Vitamin pillsMore than 40 new genetic regions have been linked with rheumatoid arthritis, some linked with the targets of existing drugs.

Rheumatoid arthritis (RA), an autoimmune disease, is one of the most common forms of arthritis, causing painful inflammation of the joints. Now an international collaboration has published findings from a massive genetic study of the disease in the journal Nature. 

The researchers performed a meta-analysis of multiple individual genome-wide association studies (GWAS), collectively representing data from just under 30,000 RA patients and over 70,000 controls, all of European or Asian ancestry.

This involved examination of around 10 million genetic variants, and resulted in the identification of 42 new genetic positions associated with increased risk of developing RA, (in addition to 59 reported previously). These 101 regions were investigated further using existing and new bioinformatics methods to identify a total of 98 candidate genes involved in RA risk. These genes and their associated biological networks were compared with the gene targets of current drugs used to treat RA, of which 27 showed overlap.

Looking at approved drugs for other conditions, the gene targets of a number of cancer treatments were also found to overlap with the RA gene, leading to the proposal that these drugs might also be of value for the treatment of RA.

Lead researcher Professor Robert Plenge of Harvard Medical School said that the genetic analysis approach could be used in the hunt for new treatments for complex diseases such as RA, whether via drug discovery or the retargeting of existing drugs.