Implication of an AGT Haplotype in a Multigene Association Study With Pregnancy Hypertension

Genetic Appraisal of RAAS-Associated SNPs: REN (rs16853055), AGT (rs3789678) and ACE (rs4305) in Preeclamptic Women Living with HIV Infection

PURPOSE OF REVIEW

The primary goal of this review article was to determine whether the three RAAS-associated SNPs, Renin-rs16853055, AGT-rs3789678 and ACE-rs4305 are genetically linked to the development of hypertension in preeclampsia. The secondary goal was to establish if there was a link between these SNPs and HIV infection.

RECENT FINDINGS

There is a paucity of findings related to the aforementioned SNPs and preeclampsia. There are no recent findings on the rs16853055 renin polymorphism. The rs3789678 angiotensinogen polymorphism correlated significantly with gestational hypertension. The rs4305 ACE polymorphism showed no significant association with the development of pregnancy-induced hypertension. There are conflicting findings when determining the relationship between ethnicity and the predisposition of preeclampsia and hypertension in relation to the discussed RAAS-associated SNPs. To date, the association between RAAS-associated SNPs and preeclamptic women co-morbid with HIV in South Africa has revealed that certain alleles of the AGT gene are more prominent in HIV-infected PE compared to normotensive pregnant HIV-infected women.

Investigation of the linkage between TNF-alfa rs1800629 polymorphism and preeclampsia risk: A meta-analysis

BACKGROUND

Preeclampsia is a serious medical condition that significantly affects expectant mothers. Growing research showed an inconsistent association between TNF-alfa rs1800629 polymorphism and preeclampsia. The current meta-analysis was aimed at examining the potential impact of rs1800629 variant on preeclampsia.

METHODS

The Cochrane Library, Google Scholar, PubMed, EMBASE, Web of Science, and other databases were searched extensively to locate and select articles up to October 30, 2023. The PRISMA 2020 recommendations were followed to perform this study. Data analysis was done by using Comprehensive Meta analysis (v 3).

RESULTS

We have included 32 articles containing 35 studies with 3,883 patients and 5,821 controls for qualitative and quantitative data analysis. We found a strong relationship between rs1800629 variant with the increased preeclampsia risk in co-dominant model 1 (OR = 1.33, p = 0.019), co-dominant model 2 (OR = 1.43, p = 0.014), dominant model (OR = 1.25, p = 0.044), over-dominant model (OR = 1.31, p = 0.021), and allelic model (OR = 1.24, p = 0.018). This study also revealed a significantly higher risk among the Asian population in the dominant (OR = 2.31, p = 0.036) and allelic model (OR = 2.02, p = 0.028). For the Caucasian population, an increased association between the rs1800629 variant and preeclampsia risk was reported in co-dominant model 1 (OR = 1.37, p = 0.011), co-dominant model 2 (OR = 1.77, p = 0.007), dominant model (OR = 1.32, p = 0.030), recessive (OR = 1.50, p = 0.047), over-dominant (OR = 1.34, p = 0.009), and allelic model (OR = 1.32, p = 0.004). Though our study showed the protective link of the TNF-alfa polymorphism to the preeclampsia risk among the Black population, no significant outcomes were observed in any genetic models (p > 0.05).

CONCLUSION

Overall, the present meta-analysis explored a consistent linkage of the TNF-alfa rs1800629 variant to the preeclampsia risk in different ethnic groups. Additional research is required to confirm the precise relationship between the rs1800629 variant and preeclampsia risk.

Pertinence between risk of preeclampsia and the renin-angiotensin-aldosterone system (RAAS) gene polymorphisms: an updated meta-analysis based on 73 studies

The aetiological mechanism of preeclampsia (PE) is unclear exactly, so we attempted to investigate the association between susceptibility to preeclampsia and renin-angiotensin-aldosterone system (RAAS) gene polymorphisms to explore the aetiology in terms of genetics. A systematic search was performed in electronic databases to identify relevant studies. Eventually 73 studies were enrolled, odds ratios were generated by 5 genetic models. In overall analysis, significant associations were detected for AGT M235T, AT1R A1166C and CYP11B2 C344T whereas negative correlation was shown for AGT T174M. As stratified by race and geography, AGT 235T allele and AT1R 1166C allele increased preeclampsia risk and AGT T174M was justified uncorrelated with preeclampsia. Our meta-analysis illustrated that AGT 235T allele and AT1R 1166C allele increased and CYP11B2 344T allele decreased preeclampsia risk while AGT T174M polymorphism did not change preeclampsia risk. Hence, pregnant women carrying high-risk genotypes need strengthened management to prevent and early identification of preeclampsia.

Angiotensinogen Gene Missense Polymorphisms (rs699 and rs4762): The Association of End-Stage Renal Failure Risk with Type 2 Diabetes and Hypertension in Egyptians

Type 2 diabetes mellitus (T2DM) and hypertension are common chronic diseases mainly associated with the development and progression of end-stage renal disease (ESRD) leading to morbidity and mortality. Gene polymorphisms linked to the renin–angiotensin (AGT)–aldosterone system (RAAS) were broadly inspected in patients with diabetic nephropathy (DN) and hypertension. This study aimed to investigate the association of AGT gene polymorphisms (rs699 and rs4762) with ESRD in T2DM hypertensive Egyptian patients. Genotyping of rs699 and rs4762 was conducted using the tetra-primers amplification refractory mutation system (ARMS-PCR). The allelic distribution analysis was performed on 103 healthy control subjects, 97 non-ESRD patients, and 104 patients with ESRD. The allelic frequencies of AGT gene polymorphisms (rs4762 and rs699) in all study participants were assessed. For the non-ESRD group, the frequencies of the alleles of AGT-rs4762 (χ² = 31.88, p < 0.001, OR = 5.17, CI 95%: 2.81–9.51) and AGT-rs699 (χ² = 4.85, p = 0.027, OR = 1.56, CI 95%: 1.05–2.33) were significantly associated with the non-ESRD group. However, for the ESRD group, the T allele was significantly higher than that in the controls (χ² = 24.97, p < 0.001, odds ratio (OR) = 4.35, CI 95%: 2.36–8.02). Moreover, AGT (rs699) genotypes showed no significant difference between the ESRD group and controls. In conclusion, AGT gene polymorphisms rs699 and rs4762 were associated with non-ESRD versus controls, without any significant risk observed in all patient groups. However, the AGT (rs4762) variant showed a significant risk in the ESRD group in comparison to controls in Egyptians.

