Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Ex Input:
Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a sensory-motor neurological disorder with a circadian component. RLS is characterized by uncomfortable sensations in the extremities, generally at night or during sleep, which often leads to an uncontrollable urge to move them for relief. Recently, genomic studies identified single-nucleotide polymorphisms in BTBD9, along with three other genes, as being associated with a higher risk of RLS. Little is known about the function of BTBD9 or its potential role in the pathophysiology of RLS. We therefore examined a line of Btbd9 mutant mice we recently generated for phenotypes similar to symptoms found in RLS patients. We observed that the Btbd9 mutant mice had motor restlessness, sensory alterations likely limited to the rest phase, and decreased sleep and increased wake times during the rest phase. Additionally, the Btbd9 mutant mice had altered serum iron levels and monoamine neurotransmitter systems. Furthermore, the sensory alterations in the Btbd9 mutant mice were relieved using ropinirole, a dopaminergic agonist widely used for RLS treatment. These results, taken together, suggest that the Btbd9 mutant mice model several characteristics similar to RLS and would therefore be the first genotypic mouse model of RLS. Furthermore, our data provide further evidence that BTBD9 is involved in RLS, and future studies of the Btbd9 mutant mice will help shine light on its role in the pathophysiology of RLS. Finally, our data argue for the utility of Btbd9 mutant mice to discover and screen novel therapeutics for RLS.

Ex Output:
Willis-Ekbom disease is also known as?


Ex Input:
P&O European Ferries (formerly Townsend Thoresen), a division of P&O Ferries, was a ferry company which operated in the English Channel from 1987 after the Herald of Free Enterprise disaster, when Townsend Thoresen was renamed P&O European Ferries, until 1999 when the Portsmouth Operations became P&O Portsmouth and the Dover Operation where merged with Stena Line AB to make P&O Stena Line.

Ex Output:
What is the ending year of P&O European Ferries?


Ex Input:
Restless legs syndrome (RLS)/Willis-Ekbom disease (WED) is a common disorder, occurring at least twice a week and causing at least moderate distress in 1.5% to 2.7% of the population. It is important for primary care physicians to be familiar with this disorder and its management. Much has changed in its management since our previous algorithm was published in 2004, including the availability of several new drugs. This revised algorithm was written by members of the Medical Advisory Board of the Willis-Ekbom Disease Syndrome Foundation based on scientific evidence and expert opinion. It considers the management of RLS/WED under intermittent RLS/WED, chronic persistent RLS/WED, and refractory RLS/WED. Nonpharmacological approaches, including mental alerting activities, avoiding substances or medications that may exacerbate RLS, and the role of iron supplementation, are outlined. Chronic persistent RLS/WED should be treated with either a nonergot dopamine agonist or a calcium channel -2- ligand. We discuss the available drugs, the factors determining which to use, and their adverse effects. We define refractory RLS/WED and describe management approaches, including combination therapy and the use of high-potency opioids.

Ex Output:

Willis-Ekbom disease is also known as?


