Prevalence of prothrombotic polymorphisms in Greece

Fibrinogen B β promoter polymorphism may not be associated with pulmonary embolism

OBJECTIVE

A prospective experiment was designed to explore all possible SNPs in the promoter region of fibrinogen B β (FGB) and reveal the influence of these SNPs on susceptibility of pulmonary embolism.

METHODS

In this 2-year randomized prospective study, we had totally recruited 203 volunteers. 58 PE patients (58 out of 145 VTE patients) and 114 healthy people were taken as case and control objects, respectively. FGB promoter was detected by gene sequencing.

RESULTS

There were 6 SNPs in FGB promoter, which were β-1420G/A, β-993C/T, β-854G/A, β-455G/A, β-249C/T, and β-148C/T. Genotype frequencies of individual SNPs between the cases and controls were not statistically significant, all p > .05. After excluding subjects of COVID-19 infection within 6 months, the statistical results (35 PE patients vs 66 healthy people) were consistent.

CONCLUSION

The susceptibility to pulmonary embolism may not be affected by any SNP in the FGB promoter region.

Associations of serum 25-hydroxyvitamin D with serum folate, cobalanin, and homocysteine concentrations and methylene tetrahydrofolate reductase (MTHFR) gene polymorphisms in healthy adults

AIM

The aim of this study was to investigate the associations of serum 25-hydroxyvitamin D [25(OH)D] with various demographic, anthropometric, and genetic characteristics and biochemical parameters in healthy Greek adults.

METHODS

Demographic (age and sex), anthropometric (body mass index/BMI), and genetic (MTHFR gene polymorphisms) characteristics and biochemical parameters (serum folate, cobalamin/Cbl, and total homocysteine/tHcy concentrations), which had been recorded and measured, among others, in the framework of periodic medical examination (military personnel) or check-up (non-military personnel) of 383 healthy Greek adults (199 men and 184 women) were analyzed. Serum 25(OH)D, tHcy, folate, and Cbl levels were determined using immunoassay methods. The MTHFR C677T and A1298C gene polymorphisms were genotyped using polymerase chain reaction and reverse hybridization.

RESULTS

Serum 25(OH)D concentrations were correlated with Cbl levels and MTHFR C677T gene polymorphism, while they had a reverse correlation with serum tHcy levels, age, and BMI. There was no significant correlation between serum 25(OH)D concentrations and sex, serum folate levels, and smoking status. Individuals with the 677TT genotype had statistically significantly lower serum 25(OH)D levels than those with the 677CC or 677CT genotype, while individuals with the 1298CC genotype had statistically significantly higher serum 25(OH)D levels than those with 1298AA or 1298AC genotype. Moreover, the reverse correlation between the serum 25(OH)D and tHcy levels was statistically significant in all six MTHFR genotypes.

CONCLUSIONS

Serum 25(OH)D levels are associated with age, BMI, serum tHcy, and Cbl levels and MTHFR C677T gene polymorphism. The most significant finding of our study is the observed reverse correlation of serum 25(OH)D levels with serum tHcy levels. Considering that vitamin D deficiency and hyperhomocysteinemia (HHcy) are associated with an increased risk for cardiovascular diseases (CVDs), we suggest that individuals with high serum tHcy levels should be further investigated for, inter alia, their serum 25(OH)D levels.

Single Nucleotide Variants (SNVs) of Angiotensin-Converting Enzymes (ACE1 and ACE2): A Plausible Explanation for the Global Variation in COVID-19 Prevalence

Background. Although it is common knowledge that the coronavirus disease of 2019 (COVID-19) and other viral infections have an uneven impact globally, the reasons for this are still indistinct. The absence of equivalent capacities worldwide in screening, testing, and reporting of cases is one of the ideas put forward to explain this discrepancy. The molecular developments are noteworthy, particularly the role played by single nucleotide polymorphisms (SNPs) in ACEs (ACE1 and ACE2). The virus can enter the host cell thanks to the transmembrane protein ACE2, which is a homolog of ACE1. Objectives. With a focus on the I/D genotype of ACE1 and the rs2285666 SNV of ACE2, we elucidated the prevalence of SNPs in ACE1 and ACE2 in various geographic locations. We examined the relationship between these SNPs and the global patterns of COVID-19 prevalence. Methods. 66 of the 127 articles obtained using PubMed, Google Scholar, and Google directly conformed to the search terms; geographical distribution of viral infections, the prevalence of COVID-19, ACE1, ACE2, SNPs, and prevalence of the DD genotype, and rs2285666. Results. The DD genotype of ACE1 and the rs2285666 SNV of ACE2 are vital in their gene expression and contribute greatly to viral disease susceptibility, development, and severity. There was generally a high prevalence of the DD genotype in Europe and America, where COVID-19 had a more devastating effect than in Asia and Africa. The prevalence of the SNV rs2285666 varied in the following order: East Asia> South Asia >America>Europe >Africa. However, there were conflicting agreements in the association of rs2285666 with COVID-19 susceptibility and prevalence. Conclusion. The ACE1 DD genotype and COVID-19 prevalence have been positively linked in a number of studies. The ACE2 rs2285666 SNV, however, has yielded no definitive results. To determine the relationship between these SNVs and COVID-19 incidence, more research is required.

