Susceptibility genes for restless legs syndrome are not associated with Parkinson disease

Abstract

Restless legs syndrome (RLS) is a neurologic condition characterized by a distressing urge to move the legs, usually accompanied by an uncomfortable sensation described as a crawling, muscle ache, or tension. It is usually brought on by rest, worse in the evening or night and partially or totally relieved by movement. RLS is a common disorder with a prevalence of 1.2–15% depending on the population.1 Although the pathophysiology of RLS remains largely unknown, the worsening of symptoms later in the day and the therapeutic effects of levodopa and dopamine agonists support a hypothesis for dysfunction in the dopamine system.2 Parkinson disease (PD) is associated with progressive dopaminergic neuronal loss, for which dopamine agonists are typically prescribed as the first course of treatment. PD is characterized by bradykinesia, resting tremor, muscle rigidity, and postural instability3; it affects >1% of the population aged >55 years and is the most common cause of parkinsonism.4 Although still controversial, several studies have indicated a higher prevalence of RLS in …