect, but say it is a useful way to group people. In a 2015 study, for instance, UCSF’s Risch and his colleagues found that 17 percent of 100,000 people had genomes indicating ancestry from more than one continent. They self-identified as belonging to any of 23 ancestral groups (for example, Afro-Caribbean, white European American, Ashkenazi Jewish) like those the Science essay calls for using. But when those 23 groupings were collapsed into seven, basically by continent, they tracked genetic ancestry fairly well.
Seven is more than three, however (the extra four groupings came from breaking Asians and Caucasians into finer classifications, such as East Asian and Pacific Islander). Yudell is waiting to hear whether the National Academy of Sciences will study the use of race, but even scientists who think race is a reasonable proxy for genetic ancestry have recognized that three is not enough.