Genetic Association Study of Restless Legs Syndrome in Chinese Population

Backgrounds: Several recent case-control studies have suggested some candidate genes being responsible for causing the restless legs syndrome (RLS). However, the association between those genes and the risk for RLS among the Asian population has not been well investigated. Objectives: The aim of the study was to investigate the genetic risk factors of RLS among the Chinese Population. Methods: A total of 158 RLS patients and 229 controls were recruited and the diagnosis of RLS was based on the criteria of International RLS Study Group. Polymer chain reaction and sequencing were used to detect 14 single nucleotide polymorphisms (SNPs) in 9 genetic loci (heme oxygenase 1 [HMOX1], HMOX2, vitamin D3 [1, 25-dihydroxyvitamin D3] receptor gene [VDR], interleukin 17A [IL17A], IL1B, NOS1, alcohol-dehydrogenase [ADH1B], gamma-aminobutyrate acid receptors[GABRR3] and GABRA4). Results: Among 14 selected SNPs, the frequency of IL1B rs1143634C allelic variant was lower in RLS patients than that in controls. Moreover, after adjustment for age and sex, rs731236 of VDR were found associated with increased risk of RLS in the dominant model. However, none of those results survived Bonferroni correction. The effects of HMOX1 and HMOX2 gene on developing RLS were not seen after the inclusion of RLS patients with a low ferritin level. Conclusions: Our study failed to replicate the association between 9 candidate genetic loci (HMOX1, HMOX2, VDR, IL17A, IL1B, NOS1, ADH1B, GABRR3 and GABRA4) and RLS in the Chinese population.