title: Hyperhomocysteinemia and C677T MTHFR genotype in patients with retinal vein thrombosis.
abstract: BACKGROUND
  Elevated homocysteine (Hcy) is associated with the risk of deep vein thrombosis, pulmonary embolism, ischemic heart disease, and stroke. Several studies have suggested that hyperhomocysteinemia (HHcy) may predispose to retinal vein thrombosis (RVT) development. The aim of this study is to investigate the relationship between Hcy, C677T methylenetetrahydrofolate reductase (MTHFR) genotype, and RVT in patients compared with controls.
  
  
  METHODS
  We evaluated the Hcy plasma level of 3114 consecutive participants in 2 Italian centers during a 2-year period. Hyperhomocysteinemia was found in 99 patients and 136 healthy participants. Of the 99 patients, 20 had RVT with a high prevalence of HHcy in the RVT subgroup (20.2%). This result suggested a possible relationship between HHcy and RVT development. We investigated 105 consecutive patients with recent diagnosis of RVT, and we compared them with 226 healthy controls to evaluate whether HHcy may be a risk factor for RVT.
  
  
  RESULTS
  the prevalence of HHcy was higher in patients compared with controls (34.3% vs 14.2%; P < .001). The MTHFR C677T genotype was found in 69 of 105 (65.7%) patients with RVT (heterozygosity: 40 of 105 and homozygosity: 29 of 105). The control group showed the presence of MTHFR C677T genotype in 169 of 226 participants (74.8%; heterozygosity: 100 of 226 and homozygosity: 69 of 226) without difference between the 2 groups (P = .08).
  
  
  CONCLUSIONS
  our study suggests that HHcy is a possible risk factor for RVT development, while no association was found between RVT and the C677T MTHFR genotype.
authors.affiliation: Hemophilia Centre, Hemostasis and Thrombosis Service, Azienda Ospedaliera "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy. gianluca.sottilotta@virgilio.it
authors.forename: Gianluca
authors.initials: G
authors.lastname: Sottilotta
authors.forename: Simona Maria
authors.initials: SM
authors.lastname: Siboni
authors.forename: Caterina
authors.initials: C
authors.lastname: Latella
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Oriana
authors.forename: Ermelinda
authors.initials: E
authors.lastname: Romeo
authors.forename: Rita
authors.initials: R
authors.lastname: Santoro
authors.forename: Dario
authors.initials: D
authors.lastname: Consonni
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Trapani Lombardo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood* / Q000235:genetics*; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012170:Retinal Vein Occlusion / Q000097:blood* / Q000235:genetics*; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)