Scientists uncover 13 new genetic variants in restless legs syndrome

Oct. 16 (UPI) -- An international team of researchers has identified 13 new genetic risk variants in patients with restless legs syndrome.

Restless legs syndrome is a chronic condition causing a person to have an overwhelming urge to move their legs, usually at bedtime leading to interrupted sleep, reduced quality of life and increased risk of depression, anxiety, high blood pressure and cardiovascular disease.

One in 10 people of European ancestry has restless legs syndrome, and one in 50 require medication for the chronic condition due to severe effects from the disorder.

"Restless legs syndrome is surprisingly common, but despite this, we know little about what causes it -- and hence how to treat it," Dr. Steven Bell, of the Department of Public Health and Primary Care at the University of Cambridge, said in a press release. "We already know that it has a strong genetic link, and this was something we wanted to explore in more detail."

The study, published in the November edition of Lancet Neurology, compared the genetic information from more than 15,000 patients with more than 95,000 controls to identify the 13 new genetic risk factors.

"We have studied the genetics of restless legs syndrome for more than 10 years and the current study is the largest conducted so far," Dr. Barbara Schormair, from the Institute of Neurogenomics at the Helmholtz Zentrum München, said. "We are convinced that the newly discovered risk loci will contribute substantially to our understanding of the causal biology of the disease."

The study identified a certain biological pathway known to be a target for the drug thalidomide, a controversial drug linked to serious birth defects when given to pregnant women decades ago. Thalidomide, now used to treat some cancers, may offer potential treatment for male patients with restless leg syndrome and female patients who are beyond reproductive age.

Prior studies of families and twins showed a strong genetic aspect to restless leg syndrome, which led to the discovery of six genetic variants originally linked to the disorder.

According to researchers, many of the genetic variants have previously been linked to neurogenesis, the growth and development of nerve cells, along with changes to the formation of neuronal circuits strengthening the theory that it is a neurodevelopmental disorder with origins occurring in utero.