The Correlation Between FGB Promoter Polymorphism and Clotting Function in Patients With Idiopathic Lower Extremity Deep Venous Thrombosis

To explore the possible single nucleotide polymorphisms (SNPs) sites in the promoter region of fibrinogen B β (FGB), and construct logistic regression model and haplotype model, so as to reveal the influence of FGB promoter SNPs on susceptibility, hemodynamics and coagulation function of lower extremity deep venous thrombosis (LEDVT) in the genetic background. LEDVT patients (120) and healthy people (120) were taken as case and control objects, respectively. SNPs and their genotypes of FGB promoter were detected by promoter sequencing and PCR-RFLP. The parameters of coagulation system were evaluated. There were 6 SNPs in FGB promoter, which were β-148C/T, β-249C/T, β-455G/A, β-854G/A, β-993C/T and β-1420G/A. The genotype and allele frequency of β-1420 G/A, β-455G/A, β-249c/T and β-148C/T were significantly different between the LEDVT group and the control group, but not β-993C/T and β-854G/A. In addition, we found that the higher the content of Fibrinogen (FG), the higher the risk of LEDVT. The risk of LEDVT increased by 4.579 times for every unit increase of fibrinogen. We also found that FG, PT and APTT in LEDVT group were higher than those in control group, while TT was lower than those in control group; Furthermore, there was no significant difference in all coagulation indexes among 6 SNP genotypes in LEDVT group, while a significant difference was found between the 2 genotypes of β-993C/T in the control group. β-993C/T may indirectly affect the susceptibility of LEDVT by improving the basic level of plasma FG.

Does Genetic Predisposition Contribute to the Exacerbation of COVID-19 Symptoms in Individuals with Comorbidities and Explain the Huge Mortality Disparity between the East and the West?

The elderly and patients with several comorbidities experience more severe cases of coronavirus disease 2019 (COVID-19) than healthy patients without underlying medical conditions. However, it is unclear why these people are prone to developing alveolar pneumonia, rapid exacerbations, and death. Therefore, we hypothesized that people with comorbidities may have a genetic predisposition that makes them more vulnerable to various factors; for example, they are likely to become more severely ill when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To test this hypothesis, we searched the literature extensively. Polymorphisms of genes, such as those that encode angiotensin-converting enzyme 1 (ACE1), have been associated with numerous comorbidities, such as cardiovascular disease, hypertension, diabetes, chronic kidney disease, and obesity, and there are potential mechanisms to explain these associations (e.g., DD-type carriers have greater ACE1 activity, and patients with a genetic alpha-1 anti-trypsin (AAT) deficiency lack control over inflammatory mediators). Since comorbidities are associated with chronic inflammation and are closely related to the renin–angiotensin–aldosterone system (RAAS), these individuals may already have a mild ACE1/ACE2 imbalance before viral infection, which increases their risk for developing severe cases of COVID-19. However, there is still much debate about the association between ACE1 D/I polymorphism and comorbidities. The best explanation for this discrepancy could be that the D allele and DD subtypes are associated with comorbidities, but the DD genotype alone does not have an exceptionally large effect. This is also expected since the ACE1 D/I polymorphism is only an intron marker. We also discuss how polymorphisms of AAT and other genes are involved in comorbidities and the severity of SARS-CoV-2 infection. Presumably, a combination of multiple genes and non-genetic factors is involved in the establishment of comorbidities and aggravation of COVID-19.