Meta-analysis of angiotensin-converting enzyme insersion/delection polymorphism and pre-eclampsia susceptibility

AIM

In recent years, there were many studies on angiotensin-converting enzyme insersion/delection (ACE I/D) polymorphism and pre-eclampsia susceptibility, but the conclusion was still inconclusive. Our study is to explore the relationship between the ACE I/D polymorphism and the risk of pre-eclampsia.

METHODS

The literature on the relationship between ACE I/D gene polymorphism and Pre-eclampsia susceptibility was obtained by searching the databases of Wanfang, VIP, Medline, CNKI, Embase, Pubmed and Springerlink, which was published from the establishment of the databases to October 2019. Taking the odds ratio (OR) value and its 95% confidence interval (CI) as the effect size, the Meta-analysis was carried out by using stata 15.0 software.

RESULTS

Thirty articles, consisting of 3184 patients and 3912 controls, were included. The results showed that allele D was compared with allele I, with the OR value of 1.29 (95% CI: 1.12 ~ 1.50, P < 0.05). Subgroup analysis showed that in Caucasians, allele D was associated with OR of 1.28 (95% CI: 1.08 ~ 1.53, P < 0.05). There was no significant difference in Asians. There was statistical significance in recessive gene model and homozygous gene model, as well as in that of Asian and Caucasian. In homozygous model, there was statistical significance, but subgroup analysis showed there was no statistical significance in Asian and Caucasian. There was no statistical significance in dominant model and heterozygous model.

CONCLUSION

The polymorphism of ACE I/D gene was associated with the risk of pre-eclampsia. Allele D and genotype DD may increase the risk of Pre-eclampsia in pregnant women.

Association study of M235T and A-6G polymorphisms in angiotensinogen gene with risk of developing preeclampsia in Iranian population

OBJECTIVE

Preeclampsia (PE) is a life-threatening complication of pregnancy that accounts for 12% of all maternal deaths worldwide. The aim of this study is to investigate the relationships between the polymorphisms of angiotensinogen (AGT) gene and preeclampsia.

MATERIAL AND METHODS

In this study, 240 unrelated preeclampsia patients and 178 normotensive women were examined. Genomic DNA was extracted then we assessed M235T(C/T) and A-6G polymorphisms of the AGT gene. Genotyping of M235T and A-6G polymorphisms were performed using SSP-PCR and MS-PCR, respectively.

RESULTS

A significant protective association was observed between A-6G G allele, A-6G A/G heterozygote genotype (OR = 0.6, p = 0.007 and OR = 0.6, p = 0.04) against PE. Furthermore, it was shown that two copies of A-6G A allele would increase PE risk (OR: 0.62, p = 0.04). Our results did not show a significant association for M235T polymorphism and PE. However, the combinations of A-6G A/A genotype and M235T T/C genotype (OR = 0.4, p = 0.02) and also A-6G A/G genotype and M235T T/C genotype (OR = 0.5, p = 0.04) in controls represented a significant protective association against PE.

CONCLUSION

According to the existence of significant correlation between two candidate polymorphisms, A-6G and M235T polymorphisms, with PE disease in our study, they may be considered as valuable factors in susceptibility to PE disease in Iranian women.

Association of hypertensive disorders of pregnancy risk and factor V Leiden mutation: A meta-analysis

AIM

To date, the conclusions of studies on a possible association between factor V Leiden (FVL, FV G1691A, rs6025) and hypertensive disorders of pregnancy (HDP) are conflicting. Here, we aimed to estimate the relationship between the risk of HDP and FVL.

METHODS

Eligible studies focused on FVL and HDP were searched from the PubMed and the Web of Science databases up to March 31, 2018. We used random effects model for the meta-analysis, and I² statistic to assess the degree of heterogeneity between all included studies. To evaluate the association between FVL and the risk of HDP, we calculated the odds ratio (OR) and 95% confidence intervals (CI) comparing cases and controls of all samples and each subgroup based on different regions.

RESULTS

Fifty citations on FVL and HDP were identified through the literature search, and a meta-analysis on the GA + AA genotype between 6041 cases and 8364 controls was conducted. The holistic analysis found that pregnant women with GA or AA genotype of FVL have a 1.97-fold (95% CI: 1.64-2.35, P < 0.00001) increased risk of HDP compared with GG carriers. While the OR are 2.23 (95% CI: 1.76-2.84, P < 0.00001) and 1.90 (95% CI: 1.12-3.23, P = 0.02) in Europe and the Middle East subgroups, respectively.

CONCLUSION

Factor V Leiden mutation is associated with an increased risk of HDP, and is particularly associated with preeclampsia and eclampsia in European women. However, further high-quality studies are warranted to confirm the possible effectiveness of FVL in HDP patients.

