OBJECTIVE: To determine the incidence of methylene tetrahydrofolate reductase (MTHFR) gene 677C-->T polymorphism and plasma homocysteine (Hcy) levels in a group of subjects who underwent coronary angiography, in an attempt to establish a correlation between these parameters and the severity of coronary artery disease (CAD) and to investigate the correlation between hyperhomocysteinemia (HHcy) and the presence of 677C-->T polymorphism. BACKGROUND: Elevated plasma Hcy level is an independent risk factor for CAD. A common mutation (677C-->T) in the gene coding for MTHFR has been reported to reduce the enzymatic activity and is associated with elevated levels of Hcy, especially in subjects with low folate intake. METHODS: The study group comprised of 84 patients with CAD and 100 age-and-sex matched controls who had no history or clinical evidence of CAD and/or MI. DNA was extracted from peripheral blood and genotypes were determined by polymerase chain reaction, restriction mapping with Hinf1, and gel electrophoresis. Conventional risk factors for CAD were prospectively documented. RESULTS: Allele and genotype frequencies in cases and control subjects were compatible with Hardy-Weinberg equilibrium. The frequencies of TT, CT, and CC genotypes among CAD patients were 4.8, 27.4, and 67.8% and in controls were 1.0, 19.0, and 80%. Hcy levels were higher in patients with triple-vessel disease compared to single and double vessel disease (P = 0.002). Multivariate analyses identified HHcy, diabetes mellitus, and hypertension as the independent predictors of CAD. CONCLUSIONS: HHcy appears to have a graded effect on the risk of CAD as well as the severity and extent of coronary atherosclerosis. Our findings support that homozygous genotype of MTHFR is a genetic risk factor for CAD. A further study with larger sample size including assessment of vitamin status is needed to better clarify the relationship between MTHFR genotypes and CAD.
OBJECTIVE: To determine the incidence of methylene tetrahydrofolate reductase (MTHFR) gene 677C-->T polymorphism and plasma homocysteine (Hcy) levels in a group of subjects who underwent coronary angiography, in an attempt to establish a correlation between these parameters and the severity of coronary artery disease (CAD) and to investigate the correlation between hyperhomocysteinemia (HHcy) and the presence of 677C-->T polymorphism. BACKGROUND: Elevated plasma Hcy level is an independent risk factor for CAD. A common mutation (677C-->T) in the gene coding for MTHFR has been reported to reduce the enzymatic activity and is associated with elevated levels of Hcy, especially in subjects with low folate intake. METHODS: The study group comprised of 84 patients with CAD and 100 age-and-sex matched controls who had no history or clinical evidence of CAD and/or MI. DNA was extracted from peripheral blood and genotypes were determined by polymerase chain reaction, restriction mapping with Hinf1, and gel electrophoresis. Conventional risk factors for CAD were prospectively documented. RESULTS: Allele and genotype frequencies in cases and control subjects were compatible with Hardy-Weinberg equilibrium. The frequencies of TT, CT, and CC genotypes among CAD patients were 4.8, 27.4, and 67.8% and in controls were 1.0, 19.0, and 80%. Hcy levels were higher in patients with triple-vessel disease compared to single and double vessel disease (P = 0.002). Multivariate analyses identified HHcy, diabetes mellitus, and hypertension as the independent predictors of CAD. CONCLUSIONS: HHcy appears to have a graded effect on the risk of CAD as well as the severity and extent of coronary atherosclerosis. Our findings support that homozygous genotype of MTHFR is a genetic risk factor for CAD. A further study with larger sample size including assessment of vitamin status is needed to better clarify the relationship between MTHFR genotypes and CAD.
Authors: Earl S Ford; S Jay Smith; Donna F Stroup; Karen K Steinberg; Patricia W Mueller; Stephen B Thacker Journal: Int J Epidemiol Date: 2002-02 Impact factor: 7.196
Authors: Mariska Klerk; Petra Verhoef; Robert Clarke; Henk J Blom; Frans J Kok; Evert G Schouten Journal: JAMA Date: 2002 Oct 23-30 Impact factor: 56.272
Authors: H Refsum; C S Yajnik; M Gadkari; J Schneede; S E Vollset; L Orning; A B Guttormsen; A Joglekar; M G Sayyad; A Ulvik; P M Ueland Journal: Am J Clin Nutr Date: 2001-08 Impact factor: 7.045
Authors: Raymond Meleady; Per M Ueland; Henk Blom; Alexander S Whitehead; Helga Refsum; Leslie E Daly; Stein Emil Vollset; Cait Donohue; Belinda Giesendorf; Ian M Graham; Arve Ulvik; Ying Zhang; Anne-Lise Bjorke Monsen Journal: Am J Clin Nutr Date: 2003-01 Impact factor: 7.045