Methylene tetrahydrofolate reductase and methionine synthase gene polymorphisms as genetic determinants of pre-eclampsia

Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

Recurrent pregnancy loss is a complex health challenge with no universally accepted definition. Inconsistency in definitions involves not only the number of spontaneous abortions (two or three) that are accepted for recurrent pregnancy loss but the types of pregnancy and gestational age at miscarriage. Due to the heterogeneity of definitions and criteria applied by international guidelines for recurrent pregnancy loss, the true incidence of recurrent miscarriage, which is reported to range from 1% to 5%, is difficult to estimate. Moreover, the exact etiology of recurrent pregnancy loss remains questionable; thus, it is considered a polyetiological and multifactorial condition with many modifiable and non-modifiable factors involved. Even after thoroughly evaluating recurrent pregnancy loss etiology and risk factors, up to 75% of cases remain unexplained. This review aimed to summarize and critically analyze accumulated knowledge on the etiology, risk factors, relevant diagnostic options, and management approach to recurrent pregnancy loss. The relevance of various factors and their proposed roles in recurrent pregnancy loss pathogenesis remains a matter of discussion. The diagnostic approach and the management largely depend on the etiology and risk factors taken into consideration by a healthcare professional as a cause of recurrent miscarriage for a particular woman or couple. Underestimation of social and health consequences of recurrent pregnancy loss leads to compromised reproductive health and psychological well-being of women after miscarriage. Studies on etiology and risk factors for recurrent pregnancy loss, especially idiopathic, should be continued. The existing international guidelines require updates to assist clinical practice.

Association of MTR gene polymorphisms with the occurrence of non-syndromic congenital heart disease: a case-control study

To exhaustively explore the association of infant genetic polymorphisms of methionine synthase (MTR) gene with the risk of non-syndromic congenital heart disease (CHD). A hospital-based case-control study involving 620 CHD cases and 620 health controls was conducted from November 2017 to March 2020. Eighteen SNPs were detected and analyzed. Our date suggested that the genetic polymorphisms of MTR gene at rs1805087 (GG vs. AA: aOR = 6.85, 95% CI 2.94-15.96; the dominant model: aOR = 1.77, 95% CI 1.35-2.32; the recessive model: aOR = 6.26, 95% CI 2.69-14.54; the addictive model: aOR = 1.81, 95% CI 1.44-2.29) and rs2275565 (GT vs. GG: aOR = 1.52, 95% CI 1.15-1.20; TT vs. GG: aOR = 4.93, 95% CI 1.93-12.58; the dominant model: aOR = 1.66, 95% CI 1.27-2.17; the recessive model: aOR = 4.41, 95% CI 1.73-11.22; the addictive model: aOR = 1.68, 95% CI 1.32-2.13) were significantly associated with the higher risk of CHD. And three haplotypes of G-A-T (involving rs4659724, rs95516 and rs4077829; OR = 5.48, 95% CI 2.58-11.66), G-C-A-T-T-G (involving rs2275565, rs1266164, rs2229276, rs4659743, rs3820571 and rs1050993; OR = 0.78, 95% CI 0.63-0.97) and T-C-A-T-T-G (involving rs2275565, rs1266164, rs2229276, rs4659743, rs3820571 and rs1050993; OR = 1.60, 95% CI 1.26-2.04) were observed to be significantly associated with risk of CHD. Our study found that genetic polymorphisms of MTR gene at rs1805087 and rs2275565 were significantly associated with higher risk of CHD. Additionally, our study revealed a significant association of three haplotypes with risk of CHD. However, the limitations in this study should be carefully taken into account. In the future, more specific studies in different ethnic populations are required to refine and confirm our findings.Trial registration: Registration number: ChiCTR1800016635; Date of first registration: 14/06/2018.