Analysis of the Epigenome in Multiplex Pre-eclampsia Families Identifies SORD, DGKI, and ICA1 as Novel Candidate Risk Genes

Pre-eclampsia is a serious heritable disorder that affects 5-8% of pregnancies worldwide. While classical genetic studies have identified several susceptibility genes they do not fully explain the heritability of pre-eclampsia. An additional contribution to risk can be quantified by examining the epigenome, in particular the methylome, which is a representation of interactions between environmental and genetic influences on the phenotype. Current array-based epigenetic studies only examine 2-5% of the methylome. Here, we used whole-genome bisulfite sequencing (WGBS) to determine the entire methylome of 13 individuals from two multiplex pre-eclampsia families, comprising one woman with eclampsia, six women with pre-eclampsia, four women with uncomplicated normotensive pregnancies and two male relatives. The analysis of WGBS profiles using two bioinformatics platforms, BSmooth and Bismark, revealed 18,909 differentially methylated CpGs and 4157 differentially methylated regions (DMRs) concordant in females. The methylation patterns support the involvement of previously reported candidate genes, including COL4A1, SLC2A4, PER3, FLT1, GPI, LCT, DDAH1, TGFB3, DLX5, and LRP1B. Statistical analysis of DMRs revealed three novel genes significantly correlated with pre-eclampsia: sorbitol dehydrogenase (SORD, p = 9.98 × 10^-6), diacylglycerol kinase iota (DGKI, p = 2.52 × 10^-5), and islet cell autoantigen 1 (ICA1, 7.54 × 10^-3), demonstrating the potential of WGBS in families for elucidating the role of epigenome in pre-eclampsia and other complex diseases.

Association between tumor necrosis factor-α-308G/A gene polymorphism and susceptibility to pre-eclampsia: An updated meta-analysis

AIMS

Although two meta-analysis have reported no association between the tumor necrosis factor-α (TNF-α)-308G/A polymorphism and susceptibility to pre-eclampsia (PE), recent studies showed the association was still controversial. Thus, we conduct an updated meta-analysis to elucidate this association.

METHODS

Studies related to TNF-α-308G/A and PE risk were retrieved from PubMed, the Web of Science, Embase, Cochrane Library, CNKI, Wanfang, CBM, VIP Database. The odds ratios (OR) and 95% confidence intervals (CIs) were calculated to estimate the association between the TNF-α-308G/A polymorphism and susceptibility to PE under the models of allelic contrast (A vs. G), recessive (AA vs. AG+GG), dominant (AA+AG vs. GG), and co-dominant (AA vs. GG).

RESULTS

22 studies (including 2459 cases and 4246 controls) were included in the meta-analysis. The overall analysis indicated that the significant association between TNF-α-308G/A polymorphism and susceptibility to pre-eclampsia existed in allele model (A vs. G: OR = 1.37, 95%CI: 1.06-1.77), but not in dominant model, recessive model, and co-dominant model. In subgroup analysis by ethnicity, pre-pregnancy BMI and pregnancy parity, the results showed the significant association between TNF-α-308G/A polymorphism and the risk of PE was obvious in Caucasian (A vs. G: OR = 1.36, 95%CI: 1.13-1.64; AA vs. GG: OR = 1.71, 95%CI: 1.03-2.86; AA+AG vs. GG: OR = 1.32, 95%CI: 1.03-1.71), Iranian (A vs. G: OR = 4.28, 95%CI: 2.01-9.11), and primipara (A vs. G: OR = 1.49, 95%CI: 1.15-1.92; AA vs. GG: OR = 2.15, 95%CI: 1.10-4.21).

CONCLUSION

Current evidence demonstrates that carriers of TNF-α (308A) allele would increase the susceptibility to PE, especially among Caucasian, Iranian and primipara.

The prevalence of unique SNPs in the renin-angiotensin system highlights the need for pharmacogenetics in Indigenous Australians

Genetic differences between ethnic populations affect susceptibility to disease and efficacy of drugs. This study examined and compared the prevalence of single nucleotide polymorphisms (SNPs) in genes of the renin-angiotensin system (RAS) in a desert community of Indigenous Australians and in non-Indigenous Australians. The polymorphisms were angiotensinogen, AGT G-217A (rs5049); AGT G+174A (rs4762); Angiotensin II type 1 receptor, AGTR1 A+1166C (rs5186); angiotensin converting enzyme, ACE A-240T (rs4291), ACE T-93C (rs4292); renin, REN T+1142C (rs5706). They were measured using allelic discrimination assays. The prevalence of REN T+1142C SNP was similar in the two populations; 99% were homozygous for the T allele. All other SNPs were differently distributed between the two populations (P < 0.0001). In non-Indigenous Australians, the A allele at position 204 of ACE rs4291 was prevalent (61.8%) whereas in the Indigenous Australians the A allele was less prevalent (28%). For rs4292, the C allele had a prevalence of 37.9% in non-Indigenous Australians but in Indigenous Australians the prevalence was only 1%. No Indigenous individuals were homozygous for the C allele of AGTR1 (rs5186). Thus the prevalence of RAS SNPs in this Indigenous Australian desert community was different from non-Indigenous Australians as was the prevalence of cytokine SNPs (as shown in a previous study). These differences may affect susceptibility to chronic renal and cardiovascular disease and may alter the efficacy of drugs used to inhibit the RAS. These studies highlight the need to study the pharmacogenetics of drug absorption, distribution, metabolism and excretion in Indigenous Australians for safe prescribing guidelines.

Genetic polymorphisms of the renin-angiotensin system in preterm delivery and premature rupture of membranes

Introduction. Premature rupture of membranes (PRM) is a late pregnancy complication commonly associated with preterm delivery (PD).Although several markers related to the renin-angiotensin system (RAS) have been evaluated in certain pregnancy complications, only the angiotensin-converting enzyme (ACE) I/D variant has been studied in PD-PRM.The aim of this survey was to investigate the association of the polymorphisms (angiotensin II type 1 [AT1] receptor T174M and M235T, renin G2805A,ACE I/D and AT1-receptor A1166C) of the genes of RAS in women with PD-PRM.

Design. Deoxyribonucleic acid samples from 89 Mexican Mestizo women with PD and PRM and 224—288 controls were studied. Polymorphisms were analysed by polymerase chain reaction-sequence specific primer assays. restricted fragment length polymorphism or sequence specific prim assays.

Results. For all loci , genotype distribution was in agreement with Hardy—Weinberg expectations in the control group. Significant intergroup difference (case vs. control) was seen for angiotensinogen (AGT) M235T polymorphism, with an increased allele M235 in affected cases (50% vs. 40% in controls).Analysis of two- locus haplotype agrees with an independent segregation of physically unlinked genes. Haplotype AGT 174T-235M was also increased (50 % vs. 40% in controls).

