"That was quite a bit of a twist I would say, as compared to what we've seen before in some other pharmacogenetic studies," Liggett says. "We found that in mostly African Americans, there is another form of this gene we are looking at which actually mimics the drug that is often used to treat heart failure, so those individuals do not need the drug at all."
As he and Dorn wrote in the journal Nature Medicine, while that version is more common in self-described African Americans, it occurs in people of all ancestries, and there are many African Americans who do not have it. For those who do not have the gene and do not take beta-blockers, 80 percent die in four to six years, he says.
Dispelling Racial Assumptions
Charles Rotimi, who directs the new NIH Intramural Center for Genomics and Health Disparities, believes genetic studies like this one will dispel racial assumptions and lead to treatments tailored to each individual's genes.
"What this study shows very clearly — which I do hope to share the message with the public — that it will help us to better appreciate that if we use the group label called African-American or Hispanic or Asian-American or European-American, that at the level of treatment of an individual, those descriptors are not precise enough to give us information that we need," Rotimi says.
"The danger in not finding this out is that we do make assumptions, like have been made about beta blockers: that they don't work in African Americans," he says. "So if a physician is going to prescribe a beta blocker, they're hesitant when they see the skin color instead of looking at that individual and saying, â€˜Does this individual carry that variant?'"
"For example," Rotimi explains, "it's entirely possible that I'm a carrier of a particular variant that my mother doesn't carry. So if you're using my mother as information to treat me, then it would be inadequate for that particular drug, although she's my mother. So I think that is a level that we need to get to. We need to understand our diversity. We need to cherish it, and we need to study it, and we need to understand the implication of that diversity at the level of drug, at the level of understanding disease distribution, as we go from one human population to the other."
"African Americans cannot be treated as if they are one group. You have to look at the individual in front of you if you are the doctor prescribing the beta blocker or any other drug, for that matter," he says.
Liggett and his team are now conducting further clinical studies aimed at developing personalized treatments for heart failure. Pate agreed to participate not only because she's supportive of biomedical research, but also because as the mother of two, she wants to know "if it's something that I'm passing on to them, to know if it's something I inherited so that we can better treat it," she says.
Liggett says, "This study will not only be used to confirm the previous study that we just published, but also we'll begin to add additional genes to see how well we can refine our predictive ability."
Pate also has a message for the public. "I think being in the health care profession, you think you know everything already and you self-diagnose," she says. She urges "getting to the doctor as soon as you realize that something's not right."
She also emphasizes the importance of a healthy lifestyle. "To eat healthy, to do exercise, it probably sounds like a clichÃ©, but it's really, really important to take care of yourself," she says.
This research was published in the journal Nature Medicine, advance online publication, April 20, 2008, and funded by the National Heart, Lung and Blood Institute of the National Institutes of Health.