Screening for multiple hereditary hypercoagulability factors using the amplification refractory mutation system

Association of inherited thrombophilia mutations and their combinations among palestinian women with unexplained recurrent miscarriage

BACKGROUND

Inherited thrombophilia (IT) has a complex pathophysiology and is associated with recurrent miscarriage (RM) by causing placental insufficiency and inhibiting fetal development. However, thrombophilia screening in unexplained RM cases is still questionable. This study aimed to investigate the association between the common eight IT mutations and their combinations among Palestinian women with unexplained RM.

METHODS

This is an unmatched case-control study with 200 women (100 unexplained RM cases, 100 controls). Eight common IT mutations namely Factor V Leiden (FVL), prothrombin gene (FII) G202120A, Methylenetetrahydrofolate Reductase (MTHFR) gene (C677T and A1298C), B-fibrinogen gene - 455G > A, FV HR2 A4070G, Plasminogen activator inhibitor 1 (PAI1) 5G/4G and Factor XIIIA (FXIIIA) V34L; were analyzed. The first five mutations were analyzed by Restriction Fragment Length Polymorphism PCR and the other three mutations were analyzed using Amplification Refractory Mutation System PCR.

RESULTS

The prevalence of the eight IT mutations among the control group was in the order PAI1 5G/4G (69%), MTHFR C677T (53%) and A1298C (47%), BFG - 455G > A (35%), FVL and FV HR2 (each 18%), FXIIIA V34L (16%) and FII G20210A (3%). Patients had a higher percentage of MTHFR A1298C (heterozygotes and mutant homozygote) compared to controls (p = 0.016). Frequencies of mutant alleles MTHFR A1298C (p < 0.001) and FXIIIA V34L (p = 0.009) were higher among patients compared to controls. No significant differences were observed for all other mutations or mutant alleles. Most patients (75%) and controls (75%) have 2-4 mutant alleles out of 8 mutant alleles studied, while 1% of patients and 2% of controls have zero mutant alleles. None of the combinations of the most often studied mutations (FVL, FII G20210A, MTHFR C1677T, and MTHFR A1298C) showed a significant difference between patients and controls.

CONCLUSIONS

There was a significant association between unexplained RM and the mutant alleles of MTHFR A1298C and FXIIIA V34L. No significant association was observed between unexplained RM and the combination of both mutant alleles for the mutations studied. This study is the first Palestinian report that evaluates eight inherited thrombophilia mutations and their alleles' combinations in unexplained RM cases.

A Prothrombotic Score Based on Genetic Polymorphisms of the Hemostatic System Differs in Patients with Ischemic Stroke, Myocardial Infarction, or Peripheral Arterial Occlusive Disease

Background

While twin studies indicate a genetic component in arterial thrombosis such as ischemic stroke, myocardial infarction (MI), or peripheral arterial occlusive disease (PAOD), the clinical relevance of hemostatic polymorphisms in arterial thrombosis is a matter of debate.

Methods

We analyzed the prevalence of 13 hemostatic polymorphisms [PAI-1, PLAT, F5 (including factor V Leiden and HR2 haplotype), F2, F7, F13A, FGB, TFPI, THBD, MTHFR, ACE, and ITGA2] in patients referred to a tertiary referral center. A “prothrombotic score” was calculated by dividing the number of risk-increasing polymorphisms for thrombosis minus the number of risk-lowering polymorphisms (F7 and F13A) by the number of polymorphisms tested.

Results

Datasets of 144 patients with prior ischemic stroke (mean age 44 ± 13 years; 65% female) were compared to 62 patients with MI or PAOD (mean age 54 ± 14 years; 47% female). The prothrombotic score was lower in MI and PAOD patients compared to stroke patients [odds ratios 2.7 (95% confidence intervals 1.1–6.2)]. Frequencies of individual polymorphisms did not differ between both groups.

Conclusion

Patients with MI or PAOD had a lower burden of prothrombotic mutations compared to patients with prior stroke, indicating that a prothrombotic state might play a different role in distinct forms of arterial thrombosis.