Conclusions. Physically unlinked genes involved in RAS segregate independently. The AGT 174—235 region is associated with PD-PRM in this population.

Genophenotypic analysis of angiotensinogen gene M235T polymorphism and preeclampsia

We studied phenotypes of the circulating renin-angiotensin-aldosterone system and circadian BP during preeclampsia depending on polymorphism of angiotensinogen gene M235T. The TT genotype or T allele of angiotensinogen M235T gene polymorphism is associated with the risk of preeclampsia. Plasma renin activity significantly decreases under conditions of preeclampsia. The TT genotype of angiotensin M235T gene polymorphism is associated with highest renin activity and highest 24-h diastolic BP in comparison with MT and MM genotypes in patients with preeclampsia. Plasma aldosterone level is lower in patients with preeclampsia, but this is not related to angiotensinogen M235T gene polymorphism.

The role of the renin-angiotensin-aldosterone system in preeclampsia: genetic polymorphisms and microRNA

The compensatory alterations in the rennin-angiotensin-aldosterone system (RAAS) contribute to the salt-water balance and sufficient placental perfusion for the subsequent well-being of the mother and fetus during normal pregnancy and is characterized by an increase in almost all the components of RAAS. Preeclampsia, however, breaks homeostasis and leads to a disturbance of this delicate equilibrium in RAAS both for circulation and the uteroplacental unit. Despite being a major cause for maternal and neonatal morbidity and mortality, the pathogenesis of preeclampsia remains elusive, where RAAS has been long considered to be involved. Epidemiological studies have indicated that preeclampsia is a multifactorial disease with a strong familial predisposition regardless of variations in ethnic, socioeconomic, and geographic features. The heritable allelic variations, especially the genetic polymorphisms in RAAS, could be the foundation for the genetics of preeclampsia and hence are related to the development of preeclampsia. Furthermore, at a posttranscriptional level, miRNA can interact with the targeted site within the 3'-UTR of the RAAS gene and thereby might participate in the regulation of RAAS and the pathology of preeclampsia. In this review, we discuss the recent achievements of genetic polymorphisms, as well as the interactions between maternal and fetal genotypes, and miRNA posttranscriptional regulation associated with RAAS in preeclampsia. The results are controversial but utterly inspiring and attractive in terms of potential prognostic significance. Although many studies suggest positive associations with genetic mutations and increased risk for preeclampsia, more meticulously designed large-scale investigations are needed to avoid the interference from different variations.

Angiotensinogen polymorphisms and post-transplantation diabetes mellitus in Korean renal transplant subjects

BACKGROUND

Post-transplant diabetes mellitus (PTDM) is a common and serious metabolic complication. Genetic polymorphisms of angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) genes have been reported to be related to diabetes mellitus and insulin sensitivity; however, the role of these genes in the development of PTDM is not known. For this purpose, we investigated the association of ACE and AGT genetic polymorphisms with PTDM.

METHODS

A total of 302 subjects without previously diagnosed diabetes who had received kidney transplants were included. One ACE single nucleotide polymorphism (SNP) (rs4291) and two AGT SNPs (rs 699 and rs 4762) were genotyped from genomic DNA with direct sequencing.

RESULTS

PTDM developed in 49 (16.2%) of 302 subjects. Subjects in the PTDM were older than those in the non-PTDM. There was a significant difference between the two groups in tacrolimus use (p=0.03). Of the three SNPs, the rs4762 of the AGT gene was significantly associated with the development of PTDM in the dominant models (p = 0.03) after adjusting for age and tacrolimus usage.

CONCLUSIONS

AGT gene rs4762 polymorphisms may serve as genetic markers for the development of PTDM. The exact molecular mechanisms still need to be clarified.

Angiotensinogen gene M235T and T174M polymorphisms and susceptibility of pre-eclampsia: a meta-analysis

There are controversies in reports on the association of the angiotensinogen (AGT) gene polymorphisms with the risk of developing pre-eclampsia (PE). We performed a meta-analysis to examine the association between the AGT polymorphisms and PE risk: M235T (31 studies involving 2555 patients and 6114 controls) and T174M (six studies involving 681 patients and 2076 controls). For the M235T polymorphism, the TT genotype increased the PE risk as compared to the MM genotype (odds ratio 1.61, 95% confidence intervals 1.22-2.14, P= 0.001). When stratified by ethnicity, the TT genotype remained significantly associated with higher PE risk in Caucasians and Mongolians but not in Africans. Similar results were also obtained under all three genetic models of the M235T polymorphism. For the T174M polymorphism, no significant association was found in the comparisons (MT vs. TT and MM vs. TT) and under any genetic models. The analysis excluding the highly significant Hardy-Weinberg equilibrium-violating studies and sensitivity analysis further strengthened the validity of these associations. No publication bias was observed in this study. This meta-analysis demonstrates that the AGT M235T polymorphism is significantly associated with PE whereas the T174M polymorphism is not.

Synergistic effects of angiotensinogen -217 G→A and T704C (M235T) variants on the risk of severe preeclampsia

BACKGROUND

The rate-limiting step of the renin-angiotensin system is the enzymatic cleavage of angiotensinogen (AGT) by renin. The aims of the present study were to investigate the association between AGT T704C (M235T) and -217 G→A polymorphisms with the risk of preeclampsia and synergistic effects of both polymorphisms on the susceptibility to preeclampsia.

METHODS

We studied AGT variants in 170 women with preeclampsia, including 84 women with mild and 86 women with severe forms of preeclampsia, and 100 age and parity matched controls.

RESULTS

There was a trend towards increased risk of severe preeclampsia in the presence of -217 AA (odds ratio (OR)=1.5, 95% confidence interval (CI)= 0.38-5.84, p=0.57) and TC+CC genotypes (OR=1.32, 95% CI= 0.67-2.58, p=0.42). However, the interaction of both alleles of -217A and 704C highly increased the risk of severe preeclampsia, by 2.23-fold, although this did not reach statistical significance. The frequency of the CC genotype of the T704C polymorphism in early-onset preeclampsia tended to be higher (35%) compared with that in patients with late-onset preeclampsia (21.7%).

