Signs you’re more at risk of restless leg syndrome

Years ago when I answered a Mirror reader’s letter about restless legs, a medical colleague at another newspaper made fun of me – claiming the condition didn’t exist and I was foolish to take it seriously.

Well, I hope he reads this.

Scientists from Cambridge University have discovered genetic clues to the cause of restless leg syndrome (RLS). The discovery could help identify those people at greatest risk of the condition and point to potential ways to treat it.

So what is RLS? It can cause an unpleasant crawling sensation in the legs and an overwhelming urge to move them. Some people feel this only occasionally, while others get symptoms every day.

Symptoms are usually worse in the evening and can severely disturb sleep.

Despite the condition being relatively common – up to one in 10 older adults have symptoms, while 2-3% need medical help – little is known about its causes.

People with RLS often have other conditions, such as depression or anxiety, cardiovascular disorders, hypertension and diabetes, but the reason why isn’t known. An international team led by researchers from the Technical University of Munich (TUM) and Cambridge University pooled and analysed data from three studies and created a powerful database with over 100,000 patients and more than 1.5 million unaffected controls. These studies compared the DNA of RLS patients and healthy controls to find genetic differences.

Co-author Dr Steven Bell from Cambridge University said: “This study is the largest of its kind into this common – but poorly understood – condition. By understanding the genetic basis of restless leg syndrome, we hope to find better ways to manage and treat it, potentially improving the lives of many millions of people affected worldwide.”

The team identified more than 140 new genes, including three on the X (female) chromosome, but no strong genetic differences between men and women, even though RLS is twice as common in women as it is men. Two of the genes are important for nerve and brain function which could potentially be targeted by existing drugs, such as anticonvulsants and early trials with them have already shown positive responses. The researchers say their genetic markers could help accurately rank the risk of severe RLS in nine out of 10 cases.

Iron deficiency is thought to trigger it, but no links to iron were found. Professor Juliane Winkelmann from TUM, one of senior authors of the study, said: “For the first time, we have achieved the ability to predict restless leg syndrome risk. It has been a long journey, but now we are empowered to not only treat but even prevent the onset of this condition in our patients.”