An international team of researchers has pinpointed the genes involved in the auto-immune system disease lupus.
The discovery is the result of a large study by the International Consortium for Systemic Lupus Erythematosus, SLEGEN led by researchers at Imperial College London.
It appears that a set of common variations in human DNA which may be linked to as many as 67 percent of all lupus cases, indicates a higher risk for lupus in women who carry them.
Lupus is a complex chronic inflammatory disease which predominately affects women; it can involve many organs and symptoms include a skin rash, pains in the joints and fatigue; it can also lead to inflammation of the kidneys and affect the heart, lungs brain and the blood.
As many as 2 million Americans have some form of lupus, it affects 50,000 people in the UK and one in every 700 Australians.
Worldwide over 5 million people are estimated to have lupus but the actual number may be higher.
Lupus is more common in African-American, Latino, Asian and Native American women than in women of other races and ethnicities.
Though the exact cause of lupus is unknown genetic variants and environmental factors are thought to be significant; while there is no cure for the disease an early diagnosis and appropriate medical treatment can reduce the inflammation and pain and halt further complications.
The researchers examined the genetic makeup of 3,000 women, 720 with the illness, and 2,337 who were free of the disease.
When they compared their genes three candidate genes with strong links to Lupus were revealed along with others with weaker links to the disease.
One of the strong candidates was the ITGAM gene which is known to play a role in the immune system and while the other genes identified were more surprising to the experts, they say they could hold the key to developing more effective therapies.
Experts say the study represents a milestone in progress towards understanding the disease and may in future lead to a test which could offer a faster diagnosis of the condition.
Lupus causes a person's own immune system to start attacking healthy tissue, and the only current treatments aim to suppress the immune system to reduce this action.
Professor Timothy Vyse, from Imperial College London, and one of the authors of the study, says a better understanding of what goes wrong with the immune system in lupus means better treatments can be designed.
The researchers are hoping to collect further blood samples from other Lupus patients to confirm the results.
The charity Lupus UK says the discovery of lupus-related genes might speed up diagnosis; as many of the symptoms are characteristic of other diseases, it can be years before a diagnosis of lupus is finally made.
Researchers from the Oklahoma Medical Research Foundation, Wake Forest University, the University of Minnesota, the University of California, the University of California, the University of Southern California and the University of Uppsala in Sweden were also involved in the study.
The scientists say the nine DNA variants are a diagnostic tool and not a confirmation of disease and they hope to identify those at highest risk of lupus, diagnose the disease earlier and hopefully find a cure.
The findings are published in the journal Nature Genetics.