Scientists have discovered eight new genes that put people at risk of developing osteoarthritis,a crippling disease that affects eight million people.
And they believe their findings,published in the Lancet,could lead to an early warning system for future generations of potential sufferers.
We have made an important first step, Prof John Loughlin,of Newcastle University,said.
Around 40 percent of over 70s suffer from the disease. But it can also strike much earlier in life,causing agonising pain joints including hips and knees.
There is no treatment for the mainly inherited disease other than painkillers or,ultimately,joint replacement.
But it is hoped this 2.2million-dollar UK-led project involving 50,000 test studies in Europe could provide vital clues.
Prof Alan Silman,of Arthritis Research UK,said: For 60 years weve known that youre twice as likely to have osteoarthritis if your parents have it,yet we havent known why.
Until we understand the cause of this complex disease,we cannot hope to find a cure. These studies could help us to finally unlock the secret, he added.