Biological Role of Folic Acid in Pregnancy and Possible Therapeutic Application for the Prevention of Preeclampsia

The rationale and importance of folic acid supplementation during pregnancy for fetal congenital defect prevention are accepted worldwide. Moreover, a sufficient plasma concentration of folates can reduce the incidence of spontaneous abortions, and support the normal expansion of placental blood vessels, ensuring physiological placental blood flow, thus promoting appropriate fetal growth and development. Furthermore, there is emerging evidence that long-term supplementation with folic acid can effectively prevent preeclampsia. Preeclampsia is unique to the human species in complications during pregnancy, which contributes to maternal and perinatal mortality worldwide. In the pathogenesis of preeclampsia abnormal placental invasion, the excess of antiangiogenic factors and maternal-placental syndrome play a key role. Increased blood levels of homocysteine during pregnancy are associated with the risk of preeclampsia. Moreover, hyperhomocysteinemia has been proposed to be an independent risk factor for preeclampsia. Folate supplementation helps to decrease elevated levels of homocysteine; thus, the role of folic acid supplementation in pregnancy is even more important. Multiple reports suggest that folate administration decreases the level of serum homocysteine and, therefore, reduce the risk and severity of preeclampsia. However, the association between folic acid supplementation and the decreased risk of preeclampsia has been investigated with controversial conclusions. Currently, the optimal dose of folic acid that is effective for preeclampsia prevention remains uncertain. In this review, we aim to summarize the accumulated knowledge on the role of folic acid in the pathogenesis of preeclampsia, and the possible impact of folate supplementation on the decreased risk of preeclampsia.

Interrelation among one-carbon metabolic (OCM) pathway-related indicators and its impact on the occurence of pregnancy-induced hypertension disease in pregnant women supplemented with folate and vitamin B12: Real-world data analysis

Background and objective

A considerable number of pregnant women who were supplemented with folate and vitamin B12 were selected as major participants in studying the one-carbon metabolic (OCM) pathway. Our study aimed to explore the effects of OCM-related indicators on pregnancy-induced hypertension (PIH) and preeclampsia (PE) in pregnant women with folate and vitamin B12 supplementation.

Subjects and methods

A total of 1,178 pregnant women who took multivitamin tablets containing 800 μg folate and 4 μg vitamin B12 daily from 3 months before pregnancy to 3 months after pregnancy were enrolled in this study. These pregnant women were classified into three groups: the normotensive group (n = 1,006), the PIH group (n = 131), and the PE group (n = 41). The information on age, weight, body mass index (BMI), number of embryos, gravidity, parity, and OCM-related indicators (serum level of homocysteine, folate, and vitamin B12; MTHFR C677T genotype) was collected.

Results

The accuracy of the prediction model based on the screened independent risk factors (hyperhomocysteine, OR = 1.170, 95% CI = 1.061-1.291; high folate status, OR = 1.018, 95% CI = 0.999-1.038; and high BMI, OR = 1.216, 95% CI = 1.140-1.297) for PIH in subjects with MTHFR CC genotype (AUC = 0.802) was obviously higher than that in subjects with MTHFR CT, TT genotype (AUC = 0.684,0.685, respectively) by receiver operating characteristic curve analysis. The homocysteine level of the PIH group was significantly higher than that of the normotensive group only in subjects with the MTHFR CC genotype (p = 0.005). A negative correlation between homocysteine and folate appeared in subjects with MTHFR CT + TT genotype (p = 0.005). A model including multiple embryos, nulliparas, and lower folate could predict the process from PIH to PE (AUC = 0.781, p < 0.0001).

Conclusion

The prediction model composed of homocysteine, folate, and BMI for PIH was suitable for subjects with MTHFR CC genotype in pregnant women with supplementation of folate and vitamin B12. Lower folate levels could be an independent risk factor in developing the process from PIH to PE.

Genetic Variants in Folate and Cobalamin Metabolism-Related Genes in Pregnant Women of a Homogeneous Spanish Population: The Need for Revisiting the Current Vitamin Supplementation Strategies

Polymorphisms of genes involved in the metabolism and transport of folate and cobalamin could play relevant roles in pregnancy outcomes. This study assessed the prevalence of genetic polymorphisms of folate and cobalamin metabolism-related genes such as MTHFR, MTR, CUBN, and SLC19A1 in pregnant women of a homogeneous Spanish population according to conception, pregnancy, delivery, and newborns complications. This study was conducted on 149 nulliparous women with singleton pregnancies. Sociodemographic and obstetrics variables were recorded, and all patients were genotyped in the MTHFR, MTR, CUBN, and SLC10A1 polymorphisms. The distribution of genotypes detected in this cohort was similar to the population distribution reported in Europe, highlighting that more than 50% of women were carriers of risk alleles of the studied genes. In women with the MTHFR risk allele, there was a statistically significant higher frequency of assisted fertilisation and a higher frequency of preeclampsia and preterm birth. Moreover, CUBN (rs1801222) polymorphism carriers showed a statistically significantly lower frequency of complications during delivery. In conclusion, the prevalence of genetic variants related to folic acid and vitamin B12 metabolic genes in pregnant women is related to mother and neonatal outcomes. Knowing the prevalence of these polymorphisms may lead to a personalised prescription of vitamin intake.

