Researchers have discovered a new set of genes that can help explain why more women suffer from arthritis than men, and the finding could also lead to new treatments for the condition.
Scientists at the Arthritis Research UK Epidemiology Unit at The University of Manchester have discovered 14 new genes that can lead to rheumatoid arthritis, adding to the 32 other genes they had already identified; the team believes it has now discovered the vast majority of disease-causing genes for the condition.
Lifestyle and environmental factors, such as smoking, diet, pregnancy and infection are thought to play a role in Rheumatoid arthritis, but it is also known that a person's genetic makeup influences their susceptibility to the condition.
The latest study, published in the journal Nature Genetics, has identified genes specific to the female X-chromosome – which could explain why three times more women than men are affected with the disease.
"This work will have a great impact on the clinical treatment of arthritis; we have already found three genes that are targets for drugs, leaving a further 43 genes with the potential for drug development, helping the third of patients who fail to respond well to current medications," first author Dr Stephen Eyre said.
"Although patients who first present at clinic have similar symptoms, it is likely that their route to developing disease has involved a varied path," Eyre added.
"The genetic findings can help divide patients into smaller groups with more similar types of rheumatoid arthritis and assist in the allocation of therapies and disease management," Eyre said in a statement.
"This groundbreaking study brought together scientists from around the world and involved the use of DNA samples from more than 27,000 patients with rheumatoid arthritis and healthy controls," said lead researcher Professor Jane Worthington.
"As a result of our findings, we now know that genetic variations at over 45 regions of the genome determine susceptibility to this form of arthritis," Worthington said.
"We observed remarkable similarities with genetic markers associated with other autoimmune diseases. Our future work will focus on understanding how the simple genetic changes alter normal biological processes and lead to disease. Ultimately, this will help us to develop novel therapies and improved targeting of existing drugs," Worthington said.
"This is the first time that a genetic association has been established between rheumatoid arthritis and the X chromosome. This could provide a useful clue in helping us to understand why rheumatoid arthritis is three times more likely to occur in women," Professor Alan Silman, medical director of Arthritis Research UK, said.