natina
07-09-2011, 03:04 AM
(CNN) -- No matter what race you consider yourself to be, you have a unique genetic makeup.
That's why, as technology improves and researchers explore new implications of the human genome, medicine is going to become more individually tailored in a model called personalized medicine.
Although we've been hearing for years that people of particular races are at higher risk for certain illnesses, personalized medicine will (in theory) make better predictions based on actual genetic makeup. And even now, race is less relevant to your own health care than you might think.
But doctors say a patient's culture -- the collection of norms, goals, attitudes, values and beliefs -- will always be important to health care, no matter how sophisticated genetic technology gets.
Biologically, what is race?
When it comes down to it there's, no clear-cut way of saying that one person "belongs" to one race or another -- in fact, a person who has the skin color and hair type typical of one race may self-identify in a completely different way.
And if you think that race comes from location-based populations, many Americans don't have a "pure" genetic heritage from only one world region. In fact, 9 million Americans identified as multiracial on the most recent census, so it's hard to make these distinctions.
You probably have genes that came from several groups of ancestral communities. Based on archaeological evidence, everyone's earliest ancestors came from Africa more than 2 million years ago, so we're all descended from the same "race" anyway.
"There are genetic ancestries -- markers that you can see -- but those don't necessarily perfectly correlate with what people consider their own race to be, because that's sort of an artificial construct," said Dr. Wendy Chung, assistant professor of pediatrics at Columbia University Medical Center.
What's behind racial patterns of disease
Although races are labels that humans have invented to categorize each other, research into reasons for race-based trends is ongoing.
There's a heart failure drug, BiDil, approved specifically for African Americans. But since race itself does not predispose people to illness, this drug remains controversial.
Sometimes race obscures underlying mechanisms for genetic traits.
For decades, doctors thought that sickle cell disease was exclusively African, but some people of Mediterranean and Indian origin also have the genetic trait. We now know that the genetic trait for sickle cell disease protects against malaria, and that it is found among people with ancestry in places where malaria is, or used to be found, biologists Marcus Feldman and Richard Lewontin point out in their essay "Race, Ancestry, and Medicine."
Race can also hide underlying social issues -- namely, poverty.
African-American life expectancy at birth is on average, about five fewer years than white Americans, according to the most recent data from the Centers for Disease Control and Prevention (http://www.cdc.gov/nchs/fastats/lifexpec.htm). But Dr. Vicente Navarro at Johns Hopkins University has shown in his research that social class is a bigger driver of U.S. life expectancy than race or gender. He points out in a 1990 Lancet study that the United States is the only Western developed nation that does not report health statistics according to class.
"You're measuring the poverty in the black populations, but if you were talking about poverty, then you would have (an) issue that you could do something about," said George Armelagos, professor of anthropology at Emory University. "We try to avoid the issues that we hope we don't have to do anything about, especially when it comes to inequality."
How genetics reduces the importance of race
Given the imperfect association between race and specific diseases, it makes sense that race would become less important to clinical medicine if your doctor could just look at your entire genome and pinpoint genetic variants that carry risk.
Genomic sequencing is getting cheaper, and researchers are working on identifying specific markers for many diseases.
For instance, we know that women who are Ashkenazi Jewish are at increased risk for carrying the BRCA1 and BRCA2 genetic mutations linked to breast cancer; there's already a test to see whether a person has those mutations, making racial origin itself irrelevant. There are also genetic predispositions to disease that have nothing to do with race.
But currently, the ability to make predictions is limited, says Michael Zwick, geneticist at Emory University School of Medicine.
"It's more than just the science or technology of being able to sequence the genome. It's interpreting the variation and how it will be applied," he said. More research is needed to translate that information into meaningful medical decisions for a patient, he said.
But race still has uses
Some anthropologists, like Armelagos, say race has already become meaningless in medicine. But doctors such as Dr. Sharonne Hayes, cardiologist and director of diversity at the Mayo Clinic, still see a purpose for race in public health.
Race has an important role in reaching populations at risk, Hayes said. Data about African-American risk can help target screening efforts for heart disease, for instance, she said. When it comes to allocating resources and focusing efforts on at-risk groups, race can be a useful tool, even if it is imperfect, she said.
And in clinical trials, it's important to get a broad representation of people so that the results aren't skewed, said Dr. Ellen Tedaldi, a professor at Temple University School of Medicine
There are genetic ancestries -- markers that you can see -- but those don't necessarily perfectly correlate with what people consider their own race to be.
