The role of factor V Leiden in maternal health and the outcome of pregnancy

Identification of genetic alterations in couples and their products of conceptions from recurrent pregnancy loss in North Indian population

Background: Recurrent pregnancy loss (RPL) is one of the most common pregnancy-related complications, which can be stressful and emotionally draining for a couple. Genetic alterations, which are responsible for RPL, can be present in either of the three genomes: mother, father, or their fetuses. In addition, environmental factors interacting with these three genomes can affect germline cells. With this aim, the present study was conducted to understand the underlying etiology of RPL using Next-generation sequencing (NGS; couple exome and TRIO exomes) in combination with cytogenetic tests [karyotyping and chromosomal microarray (CMA)]. Material & Methods: In present study we recruited 61 couples with RPL (history of ≥ 2 abortions) and 31 products of conceptions (POCs). For all couples karyotyping was done at the time of recruitment, followed by collection of POC samples and parental blood samples. Before processing POC samples for CMA, they were checked for maternal cell contamination (MCC) by QF-PCR. In POC samples with no pathogenic variant, TRIO exome sequencing was done. Further, in case of unavailability of POC sample, couple exome sequencing was done for RPL couples. Results: In six individuals out of 61 couples (5%), abnormality in karyotypes was detected. Among 116 normal karyotypes, there were 11 heteromorphisms (9.5%), for which the couples had to be counselled and reassured. Out of the 31 POCs, 10 were excluded because of MCC (around 30%) and one had major aneuploidy. CMA in POCs identified pathogenic copy number variations (CNVs) in 25% of cases (5/20) and variant of unknown significance (VUS) in 20% of cases (4/20). Autosomal trisomy was the most frequent chromosomal abnormality diagnosed. NGS was performed to establish single-gene causes of RPL. Couple exome sequencing was performed in 20 couples, and 14 were found to be carriers for autosomal recessive conditions. A total of 50 potential disease-causing variants in 40 genes were identified in 33 of 40 individuals (82.5%). Putative causative variants were identified in 37.5% of the TRIO cases (3/8). Mutations in few important genes (SRP54, ERBB4, NEB, ALMS, ALAD, MTHFR, F5, and APOE), which are involved in vital pathways, early embryonic development, and fetal demise, were identified in the POCs. Conclusion: It enhances our understanding of prenatal phenotypes of many Mendelian disorders. These mutated genes may play an auxiliary role in the development of treatment strategies for RPL. There was no correlation of the number of abortions with etiological yield of any technique to detect the cause of RPL. This study shows the utilization of combination of techniques in improving our understanding of the cause of early embryonic lethality in humans.

Pulmonary thromboembolism and role of factor v Leiden in its development: Review of literature

Pulmonary embolism (PE) and deep vein thrombosis (DVT) are associated with considerable morbidity and mortality, and for as much as twenty-five percent of PE patients the primary clinical appearance is unexpected death. Diagnosis of PE is based on clinical suspicious at first, but sometimes its diagnostics can be extremely difficult. Newly increased interest in an inherited thrombophilic states has been provoked by the discovery of several common inherited abnormalities, i.e. the prothrombin (PT) gene G20210A, Factor V Leiden (FVL) mutation (Arg506Gln), hyperhomocystenemia and homocysteiuria, Wein-Penzing defect, Sticky Platelet Syndrome (SPS), Quebec platelet disorder (QPD) and Sickle Cell Disease (SCD). PE incidence rates increase in recent years. The only explanation at this moment is increased awareness of PE, especially after any kind of surgery, immobile state or unexplained shorthness of breath.

A case of pulmonary thromboembolism due to coagulation factor V Leiden in Japan ~ usefulness of next generation sequencing~

Background

Because the venous thromboembolisms (VTEs) due to the coagulation factor V R506Q (FV Leiden) mutation is often seen in Caucasians, the VTE onset in Japan has not been reported.

Case presentation

A 34-year-old man from north Africa experiencing sudden dyspnea went to a hospital for advice.

The patient had pain in his right leg and a high plasma D-dimer level. A contrast-enhanced computed tomography scan revealed a contrast deficit in the bilateral pulmonary artery and in the right lower extremity. The patient was diagnosed with VTE, and anticoagulation therapy was initiated. Our targeted gene panel sequencing revealed that the occurrence of VTE was attributed to a presence of the FV Leiden mutation.

Conclusions

This is the first report demonstrating VTE caused by the FV Leiden mutation in Japan.

Preeclampsia: Definitions, screening tools and diagnostic criteria in the supersonic era

Preeclampsia is still a major risk factor for maternal-fetal health. Therefore, early identification of pregnant women at risk for preeclampsia is a big priority in obstetrics in order to decrease the mortality and morbidity associated with this disease. On the basis of well known and new pathophysiological mechanisms of preeclampsia, different biochemical and ultrasonographic parameters have been investigated in the literature, without finding an ideal marker for early screening. In this brief review, we present the best studied ultrasonographic markers and the most recent genetic factors and promising emerging biomarkers of preeclampsia, to date. We hope that in the future the combination of these tests will allow us to predict which women are at risk of preeclampsia.

