title: Absence of association between a common mutation in the methylenetetrahydrofolate reductase gene and the risk of coronary artery disease.
abstract: BACKGROUND
  Elevated total plasma homocysteine levels are associated with an increased risk of coronary artery disease. Plasma homocysteine levels are influenced by nutritional and hereditary factors. A point mutation (cytosin to thymidine substitution; C677-->T) in the gene encoding methylenetetrahydrofolate reductase (MTHFR), has been reported to render the enzyme thermolabile and has been associated with elevations in homocysteine levels in homozygous carriers (TT genotype).
  
  
  METHODS
  To examine the hypothesis that the T allele (coding for the thermolabile defect of MTHFR) influences the risk of coronary artery disease, we genotyped 340 patients with coronary artery disease and 105 control subjects in whom coronary artery disease was excluded by coronary angiography. Furthermore, we studied the genotype frequency in 104 age- and sex-matched healthy persons as a control group without signs of atherosclerotic disease.
  
  
  RESULTS
  Allele frequencies for C (wild-type allele) and T allele (mutant allele) were 0.68 and 0.32 respectively in the healthy control subjects, 0.66 and 0.34 respectively in patients with angiographically excluded coronary artery disease and 0.69 and 0.31 respectively in coronary artery disease patients (P = NS). The allele frequencies of the total study population were 0.68 and 0.32.
  
  
  CONCLUSIONS
  Our data show that homozygosity for the C677-->T mutation in this European population is not associated with increased risk of coronary artery disease. This finding suggests that the C677-->T mutation of the MTHFR gene does not represent a marker for increased cardiovascular risk.
authors.affiliation: Department of Internal Medicine, University of Jena, Germany. DREI@polkim.med.uni-jena.de
authors.forename: D
authors.initials: D
authors.lastname: Reinhardt
authors.forename: H H
authors.initials: HH
authors.lastname: Sigusch
authors.forename: S F
authors.initials: SF
authors.lastname: Vogt
authors.forename: K
authors.initials: K
authors.lastname: Farker
authors.forename: S
authors.initials: S
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Hoffmann
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003327:Coronary Disease / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics*; D012307:Risk Factors
chemical_list: D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)