Genetic variant predicts heart disease risk

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(This article was originally published in Technology Review online on January 30, 2008.)

A newly identified risk factor for heart disease also seems to indicate which patients will benefit from popular statin therapies.

Heartsick: There have been many false leads in identifying risk genes for heart disease, so the burden of proof for those studies should be much higher than usually required, some experts say.

Testing for a genetic variation could predict the likelihood that a patient will respond well to certain statins. But some researchers say it’s too soon to use the variation to determine treatment.

Researchers from Celera reported yesterday in the Journal of the American College of Cardiology that a single substitution in the sequence of a gene called KIF6 makes people both more susceptible to heart attacks and more responsive to certain drugs that lower cholesterol. Though there is no known biological explanation linking the variation to heart disease, the study found that it increases the risk of heart attacks and strokes by 55 percent.

Celera, the company best known for sequencing the human genome, examined 35 single-nucleotide polymorphisms (SNPs) in 30,000 patients. Of those, “KIF6 is by far the most significant,” says Thomas J. White, chief scientific officer at Celera. In fact, nearly 60 percent of the study population was found to carry the KIF6 variant. (According to the study, these findings take into account other factors, such as smoking, high blood pressure, and cholesterol levels.)

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Held to ransom

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(This Opinion column ran on Nature’s news site on March 26, 2007. You can download a pdf of the original post.)

A pharma giant’s decision to withhold new drugs from Thailand will only hurt patients, says Apoorva Mandavilli.

Is there ever a good enough reason to deny life-saving medicines to an entire country’s citizens? I say no. But it seems pharmaceutical giant Abbott begs to differ.

The Chicago-based company decided on 14 March not to introduce in Thailand any of its seven new drugs — including an antibiotic, an important AIDS drug called Kaletra and medicines to treat blood clots, kidney disease and high blood pressure. Without this crucial registration, the drugs cannot be imported to or sold in that country.

It seems to me that Abbott is, in effect, holding millions of Thais’ lives hostage to force their government to respect its patents. This is good business?

The price of drugs varies from place to place.

What’s shocking to me is that the company is making no bones about the fact that its decision is retaliation against Thailand’s decision in January to issue ‘compulsary licenses’ allowing some locals to import or make cheap copies of Abbott’s new version of Kaletra. “This matter is about intellectual property and the integrity of the patent system,” Abbott spokeswoman Melissa Brotz said in a statement.

Lofty words, but I’m reminded more of a schoolyard fight.

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Low-fat diet a bust?

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(This article was #53 in Discover Magazine’s top 100 stories of 2006.)

The largest-ever experimental study examining whether a low-fat diet can prevent cancer and heart disease brought discouraging results. After following 48,835 postmenopausal women for eight years, scientists concluded that cutting fat from the diet doesn’t significantly reduce the incidence of breast or colorectal cancer, heart disease, or stroke. Results of the $415 million trial, part of the National Institutes of Health’s Women’s Health Initiative, were reported in three papers in the Journal of the American Medical Association.

Revised ideas about the role of fat in disease could help explain the murky data, notes Michael Thun, who heads epidemiological research for the American Cancer Society. For example, women in the study cut their total fat intake rather than specifically targeting saturated fats and trans fats, which are now known to contribute to heart disease risk. Cancer researchers are also starting to focus more on risks from obesity. “The evidence base has become very strong that it’s being fat rather than eating fat that’s associated with risk,” Thun says.

He and others plan to follow the women for an additional five years for more information. Meanwhile, the best advice from experts is to eat less saturated and trans fats and more fruits and vegetables.