title: Genetic polymorphisms associated with retinal vein occlusion: a Greek case-control study and meta-analysis.
abstract: BACKGROUND
  The genetic background of retinal vein occlusion (RVO) remains unclear. In the current study, we aimed to replicate polymorphisms related to thrombophilia/hypofibrinolysis in a Greek population and also systematically summarize current evidence available on the topic.
  
  
  METHODS
  A total of 48 RVO patients and 53 controls were genotyped for factor V H1299R and V Leiden, β-fibrinogen G455A, PAI-1 4G/5G, ACE I/D, HPA1, prothrombin G20210A, factor XIII Val34Leu, MTHFR A1298C and C677T polymorphisms. We examined the association between RVO and the above polymorphisms under a per-allele genetic model in a Greek unrelated case/control population. Additionally, searching PubMed up to January 2012, we identified existing evidence on these polymorphisms and performed meta-analyses.
  
  
  RESULTS
  A total of three polymorphisms had nominally significant associations with RVO. These associations pertained to ACE D allele (odds ratio, OR, 2.08 [95% CI, 1.12-3.85], p = 0.02); factor XIII 34Leu allele (OR = 0.41 [95% CI, 0.18-0.95], p = 0.037] and MTHFR 677T variant (OR = 2.20 [95% CI 1.10-4.40], p = 0.026). We performed a meta-analysis on the associations between RVO and PAI-1 (n = 5), factor V Leiden (n = 21), MTHFR C677T (n = 19) and prothrombin G20210A (n = 21). We observed nominally significant associations only for PAI-1 (OR = 1.27 [95% CI, 1.02-1.60, p = 0.036]) (I(2) = 44.7%), and factor V Leiden (OR = 1.40 [95% CI, 1.07-1.84, p = 0.015]) (I(2) = 3.6%) using random effects model.
  
  
  CONCLUSIONS
  Our results suggest that there may be an association between increased risk for RVO and ACE I/D, MTHFR C677T, PAI-1 4G/5G and factor V Leiden polymorphisms, whereas the Val34Leu variant may exert a protective effect.
authors.affiliation: Department of Ophthalmology, University of Ioannina School of Medicine, Ioannina, Greece.
authors.forename: Georgia G
authors.initials: GG
authors.lastname: Yioti
authors.forename: Orestis A
authors.initials: OA
authors.lastname: Panagiotou
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Vartholomatos
authors.forename: Nikolaos I
authors.initials: NI
authors.lastname: Kolaitis
authors.forename: Chrisavgi N
authors.initials: CN
authors.lastname: Pappa
authors.forename: Evangelos
authors.initials: E
authors.lastname: Evangelou
authors.forename: Maria I
authors.initials: MI
authors.lastname: Stefaniotou
mesh_terms: D000368:Aged; D000483:Alleles; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005165:Factor V / Q000235:genetics*; D005260:Female; D005838:Genotype; D006115:Greece; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D016017:Odds Ratio; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D011110:Polymorphism, Genetic; D012170:Retinal Vein Occlusion / Q000235:genetics*
chemical_list: D015415:Biomarkers; D017395:Plasminogen Activator Inhibitor 1; C051321:SERPINE1 protein, human; C095381:factor V Leiden; D005165:Factor V; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2); C488034:ACE protein, human; D007703:Peptidyl-Dipeptidase A