Methylenetetrahydrofolate reductase (MTHFR) C677T genetic polymorphism and late infarct-related coronary artery patency after thrombolysis

Biochemical Association of MTHFR C677T Polymorphism with Myocardial Infarction in the Presence of Diabetes Mellitus as a Risk Factor

Myocardial infarction (MI) is a cardiovascular disease that occurs due to the blockage of the coronary artery. Subsequently, cardiac muscles receive a lower oxygen supply, which leads to the death of cardiac muscles. The etiology of MI is linked to various environmental, occupational, and genetic factors. Various studies have been conducted on the polymorphism of genes involved in MI. Previous studies have shown that different variants of the methylene tetrahydrofolate reductase (MTHFR) gene are involved in causing MI by altering the metabolism of folate and homocysteine. However, the genetic polymorphism of MTHFR C677T (rs1801133) and its association with MI in the presence of diabetes mellitus (DM) as a risk factor still needs to be investigated. This study recruited 300 participants who were divided into three groups, i.e., the control, MI, and MI-DM. The blood samples collected from the study participants were subjected to various biochemical tests and their clinical parameters were monitored. MTHFR C677T (rs1801133) genotyping was performed by Tetra ARMS PCR using predetermined primers. The MTHFR C677T (rs1801133) polymorphism was associated with MI in the presence of DM as a risk factor among the participants. The MTHFR C677T (rs1801133) T/T homozygous genotype was found to be significant among MI patients in the presence of DM as a risk factor.

C667T and A1298C polymorphisms of methylenetetrahydrofolate reductase gene and susceptibility to myocardial infarction: A systematic review and meta-analysis

MTHFR C677T and A1298C polymorphisms have been reported to be associated with the risk of myocardial infarction (MI), although the results of previous studies have been inconsistent. The aim of this study was to explore whether these polymorphisms play a role in the genetic susceptibility to MI. A comprehensive search of MEDLINE and EMBASE databases was conducted for studies evaluating the association between the C667T and A1298C polymorphisms and MI risk. Odds ratios (OR) with 95% confidence intervals (CIs) were calculated to assess the strength of association in the dominant model, recessive model, allelic model, and genotypes contrast. A total of 47 studies were finally included in this meta-analysis. Overall, the results showed no statistically significant association between C667T and A1298C polymorphisms and MI risk. However, in subgroup analysis by ethnicity, the T allele of C677T polymorphism was associated with a 63% increased risk of MI compared with the C allele (T vs. C, OR=1. 63, 95%CI=1.15-2.10, fixed effects) in African populations, while compared to wild homozygote genotype, CT genotype was associated with a decreased risk of MI in North American populations (CT vs. CC, OR=0.81, 95%CI=0.64-0.98, fixed effects). Moreover, C677T polymorphism had a protective effect against MI risk under the dominant model (OR=0.93, 945%CI=0.87-0.99, fixed effects) in elderly (≥50) population. The A1298C polymorphism was not significantly associated with MI risk. Unlike A1298C polymorphism, C677T polymorphism was associated with risk of MI in African, North American, and elderly populations.

Methylenetetrahydrofolate reductase C677T mutation in patients with alopecia areata in Turkish population

OBJECTIVE

Methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme regulating folate metabolism and it is thought to influence DNA methylation and nucleic acid synthesis. Mutations in the MTHFR gene have been associated with several autoimmune disorders in previous studies. Alopecia areata (AA) is considered to be a tissue-specific autoimmune disease as the hair follicle has been targeted and antibodies to their own hair follicle structures have been developed. Since there is a common shared pathway between AA and other autoimmune disorders, we aimed to investigate a possible association between the MTHFR gene C677T mutation and AA susceptibility in the Turkish population.

METHODS

The study included 136 patients affected by AA and 130 healthy controls. Genomic DNA was isolated and genotyped using a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay for the MTHFR gene C677T mutation.

RESULTS

The distributions of genotype and allele frequencies of MTHFR gene C677T mutation were statistically different between AA patients and the control group (p=0.036 and p=0.011, respectively). High differences were also observed when the patients and controls were compared according to CC versus CT+TT (p=0.012). CT+TT genotypes and T allele of MTHFR gene C677T mutation were found to be a susceptibility factor for AA in the Turkish population.

