Investigation of MTHFR gene C677T polymorphism in cardiac syndrome X patients.

BACKGROUND: Definition of Cardiac Syndrome X (CSX) refers to groups of patients with positive exercise stress test and normal epicardial coronary arteries on coronary angiography accompanied by chest pain. Although the etiology of CSX is not completely understood, there is a common consensus that its pathophysiology may be associated with endothelial dysfunction resulting in impaired coronary flow. Some polymorphisms observed on the MTHFR gene cause inactivation of the MTHFR enzyme, leading to hyperhomocysteinemia and homocysteinuria, which are prominent risk factors of cardiovascular and cerebrovascular diseases. It was aimed to explain the association of the endothelial dysfunction, which is thought to play a role in the pathophysiology of CSX, with C677T polymorphism on MTHFR gene based on genetic basis. METHODS: A total of 176 CSX patients and 196 healthy subjects with similar age and clinical features were compared in terms of C677T polymorphism of the MTHFR gene. RESULTS AND CONCLUSION: There was no significant difference in terms of MTHFR gene C677T polymorphism between CSX patients and controls. When genotypic distribution was compared based on gender in both patients and controls, no significant difference was found between male and female subjects (P>.05). As fasting blood sugar and urea values were significantly higher, alanine aminotransferase and gamma-glutamyl transferase levels were significantly lower in the patients than the controls (P<.05). Described family story of the patients was significantly higher than the controls (P<.05). These suggest that homocysteine metabolism in CSX is not directly related to the endothelial dysfunction and thus the effect on the microvascular circulation.

Does Inflammation Have a Role in the Pathogenesis of Cardiac Syndrome X? A Genetic-Based Clinical Study With Assessment of Multiple Cytokine Levels.

We compared Turkish patients with cardiac syndrome X (CSX) and controls with respect to serum pro- and anti-inflammatory cytokine levels, as well as the single-nucleotide polymorphisms located in the promoter regions of their related genes. This study included 111 consecutive patients angiographically diagnosed with CSX and 111 healthy controls with similar demographic characteristics. Serum interleukin (IL) 6, tumor necrosis factor α (TNF-α), and IL-10 levels were measured, and the genotypes of the patients and controls were determined using standard methods. Serum IL-6 and IL-10 levels were significantly higher in the CSX group than in the control group (P < .01, respectively). Serum TNF-α level was lower in the CSX group than in the control group (P < .001). On the other hand, participants with CSX and healthy controls were not significantly different with respect to the genotype distributions of IL-6, TNF-α, and IL-10 genes. As a result of our study, both pro-inflammatory and anti-inflammatory cytokines may play a role in the pathogenesis of CSX. In contrast, the studied gene polymorphisms did not influence CSX pathogenesis.