CONCLUSIONS

The present study demonstrates that both variants of AGT -217 G→A and T704C might work in synergism to influence the risk of severe preeclampsia, which needs to be confirmed in studies with larger sample size.

Linking preeclampsia and cardiovascular disease later in life

Preeclampsia (PE), which is defined as new onset hypertension after 20 weeks of pregnancy accompanied by proteinuria, is characterized by inadequate placentation, oxidative stress, inflammation and widespread endothelial dysfunction. A link between PE and long-term risk of cardiovascular disease (CVD) was suggested by retrospective studies, which found that PE was associated with a 2–3-fold risk of CVD later in life, with a 5–7-fold risk in the case of severe and/or early-onset PE. Recently, meta-analyses and prospective studies have confirmed the association between PE and the emergence of an unfavorable CVD risk profile, in particular a 3–5-fold increased prevalence of the metabolic syndrome only 8 years after the index pregnancy. PE and CVD share many risk factors, including obesity, hypertension, dyslipidemia, hypercoagulability, insulin resistance and both entities are characterized by endothelial dysfunction. PE and CVD are complex traits sharing common risk factors and pathophysiological processes, but the genetic link between both remains to be elucidated. However, recent evidence suggests that genetic determinants associated with the metabolic syndrome, inflammation and subsequent endothelial dysfunction are involved. As the evidence now supports that PE represents a risk factor for the emergence of the metabolic syndrome and CVD later in life, the importance of long-term follow-up assessment of CVD risk beginning early in women with a history of PE must be considered and translated into new preventive measures.

AGT M235T polymorphism contributes to risk of preeclampsia: evidence from a meta-analysis

Objective: Preeclampsia a hypertensive disorder of pregnancy that mainly manifests as high blood pressure and proteinuria. Angiotensinogen (AGT) plays important roles in the regulation of blood pressure. The purpose of this study was to investigate the relationship between AGT M235T polymorphism and risk of preeclampsia using a meta-analysis. Methods: In this meta-analysis, 22 studies were selected by searching PubMed, EMBASE, ISI and CNKI databases up to October 2011. Crude odds ratios with corresponding 95% confidence intervals were used to evaluate the association between the AGT M235T polymorphism and risk of preeclampsia. Subgroup analyses were conducted by ethnicity and parity. Results: The TT genotype of the AGT M235T polymorphism was associated with elevated risk of preeclampsia in the overall analysis. In subgroup analysis according to ethnicity, increased risks were also found in Caucasians. After stratification based on parity, the excess risk was found in multigravida. Conclusions: These results showed that the TT genotype may play critical roles in the development of preeclampsia.

Agonistic autoantibodies to the angiotensin II type I receptor cause pathophysiologic characteristics of preeclampsia

BACKGROUND

Preeclampsia (PE), new-onset hypertension with proteinuria during pregnancy, is associated with increased reactive oxygen species, the vasoactive peptide endothelin-1 (ET-1), T and B lymphocytes, soluble antiangiogenic factors sFlt-1 and sEndoglin (sFlt-1 and sEng), and agonistic autoantibodies to the angiotensin II type I receptor (AT1-AA).

OBJECTIVES

One important area of investigation for our laboratory was to determine what role AT1-AA plays in the pathophysiology associated with PE.

METHODS

To achieve this goal, we examined the effect of AT1-AA suppression on hypertension in response to placental ischemia as well as the effect of AT1-AA on increased blood pressure, ET-1, reactive oxygen species, and sFlt-1 in normal pregnant rats (NP).

RESULTS

We demonstrated reductions in uterine perfusion pressure (RUPP) to be a stimulus for AT1-AA during pregnancy. We utilized the technique of B-cell depletion to suppress circulating AT1-AA in RUPP rats and found that AT1-AA suppression in RUPP rats was associated with lower blood pressure and ET-1 activation. To determine a role for AT1-AA to mediate hypertension during pregnancy, we infused purified rat AT1-AA (1:50) into NP rats, and analyzed blood pressure and soluble factors. We consistently found that AT1-AA infused rats had significantly increased AT1-AA and blood pressure above NP rats. This hypertension was associated with significantly increased ET-1 in renal cortices (11-fold) and placenta (4-fold), and there was an approximately 2- to 3-fold increase in placental oxidative stress. Furthermore, antiangiogenic factors sFlt-1 and sEng were significantly increased in the AT1-AA induced hypertensive group compared with the NP controls.

CONCLUSIONS

Collectively, these data indicated an important role for AT1-AA stimulated in response to placental ischemia that caused hypertension during pregnancy.

Angiotensin converting enzyme insertion/deletion polymorphism and risk of pregnancy hypertensive disorders: a meta-analysis

BACKGROUND

The angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been reported inconsistently as being associated with risk of pregnancy hypertensive disorders (PHDs). We examined these associations by performing a meta-analysis.

METHODS

Two investigators independently consulted the Medline, Embase, CNKI, and Chinese Biomedicine databases. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated in fixed- and random-effects models when appropriate. Subgroup analyses were performed by ethnicity, types of PHD (gestational hypertension, pre-eclampsia and eclampsia), country and Hardy-Weinberg equilibrium (HWE) in controls.

RESULTS

This meta-analysis included 30 case-control studies with 3523 cases and 4817 controls. Overall, we found that the DD variant of the ACE I/D polymorphism was associated with a significantly increased PHD risk. In the subgroup analysis by ethnicity, the results suggested that the DD genotype was significantly associated with risk of PHD development among Asians and Caucasians. Moreover, when stratifying by types of PHD, a significantly increased risk was observed for pre-eclampsia. Interestingly, when stratifying by country, a significantly elevated risk was found among 'others' countries (those that were not China or Korea). Limiting the analysis to the studies within HWE, the results were persistent and robust.