Genetic susceptibility to deep venous thromboembolism: the roles of inherited thrombophilia polymorphisms

Recently much attention has been paid to the possibly considerable role of the thrombophilic gene polymorphisms in the pathogenesis of deep venous thromboembolism (DVT). However, the reported results are controversial. Hence, this study aimed to disclose the association between factor VII (FVII) 10976G/A, angiotensin-converting enzyme (ACE; intron 16 I/D), glycoprotein Ia (GPIa) 807C/T, tissue-type plasminogen activator (t-PA; intron 8 D/I) and tissue-factor pathway inhibitor 536C/T polymorphisms and DVT. We investigated these gene polymorphisms in 693 study participants including 193 patients who showed clinical symptoms of DVT and 500 healthy individuals without both personal and family histories of thromboembolic disorders. Genotyping was performed using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique. Comparison of genotypes distribution revealed that the FVII 10976G/A polymorphism was significantly related with DVT (P < 0.05), whereas there was no association between the ACE (intron 16 I/D), GPIa807C/T, t-PA (intron 8 D/I) and tissue-factor pathway inhibitor 536C/T gene polymorphisms and DVT (P > 0.05). In addition, the prevalence of homozygote genotype and mutant allele for FVII 10976G/A polymorphism was significantly higher in cases compared with controls (P < 0.05). Taken together, our data provide evidence to support the hypothesis that FVII 10976G/A polymorphism may be associated with a predisposition to DVT.

Polymorphism and synergism of angiotensin-converting enzyme (ACE) and plasminogen activator inhibitor-1 (PAI-1) genes in coronary artery disease

INTRODUCTION

Among the genetic factors for coronary artery diseases, PAI-1 4G/5G and ACE I/D polymorphisms can be noted. This study was carried out to investigate the association of these two polymorphisms and their synergism in coronary artery disease (CAD) from a sample of the Iranian population.

MATERIALS AND METHODS

Sixty-one patients with a history of CAD and 92 healthy controls participated in our study. After DNA extraction from leukocytes, PCR was performed to characterize PAI-1 4G/5G and ACE I/D polymorphisms, using an amplification refractory mutation system technique.

RESULTS

In the studied patients, PAI-1 polymorphisms were 24.6%, 45.9%, and 29.5% for 4G/4G, 4G/5G and 5G/5G, respectively; the values for controls were 20.7%, 42.2% and 37.0%. The distribution rates of genotypes I/I, I/D and D/D in patients accounted for 29.5%, 45.9% and 24.6%; in the control group these figures were estimated to be 40.2%, 40.2% and 19.6%.

CONCLUSION

Single and multivariate analyses showed a significant difference for the conventional risk factors, including hypertension, diabetes, hyperlipidemia, smoking and family history, for CAD between patients and controls (p value ≤ 0.001). However, no significant correlation was demonstrated considering ACE and PAI-1 polymorphisms either in association with 4G/4G or D/D genotypes or a combination of them in the Iranian population in the current study.

Polymorphisms in thrombophilic genes are associated with deep venous thromboembolism in an Iranian population

It has been revealed that the inherited thrombophilia increases the risk of thrombosis in the venous system. To study the association of factor V G1691A, factor V HR2 (4070A/G), prothrombin G20210A, and PAI-1 (- 675 I/D, 5G/4G) polymorphisms with deep venous thromboembolism (DVT), these polymorphisms were investigated. A total of 193 patients who presented clinical symptoms of deep venous thromboembolism including 103 men and 90 women, and 500 healthy individuals without both personal and family histories of thromboembolic disorders including 275 men and 225 women were recruited into the study. Genotyping was carried out using the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) technique. Our results showed that the genotype distribution for FV (G1691A and A4070G) and PAI-1 4G/5G polymorphisms in DVT patients were significantly higher than healthy control (P < 0.05). Also, the mutant allele frequencies for all studied polymorphisms differed significantly between the case and control groups (P < 0.05). We concluded that the prevalence of FV (G1691A and A4070G) and PAI-1 4G/5G polymorphisms increased the risk of DVT occurrence in subjects. These findings provide additional evidence to support the hypothesis that thrombophilic gene polymorphisms are involved in vascular thromboembolism.

