Prevalence of factor V Leiden, prothrombin and methylene tetrahydrofolate reductase mutations in women with adverse pregnancy outcomes in Lebanon

The prevalence of Factor V Leiden (Arg506Gln) mutation in King Khalid University Hospital patients, 2017-2019

Arg506Gln mutation is responsible for one of the procoagulant factors and most common inherited thrombophilia in the Factor V Leiden (FVL) family. The replacement of the missense mutation for Arg506Gln / R506Q is at 1691st position from Guanine to Adenine with the modification of the amino acid from arginine to glutamine. The aim of this study was to investigate the current prevalence of the G1691A mutation in the FVL gene in the capital city’s King Khalid University Hospitals (KKUH). Since 2017–2019 we have recruited 482 patients in these cross-sectional studies to test the G1691A mutation in KKUH’s FVL gene. DNA was extracted using 2mL of the EDTA blood and genotyping was performed with polymerase chain reaction and the data was analyzed using Sanger sequencing. In this study, 4.4% of the G1691A mutation was found to be positive (combined heterozygous-GA and homozygous-AA variants) and 95.6% of them with negative, i.e., homozygous normal-GG genotypes. Our study concludes that with the advances in genetic testing and their recent availability, early mutation detection could approve the genotype risks for many patients and this mutation is not as rare as previously believed in the Saudi region as our study has established with a 4.4 percent prevalence.

Factor V Leiden G1691A and Prothrombin Gene G20210A Mutations on Pregnancy Outcome

Factor V Leiden (FVL) G1619A mutation and prothrombin gene (PTG) G20210A are the most common inherited thrombophilias. They have been associated with various obstetric complications such as venous thromboembolism, recurrent pregnancy loss, preeclampsia, abruptio placentae, and small for gestational age fetus. The prevalence of these two mutations is 3-15% in Caucasians and is assumed to be far less common in other ethnic populations. However, there have been several controversies regarding advising routine screening of these thrombophilias because of a widely variable strength of association between different ethnic groups, as well as contradictory conclusions by different studies in regards to the association. In this study, the literature was analyzed thoroughly for the effect of FVL G1619A and PTG G20210A mutations on various obstetric outcomes. A review of multiple case-control and prospective studies suggests that despite the availability of robust data on this subject the results remain inconclusive and insubstantial. Further superior quality research, preferably prospective studies, is warranted to conclusively establish this relationship and to enable practitioners to follow a definitive protocol in the screening of various populations for these mutations to achieve an improved pregnancy outcome.

Comparative risks and predictors of preeclamptic pregnancy in the Eastern, Western and developing world

Preeclampsia (PE) is a complication of pregnancy characterized by hypertension (HTN-Preg), and often proteinuria. If not managed promptly, PE could lead to eclampsia and seizures. PE could also lead to intrauterine growth restriction (IUGR) and prematurity at birth. Although PE is a major cause of maternal and fetal morbidity and mortality, the underlying mechanisms are unclear. Also, there is a wide variability in the incidence of PE, ranging between 2 and 8% of pregnancies in the Eastern, Western and Developing world, suggesting regional differences in the risk factors and predictors of the pregnancy-related disorder. Several demographic, genetic, dietary and environmental factors, as well as maternal circulating biomarkers have been associated with PE. Demographic factors such as maternal race and ethnicity could play a role in PE. Specific genetic polymorphisms have been identified in PE. Maternal age, parity, education and socioeconomic status could be involved in PE. Dietary fat, protein, calcium and vitamins, body weight, and environmental factors including climate changes and air pollutants could also play a role in PE. Several circulating cytoactive factors including anti-angiogenic factors and cytokines have also been associated with PE. Traditional midwifery care is a common practice in local maternity care units, while advanced perinatal care and new diagnostic tools such as uterine artery Doppler velocimetry have been useful in predicting early PE in major medical centers. These PE risk factors, early predictors and diagnostic tools vary vastly in different regions of the Eastern, Western and Developing world. Further understanding of the differences in the demographic, genetic, dietary and environmental factors among pregnant women in different world regions should help in designing a region-specific cluster of risk factors and predictors of PE, and in turn provide better guidance for region-specific tools for early detection and management of PE.