CONCLUSION

This meta-analysis suggests that the I/D polymorphism of ACE may be associated with PHD risk, especially among Asians and Caucasians.

Association of the variants in AGT gene with modified drug response in Korean aspirin-intolerant asthma patients

The angiotensinogen (AGT) gene enhances the effect of several bronchoconstrictors and produces a peptide that is accumulated in the airways of asthma patients; events that may underpin the pathogenesis of aspirin-intolerant asthma (AIA). To carry out a case-control analysis between AGT and aspirin-induced bronchospasm following treatment with an anti-asthma drug, montelukast (MLK), 38 single nucleotide polymorphisms (SNPs) in AGT were genotyped in 56 AIA cohort. Genotyping was performed with TaqMan assay and haplotypes were inferred using PHASE algorithm ver. 2.0. Statistical analyses of each SNPs and haplotypes were performed using SAS version 9.1. Among 13 variants displaying significant signals, two SNPs (+2401C>G and +2476C>T) in the intronic region of AGT were significantly associated with modification of drug response even after correction for multiple testing (P=0.0009-0.002; P(corr)=0.02-0.03). Furthermore, the two variants also exhibited associations with MLK response rate (P=0.0003-0.0006; P(corr)=0.006-0.01). Although our results are preliminary and further replication in a larger-scale group of subjects should be warranted, these observations provide evidence that AGT variants might be one of genetic factors involved in the response of anti-asthma drugs in AIA patients.

Angiotensin II type 1 autoantibody induced hypertension during pregnancy is associated with renal endothelial dysfunction

BACKGROUND

Previous investigations suggested that agonistic autoantibodies to the angiotensin II type I receptor (AT1-AA) might mediate a hypertensive response through dysregulation of the endothelin-1 system. AT1-AA induced hypertension was attenuated by the AT1 receptor and/or endothelin-1 type A receptor antagonists.

OBJECTIVES

This study was undertaken to determine if AT1-AA induced hypertension was associated with renal endothelial dysfunction.

METHODS

We compared the vascular reactivity of renal interlobar arteries from normal pregnant control rats and AT1-AA long-term infused pregnant rats in the presence and absence of endothelin type A (ET(A)) receptor antagonism. Renal endothelial function was tested using isolated renal interlobar arteries in a pressure myograph, which were exposed to acetylcholine or sodium nitroprusside.

RESULTS

Vasodilatory responses to the endothelial-dependent agonist acetylcholine were impaired in AT1-AA rats (74 [10]%) compared with normal pregnant controls (95 [5]%, P < 0.05). In the presence of ET(A) receptor antagonism, no differences were observed between controls or the AT1-AA treated group with regard to endothelial-dependent (acetylcholine) relaxation.

CONCLUSION

AT1-AA induced hypertension during pregnancy was associated with disparate renal endothelial responses to acetylcholine. The difference in renal vascular responses between AT1-AA and normal pregnant rats was abolished by ET(A) receptor blockade.

Maternal/newborn genotype contribution of the renin–angiotensin system (Met235Thr, Thr174Met, I/D-ACE, A2350G-ACE, A1166C-AT2R1, C3123A- AT2R2, 83A/G-REN) to the risk of pre-eclampsia: a Romanian study

Introduction: We evaluated the association of the mutated genotypes Met235Thr-AGT, Thr174Met-AGT, I/D-ACE, A2350G-ACE, A1166C-AT2R1, C3123A-AT2R2, 83A/G-REN with the risk and outcome of pre-eclampsia; we also investigated whether genes in newborns increase maternal risk of pre-eclampsia.

Materials and methods: Thirty-six pairs of pre-eclamptic women and their newborns were genotyped, along with 71 pairs of controls (mothers/newborns) using PCR-RFLP analysis.

Results: The Thr235/Thr235 (OR 3.44, p = 0.01), DD (OR 2.66, p = 0.039), CC1166 (OR 5.56, p = 0.04), AA3123 (OR 3.77, p = 0.03) and GG83 (OR 8.32, p = 0.006) genotypes are significantly associated with pre-eclampsia. Women with pre-eclampsia positive for Met235Thr (34.64 ± 3.92 weeks vs. 38 ± 2 weeks), Thr174Met (32.58 ± 3.92 weeks vs. 36.38 ± 3.25 weeks), I/D (34.47 ± 3.67 weeks vs. 38.33 ± 3.5 weeks) delivered at a significant lower gestational age compared with pre-eclamptic women with a normal genotype. Newborns from women with pre-eclampsia positive for Thr174Met (2190 ± 820.21 g vs. 2702.08 ± 967.23 g), I/D (2399.33 ± 938.38 g vs. 3191.66 ± 684.40 g) had a significant lower birth weight compared with newborns from women with normal pregnancies. When both the mother and the newborn were positive for Met235Thr, I/D, A2350G, A1166C or 83A/G polymorphisms, the risk for pre-eclampsia was significantly increased at 6.67 ( p < 0.01), 5 ( p < 0.01), 3.33 ( p = 0.006), 2.72 ( p = 0.04) and 7.8 ( p < 0.01), respectively.

Conclusions: The results of our study confirm that, in pre-eclampsia, both maternal and newborn genetic variations implicated in blood pressure regulation are important.

The associations between maternal and fetal angiotensinogen M235T polymorphism and pregnancy-induced hypertension in Chinese women

This study was to investigate whether the maternal and fetal angiotensinogen (AGT) M235T polymorphism were associated with the risk of pregnancy-induced hypertension (PIH) in Chinese Han ethnic women. Using a case-control mother-baby dyads study, a total of 226 maternal/offspring pairs were recruited at Anyang Maternal and Child Health Hospital from January 2008 to December 2009. Genomic DNA was extracted from maternal venous and cord blood. We genotyped the AGT M235T polymorphism by using PCR-RFLP assay and examined the association with PIH using logistic regression analysis. In the current study, the maternal AGT M235T polymorphism showed no effect on the risk of PIH (P = .786) while the fetal AGT M235T polymorphism is significantly associated with PIH in Chinese Han ethnic women (P = .004). The fetus carrying TT genotype is a protective factor in developing PIH in the study population (OR = .28, 95% CI = .14-0.59).

