Gene tied to muscle pain from cholesterol drugs

By Gene Emery

BOSTON (Reuters) - British researchers have located a gene responsible for muscle pain or weakness experienced by some people taking statin drugs to fight "bad" cholesterol, they reported on Wednesday.

The discovery could lead to routine testing to identify patients who should be given a different class of drug, or those who should be kept on a lower dose.

The group, led by Rory Collins of the University of Oxford, used new technology to rapidly scan about 300,000 points on the human genetic code in hopes of finding something different in the 85 who developed the muscle weakness, compared a similar group of 90 people who did not.

They found it on a gene involved in the way the liver regulates statin levels.

People who had two normal genes had only a 0.6 percent risk of developing muscle weakness, known as myopathy, during the first year of taking 80 milligrams daily of the Merck drug Zocor, known generically as simvastatin.

If a patient had one normal and one abnormal gene, which is the case in about 30 percent of the people studied, the risk increased to 3 percent.

With two abnormal genes, found in 2 percent of the population, the likelihood of developing muscle weakness climbed to 18 percent.

That abnormal gene now appears to be responsible for 60 percent of myopathy cases, researchers said.