Category B - full version without watermark 720x576 (check terms and conditions at www.teledesign.de) The version with watermark is for free to embed . Description: Researchers conclude that a region of DNA contains variants associated with an increased risk of gout. They say that further investigation of the gene will help to clarify "the complex relationships between" genes and how gout manifests physically in humans. Uric acid, which is found naturally in the blood stream, is formed as the body breaks down waste products, mainly those containing purine, a substance that is produced by the body and is also found in high concentrations in some foods. Normally, the kidneys filter uric acid out of the blood and excrete , it in the urine. Sometimes, however, the body produces too much uric acid or the kidneys aren't efficient enough at filtering it from the blood, and it builds up in the blood stream, a condition known as hyperuricemia. High levels of uric acid circulating in the blood can cause urate crystals to settle in the tissues of the joints. Gout is a form of acute arthritis that causes severe pain and swelling in the joints. It most commonly affects the big toe. Gout usually comes on suddenly, goes away after 5-10 days, and can keep recurring.