title: Hyperhomocyst(e)inemia, but not methylenetetrahydrofolate reductase C677T mutation, as a risk factor in branch retinal vein occlusion.
abstract: OBJECTIVE
  To determine whether hyperhomocyst(e)inemia and methylenetetrahydrofolate reductase (MTHFR) C677T mutation are associated with branch retinal vein occlusion (BRVO).
  
  
  METHODS
  Retrospective, case-control study.
  
  
  METHODS
  The study cohort consisted of 84 consecutive patients with branch retinal vein occlusion and 84 controls, matched for age and gender.
  
  
  METHODS
  Fasting plasma homocyst(e)ine, folate, and vitamin B(12) levels, MTHFR C677T genotypes.
  
  
  RESULTS
  Mean plasma homocyst(e)ine levels were significantly higher in patients than in controls (11.4 +/- 4.3 micromol/l vs. 9.9 +/- 2.8 micromol/l; P = 0.002). An increase of plasma homocyst(e)ine level by 1 micromol/l was associated with an odds ratio of 1.19 (95% confidence interval 1.06-1.34; P = 0.004). Mean plasma folate levels were significantly lower in patients than in the control group (4.5 +/- 2.1 ng/ml vs. 5.6 +/- 2.1 ng/ml; P = 0.007). The prevalence of the homozygous genotype of the MTHFR C677T mutation did not differ significantly between patients and controls.
  
  
  CONCLUSIONS
  Our results suggest that hyperhomocyst(e)inemia, but not homozygosity for the MTHFR C677T mutation, is associated with BRVO. Increased plasma homocyst(e)ine levels in our study are not the result of an increased prevalence of the homozygous genotype of MTHFR C677T mutation.
authors.affiliation: Department of Ophthalmology, Karl-Franzens University, Graz, Austria. martin.weger@kfunigraz.ac.at
authors.forename: Martin
authors.initials: M
authors.lastname: Weger
authors.forename: Olaf
authors.initials: O
authors.lastname: Stanger
authors.forename: Hannes
authors.initials: H
authors.lastname: Deutschmann
authors.forename: Werner
authors.initials: W
authors.lastname: Temmel
authors.forename: Wilfried
authors.initials: W
authors.lastname: Renner
authors.forename: Otto
authors.initials: O
authors.lastname: Schmut
authors.forename: Franz
authors.initials: F
authors.lastname: Quehenberger
authors.forename: Jürgen
authors.initials: J
authors.lastname: Semmelrock
authors.forename: Anton
authors.initials: A
authors.lastname: Haas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications*; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D016017:Odds Ratio; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D017354:Point Mutation; D012170:Retinal Vein Occlusion / Q000097:blood / Q000201:enzymology / Q000209:etiology* / Q000235:genetics; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12