title: Influence of combined methionine synthase (MTR 2756A > G) and methylenetetrahydrofolate reductase (MTHFR 677C > T) polymorphisms to plasma homocysteine levels in Korean patients with ischemic stroke.
abstract: OBJECTIVE
  Methionine synthase (MTR) and 5,10-methylenetetrahydrofolate reductase (MTHFR) are the main regulatory enzymes for homocysteine metabolism. The present case- control study was conducted to determine whether there is an association between the MTR 2756A > G or MTHFR 677C > T polymorphism and plasma homocysteine concentration in Korean subjects with ischemic stroke.
  
  
  METHODS
  DNA samples of 237 patients who had an ischemic stroke and 223 age and sex-matched controls were studied. MTR 2756A > G and MTHFR 677C > T genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).
  
  
  RESULTS
  Frequencies of mutant alleles for MTR and MTHFR polymorphisms were not significantly different between the controls and cases. The patient group, however, had significantly higher homocysteine concentrations of the MTR 2756AA and MTHFR 677TT genotypes than the control group (p=0.04 for MTR, p=0.01 for MTHFR). The combined MTR 2756AA and MTHFR 677TT genotype (p= 0.04) and the homocysteine concentrations of the patient group were also higher than those of the controls. In addition, the genotype distribution was significant in the MTHFR 677TT genotype (p=0.008) and combined MTR 2756AA and MTHFR 677TT genotype (p=0.03), which divided the groups into the top 20% and bottom 20% based on their homocysteine levels.
  
  
  CONCLUSIONS
  The results of the present study demonstrate that the MTR 2756A > G and MTHFR 677C > T polymorphisms interact with elevated total homocysteine (tHcy) levels, leading to an increased risk of ischemic stroke.
authors.affiliation: Institute for Clinical Research, Bundang CHA General Hospital, College of Medicine, Pochon CHA University, 351 Yatap-Dong, Bundang-Gu, Seongnam, Korea.
authors.forename: Ok Joon
authors.initials: OJ
authors.lastname: Kim
authors.forename: Sun Pyo
authors.initials: SP
authors.lastname: Hong
authors.forename: Jung Yong
authors.initials: JY
authors.lastname: Ahn
authors.forename: Seung Ho
authors.initials: SH
authors.lastname: Hong
authors.forename: Tae Sun
authors.initials: TS
authors.lastname: Hwang
authors.forename: Soo Ok
authors.initials: SO
authors.lastname: Kim
authors.forename: Wangdon
authors.initials: W
authors.lastname: Yoo
authors.forename: Doyeun
authors.initials: D
authors.lastname: Oh
authors.forename: Nam Keun
authors.initials: NK
authors.lastname: Kim
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000235:genetics*; D000368:Aged; D004247:DNA / Q000097:blood / Q000235:genetics; D005260:Female; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D020521:Stroke / Q000097:blood / Q000201:enzymology / Q000235:genetics*
chemical_list: D006710:Homocysteine; D004247:DNA; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase