title: Thrombophilic risk factors in different types of retinal vein occlusion in Tunisian patients.
abstract: BACKGROUND
  Retinal vein occlusion (RVO) is the second most common cause of vision loss because of retinal vascular disease. There are 2 types of RVO: branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). The pathogenesis of RVO is multifactorial. The role of factor V Leiden (FVL) and prothrombin mutations was examined in patients with CRVO and BRVO.
  
  
  METHODS
  FVL and prothrombin were investigated by extracting DNA of 88 patients with RVO. Sixteen of the patients were diagnosed with CRVO, 4 with hemispheric retinal vein occlusion, and 68 with BRVO. The genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism.
  
  
  RESULTS
  Significant differences were found in the frequencies of the genotypes for both the FVL (G1691A) (P<10(-3), odds ratio [OR]=17.4, confidence interval [CI]=6.20-59) and prothrombin (G20210A) (P=.007, OR=5.11, CI=1.30-29) polymorphisms between RVO patients and healthy controls. Additionally, the frequency of the GA genotype for the G1691A polymorphism was significantly higher among the patients in a subset of BRVO compared with controls (P<10(-3), OR=21.4, CI=7.34-74.2). However, no statistically significant differences were found in the frequencies of the prothrombin G20210A polymorphism between the BRVO group and healthy controls (P=.09, OR=3.13, CI=64-19.9). The frequency of both G1691A and G20210A genotypes among the patients of a CRVO subgroup was significantly higher compared with controls (P<10(-3), OR=11.4, CI=2.94-44.2; P=.007, OR=10.8, CI=2.15-54.1, respectively), suggesting an association between these polymorphisms and CRVO.
  
  
  CONCLUSIONS
  Large study would be required to understand completely the contribution of these markers in the risk of all types of RVO.
authors.affiliation: Faculté des Science de Tunis, Université Tunis el Manar, El Manar, Tunisie; Laboratoire de Biologie Moléculaire, Service d'Hématologie, Hôpital Militaire Principal d'Instruction de Tunis, Montfleury, Tunisie.
authors.forename: Meriem
authors.initials: M
authors.lastname: Mrad
authors.affiliation: Laboratoire de Biologie Moléculaire, Service d'Hématologie, Hôpital Militaire Principal d'Instruction de Tunis, Montfleury, Tunisie; Académie Militaire Fondouk Jédid, Nabeul, Tunisie. Electronic address: fnajiba@yahoo.fr.
authors.forename: Najiba
authors.initials: N
authors.lastname: Fekih-Mrissa
authors.affiliation: Faculté de Médecine de Tunis, Université Tunis el Manar, Tunis, Tunisie; Service d'Ophtalmologie, Hôpital Militaire Principal d'Instruction de Tunis, Montfleury, Tunisie.
authors.forename: Cheima
authors.initials: C
authors.lastname: Wathek
authors.affiliation: Faculté de Médecine de Tunis, Université Tunis el Manar, Tunis, Tunisie; Service d'Ophtalmologie, Hôpital Militaire Principal d'Instruction de Tunis, Montfleury, Tunisie.
authors.forename: Riadh
authors.initials: R
authors.lastname: Rannen
authors.affiliation: Faculté de Médecine de Tunis, Université Tunis el Manar, Tunis, Tunisie; Service d'Ophtalmologie, Hôpital Militaire Principal d'Instruction de Tunis, Montfleury, Tunisie.
authors.forename: Salem
authors.initials: S
authors.lastname: Gabsi
authors.affiliation: Laboratoire de Biologie Moléculaire, Service d'Hématologie, Hôpital Militaire Principal d'Instruction de Tunis, Montfleury, Tunisie; Faculté de Pharmacie, Université de Monastir, Monastir, Tunisie.
authors.forename: Nasreddine
authors.initials: N
authors.lastname: Gritli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D002648:Child; D005165:Factor V / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011516:Prothrombin / Q000235:genetics*; D012170:Retinal Vein Occlusion / Q000235:genetics*; D012307:Risk Factors; D019851:Thrombophilia / Q000235:genetics*; D014416:Tunisia; D055815:Young Adult
chemical_list: C095381:factor V Leiden; D005165:Factor V; D011516:Prothrombin
keywords: G1691A; G20210A; Retinal vein occlusion; branch retinal vein occlusion; central retinal vein occlusion; polymerase chain reaction–restriction fragment length polymorphism