title: The Role of TOR1A Polymorphisms in Dystonia: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  A number of genetic loci were found to be associated with dystonia. Quite a few studies have been contacted to examine possible contribution of TOR1A variants to the risk of dystonia, but their results remain conflicting. The aim of the present study was to systematically evaluate the effect of TOR1A gene SNPs on dystonia and its phenotypic subtypes regarding the body distribution.
  
  
  METHODS
  We performed a systematic review of Pubmed database to identify all available studies that reported genotype frequencies of TOR1A SNPs in dystonia. In total 16 studies were included in the quantitative analysis. Odds ratios (ORs) were calculated in each study to estimate the influence of TOR1A SNPs genotypes on the risk of dystonia. The fixed-effects model and the random effects model, in case of high heterogeneity, for recessive and dominant mode of inheritance as well as the free generalized odds ratio (ORG) model were used to calculate both the pooled point estimate in each study and the overall estimates.
  
  
  RESULTS
  Rs1182 was found to be associated with focal dystonia in recessive mode of inheritance [Odds Ratio, OR (95% confidence interval, C.I.): 1.83 (1.14-2.93), Pz = 0.01]. In addition, rs1801968 was associated with writer's cramp in both recessive and dominant modes [OR (95%C.I.): 5.99 (2.08-17.21), Pz = 0.00009] and [2.48 (1.36-4.51), Pz = 0.003) respectively and in model free-approach [ORG (95%C.I.): 2.58 (1.45-4.58)].
  
  
  CONCLUSIONS
  Our meta-analysis revealed a significant implication of rs1182 and rs1801968 TOR1A variants in the development of focal dystonia and writer's cramp respectively. TOR1A gene variants seem to be implicated in dystonia phenotype.
authors.affiliation: Department of Neurology, Laboratory of Neurogenetics, University of Thessaly, University Hospital of Larissa, Larissa, Greece.
authors.forename: Vasileios
authors.initials: V
authors.lastname: Siokas
authors.affiliation: Department of Neurology, Laboratory of Neurogenetics, University of Thessaly, University Hospital of Larissa, Larissa, Greece.
authors.forename: Efthimios
authors.initials: E
authors.lastname: Dardiotis
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece.
authors.forename: Evangelia E
authors.initials: EE
authors.lastname: Tsironi
authors.affiliation: Second Department of Neurology, University of Athens, School of Medicine, "Attikon" University Hospital, Athens, Greece.|International Clinical Research Center, St. Anne's University Hospital in Brno, Brno, Czech Republic.
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsivgoulis
authors.affiliation: Department of Neurology, Laboratory of Neurogenetics, University of Thessaly, University Hospital of Larissa, Larissa, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Rikos
authors.affiliation: Department of Neurology, Laboratory of Neurogenetics, University of Thessaly, University Hospital of Larissa, Larissa, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Sokratous
authors.affiliation: Department of Vascular Surgery, University Hospital of Larissa, University of Thessalia Medical School, Larissa, Greece.
authors.forename: Stylianos
authors.initials: S
authors.lastname: Koutsias
authors.affiliation: Department of Neurosurgery, University of Thessaly, University Hospital of Larissa, Larissa, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Paterakis
authors.affiliation: Department of Neurology, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Georgia
authors.initials: G
authors.lastname: Deretzi
authors.affiliation: Department of Neurology, Laboratory of Neurogenetics, University of Thessaly, University Hospital of Larissa, Larissa, Greece.
authors.forename: Georgios M
authors.initials: GM
authors.lastname: Hadjigeorgiou
mesh_terms: D016208:Databases, Factual; D004421:Dystonia / Q000235:genetics* / Q000473:pathology; D020821:Dystonic Disorders / Q000235:genetics / Q000473:pathology; D020022:Genetic Predisposition to Disease; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide
chemical_list: D018832:Molecular Chaperones; C108175:TOR1A protein, human