Distribution of MTHFR C677T Gene Polymorphism in Healthy North Indian Population and an Updated Meta-analysis

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of folate pathway. Several polymorphisms were reported in MTHFR gene but C677T polymorphism is most studied and it has been reported to be risk factor for several diseases/disorders. The present study was designed to explore the frequency of MTHFR C677T polymorphism in North Indian healthy population. In addition to this a meta-analysis of published articles was also performed to estimate the global prevalence of MTHFR C677T polymorphism. A total of 1000 unrelated healthy subjects were selected for MTHFR C677T polymorphism analysis. Different databases were searched for eligible articles. Prevalence proportion with 95 % CI was used to determine global prevalence of T allele and TT genotype. Meta-analysis was performed by Open meta-analyst. In 1000 blood samples analyzed, the frequency of T allele and TT genotype was 11 and 1 % respectively. Results of the meta-analysis showed that the global prevalence of T allele and TT genotype were 24.0 % (95 % CI 21.7-26.5) and 7.7 % (95 % CI 6.5-8.9) respectively. In sub-group meta-analysis, the lowest frequency of T allele was found in Africans (10.3 %; 95 % CI 3.8-16.8), and highest in Europeans (34.1 %; 95 % CI 31.9-36.3). The frequency of T allele in the North India is 11 %. The results of the meta-analysis showed that the frequency of the T allele and the TT genotype of C677T is highest in the Caucasian population.

Bosnian study of APOE distribution (BOSAD): a comparison with other European populations

BACKGROUND

The ε2, ε3 and ε4 alleles of APOE gene have been associated with several diseases in different populations. Data on the frequency of alleles are used in both a clinical and evolutionary context. Although the data on frequency of these alleles are numerous, there are no reports for the population of Bosnia and Herzegovina.

AIM

To estimate the frequency of APOE alleles in a healthy Bosnian population and compare it to data for other European populations.

SUBJECTS AND METHODS

Overall, 170 unrelated Bosnian subjects (108 female and 62 male), aged 53.0 (±5.0) years were included in this study. Genotypes were determined by real-time PCR.

RESULTS

In our group the prevalence of heterozygotes E2/E3, E2/E4 and E3/E4 was 20.6%, 3.5% and 12.9%, respectively, while the prevalence of homozygotes E2/E2, E3/E3, E4/E4 was 0.6%, 61.2% and 1.2%, respectively, with a mean frequency of ε2, ε3 and ε4 alleles of 12.6%, 78.0% and 9.4%, respectively.

CONCLUSIONS

In studied European populations we observed a linear, gradually increasing trend in the frequency of ε4 allele from South to North (Pearson's test 0,7656, p value <0.00001), and the Bosnian population fits into this pattern perfectly.

Plasma Homocysteine, Serum Folic Acid, Serum Vitamin B12, Serum Vitamin B6, MTHFR, and Risk of Normal-Tension Glaucoma

BACKGROUND

This meta-analysis aims to comprehensively evaluate the association between total homocysteine (tHcy) levels, serum folic acid, vitamin B12, vitamin B6 levels, methylenetetrahydrofolate reductase (MTHFR) C677T genotype, and risk of normal-tension glaucoma (NTG).

MATERIALS AND METHODS

A systematic search of the EMBASE and PubMed databases was performed to evaluate plasma tHcy levels, serum folic acid, B vitamins' mean difference, and odds ratios of MTHFR C677T genotype between cases and controls.

RESULTS

A total of 7 studies including 458 cases and 555 controls meeting the inclusion criteria were involved in this meta-analysis. There were 4 studies for tHcy (149 cases and 148 controls), 2 studies for vitamin B6, vitamin B12, and folate (90 cases and 82 controls), and 4 studies for MTHFR (343 cases and 449 controls). Overall, the mean plasma tHcy levels, serum folic acids, vitamin B12, and vitamin B6 levels were 1.16 μmol/L [95% confidence interval (CI), -0.13, 2.45], -0.62 μmol/L (95% CI, -1.98, 0.74), 5.81 μmol/L (95% CI, -3.53, 15.14), and -16.79 μmol/L (95% CI, -86.09, 52.51). MTHFR TT genotype was found to be unrelated to NTG risk (odds ratio=1.08; 95% CI, 0.69, 1.69).

CONCLUSION

NTG is not associated with elevated plasma tHcy, serum folic acid, serum vitamin B12, serum vitamin B6, and MTHFR C677T genotype.

