Arthritis study reveals why gender bias is all in the genes

Researchers have pieced together new genetic clues to the arthritis puzzle in a study that brings potential treatments closer to reality and could also provide insights into why more women than men succumb to the disabling condition.

Rheumatoid arthritis – which affects about 1 per cent of the world's population – is a complicated disease. Lifestyle and environmental factors, such as smoking, diet, pregnancy and infection are thought to play a role, but it is also known that a person's genetic makeup influences their susceptibility to 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.

The Manchester researchers' 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 present with the disease.

First author Dr Stephen Eyre says, ''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.

''Although patients who first present at clinic have similar symptoms, it is likely that their route to developing disease has involved a varied path. 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.''