--Dr. Wendy Chung
http://www.cnn.com/2011/HEALTH/07/08/race.personalized.medicine/index.html?&hpt=hp_c2
That's why, as technology improves and researchers explore new implications of the human genome, medicine is going to become more individually tailored in a model called personalized medicine.
Although we've been hearing for years that people of particular races are at higher risk for certain illnesses, personalized medicine will (in theory) make better predictions based on actual genetic makeup. And even now, race is less relevant to your own health care than you might think.
But doctors say a patient's culture -- the collection of norms, goals, attitudes, values and beliefs -- will always be important to health care, no matter how sophisticated genetic technology gets.
Biologically, what is race?
When it comes down to it there's, no clear-cut way of saying that one person "belongs" to one race or another -- in fact, a person who has the skin color and hair type typical of one race may self-identify in a completely different way.
And if you think that race comes from location-based populations, many Americans don't have a "pure" genetic heritage from only one world region. In fact, 9 million Americans identified as multiracial on the most recent census, so it's hard to make these distinctions.
You probably have genes that came from several groups of ancestral communities. Based on archaeological evidence, everyone's earliest ancestors came from Africa more than 2 million years ago, so we're all descended from the same "race" anyway.
"There are genetic ancestries -- markers that you can see -- but those don't necessarily perfectly correlate with what people consider their own race to be, because that's sort of an artificial construct," said Dr. Wendy Chung, assistant professor of pediatrics at Columbia University Medical Center.
What's behind racial patterns of disease
Although races are labels that humans have invented to categorize each other, research into reasons for race-based trends is ongoing.
There's a heart failure drug, BiDil, approved specifically for African Americans. But since race itself does not predispose people to illness, this drug remains controversial.
Sometimes race obscures underlying mechanisms for genetic traits.
For decades, doctors thought that sickle cell disease was exclusively African, but some people of Mediterranean and Indian origin also have the genetic trait. We now know that the genetic trait for sickle cell disease protects against malaria, and that it is found among people with ancestry in places where malaria is, or used to be found, biologists Marcus Feldman and Richard Lewontin point out in their essay "Race, Ancestry, and Medicine."
Race can also hide underlying social issues -- namely, poverty.
African-American life expectancy at birth is on average, about five fewer years than white Americans, according to the most recent data from the Centers for Disease Control and Prevention (http://www.cdc.gov/nchs/fastats/lifexpec.htm). But Dr. Vicente Navarro at Johns Hopkins University has shown in his research that social class is a bigger driver of U.S. life expectancy than race or gender. He points out in a 1990 Lancet study that the United States is the only Western developed nation that does not report health statistics according to class.
"You're measuring the poverty in the black populations, but if you were talking about poverty, then you would have (an) issue that you could do something about," said George Armelagos, professor of anthropology at Emory University. "We try to avoid the issues that we hope we don't have to do anything about, especially when it comes to inequality."
How genetics reduces the importance of race
Given the imperfect association between race and specific diseases, it makes sense that race would become less important to clinical medicine if your doctor could just look at your entire genome and pinpoint genetic variants that carry risk.
Genomic sequencing is getting cheaper, and researchers are working on identifying specific markers for many diseases.
For instance, we know that women who are Ashkenazi Jewish are at increased risk for carrying the BRCA1 and BRCA2 genetic mutations linked to breast cancer; there's already a test to see whether a person has those mutations, making racial origin itself irrelevant. There are also genetic predispositions to disease that have nothing to do with race.
But currently, the ability to make predictions is limited, says Michael Zwick, geneticist at Emory University School of Medicine.
"It's more than just the science or technology of being able to sequence the genome. It's interpreting the variation and how it will be applied," he said. More research is needed to translate that information into meaningful medical decisions for a patient, he said.
But race still has uses
Some anthropologists, like Armelagos, say race has already become meaningless in medicine. But doctors such as Dr. Sharonne Hayes, cardiologist and director of diversity at the Mayo Clinic, still see a purpose for race in public health.
Race has an important role in reaching populations at risk, Hayes said. Data about African-American risk can help target screening efforts for heart disease, for instance, she said. When it comes to allocating resources and focusing efforts on at-risk groups, race can be a useful tool, even if it is imperfect, she said.
And in clinical trials, it's important to get a broad representation of people so that the results aren't skewed, said Dr. Ellen Tedaldi, a professor at Temple University School of Medicine
There are genetic ancestries -- markers that you can see -- but those don't necessarily perfectly correlate with what people consider their own race to be.
--Dr. Wendy Chung
http://www.cnn.com/2011/HEALTH/07/08/race.personalized.medicine/index.html?&hpt=hp_c2