Association of Hemostatic Gene Polymorphisms With Early-Onset Ischemic Heart Disease in Egyptian Patients

The association between hereditary thrombophilia and venous thrombosis is well established but controversial data exist with respect to arterial thrombosis. We performed a pilot study on 31 patients with acute myocardial infarction (AMI), 21 patients with unstable angina (UA), and 20 healthy volunteers to investigate the role of various hemostatic gene polymorphisms in young Egyptian patients, who survived their first ischemic heart disease (IHD). Thrombophilic gene polymorphisms were tested using multiplex polymerase chain reaction and reverse-hybridization technique. We showed an increased risk of AMI with factor V (FV) Leiden and prothrombin G20210A heterozygosity. The increased risks of UA was associated with GA and A allele of fibrinogen β-455G→A polymorphism. Conversely, factor XIII (FXIII) Val34Leu GT and T allele were protective in the UA group. Nevertheless, the prevalence of FV H1299R, plasminogen activator inhibitor 1 4G/5G, glycoprotein IIIa C1565T, 5,10-methylenetetrahydrofolate reductase C677T, and A1298C mutations did not differ between patients with IHD and controls. The data have clinical implications regarding screening and thromboprophylaxis in high-risk individuals younger than 40 years.

Prevalence of genetic prothrombotic risk factors: 1691G > A FV, 20210G > A PT and 677C > T MTHFR mutations in the Bosnian population

BACKGROUND

Venous thrombosis (VT) affects 1-2 out of 10(3) individuals each year. Mutations of 1691G > A FV gene, 20210G > A PT gene and 677C > T gene MTHFR are common in Europe and increase the risk of venous thrombosis. To the authors' knowledge, this is the first report on the prevalence of these mutations in the general population of Bosnia and Herzegovina.

AIM

The aim of this study was to simultaneously analyse main VT associated polymorphisms and compare the results with those published for other European populations.

DATA SOURCES

Electronic databases including Medline and Embase were searched from 1995 to December 2013.

SUBJECTS AND METHODS

The subjects of the study consisted of 100 unrelated healthy people from Bosnia and Herzegovina (82 female and 18 male). The mean age of the cohort was 58.8 (± 10.7) years. PCR-RFLP was used for measurement of allele frequencies.

RESULTS

All three SNPs were found to be polymorphic, with allele frequencies of 6.0%, 6.0% and 37.5% for 1691A FV, 20210A PT and 677T MTHFR, respectively.

CONCLUSION

Further studies on larger cohorts with an adequate female-to-male ratio are necessary to confirm a high prevalence of hereditary thrombophilia in the Bosnian population.

Apolipoprotein E polymorphisms and ischaemic stroke: a two-center Greek study

BACKGROUND AND PURPOSE

Apolipropotein E(apoE) is a plasma protein exhibiting three common isoforms (E2, E3, E4). Its involvement in lipoprotein metabolism may have an impact on stroke occurrence. As results in the literature are inconclusive further studies are needed to elucidate its role. Our objective was to study the role of apoE isoforms and the interplay with environmental risk factors in patients with first ischaemic stroke occurrence in the Greek population.

METHODS

Three hundred and twenty-nine patients with first-ever ischaemic stroke were included in our study. Strokes of cardioembolic origin and patients with autoimmune or prothrombotic syndromes were excluded. A control group of 361 subjects with no stroke history were also included in our study. Risk factors (hyperlipidemia, hypertension, diabetes mellitus and smoking) were assessed. ApoE alleles were determined in all subjects participating in the study.

RESULTS

Genotype ε3/ε3 was found to have a protective role against stroke occurrence compared with other genotypes (odds ratio 0.674, 95% confidence interval 0.480-0.946) especially in the female patient subgroup. In multivariate analysis after adjustment for age, body mass index (BMI), hypertension, dyslipidemia, diabetes mellitus and smoking, the role of genotype was limited and outweighed by risk factors in both genders. No association between apoE alleles and BMI, cholesterol, triglycerides or high-density lipoprotein plasma levels was noted.

CONCLUSIONS

Our study was indicative of a protective role of the ε3/ε3 genotype, especially in female patients. However, risk factors such as age, BMI, hypertension, dyslipidemia, diabetes mellitus and smoking have a strong impact on stroke occurrence and outweigh the protective role of the ε3/ε3 genotype.

Factor V Leiden, prothrombin 20210G>A, MTHFR 677C>T and 1298A>C, and homocysteinemia in Tunisian blood donors

Specific genetic conditions are known to be associated with high risk of venous thromboembolism. This genetic basis varies widely between ethnic groups. We investigated the distribution of four inherited polymorphisms in 113 unselected Tunisian blood donors by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The allele frequencies of Factor V Leiden (FVL), prothrombin 20210G>A, methylenetetrahydrofolate reductase (MTHFR) 677C>T, and MTHFR 1298A>C mutations were 3, 0.9, 30, and 31%, respectively. The MTHFR 677C>T polymorphism was influenced by age. Twenty-nine of the 113 blood donors demonstrated more than one genetic markers. Hyperhomocysteinemia was found in 12 subjects, and it was statistically associated to the MTHFR 677TT genotype. Principal component analysis allowed disclosing the resemblance between Mediterranean populations. Our findings may be helpful for population genetics study, and provide epidemiologic database for further studies in thrombosis field among Tunisians.

