ANCESTRY TRUMPS RACE IN PREDICTING EFFICACY OF DRUG TREATMENTS
November 11, 2004
Studies claim that at least 29 medicines are safer for some racial groups than others, strongly suggesting that race is biologically real, reports the Wall Street Journal.
- A drug for congestive heart failure had failed in two large clinical studies in the 1980s that included both blacks and whites; but in a trial enrolling only African Americans, the outcome was dramatically different.
- Those receiving the drug BiDil did so much better than those receiving a placebo, announced manufacturer NitroMed, that it was ethically obliged to halt the trial and offer BiDil to all participants.
But new genetic data shows that racial categories are far too broad. For one thing, there is more variation within a race than between races. A white person and a black person may be more genetically similar, measured by the amount of DNA they have in common, than two blacks, says the Journal:
- About 30 percent of white Americans have enough non-European ancestry -- more than 10 percent -- to make self-reported race an unreliable indicator of their generic make-up.
- Many of these people might be good candidates for BiDil, but if their doctors see them as white they won't receive it, notes Howard University biologist Charles Rotimi.
As a result, geneticists are inching away from the blunderbuss category of race and toward the more precise one of ancestry.
Ancestry reflects genetic variants fairly precisely, says the Journal. Thus, a smaller ethnic grouping, such as Cheyenne or Irish, reflects real genetic differences. But they get washed out when you use the larger category of race.
Francis Collins, director of the National Human Genome Institute, says that every attempt should be made to determine individual genetic profiles and stop using race, which is a very poor proxy for genetic variants that affect health.
Source: Sharon Begley, "Ancestry Trumps Race in Predicting Efficacy of Drug Treatments," Wall Street Journal, October 29, 2004.
For WSJ text (subscription required) http://online.wsj.com/article/0,,SB109899480880058817,00.html
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