By Kenneth J. Cooper
A Stanford University geneticist, Carlos D. Bustamante, is leading an effort to include more Hispanics and African-Americans in genetic research critical to determining root causes of many diseases. He has been critical of such research that has often focused largely on white populations.
Work by the award-winning geneticist, who was born in Venezuela, has helped to expand testing in a global study that is known as the 1000 Genomes project and was launched in 2008 to map the genes of at least 1,000 people worldwide. An international group of scientists is taking DNA samples, analyzing them and sharing the findings.
The study started with samples taken in Europe, Asia, Africa and the United States. But Bustamante immediately recognized that South America was missing from the project, which the National Institutes of Health (NIH) is coordinating. He successfully pressed for adding Colombia, Peru, Puerto Rico and Barbados.
“We’re one of the groups that have really been very passionate about studying African-American populations and studying Hispanic-Latino populations so that they get brought into the fold of medical genetics research,” says Bustamante, speaking for himself and fellow researchers in his Stanford lab.
Early results from the 1000 Genomes project exemplify the significance of genetic research and the severe downside for populations not included in the testing. Already, the research has found that small genetic variations help to explain why some groups are more at risk for cancer and diabetes.
What’s clear is that lack of diversity has occurred for some time. A 2009 review of nearly 400 studies worldwide found that more than 90 percent have examined only people of European descent. Duke University researchers counted 26 studies of Asians, three of Hispanics, two of Native Americans and none of African-Americans. Another 11 studies tested people from a mix of racial and ethnic backgrounds.
“NIH has a lot of responsibility” for the racial-ethnic imbalance, says Dr. Esteban Burchard, a Mexican-American geneticist at the University of California, San Francisco. “They’re happy to take our tax dollars, but they don’t distribute them equally.”
NIH has acknowledged the imbalance despite a policy adopted in 1985 encouraging inclusion of minorities in studies it funds. Since that year, federal law has mandated that all NIH-funded research include minorities.
“I don’t think enough of them have been studied,” says Charles Rotimi, director of NIH’s Center for Research on Genomics and Global Health. “There needs to be a commitment from the various institutes to fund these large-scale studies.”
Jean McEwen, a program director at the National Human Genome Research Institute, says the five-year, $120 million 1000 Genomes study started as a pilot project intended for expansion. She says it took time to secure government approval in some countries or, in others, to identify scientific partners, which she says Bustamante did for the South American and Caribbean countries.
“It’s really just a practical matter,” McEwen says of the initial omission of countries in those regions.
Bustamante and Burchard, also a physician, indicate that Bustamante encountered resistance to broadening the 1000 Genomes project, which has funding from NIH, a private British trust and two genetics institutes in China.
Burchard says Bustamante has been “really pushing the field, bending the steel, to look at other populations” and has succeeded because he has leverage as a respected professor at Stanford and, previously, Cornell University, with three degrees from Harvard University. Last year, Bustamante, 36, won a MacArthur Foundation “genius award.”
Beyond 1000 Genomes, Rotimi says NIH has funded so few genetic studies of minorities for many reasons. He and McEwen cite difficulty recruiting minorities, who tend to be skeptical of medical research because of past abuses, as in the Tuskegee study of syphilis in African-American men from 1932 to 1972.
McEwen, who does community outreach for 1000 Genomes, emphasizes the recruitment problems. But Rotimi says “perhaps one of the biggest problems” is the small number of minority geneticists, who tend to “navigate towards their own communities.”
“By that alone, you’re going to have fewer studies” of minorities, Rotimi says. A related reason, he adds, is that historically black and Hispanic-serving colleges often lack adequate labs and other equipment to make grant applications by their professors competitive with those from researchers at Harvard and Johns Hopkins University, leading recipients of NIH funds.
“One of the reasons that researchers say they study white populations is that they’re easier to study, they’re more homogeneous, blah-blah-blah,” Bustamante says. “But it’s really that they haven’t really done enough to engage minority populations.”
The field of genetics, Burchard says, is “amazingly non-diverse. We have very few minority scientists.”
Besides himself and Bustamante, who are Hispanic, Burchard named Rick Kittles of the University of Illinois at Chicago, saying, “To my knowledge, he’s the only African-American geneticist in the country who has any credibility.”
Kittles has been researching prostate cancer, which afflicts African-American men at a rate higher than that for any other racial-ethnic group in the country. He started the NIH-funded study in the 1990s while at Howard University, one of three historically black colleges with a medical school. Five Hispanic-serving institutions also have one, and a sixth is not yet operating, according to the Hispanic Association of Colleges and Universities.
Burchard specializes in seeking genetic reasons that a disease is more prevalent in one group than another. Since 1997, he has conducted an NIH-funded study of asthma, trying to find reasons for an extreme disparity among Hispanics. Puerto Ricans have the nation’s highest rate of asthma, while Mexican-Americans have the lowest, according to the federal Centers for Disease Control and Prevention (CDC) in Atlanta.
“We’re not sure where the difference is coming from,” he says.
In general, Puerto Ricans and Mexican-Americans are of mixed European, Native American and African ancestry, Burchard says. His study examines whether the disparity in asthma rates is related to genetic differences in those three groups that populated Puerto Rico and Mexico.
According to the CDC, Puerto Ricans are more than twice as likely as non-Hispanic whites to have asthma and 80 percent more likely than African-Americans, who are included in Burchard’s study. Bustamante is collaborating on the asthma research.
Burchard and his colleagues are also looking for genetic factors that may explain disparities in heart and kidney disease, breast cancer, obesity and types of lung disease other than asthma.
Such research holds the medical promise of finding better treatments that reduce the health disparities experienced by minorities. Still, “genome-wide association studies,” as they are technically known, have critics.
Prominent among them is Troy Duster, a professor of sociology and bioethics at New York University, who criticizes studies that look only at genetic causes of disease, ignoring environmental and social factors such as diet, exercise and stress caused by perceived racism. “I think this is a huge issue,” he says. “You can’t just do one kind of study.”
Burchard says his asthma study is in fact examining environmental and social factors behind the disease, not just genetic ones.
Duster, who has written academic articles on the subject, expresses concern that the genetic studies make racial differences appear more scientific then they actually are. “My objection to those kinds of studies is that they are making it sound as if race is understood to be a biological phenomenon,” he says.
The idea that race has a biological aspect may comfort those who believe that the races are so different they should live apart. There is evidence that it already has.
In 2007, David Duke, a former national director of the Knights of the Ku Klux Klan and former Louisiana state representative, praised Burchard’s research. “I do think your work and others who show real biological differences between races is important,” Duke wrote to Burchard in an e-mail that Duke posted on his website. “You show that race is truly real, not a societal construct or some sort of conspiracy theory.”
Burchard shrugs off Duke’s embrace.
“Regardless of what you develop, whether it’s nuclear energy or biologic information, you’re always going to have some perverted individuals trying to manipulate it to their gain,” he says. “But that doesn’t mean that we should stop doing science.”
As for Duster’s criticism about how race is seen because of genetic studies, Burchard maintains that science is on his side.
“We know that there are biologic differences,” he says. “Rather than trying to be politically correct and burying our heads in the sand, we should be looking at these differences and trying to use these differences to untangle disease.”
Bustamante says he and coworkers in his lab try to “figure out ways to increase diversity in medical genetics research, both in the U.S. and out” because otherwise “studies will get developed and done that don’t benefit everybody.”