Nov 4 : The largest-ever study of the genetics behind common diseases has identified the gene responsible for rheumatoid arthritis (RA).

Researchers at the University of Manchester said they have identified a genetic variant on chromosome 6 that is associated with RA, the most common form of inflammatory arthritis.

Professor Jane Worthington and her team investigated nine genetic regions identified earlier this year as potentially harbouring DNA variants determining susceptibility to RA.

And in this week’s Nature Genetics magazine they unequivocally confirmed the association to one of the variants on chromosome 6. Though this variant is not located in a gene, Worthington suggests that it may influence the behaviour of a gene known to cause the inflammation.

RA is a chronic inflammatory disease that can affect nearly all joints in the body, particularly the hands and feet. Complications such as lung disease can occur. In addition, patients with RA are more likely to die from cardiovascular disease and some cancers.

Some people respond well to treatment, but most suffer a lifetime of disability.

Worthington and her team made their findings as part of the largest-ever study of the genetics behind common diseases, the £9 million Wellcome Trust Case Control Consortium.

The study has given a major boost to the understanding of the genetics of seven common diseases, including RA. (IANS)