CONCLUSION

The results suggest that MTHFR gene C677T mutation may have an effect on the risk of alopecia areata in the Turkish population. This is the first study reporting the association between the MTHFR (C677T) genotype and AA.

The rs1801133 polymorphism of methylenetetrahydrofolate reductase gene- the association with 5-year survival in patients with ST-elevation myocardial infarction

PURPOSE

Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in endothelial nitric oxide synthase (eNOS) coupling and homocysteine metabolism. The rs1801133 polymorphism of the MTHFR gene affects risk of coronary artery disease. We assessed its influence on 5-year survival of patients with ST-elevation acute myocardial infarction (STEMI).

MATERIAL/METHODS

The study group comprised consecutive patients with STEMI. Genotyping was performed with a TaqMan SNP Genotyping Assay using the ABI 7500 Real Time PCR System (Applied Biosystems). The analyzed end-point was all-cause 5-year survival.

RESULTS

The study group comprised 637 patients (mean age 62.3 ± 11.9 years; 25.1% females, n=160; 5-year mortality 16.3%, n=104). The percentages of TT, CT and CC genotypes were: 10.8 (n=69), 39.7 (n=253) and 49.45 (n=315), respectively. No significant differences in clinical characteristics were identified between the genotypes (p>0.05 for all parameters). Eleven (15.9%) TT homozygotes, 40 (15.8%) heterozygotes and 53 (16.8%) CC homozygotes died during follow up (p=0.99 log-rank test). TT homozygotes presented only weak and insignificant tendency towards higher mortality rates in subgroups of patients ≤75 years old (15.6 vs. 11.54%, p=0.35) or with intermediate risk according to the GRACE risk score (13.3% vs. 8.76%, p=0.42).

CONCLUSIONS

The rs1801133 polymorphism did not show significant association with 5-year survival.

MTHFR C677T polymorphism and its relationship to myocardial infarction in the Eastern Black Sea region of Turkey

BACKGROUND AND AIMS

An association of homozygous MTHFR 677T genotypes with elevated plasma homocysteine level has been documented, but results are still controversial. We aimed to investigate prevalence of the C677T polymorphism in patients with acute myocardial infarction (MI) in the Eastern Black Sea region of Turkey.

METHODS

We studied genomic DNA of 231 unrelated patients (aged 59 ± 13 years; 175 male, 56 female) with first anterior acute MI and 242 healthy controls (aged 54 ± 19 years; 182 male, 60 female) using real-time polymerase chain reaction kits for the MTHFR C677T mutation.

RESULTS

Prevalence of MTHFR C677T mutant genotype was 49.1% (CT: 45.8%, TT: 3.3%) in controls and 48.45% (CT: 38.5%, TT: 9.95%) in patients with acute MI. The TT mutation was more frequent in patients with acute MI than in controls (9.95 vs. 3.3%) (OR; 3.23, 95% CI; [1.34-8.05], p = 0.003).

CONCLUSIONS

The MTHFR gene homozygote TT mutation is a risk factor for patients with MI in the eastern Black Sea Turkish Population.

Pharmacogenetics in cardiovascular antithrombotic therapy

Thrombosis is the most important underlying mechanism of coronary artery disease and embolic stroke. Hence, antithrombotic therapy is widely used in these scenarios. However, not all patients achieve the same degree of benefit from antithrombotic agents, and a considerable number of treated patients will continue to experience a new thrombotic event. Such lack of clinical benefit may be related to a wide variability of responses to antithrombotic treatment among individuals (i.e., interindividual heterogeneity). Several factors have been identified in this interindividual heterogeneity in response to antithrombotic treatment. Pharmacogenetics has emerged as a field that identifies specific gene variants able to explain the variability in patient response to a given drug. Polymorphisms affecting the disposition, metabolism, transporters, or targets of a drug all can be implicated in the modification of an individual's antithrombotic drug response and therefore the safety and efficacy of the aforementioned drug. The present paper reviews the modulating role of different polymorphisms on individuals' responses to antithrombotic drugs commonly used in clinical practice.