Maternal angiotensinogen (AGT) haplotypes, fetal renin (REN) haplotypes and risk of preeclampsia; estimation of gene-gene interaction from family-triad data

Background

Preeclampsia is a debilitating disorder affecting approximately 3% of pregnant women in the Western world. Although inconclusive, current evidence suggests that the renin-angiotensin system may be involved in hypertension. Therefore, our objective was to determine whether the genes for placental renin (REN) and maternal angiotensinogen (AGT) interact to influence the risk of preeclampsia.

Methods

Three haplotype-tagging SNPs (htSNPs) covering REN (rs5705, rs1464818, and rs3795575) and another three covering AGT (rs2148582, rs2478545 and rs943580) were genotyped in 99 mother-father-child triads of preeclampsia pregnancies. We estimated relative risks (RR) conferred by maternal AGT and fetal REN haplotypes using HAPLIN, a statistical software designed to detect multi-marker transmission distortion among triads. To assess a combined effect of maternal AGT and fetal REN haplotypes, the preeclamptic triads were first stratified by presence/absence of maternal AGT haplotype C-T-A and tested for an effect of fetal REN across these strata.

Results

We found evidence that mothers carrying the most frequent AGT haplotype, C-T-A, had a reduced risk of preeclampsia (RR of 0.4, 95% CI = 0.2-0.8 for heterozygotes and 0.6, 95% CI = 0.2-1.5 for homozygotes). Mothers homozygous for AGT haplotypes t-c-g and C-c-g appeared to have a higher risk, but only the former was statistically significant. We found only weak evidence of an overall effect of fetal REN haplotypes and no support for our hypothesis that an effect of REN depended on whether the mother carried the C-T-A haplotype of AGT (p = 0.33).

Conclusion

Our findings indicate that the mother's AGT haplotypes affect her risk for developing preeclampsia. However, this risk is not influenced by fetal REN haplotypes.

Tumour necrosis factor (-308A) polymorphism in pre-eclampsia: meta-analysis of 16 case-control studies

BACKGROUND

The guanine to adenine transition at position -308 nucleotides in the tumour necrosis factor promoter region (TNF -308A) is a putative genetic risk factor for pre-eclampsia/eclampsia (PE/E). However, association studies have reported conflicting findings and have generally been underpowered to exclude modest effect sizes.

AIM

To assess and synthesise the available evidence for the association of the TNF (-308A) polymorphism with PE/E.

METHODS

Systematic review and random effects meta-analysis of genetic association studies.

RESULTS

Sixteen eligible case-control studies in which a total of 1919 patients with PE/E and 2374 controls participated were identified. The studies were generally small but of reasonable methodological quality. Random effects meta-analysis improved the precision of the estimate of effect size but did not detect a statistically significant association: pooled relative risk 1.02 (95% confidence interval 0.86 to 1.20).

CONCLUSIONS

The available data are not consistent with more than a very modest association between the TNF (-308A) allele and PE/E. Screening pregnant women for this allele in order to guide antenatal surveillance or treatment is unwarranted. Future research efforts should focus on alternative candidate genes.

Preeclampsia risk and angiotensinogen polymorphisms M235T and AGT -217 in African American and Caucasian women

INTRODUCTION

Genetic variants of the angiotensinogen gene have been linked to both hypertension and preeclampsia. The M235T polymorphism is more common in hypertension and preeclampsia in some populations. A polymorphism in the angiotensinogen basal promoter region of AGT -217 is more common in African Americans with hypertension. The authors investigated the frequency of M235T and AGT -217 in Caucasian and African American women with and without preeclampsia.

METHODS

The study was a nested case-control study of primiparous women with singleton pregnancies. Genomic DNA from preeclamptic and control subjects underwent polymerase chain reaction amplification and restriction digestion.

RESULTS

The M235T and AGT -217 polymorphisms were both more common in African American women; however, the variants were not more common in preeclampsia.

CONCLUSION

The frequency of angiotensinogen polymorphisms M235T and AGT -217 is different by race; however, these polymorphisms are not associated with an increased risk of preeclampsia.

Genes and the preeclampsia syndrome

Preeclampsia is specific to pregnancy and is still a leading cause of maternal and perinatal mortality and morbidity, affecting about 3% of women, but the underlying pathogenetic mechanisms still remain unclear. Immune maladaptation, placental ischemia and increased oxidative stress represent the main components discussed to be of etiologic importance, and they all may have genetic implications. Since the familial nature of preeclampsia is known for many years, extensive research on the genetic contribution to the pathogenesis of this severe pregnancy disorder has been performed. In this review, we will overview the linkage and candidate gene studies carried out so far as well as summarize important historical notes on the genetic hypotheses generated in preeclampsia research. Moreover, the influence of maternal and fetal genes and their interaction as well as the role of genomic imprinting in preeclampsia will be discussed.

Evolutionary changes of astroglia in Elasmobranchii comparing to amniotes: a study based on three immunohistochemical markers (GFAP, S-100, and glutamine synthetase)

