Researchers have identified more than 40 new areas in human DNA that could increase the risk of rheumatoid arthritis.
The study, published in Nature, looked at 30,000 patients and is the largest conducted so far and could help in creating drugs to target these 'faulty' areas.
The team of international researchers compared the DNA of those with the disease with those of healthy people and found 42 'faulty' areas linked to the disease.
According to lead researcher Professor Robert Plenge of Harvard Medical School, they were able to treat the weakness produced by one of these areas using a drug that wasn't made to treat the genetic problem. But this did prove that drugs could be developed to treat the effects of anomalies found in DNA.
"What this offers in the future is an opportunity to use genetics to discover new medicines for complex diseases like rheumatoid arthritis to treat or even cure the disease," he said.
But some have argued that identifying genetic weak areas for complex diseases -- known as single nucleotide polymorphisms (SNPs) -- is not helpful in treating such diseases, and that there is no evidence of any drug effectively reducing the effects of the disease.
The study also found SNPs in rheumatoid arthritis patients that also occur in patients with some types of blood cancer. According to Professor Jane Worthington, director of the center for genetics in Manchester, drugs already used to treat cancer could be used to treat rheumatoid arthritis.
"It might allow us a straightforward way to add therapies we have to treat patients with rheumatoid arthritis," she said.