Evaluation of Gestational Diabetes Mellitus Risk in South Indian Women Based on MTHFR (C677T) and FVL (G1691A) Mutations

We aimed to scrutinize the extent to which single amino acid substitutions in the MTHFR and factor V Leiden (FVL) genes affect the risk of gestational diabetes mellitus (GDM) in pregnant women of South Indian descendant. This case-control study was implemented once the ethical approval has been obtained. Overall, 237 women were recruited in this study: 137 had been diagnosed with GDM and the remaining 100 women were used as normal controls or non-GDM. The diagnosis of GDM was confirmed with biochemical analysis, i.e., GCT and oral glucose tolerance tests. Five milliliters of peripheral blood was collected and used for biochemical and molecular analyses. DNA was isolated, and genotyping for MTHFR (C677T) and FVL (G1691A) mutations was performed using PCR-RFLP. FVL (G1691A) locus was not polymorphic in the investigated sample. There was no significant difference in the allele and genotype frequencies of C677T polymorphism between GDM and non-GDM women (p = 0.8892).

Laboratory referral rates of genetic tests for thrombophilia workup in a major referral center

AIMS

The rate of laboratory referrals for thrombophilia patients' genetic workup was assessed and compared among the medical and surgical specialties and subspecialties at a major tertiary care center in Lebanon.

METHODS

DNA extraction was performed using the PEL-FREEZ extraction kit (PEL-FREEZ; DYNAL) and the Factor V, prothrombin, and methylenetetrahydrofolate reductase genotypic profiles were done using the FV-PTH-MTHFR StripAssay kit (ViennaLab) that employs a polymerase chain reaction-reverse hybridization method. A total of 2238 referred cases were analyzed.

RESULTS

Around 42.23% of all referred cases turned out to have a thrombosis-associated mutation. Referrals from medical and surgical specialties were almost equal. In the surgical specialty, most referrals came from the department of Obstetrics and Gynecology, while in the medical speciality, most of the workup referrals originated from the Hematology/Oncology physicians. However, low referral rates were reported from the emergency department and family medicine practitioners.

CONCLUSION

Genetic testing for thrombophilia workup is gaining more importance among the different medical and surgical specialties and is worth being introduced into the offered test lists of all established molecular diagnostics laboratories.

Epidemiology of activated protein C resistance and factor v leiden mutation in the mediterranean region

Venous thromboembolic disorders (VTE) are serious disorders with high morbidity and mortality rates. Many genetic and acquired risk factors were identified to cause VTE. The most common genetic risk factor is Factor V Leiden mutation (FVL). FVL was found in high percentage of populations of Caucasian origin but was almost absent in non-Caucasians. It was also reported in populations living in North Africa and the Middle East. This review article briefly explains FVL and how it causes VTE, the distribution of FVL worldwide, and then it elaborates on the epidemiology of FVL in the Mediterranean Region and how this brought speculations that FVL might have originated in the Eastern Mediterranean area.

Association of inherited thrombophilia with recurrent pregnancy loss in palestinian women

Objective. This study aimed at analyzing the association between recurrent pregnancy loss (RPL) and factor V G1691A (FVL), prothrombin G20210 (FII); and MTHFR C677T (MTHFR) in Palestinian women. Method. We studied 329 Palestinian women with RPL and/or stillbirth (SB); and compared them to 402 healthy reproductive Palestinian women. Cases and controls were tested for the above mutations. Odds ratio (OR) at confidence interval (CI) of 95% was used as a measure of association between the mutations and RPL. Results. Our statistical analysis showed a slightly increased association, which was not significant between FVL and RPL (OR 1.32, 95% CI 0.90-1.94), and no association between FII (OR 0.84, 95% CI 0.38-1.92), MTHFR (OR 0.58, 95% CI 0.32-1.03), and RPL. Further analysis of RPL subgroups revealed an association between FVL and first-trimester loss (OR 1.33, 95% CI 0.892-1.989), and second-trimester loss (OR 1.13, 95% CI 0.480-2.426), both were not statistically significant. Furthermore, the only statistically significant association was between FVL and SB (OR 2.0, 95% CI 1.05-3.70). Conclusion. Our analysis had failed to find a significant association between FVL, FII, MTHFR; and RPL in either the first or second trimester. FVL was significantly associated with fetal loss if the loss was a stillbirth.