Can Factor V Leiden and prothrombin G20210A testing in women with recurrent pregnancy loss result in improved pregnancy outcomes?: Results from a targeted evidence-based review

Women with recurrent pregnancy loss are offered Factor V Leiden (F5) and/or prothrombin G20210A (F2) testing to identify candidates for anticoagulation to improve outcomes. A systematic literature review was performed to estimate test performance, effect sizes, and treatment effectiveness. Electronic searches were performed through April 2011, with review of references from included articles. English-language studies addressed analytic validity, clinical validity, and/or clinical utility and satisfied predefined inclusion criteria. Adequate evidence showed high analytic sensitivity and specificity for F5 and F2 testing. Evidence for clinical validity was adequate. The summary odds ratio for association of recurrent pregnancy loss with F5 in case-controlled studies was 2.02 (95% confidence interval, 1.60-2.55), with moderate heterogeneity and suggestion of publication bias. Longitudinal studies in women with recurrent pregnancy loss or unselected cohorts showed F5 carriers were more likely to have a subsequent loss than noncarriers (odds ratios: 1.93 and 2.03, respectively). Results for F2 testing were similar. For clinical utility, evidence was adequate that anticoagulation treatments were ineffective (except in antiphospholipid antibody syndrome) and had treatment-associated harms. The certainty of evidence is moderate (high, moderate, and low) that anticoagulation of women with recurrent pregnancy loss and F5/F2 variants would currently lead to net harms.

Does marriage between first cousins have any predictive value for maternal and perinatal outcomes in pre-eclampsia?

AIM

To assess the consequences of consanguineous unions between first cousins on the severity of pre-eclampsia and associated perinatal morbidity.

METHODS

Six hundred and eighty-six women admitted with a diagnosis of pre-eclampsia were included. The study group consisted of 62 preeclamptic women with a union between first cousins. The remaining patients admitted throughout the same period (n = 624) served as controls. The groups were compared regarding the presence of severe pre-eclampsia, hemolysis elevated liver enzymes low platelets (HELLP) syndrome, eclampsia, placental abruption, hematological complications, renal failure, requirement for antihypertensive or magnesium sulfate treatments, cesarean section for acute fetal distress, birthweight, Apgar scores, perinatal mortality and neonatal morbidity including admission to the neonatal intensive care unit, respiratory distress syndrome, sepsis, convulsions, intracranial hemorrhage, hypoglycemia, hypocalcemia, and jaundice. Student's t-test, chi(2)-test and logistic regression analysis were used for statistical evaluation.

RESULTS

Univariate analysis yielded significant differences in parity (P = 0.034), maternal platelet counts (P = 0.02), and maternal serum potassium levels (P = 0.016) among the groups. Respiratory distress syndrome was more frequent (P = 0.043) in infants of unrelated couples. Multivariate analysis, controlling for the confounding factors, revealed that marriages between first cousins had no effect on any of our outcome variables including neonatal respiratory distress syndrome.

CONCLUSIONS

Third-degree consanguinity in terms of a union between first cousins seems to have no effect on the development of maternal and perinatal complications in established pre-eclampsia.

Fetal and Neonatal Thrombophilia

Thrombophilia of the fetus and neonate may contribute to higher prevalence of perinatal thrombosis. Due to the potential interaction between thrombophilic risk factors of the neonate and maternal thrombophilia and placental vasculopathy, we recommend thrombophilia assessment be performed in any child and in the mother in case of perinatal thrombosis. Further attention and larger prospective studies are required to establish the role of thrombophilic risk factors in the pathogenesis of any other perinatal complications.

Inherited and acquired thrombophilia: Pregnancy outcome and treatment

Maternal thrombophilias increases the risk of an adverse pregnancy outcome. An extensive literature review highlights the role of inherited and acquired thrombophilic disorders in spontaneous abortion, both early and late, recurrent or isolate, in intrauterine growth retardation, in placenta abruption, in pre-eclampsia and in venous thromboembolism. We have particularly focused attention on the following factors: antithrombin III (ATIII), proteins C (PC) and S (PS) deficiencies, genetic mutations particularly factor V Leiden (FVL), prothrombin gene G20210A (PTM) and the thermolabile variant of the methylene tetrahydrofolate reductase C677T (MTHFR) gene, lupus anticoagulant (LAC) and anticardiolipin antibodies, VIIIc factor, hyperhomocysteinemia and acquired activated protein C resistance. Appropriate treatment can improve pregnancy outcome without teratogenic effects.