Six new genetic indicators for rheumatoid arthritis

Researchers from Brigham and Women’s Hospital (BWH) and colleagues have uncovered specific locations on chromosomes (loci) linked to rheumatoid arthritis (RA), a progressive autoimmune disease that attacks the joints and other organs. Variations in the genetic sequence at these locations imply a risk of developing RA. These findings appear in the September 14, 2008 advance on-line issue of Nature Genetics.

A painful and sometimes disabling disease, RA afflicts up to one percent of the global population and an average of two million people in the US. “Learning of new loci linked to RA can help researchers determine how variations there effect the immune system, as well as fuel research for new treatments,” said Robert Plenge, MD, of the Division of Rheumatology, Immunology and Allergy at BWH.

The discovery of a particular location, CD40 – a gene linked to mediating immune and inflammatory responses – is important because CD40 has been a target for therapy in the past. By confirming that genetic variations at this location implies risk of developing RA, researchers have provided a basis for continuing investigation of CD40 to help determine therapy for the disease.

In addition to the six loci researchers found, seven other loci have previously been shown to imply risk for RA if variations occur. Plenge said, “This study supports the idea that there are many more locations on chromosomes that are linked with determining risk of developing this disease.”  He emphasises, “Each discovery of a new locus is like finding another puzzle piece that helps us put together a better understanding of RA."

(Source: Nature Genetics: Brigham and Women’s Hospital: September 2008)