Prothrombin gene G20210A mutation and obstetric complications

OBJECTIVE

To estimate whether maternal carriage of the prothrombin gene G20210A mutation is associated with pregnancy loss, preeclampsia, placental abruption, or small for gestational age (SGA) neonates in a low-risk, prospective cohort.

METHODS

This was a secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development factor V Leiden study, a multicenter, prospective, observational cohort of 5,188 unselected singleton gestations. A total of 4,167 first-trimester samples were available for analysis and were tested for the prothrombin G20210A mutation. Obstetric complications were compared between women with and without the prothrombin G20210A mutation by univariable and multivariable analysis.

RESULTS

A total of 157 (3.8%) women had the prothrombin gene mutation (156 heterozygous and one homozygous). Carriers of the prothrombin G20210A mutation had similar rates of pregnancy loss, preeclampsia, SGA neonates, and abruption compared with noncarriers. Results were similar in a multivariable analysis controlling for age, race, prior pregnancy loss, prior SGA neonates, and family history of thromboembolism. Three thromboembolic events occurred in women testing negative for the mutation.

CONCLUSION

There was no association between the prothrombin G20210A mutation and pregnancy loss, preeclampsia, abruption, or SGA neonates in a low-risk, prospective cohort. These data raise questions about the practice of screening women without a history of thrombosis or adverse pregnancy outcomes for this mutation.

LEVEL OF EVIDENCE

II.

Genetic thrombophilias and intrauterine growth restriction: a meta-analysis

OBJECTIVE

To estimate the relationship between inherited thrombophilias and intrauterine growth restriction (IUGR) using meta-analytic techniques.

METHODS

A literature review identified case-control and cohort studies evaluating the relationship between IUGR and the following thrombophilias: homozygous or heterozygous factor V Leiden or prothrombin (PT) G20210A mutations and homozygous methylenetetrahydrofolate reductase (MTHFR) C677T mutation. Using mixed effects and random-effects models, the association between thrombophilias and IUGR was explored. Publication bias was assessed with funnel plots and corrected for with Duval and Tweedie's trim-and-fill method.

RESULTS

The following number of related studies were found: studies evaluating relationships between factor V Leiden mutation and IUGR, 12 case-control and four cohort; between PT mutation and IUGR, 11 case-control and 0 cohort; and between MTHFR C677T homozygosity and IUGR, 10 case-control and two cohort. The overall summary odds ratio (OR) for the association between factor V Leiden and IUGR was significant (OR 1.23, 95% confidence interval [CI] 1.04-1.44); however, this was mainly driven by the positive association seen in the case-control studies (OR 1.91, 95% CI 1.17-3.12). The association between PT and IUGR was only explored in case-control studies yielding a summary OR that was not significant (OR 1.52, 95% CI 0.98-2.35). The overall summary OR for the association between MTHFR and IUGR was not significant (OR 1.01, 95% CI 0.88-1.17), but was significant for the case-control studies alone (OR 1.35, 95% CI 1.04-1.75). For both factor V Leiden and MTHFR mutations, a funnel-plot analysis of the case-control studies suggests publication bias. When the trim-and fill-method was used to correct for the publication bias, these summary estimates were no longer significant.

CONCLUSION

The association between inherited thrombophilias and IUGR can only be discerned in case-control studies and seems to be largely because of publication bias.

LEVEL OF EVIDENCE

III.