Over 100 genetic risk markers for rheumatoid arthritis identified

Researchers from Arthritis Research UK Centre for Genetics and Genomics at The University of Manchester have helped discover a further 42 genetic markers associated with rheumatoid arthritis in the largest international study to date on the topic.

Scientists in 38 separate institutions across seven countries contributed data from their own studies so that a much more powerful single combined analysis could be performed that examined over 10 million genetic markers in over 100,000 individuals, 29,880 of whom have rheumatoid arthritis.

As a result of the analysis, a study published in the journal Nature today (25 December), DNA variations at 42 regions of the genome were found to be associated with RA adding to the 61 that were already known about.

Professor Jane Worthington, director of the Centre for Genetics and Genomics and and National Institute for Health Research (NIHR) Manchester Musculoskeletal Biomedical Unit theme lead, says, ''What's exciting about this study is that in addition to dramatically increasing our knowledge of genetic susceptibility to RA, for the first time we have found some similarities between RA and some cancers affecting the blood.

''Some of these conditions already have effective therapies approved for use and these findings open the door to possible evaluation of the drugs for treatment of RA.''

Steve Eyre, the lead scientist in the RA group at The University of Manchester, says, ''It was challenging and exciting to be part of the largest ever genetic study for RA and very rewarding that the results really add to our understanding of the processes that underpin this chronic condition.''

The study involved academics from the Cambridge, USA, Japan, Australia, Canada, South Korea, Sweden, France, Spain, China, The Netherlands and Estonia.

Arthritis Research UK medical director Professor Alan Silman comments, ''Combining data from a large number of national and international genetic studies into one single and extremely powerful analysis has revealed 42 new genetic regions associated with rheumatoid arthritis. This almost doubles the number of previously-known risk regions and adds a significant amount to the current knowledge and understanding of the genetic basis of this condition.

''Further work is now required to investigate these risk regions in more detail, to enable us to understand how they are involved in disease development. In addition, the results of this work have identified similarities with some other conditions which suggests that evaluation of existing treatments could be beneficial and may lead to new and improved therapies for  the half a million people currently living with rheumatoid arthritis.''