ORLANDO, Fla. (Ivanhoe Newswire) -- Rheumatoid arthritis (RA) is a debilitating condition affecting between one and two percent of the U.S. population. To date, doctors are not able to predict in whom RA will develop, but researchers have found a link to a genetic mutation in chromosome 9, which may help doctors identify patients who are predisposed to the condition.

RA is characterized by an inflammation of the lining of joints and affects people of all ages. According to doctors, delayed diagnosis and treatment can lead to long-term joint damage, resulting in loss of function, disability and even death. Giving doctors a way to identify patients who are predisposed to the condition could reduce the impact of the disease.

"Having a gene that identifies a population of patients at risk for developing rheumatoid arthritis allows one to follow these people more closely, looking for early signs of rheumatoid arthritis that might be treated aggressively to achieve the best possible outcome, thereby preventing disability and increased mortality," Jonathan Kay, M.D., told Ivanhoe. He is the director of the Rheumatology Clinical Research Unit at Massachusetts General Hospital in Boston and an associate clinical professor of medicine at Harvard Medical School.

Dr. Kay added there are also environmental factors believed to be linked to the development of RA, the strongest of which is cigarette smoking. "It is important to continue to look for potential associations between rheumatoid arthritis and environmental factors so that one can modify an individual's risk of developing rheumatoid arthritis, even if she or he is geneticly predisposed," Dr. Kay said.

SOURCE: Ivanhoe interview with Jonathan Kay, M.D.; The New England Journal of Medicine, published online Sept. 5, 2007