Associations between the TNMD rs4828038 and ACE2 rs879922 polymorphisms and preeclampsia susceptibility: a case-control study

A case-control study was designed to investigate the association between the angiotensin converting enzyme 2 (ACE2) rs879922, glucose-6-phosphate dehydrogenase (G6PD) rs1050828, and tenomodulin (TNMD) rs4828038 single nucleotide polymorphisms (SNPs), and preeclampsia. A total of 356 Han Chinese pregnant women (170 controls and 186 cases) were recruited into the study. ACE2 rs879922, G6PD rs1050828, and TNMD rs4828038 were tested by the targeted next-generation sequencing technology and the data were analyzed using SPSS version 18. Genotyping of results revealed that patients with the CC/CT genotype in SNP rs4828038 or CC/CG genotype in SNP rs879922 had a significantly decreased susceptibility to late-onset preeclampsia (CC/CT versus TT: OR = 0.543, 95% CI = 0.378 to 0.779, p = .001; CC/CG versus GG: OR = 0.510, 95% CI = 0.038 to 0.860, p = .012). Our study found that the polymorphisms TNMD rs4828038 and ACE2 rs879922 might be associated with late-onset preeclampsia.IMPACT STATEMENTWhat is already known on this subject? Preeclampsia is associated with multiple SNPs, and ACE2 rs879922, G6PD rs1050828, and TNMD rs4828038 are related to essential hypertension and glucose and lipid metabolism disorders. Essential hypertension, diabetes, and dyslipidemia are risks for preeclampsia. The associations between those three SNPs and preeclampsia have not been reported.What do the results of this study add? The polymorphisms of TNMD rs4828038 and ACE2 rs879922 might be associated with the risk of late-onset preeclampsia. There was no relationship between SNP rs1050828 and preeclampsia.What are the implications of these findings for clinical practice and/or further research? TNMD rs4828038 and ACE2 rs879922 might be target sites for genetic diagnosis and therapy, and the levels of mRNA and protein in pregnant women with preeclampsia should be further tested.

A narrative review on the role of folate-mediated one-carbon metabolism and its associated gene polymorphisms in posing risk to preeclampsia

Preeclampsia (PE) presents a major obstetrical problem for mother and fetus which is characterized by the onset of hypertension and proteinuria in formerly normotensive women. Altered folate-mediated one-carbon metabolism is one of the factors for PE development either due to nutritional insufficiencies such as folate deficiency or polymorphisms in genes that code for the key enzymes of the cycle. Commonly, there are four genes in the cycle whose polymorphisms have been described in relation to PE. These factors could cause elevation of homocysteine; the toxic metabolite, which subsequently leads to the development of PE. Sufficient levels of folate have been considered important during pregnancy and may reduce the risk of development of PE. This review aims at discussing genetic polymorphisms and nutritional deficiencies as probable predisposing factors and suggests considering fetal genotypes, varied ethnicities, and interaction of various other factors involved to render better conclusiveness to the present studies.

Relationship of PD-1 (PDCD1) and PD-L1 (CD274) Single Nucleotide Polymorphisms with Polycystic Ovary Syndrome

