In a major breakthrough scientists discovered 14 genes behind rheumatoid arthritis that could pave way for a cure.
Lifestyle and environmental factors, such as smoking, diet, pregnancy and infection may cause the complicated disease, but a person's genetic make-up also influences their susceptibility.
Manchester University scientists believe they now know most of the disease-causing genes with the latest research identifying ones specific to the female X-chromosome.
The discovery, published in the journal Nature Genetics, could explain why three times more women than men develop the illness and scientists can use these findings to try to stop the disease from developing.
"This work will have a great impact on the treatment of arthritis. We have already found three genes that are targets for drugs, leaving 43 genes with the potential for drug development, helping the third of patients who fail to respond well to current medications," the Daily Express quoted study author Dr Stephen Eyre as saying.
"The genetic findings can help divide patients into smaller groups with more similar types of rheumatoid arthritis and assist in the allocation of therapies," he noted.
The team studied 27,000 DNA samples to identify the new genes and move closer to improving the lives of rheumatoid arthritis sufferers.
Professor Alan Silman, medical director of Arthritis Research UK, added: "We hope that this research will lead to a greater understanding of the disease and allow us to develop targeted drug treatments for the people currently living with rheumatoid arthritis.