Genes pinpoint people at risk for gout: study

By Will Dunham

WASHINGTON (Reuters) - Scientists have pinpointed three genes related to the high blood levels of uric acid that cause gout in a step that could help identify people at special risk for this common and painful type of arthritis.

People who had specific variants of these genes were up to 30 to 40 times more likely to develop gout than those without them, U.S. and Dutch researchers wrote in the Lancet medical journal on Thursday.

The scientists examined genetic information from 26,714 people to locate genes associated with gout.

Previous research had implicated a gene called SCLA29, and this study confirmed that. It identified two other genes, ABCG2 and SLC17A3, that can raise gout risk.

The genes seem to be involved in how the kidneys handle uric acid, the researchers said. Knowing their role in raising gout risk could help inspire the development of drugs for the condition that target these genes, the researchers said.

The findings also indicate that genetic tests could be used to identify people at risk for gout before symptoms develop.

"The ultimate hope is that one day we can determine who's at high risk for gout and who's not, and perhaps even determine who's going to respond better to different therapies based on what their genotypes are," Dr. Caroline Fox of the U.S. National Heart Lung and Blood Institute, who helped lead the study, said in a telephone interview.

The institute is part of the U.S. National Institutes of Health.

Gout is a painful inflammation of the joints that can result from a buildup of uric acid in the blood. Aside from genetic factors, gout is related to alcohol abuse, obesity, high blood pressure, a diet heavy in meat and cheese and certain medications.

Left untreated, gout can lead to permanent joint damage. Gout is increasingly common, with 3 million people in the United States and 700,000 in Britain having it.

Uric acid is a chemical produced when the body breaks down a substance called purine found in many foods and drinks. Uric acid typically is carried in the blood, travels through the kidneys and leaves the body in urine.

Kidney stones and kidney failure also can result from high uric acid levels.

"An important unanswered question is whether we can use genetic risk information to motivate people to change their behavior. For gout, we know that moderate changes in diet and alcohol consumption can lower uric acid levels," Dr. Josef Coresh of Johns Hopkins University, one of the researchers, said in a statement.