This study is to investigate the relationship of programmed cell death 1 (PD-1; also known as PDCD1) and programmed death-1-ligand 1 (PD-L1; also known as CD274) single nucleotide polymorphisms (SNPs) with polycystic ovary syndrome (PCOS). This study enrolled 330 PCOS patients and 350 matched controls. ELISA was used to detect the PD-1 and PD-L1 levels in serum. SnaPshot genotyping was performed to analyze the PD-1 and PD-L1 genotyping. Linkage disequilibrium and haplotype of TagSNP loci of PD-1 and PD-L1 genes were also detected. The relationship of genotypes and alleles with PCOS was analyzed. The levels of PD-1 and PD-L1 in the serum of PCOS patients were significantly lower than those in the control group (P < 0.01). The haplotype TT of PD-1 gene at rs10204525 and rs7421861 loci was significantly lower in the PCOS group than in the control group (P < 0.001, OR = 0.67, and 95%CI = 0.54‐0.84). PD-L1 gene SNP loci rs2282055, rs2890658, rs10125854, and rs702275 had linkage disequilibrium. The haplotypes TAAA, GAAC, GAGC, GCAA, and TCGA of PD-L1 gene SNP loci were significantly higher in PCOS patients than in the control group, whereas haplotypes GAAA, TAAC, TCAA, GCGA, GCAC, and TCGC of PD-L1 gene SNP loci were significantly lower in PCOS patients than in the control group. PD-1 and PD-L1 SNPs may be related to the pathogenesis of PCOS. PD-1 gene SNP loci rs10204525 and rs7421861 and PD-L1 gene SNP loci rs2282055, rs2890658, rs10125854, and rs702275 may be new candidate polymorphic loci for PCOS.

MTR-G is a high-risk allele for lower-extremity arteriosclerotic occlusion

OBJECTIVE

This study investigated the relationship between the MTRA2576G polymorphism of the key enzyme in homocysteine metabolism and deep vein thrombosis (DVT), chronic venous insufficiency (CVI) and arteriosclerotic occlusion (ASO) of the lower extremities.

METHODS

Genomic DNA was extracted from the peripheral blood of patients with lower-extremity vascular diseases, including 125 cases of DVT, 125 cases of CVI and 125 cases of ASO. DNA samples extracted from 197 healthy individuals were used as control samples. PCR-RFLP was used to investigate the polymorphisms of MTR in these subjects.

RESULTS

The frequency of the G allele in MTR was 6.8%, 6.1% and 12.8% for the DVT group, CVI group and ASO group, respectively (p = 0.003). The frequency of the GG allele was 13.6%, 12.2% and 22.4% for the DVT group, CVI group and ASO group, respectively (p = 0.014). Only the allele frequency of GG in the ASO group was higher than that in the control group, and the disease risk was also 1.3 times higher than that in the control group (OR = 1.299, 95% CI = 1.025 ∼ 2.575).

CONCLUSION

Patients with the G allele in MTR have a high risk for ASO, and the GG allele is a risk gene for ASO.

Systematic and meta-analysis of factors associated with preeclampsia and eclampsia in sub-Saharan Africa

Background

Preeclampsia and eclampsia are common complications of pregnancy globally, including sub-Saharan African (SSA) countries. Although it has a high burden on maternal and neonatal mortality and morbidity, evidence on the risk of the problem is limited. Therefore, the aim of this review was to examine the factors associated with preeclampsia and eclampsia among mothers in SSA countries.

Methods

We searched article from SSA countries using electronic database MEDLINE, EMBASE, PubMed, CINAHL published in English from January 2000 to May 2020. Two reviewers independently screened, extracted and assessed the quality of the articles. Both random and fixed effect model were used for analysis. Heterogeneity of the studies and publication bias were checked. STATA 16 used for analysis.

Results

Fifty-one studies met the inclusion criteria and included in this review. The following factors were identified through meta-analysis: being primiparous (OR: 2.52; 95% CI:1.19, 3.86), previous history of maternal preeclampsia/eclampsia (OR:5.6; 95% CI:1.82, 9.28), family history of preeclampsia/eclampsia (OR:1.68; 95% CI:1.26, 2.11), high maternal body mass index (OR: 1.69; 95% CI:1.17, 2.21), chronic hypertension (OR: 2.52; 95% CI:1.29, 3.74), anaemia during pregnancy (OR: 3.22; 95% CI:2.70, 3.75) and lack of antenatal care visits (OR: 2.71; 95% CI:1.45, 3.96). There was inconclusive evidence for a relationship with a number of other factors, such as nutrition and related factors, antenatal care visits, birth spacing, and other factors due to few studies found in our review.

Conclusions

The risk of preeclampsia and eclampsia is worse among women who have a history of preeclampsia/eclampsia (either themselves or family members), primiparous, obesity and overweight, living with chronic disease, having anaemia during pregnancy and absence from ANC visits. Therefore, investment must be made in women’s health needs to reduce the problem and health service providers need to give due attention to high-risk women.