Prevalence of thrombophilic gene polymorphisms in an azari population of iran

There is several evidence suggests that thrombophilic gene polymorphisms may influence susceptibility to thromboembolic events. The prevalence of these polymorphisms is different in various races and ethnics. Accordingly, we studied the prevalence of Factor V (G1691A and A4070G), prothrombin G20210A and PAI-1 4G/5G in healthy northwest population of Iran. In this prospective study, 500 healthy individuals, who had no history of both personal and family history of thromboembolic disorders, were selected as a sample of healthy population in northwestern Iran. Genotyping of these polymorphisms was performed using the amplification refractory mutation system-polymerase chain reaction method. No significant differences were detected between the expected and observed frequencies of FV G1691A and A4070G, prothrombin G20210A polymorphisms (P>0.05), while the expected frequency of 4G allele was significantly more than observed frequency in the studied population (P<0.01). These findings were compared with other reports from various populations. In conclusion, the allele frequency for FV G1691A and PAI-1 4G/5G polymorphisms showed relative consistency compared to those of previous studies, while the incidence pattern of FV A4070G polymorphism in Northwestern population of Iran showed conflicting results regarding other studied population. The prothrombin G20210A polymorphism was observed at a higher frequency than other studied populations.

The association between thrombophilic gene mutations and recurrent pregnancy loss

PURPOSE

To determine whether the Factor V (1691G/A), Factor V HR2 (4070A/G), Prothrombin (20210G/A), PAI-1 (-675 I/D, 5G/4G), ACE (intron 16 I/D), Factor VII (Gln353Arg), Factor XIII (Val34Leu), β-fibrinogen (-455G/A), Glycoprotein Ia (807C/T), tPA (intron 8 D/I) gene mutations could be risk factors for recurrent pregnancy loss (RPL).

METHODS

Genotyping of thrombophilic gene mutations were carried out by amplification Refractory Mutation System-PCR (ARMS-PCR) method after DNA extraction.

RESULTS

We found that the mutant allele frequencies of Factor V (1691G/A), Factor V HR2 (4070A/G), Prothrombin (20210G/A), PAI-1 (-675 I/D, 5G/4G), Factor XIII (Val34Leu) and β-fibrinogen (-455G/A) were more seen in the case group compared with the healthy control; However, the difference between the two group is not statistically significant (p > 0.05). Whilst the mutant allele frequencies of other studied genes were lower in the case in comparison to the fertile control women (p > 0.05).

CONCLUSION

Taken together, our data has shown that the prevalence of thrombophilic gene mutations was similar in women with RPL and healthy controls. Therefore, it appears that further studies on large-scale population and other genetic variants will be needed to conclusively find candidate genes for RPL unknown etiology in the future.

Methylenetetrahydrofolate Reductase C677T and A1298C Mutations in Women with Recurrent Spontaneous Abortions in the Northwest of Iran

Introduction. Recurrent spontaneous abortion (RSA) is a significant obstetrical complication that may occur during pregnancy. Various studies in recent years have indicated that two common mutations (C677T and A1298C) of the methylenetetrahydrofolate reductase (MTHFR) gene are risk factor for RSA. This study was carried out to determine the influence of (C677T and A1298C) of the methylenetetrahydrofolate reductase (MTHFR) gene mutations with RSA. Materials and Methods. A total of 139 women were included in this study: 89 women with two or more consecutive miscarriages and 50 healthy controls. Total genomic DNA was isolated from blood leukocytes. To determine the frequency of the two common C677T and A1298C MTHFR gene mutations in the patients and controls, we used two methods, amplification refractory mutation system-PCR and PCR-restriction fragment length polymorphism. Results. There is no significant difference in the prevalence of 677T/T genotype among women with RSA and healthy controls (P = 0.285). Also no statistically significant difference in the frequency of A1298C MTHFR gene mutation was detected between the two groups (P = 0.175 ). Conclusion. In conclusion, the results indicate that the Amplification Refractory Mutation System-PCR method was in complete concordance with the results obtained by standard PCR-restriction fragment length polymorphism method. The results also show no significant difference in MTHFR C677T/A1298C genotype distribution among the two groups; therefore, further studies on larger population and other genetic variants to better understand the pathobiology of RSA are needed.

Evolving methods for single nucleotide polymorphism detection: Factor V Leiden mutation detection

BACKGROUND

The many techniques used to diagnose the Factor V Leiden (FVL) mutation, the most common hereditary hypercoagulation disorder in Eurasians, and the most frequently requested genetic test reflect the evolving strategies in protein and DNA diagnosis.

METHODS

Here, molecular methods to diagnose the FVL mutation are discussed.

