It is hoped that the discovery will lead to more reliable diagnostics and better treatment for a significant number of people.
"This gene variant could be one of the single largest genetic causes of complex diseases with inflammatory components," said Fredrik Piehl, Associate professor at Karolinska Institutet and researcher at the CMM.
"There is also a chance that other diseases are affected by this gene variant."
The gene variant was observed in about 2,000 patients to ascertain if there was a link to human diseases. The risk of developing rheumatism, MS or a myocardial infarction increases by 20% to 40% of carriers.
The affected gene, MHC2TA, is not new to researchers, but this is the first time that its link to the illnesses has been established.
Fredrik Piehl pointed out that there are other risk factors that also need to be taken into account, such as inheritance and the influence of the environment.
"However, we will be able to tackle illnesses at an earlier stage, for example with medicines that can change the activity of the gene," he said. "And maybe we can encourage the patient to change their lifestyle, by stopping smoking, for example."
The question remains as to why such an apparently dangerous gene has been able to survive in our physiological system for so long, instead of being rejected through the evolutionary process.
"It probably serves a function in another part of the body's system which we don't fully understand yet," commented Tomas Olsson, who led the study.
Photo on previous page: Photographer: Marie Ullnert / Copyright: Pressens Bild / Source: www.imagebank.sweden.se