Monday, December 1, 2008

A rare follow-up

Some more articles related to this post.

Race, genes, and illness:
Does a "genetic component" cause a higher rate of premature births among black mothers? Do black people carry certain gene variants that give them weaker hearts? Do Asians have special genes that enable the drug Iressa to fight non-small cell cancer better in their lungs?

Yes, indeed, authors of several recent medical studies claim. More and more, researchers are holding out the hope that genetic differences may finally explain a good part of the troubling health disparities among races. Perhaps then, the reasoning goes, the powerful tools of molecular biology may help solve them.


So far, the claims about race and medical genetics remain disturbingly fuzzy. What's meant by a "genetic component," for instance? The team at Washington University in St. Louis that studied early births accounted for other known variables, such as lack of prenatal care, and found that the higher rate among black women persisted. Based on the trends they saw, the group concluded there were racial differences at the genetic level - despite lack of any data on genes.

The Johns Hopkins School of Medicine researchers studying heart function had used magnetic resonance imaging to compare heart muscle contractions in Chinese-Americans, whites, Hispanics, and African-Americans. They also pointed to genetic differences as a likely cause. But they hadn't yet looked at any genes, either.

Genes explain race disparity in response to a heart drug:
Doctors in the United States who treat patients with heart failure have long been puzzled by a peculiar observation. Many black patients seem to do just as well if they take a mainstay of therapy, a class of drugs called beta blockers, as if they do not. It is almost as if they were immune to the drugs.

Now researchers at Washington University and the University of Maryland have discovered why: these nonresponsive patients have a slightly altered version of a gene that muscles use to control responses to nerve signals. People with this altered gene are making what amounts to their own version of beta blockers all the time. As many as 40 percent of blacks and 2 percent of whites have the gene variant, the researchers report.

The findings, heart failure specialists say, mean that people with the altered gene might be spared taking what may be, for them, a useless therapy. And since patients with heart failure typically take multiple drugs, which can interact and cause side effects like fatigue, getting rid of a drug that is not helping can be a huge benefit.

Of course, race doesn't exist... somehow.

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