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A place for race in medicine?
- Drugs for specific races could improve
treatment - or endorse
prejudice.
By Gregory M. Lamb
Ever since the fall of the Nazis, the world has tried to keep the
biology of racial disparity under wraps. It has been acceptable to link
racialdifferences to social and cultural factors. One race
mightunderperform another because of upbringing or poverty. But
suggesting
biology as the cause for those differences - like "The Bell Curve" did a
decade ago when it looked at academic achievement - was strictly taboo.
Now, a new and unexpected force - medicine - is pulling back the covers.
By taking a close look at minute differences in people's
genetic codes, researchers and drug companies are beginning to create
racially based drugs and treatments.
Given the prospect of targeting treatment, some scientists argue that
the subject at least ought not to be taboo. Even if race eventually
proves to be a crude and insufficient means of understanding genetic
differences, it can play an important interim role, they say. Others
worry that these voices fail to capture the larger picture: how past
claims of "scientific" race and ethnic differences, now debunked, have
been used to oppress, even kill, minorities.
"To use the rhetoric of science to sell the idea that historical
inequity should be embraced as biological inevitability is an insult to
those who value a common humanity," wrote researcher Richard Cooper of
the Loyola University medical school in a January article in the
American Psychologist. "Race is not a concept that emerged from within
modern genetics; rather, it was imposed by history, and its meaning is
inseparable from that cultural origin."
Indeed, scholars in recent decades had concluded that racial
designations are fuzzy, so hard to pin down that people's
self-reporting of their race had become the only useful method of
designating race. In the 1990s the work of the Human Genome Project an
international effort to sequence and map all human genes - seemed to add
legitimacy to this view. At the genetic level, humans are nearly
indistinguishable from one another, 99.9 percent alike.
But as the genome project neared completion in 2003, scientists began to
look harder at the 0.1 percent of genes that differ. Their hope: that
understanding these differences would open up a new era of medicine
based on each patient's genetic makeup.
In recent months, race-based medicine has gained momentum: The Food and
Drug Administration is expected to approve the drug
BiDil in June, making it the first "ethnic drug" on the market. After
failing in a broader study, BiDil was shown to be effective in treating
heart failure in a clinical study that included only African-Americans.
.The HapMap Project, expected to be completed this year, aims to map
haplotypes - sets of closely linked genes that tend to be inherited
together. Such a map would be a rich resource, say researchers, in
finding genes that affect diseases and individual responses to drugs.
The project is studying samples from people in Nigeria, Japan, China,
and the United States. Some worry that analyzing differences by country
could be used to suggest racial differences.
.African-Americans need higher doses of one medication used to treat
asthma than Caucasians, suggesting "an inherent predisposition" in
blacks not to absorb the medicine as easily, says a study in the
February issue of the journal Chest.
.A study in the American Journal of Human Genetics showed acorrelation
between the way participants identified themselves by race
with groupings of genetic "signposts" among their DNA. "This shows that
people's self-identified race/ ethnicity is a nearly perfect indicatorof
their genetic background," said Neil Risch, who led the study at
Stanford University's medical school.
A study by biotech firm Perlegen Sciences, published in a Feb.18 edition
of Science, found variations in the SNPs of people that
matched their ethnic backgrounds. SNPs (single nucleotidepolymorphisms)
are small changes in the sequence of DNA between
individuals.
"As more and more SNP patterns are discovered, and they coincide with
social groups, they will place in the hands of those who want to see it
evidence for the genetic explanation for complex behaviors," says Troy
Duster, president of the American Sociological Association.The idea that
intelligence, physical ability, predisposition to crime, or even
religious beliefs may have a simple genetic explanation easily grabs the
public's interest, he says. But these conclusions are "hugeand
unwarranted leaps from SNP patterns."
Much of what we're seeing in human illness can be explained by "issues
as prosaic and mundane as access to healthy water and good
nutrition," says Professor Duster, who teaches at New York University
and the University of California at Berkeley. For example: A 2002report
by the Institute of Medicine showed that racial and ethnicminorities
tend to receive lower-quality healthcare than whites, evenif factors
such as insurance status, income, age, and severity of condition are
similar.
Many in the field are calling for broader international studies to make
sure the bigger picture emerges. Studies comparing white and
blackAmericans, for example, have shown that blacks have higher rates of
hypertension, suggesting a genetic difference. But earlier this year
research by Dr. Cooper and a team at Loyola showed that although
African-Americans do show higher levels than North American whites,
whites have higher levels than Nigerians and Jamaicans, who are
"ethnically" black. Overall, the range of levels of hypertension among
blacks in the study ranged from 14 to 44 percent while in whites it was
higher, 27 to 55 percent. 'Race' and 'ethnicity' are poorly defined
terms that serve as flawed surrogates for multiple environmental and
genetic factors in disease causation, including ancestral geographic
origins, socioeconomic status, education, and access to health care,"
wrote Francis Collins, the head of the National Human Genome Research
Institute (NHGRI), last fall. "Research must move beyond these weak and
imperfect proxy relationships to define the more proximate factors that
influence health."
Race, Duster worries, "can leave its own indelible mark once given even
the temporary imprimatur of scientific legitimacy by molecular
genetics."
But other researchers say they expect to keep finding genetic racial
differences and that society must learn to become comfortable
with the idea. "New forms of scientific knowledge will point out more
and more ways in which we are diverse," wrote geneticist James Crow, a
professor emeritus at the University of Wisconsin, in a 2002 article. "I
hope that differences will be welcomed, rather than accepted grudgingly.
Who wants a world of identical people, even if they are Mozarts or
Jordans?"
Even 0.1 percent in differences among humans includes millions of
variables and "those differences are very important," says Kim
Nickerson, co-editor of a special issue of American Psychologist in
January focused on race and genes. Where the field is headed is far from
settled, he adds. "We're years away from a practical application of much
of what we might find in terms of the individual differences."
Can scientists - and the public - hold these two seemingly conflicting
ideas in mind at once: that we are genetically different but we are also
all one species?
"I think race is an important variable" in understanding genetics, says
Vence Bonham, senior adviser to the NHGRI. But "individuals of the human
race are of one race.... And we need to make sure that's the message
that the public understands."
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