A study of 19 French-Canadian families whose members have a tendency to have Restless Legs Syndrome confirmed at least one gene is behind the unsettling condition, researchers said on Monday.

Restless Legs Syndrome is one of the leading causes of insomnia. Sufferers are kept awake by unpleasant sensations in their legs such as tickling, burning, pricking, or muscle aches, relieved only by getting up and walking.

Previous research on twins has suggested the genetic offender linked to the syndrome is located on chromosome 12q.

After analyzing the DNA of 276 individuals from several generations of the French-Canadian families that exhibited a higher-than-normal incidence of the syndrome, researcher Alex Desautels of the University of Montreal confirmed the offending gene, adding that at least one other unidentified gene is likely involved.

“Although the background of restless leg syndrome is most likely complex, this finding may offer a new starting point for further dissecting the genetic cause of (the syndrome),” Desautels wrote in the Archives of Neurology.

The syndrome affects up to 15 percent of the U.S. population.