title: Tef polymorphism is associated with sleep disturbances in patients with Parkinson's disease.
abstract: OBJECTIVE
  Circadian mechanisms play an important role in the regulation of sleep. A circadian clock-controlled gene, Tef, has been suggested to be associated with depressive symptoms, restless legs syndrome, and slow wave sleep in patients with sleep disorders. The present study sought to explore the association between Tef and sleep disturbances in patients with Parkinson's disease (PD).
  
  
  METHODS
  Three hundred and ninety-two unrelated patients with PD were recruited for this study. All of them completed the PD Sleep Scale (PDSS) and other clinical and demographic assessments. rs738499, a single nucleotide polymorphism of the Tef gene, was genotyped by polymerase chain reaction-restriction fragment length polymorphism.
  
  
  RESULTS
  Mean total PDSS scores were 111.5 (standard deviation [SD] 23.0) in the TT genotype and 122.2 (SD 18.2) in the TG+GG genotypes (P<0.01). Significant differences were found between genotypes (TT vs TG+GG) for 14 item scores (all P<0.05). Total and item scores displayed negative associations with the TT genotype (all P<0.05) except Item 2 (P=0.178). Linear regression adjusted for gender, duration, depression and disease severity showed that the polymorphism could explain 0.9% of the variance in PDSS scores.
  
  
  CONCLUSIONS
  These preliminary results suggest that the TT genotype in Tef rs738499 is associated with sleep disturbances in PD. Depression and disease severity are the main contributors to these findings, but rs738499 itself is an independent risk factor.
authors.affiliation: Department of Neurology, Affiliated Brain Hospital of Nanjing Medical University, Nanjing, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Hua
authors.forename: Weiguo
authors.initials: W
authors.lastname: Liu
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Haixia
authors.initials: H
authors.lastname: Ding
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Xiao
mesh_terms: D000368:Aged; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics*; D002940:Circadian Rhythm / Q000235:genetics*; D003863:Depression / Q000453:epidemiology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics; D005838:Genotype; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012307:Risk Factors; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000235:genetics*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; C489490:TEF protein, human