RESULTS

Protein-based detection assays include the conventional functional activated protein C resistance coagulation test and the recently reported antibody-mediated sensor detection; and DNA-based assays include approaches that use electrophoretic fractionation e.g., restriction fragment length polymorphism, denaturing gradient gel electrophoresis, and single-stranded conformational PCR analysis, DNA hybridization (e.g., microarrays), DNA polymerase-based assays, e.g., extension reactions, fluorescence polarization template-directed dye-terminator incorporation, PCR assays (e.g., amplification-refractory mutation system, melting curve analysis using real-time quantitative PCR, and helicase-dependent amplification), DNA sequencing (e.g., direct sequencing, pyrosequencing), cleavase-based Invader assay and ligase-based assays (e.g., oligonucleotide ligation assay and ligase-mediated rolling circle amplification).

CONCLUSION

The method chosen by a laboratory to diagnose FVL not only depends on the available technical expertise and equipment, but also the type, variety, and extent of other genetic disorders being diagnosed.

Association of angiotensin-converting enzyme intron 16 insertion/deletion polymorphism with history of foetal loss

Introduction. The angiotensin-converting enzyme (ACE) intron 16 insertion/deletion (I/D) polymorphism is associated with ACE activity and has been discussed as a risk factor for pre-eclampsia. Disturbances of uteroplacental circulation are involved in the pathogenesis of pre-eclampsia. In this study, we tested whether the ACE I/D genotype is associated with history of foetal loss (FL) or uteroplacental dysfunction (UPD).

Patients and methods. ACE I/D genotype was determined in 312 women presenting with a history of FL and 112 women admitted because of UPD. The association of the ACE I/D genotype with FL or UPD was assessed in a case-control study using 527 patients with diagnoses other than FL or UPD. To exclude potential biases due to associations of this genotype with other diagnoses, we additionally performed a case-control study using 553 healthy controls. Results. ACE I/D genotype was significantly associated with history of FL in both case-control studies (patient controls: odds ratio 1.52, p<0.02; healthy controls: odds ratio 1.48, p=0.02). There was no evidence for allele-dose dependency. No association of the ACE I/D genotype with UPD could be detected.

Conclusions. The ACE I/D genotype exhibits a statistically significant association with a history of FL. These results corroborate an involvement of the renin-angiotensin system in pregnancy complications.

Use of Heparin in Women With Early and Late Miscarriages With and Without Thrombophilia

Objective: In women with a history of recurrent miscarriage, the risk of miscarriage in a subsequent pregnancy is about 30% to 40%. In patients with thrombophilia, the risk is even higher. Placental thrombosis has been found in women with unexplained recurrent miscarriage independent of thrombophilia. In addition, proinflammatory changes, for example, altered Th1 to Th2 cytokine ratio and complement activation, have been repeatedly demonstrated in these women. Because of the fact that heparin has both anticoagulative and anti-inflammatory effects, the current study evaluated the efficacy of low-molecular-weight heparin (LMWH) in unexplained abortions. Study Design: A total of 164 women with unexplained early and late miscarriages presented in our hemostaseological clinic for thrombophilia screening. For these 164 women, 82 subsequent pregnancies in 79 patients were treated with subcutaneous LMWH independently of thrombophilia. In 54/82 unselected pregnancies, 100 mg aspirin was administered in addition to LMWH. Two patients were excluded due to termination of pregnancy. Results: Overall, 83.8% (67/80) of pregnancies resulted in live births. In 22/79 women (27.8%), thrombophilia markers were positive. Most noteworthy, patients with thrombophilia markers had live births at a similar frequency as patients without those parameters. No severe side effects of LMWH were seen. Conclusions: Our data support the notion that LMWH is efficacious in patients with recurrent abortions and thrombophilia. We demonstrated the same effect of LMWH in women with unexplained abortions without thrombophilia. The potential mechanism of action of LMWH in early and late abortions warrants further study.

Marburg I polymorphism of factor VII–activating protease is associated with idiopathic venous thromboembolism

The factor VII–activating protease (FSAP) variant Marburg I is known to attenuate the profibrinolytic system in vitro and was recently shown to be a significant predictor for the evolution and progression of carotid stenosis. The objective of this case-control study was to assess FSAP Marburg I's role in the occurrence of venous thromboembolism (VTE). The frequency of FSAP Marburg I was significantly increased in patients with a history of VTE (17 of 213 patients, 8.0%, P = .014) or idiopathic VTE (12 of 103 patients, 11.7%, P = .002) compared to healthy controls (5 of 213 controls, 2.3%). Logistic regression analysis confirmed FSAP Marburg I to be an independent risk factor for VTE (odds ratio, 3.5; 95% confidence interval [CI], 1.2-10.0) and idiopathic VTE (odds ratio, 6.2; 95% CI, 2.0-18.9).