Restless Legs Syndrome: A Real Discomfort Scientists from separate international studies have found gene variants linked with restless legs syndrome, or RLS. These insights, published in the New England Journal of Medicine and Nature Genetics, have helped legitimize the neurological condition, which some experts have dismissed as a phantom disorder. RLS is characterized by a deep tingling, itching, gnawing sensation and involuntarily leg movement while at rest or asleep, often causing insomnia. Up to 10 percent of Americans are affected by restless legs syndrome, most of them middle aged or older. Though medication is currently available, genetic research could produce targeted treatments for RLS sufferers.