Cross-sectional study of risk factors for atherosclerosis in the Azorean population

BACKGROUND

Atherosclerosis-a major cause of vascular disease, including ischemic heart disease (IHD), is a pathology that has a two-fold higher mortality rate in the Azorean Islands compared to mainland Portugal.

AIM

This cross-sectional study investigated the role of genetic variation in the prevalence of atherosclerosis in this population.

SUBJECTS AND METHODS

A total of 305 individuals were characterized for polymorphisms in eight susceptibility genes for atherosclerosis: ACE, PAI1, NOS3, LTA, FGB, ITGB3, PON1 and APOE. Data were analysed with respect to phenotypic characteristics such as blood pressure, lipid profile, life-style risk factors and familial history of myocardial infarction.

RESULTS

In the total sample, frequencies for hypercholestrolemic, hypertensive and obese individuals were 63.6%, 39.3% and 23.3%, respectively. The genetic profile was similar to that observed in other European populations, namely in mainland Portugal. No over-representation of risk alleles was evidenced in this sample.

CONCLUSIONS

One has to consider the possibility of an important non-genetic influence on the high cholesterolemia present in the Azorean population. Since diet is the most important life-style risk factor for dyslipidemia, studies aiming to evaluate the dietary characteristics of this population and its impact on serum lipid levels will be of major importance.

Portal, splenic and mesenteric vein thrombosis in a patient double heterozygous for factor V Leiden and prothrombin G20210A mutation

We herein report a 56-year-old man who presented with abdominal pain, diarrhea and a 22-kg-weight loss over 4 months. He was on acenocoumarol treatment because of portal, splenic and mesenteric vein thrombosis (PSMVT) 3 months before, with admission international normalized ratio (INR):1.6. Doppler ultrasonography and helical computerized tomographic scan of the abdomen showed complete thrombosis of the extrahepatic portal vein extending into the superior mesenteric vein and splenic vein. The manifestation of thrombosis was in the absence of provocative stimuli or local cause. The patient had a negative history of venous thromboembolism. Thrombophilia workup revealed double heterozygosity for factor V Leiden and prothrombin G20210A mutation. He was immediately started with intravenous unfractionated heparin, followed by oral anticoagulation with target INR 2-3. Five days after a Doppler examination showed significant improvement in the flow within the portal vein, and a computerized tomographic scan of the abdomen 1 month later showed extensive recanalization of the portal venous system. The patient is now 36 months out from the second PSMVT episode and is doing well although maintaining oral lifelong anticoagulation. The case is of particular interest in that PSMVT was the first manifestation of this combined disorder. We conclude that all patients presenting with unexplained PSMVT should be investigated for the presence of a hypercoagulable state. Anticoagulation should be considered in all patients with this diagnosis and should be a lifelong therapy in those with an underlying thrombophilia.

Prevalence of angiotensin-converting enzyme, methylenetetrahydrofolate reductase, Factor V Leiden, prothrombin and apolipoprotein E gene polymorphisms in Morocco

BACKGROUND

Evidence of the influence of genetic risk factors on cardiovascular diseases is more or less established. These genetic factors are involved in several pathways affecting blood pressure regulation, blood coagulation, homocysteine and lipid metabolisms.

AIM

We evaluated frequencies of five genetic polymorphisms to assess their informativeness as markers for prospective clinical studies.

SUBJECTS AND METHODS

182 healthy Moroccan subjects were genotyped for ACE I/D by amplification alone and by amplification followed by enzymatic digestion for other polymorphisms.

RESULTS

Allele frequencies of ACE ID, MTHFR C677T were 76.6%, 26.9% for D and T alleles, respectively. APOE polymorphism showed 11.3%, 78.6% and 10.2% for the alleles E2, E3 and E4, respectively. The frequency for FII G20210A polymorphism was around 2.7% for A allele. Our data showed an absence of FVL mutation. Using allele frequencies, genetic distances between Moroccan and other populations revealed an independent variability of these polymorphisms.

CONCLUSION

These values appear to be influenced by findings in European and African peoples, and may be considered in assessing the clinical significance of a predisposition to cardiovascular disease.