This paper supplements former studies on elasmobranch species with an immunohistochemical investigation into glutamine synthetase and S-100 protein, in addition to GFAP, and extends its scope to the representatives of almost every group of Elasmobranchii: squalomorph sharks, galeomorph sharks, skates (Rajiformes) and rays (Torpediniformes and Myliobatifomes). More glial elements were labeled by S-100 protein, and even more so by using glutamine synthetase immunostaining than by GFAP: more astrocytes (mainly non-perivascular ones) were detected in the telencephalon of sharks, skates and rays. Only the markers S-100 and glutamine synthetase, but not GFAP, characterized the Bergmann-glia of skates and rays and astrocyte-like non-ependymal cells in Squalus acanthias. Another squalomorph shark species, Pristiophorus cirratus, however, had GFAP immunopositive astrocytes. Of all the species studied, the greatest number of GFAP positive astrocytes could be observed in Mobula japanica (order Myliobatiformes), in each major brain part. According to anatomical location, perivascular glia comprised varied types, including even a location in Mobula, which can also be found in mammals. Remnants of radial glia were found in confined areas of skates, less so in rays. In the rhombencephalon and in the spinal cord modified ependymoglia predominated in every group. In conclusion, there was no meaningful difference between the astroglial architectures of squalomorph and galeomorph sharks. The difference in the astroglial structure between sharks and batoids, however, was confined to the telencephalon and mesencephalon, and did not take place in the rhombencephalon, the latter structure being quite similar in all the species studied. The appearance of astrocytes in the relatively thin-walled shark telencephalon, however, indicates that the brain thickening promoted the preponderance of astrocytes rather than their appearance itself. Although the evolutionary changes of astroglia had some similarities in Elasmobranchii and Amniota, there was one meaningful difference: in Elasmobranchii astrocytes did not prevail in conservative brain regions as they did in the progressive brain regions.

The genetic aspects of pre-eclampsia: achievements and limitations

Pre-eclampsia, a life-threatening disease during pregnancy, is a leading cause of global maternal mortality. Although there is substantial evidence of a genetic background, the complexity of the processes involved and nature of the maternal-fetal phenomenon do not make the search for the causative genes easy. Recent retrospective studies on the subject suggest the heritable allelic variations, particularly the utero-placental renin-angiotensin system with defective placental vascular development, could become the cornerstone for the genetics of pre-eclampsia and hence might well be associated with such defective development. Moreover, the role of immune mechanisms (immune maladaptation) deserves not to be ignored. Large-scale studies entailing genomewide scanning, sib-pair linkage analysis, and family-based association studies with appropriate power to detect genes with a lower relative risk are necessary to understand the puzzle of the disease. Moreover, recently, the importance of epigenetic features and the effect of imprinted genes related to trophoblast growth as well as fetal development on hypertension in pregnancy have been highlighted. All these possibilities are intuitively attractive and are supported by some circumstantial evidence. Although the consistent tenor of a series of papers instill some confidence, we need meticulously designed larger-scale investigations including large numbers of affected women and their babies to provide the analytic stringency essential to study the polygenic multifactorial basis of pre-eclampsia.

Assessment of the prevalence of the 985A>G MCAD mutation in the French-Canadian population using allele-specific PCR

Inherited deficiency of medium-chain acyl-CoA dehydrogenase (MCAD) is a severe, sometimes fatal disorder. A single mutation in the MCAD gene, 985A>G, is involved in approximately 90% of cases. To evaluate the relevance of implementing a systematic population-based screening program in the province of Quebec using a biochemical test, we measured the prevalence of this mutation in a set of anonymous newborn samples from the Quebec City area, a region where the majority of its inhabitants are French-Canadians. An allele-specific polymerase chain reaction assay was designed and used to detect the mutation in 7143 DNA samples obtained from consecutive anonymous newborns. Pools of eight DNA samples were genotyped in parallel for the same mutation to validate this pooling strategy. The allelic frequency of the MCAD 985A>G mutation was found to be 0.71% and the carrier frequency 1:71 (95% confidence interval 1:55 to 1:98). This estimate predicts a homozygous frequency of 1:19,837. Ninety-nine heterozygous carriers and one homozygous individual were identified out of 7143 samples. There was 100% concordance between the individual and pooled analyses, and the pooling strategy reduced the total genotyping costs by approximately 70%. The carrier frequency estimated for this population is similar to other northwestern European populations and would support implementation of systematic newborn screening (such as tandem mass spectrometry screening) for this disease. Pooling DNA samples followed by genotyping appears to be cost-effective for estimating prevalence of rare mutations.

The combination of ApoCIII, hepatic lipase and hormono sensitive lipase gene polymorphisms suggests an association with susceptibility to gestational hypertension

Dyslipidemia and insulin resistance contribute to the endothelial cell dysfunction in hypertensive disorders of pregnancy (HDP) and increase the long-term risk of cardiovascular disease (CVD). The genes linking susceptibility to gestational hypertension (GH) and/or preeclampsia (PE) to the long-term risk of CVD are still unknown. We evaluated the potential association between 14 polymorphisms from six genes involved in lipid metabolism and insulin action and the risk of HDP: namely the lipoprotein lipase (LPL), hepatic lipase (LIPC), hormone sensitive lipase (LIPE), cholesteryl ester transfer protein (CETP), ApoCIII and ApoE gene polymorphisms. Overall, 169 women with HDP [proteinuria (PE) and gestational hypertension without proteinuria (GH)] and 169 controls matched for age and year of delivery were genotyped. Homozygosity of the -514T allele of the -514C > T polymorphism (LIPC gene) decreased the risk of GH (OR = 0.17, CI(95): 0.02-0.76), while there were more -60G carriers of the -60C > G LIPE gene polymorphism (OR = 3.51, CI(95):1.02-12.10) among GH cases, but not in PE cases. The common ApoCIII two-locus -482CC/3238CC genotype was lower in women with GH compared with controls (OR = 0.53, CI(95): 0.3-0.9). The combined frequency of at-risk genotypes was higher in cases of GH compared with controls [one at-risk genotype: OR = 3.38 (95% CI: 0.48-41.8); two or more at-risk genotypes: OR = 7.14 (95% CI: 1.21-92.3, P = 0.01)], suggesting a gene-dose effect. We conclude that the combined effect of LIPC, LIPE and ApoCIII gene polymorphisms may increase the likelihood of GH, but seemingly not of PE.

Angiotensin-converting enzyme I/D polymorphism and preeclampsia risk: evidence of small-study bias

BACKGROUND

Inappropriate activation of the renin-angiotensin system may play a part in the development of preeclampsia. An insertion/deletion polymorphism within the angiotensin-I converting enzyme gene (ACE-I/D) has shown to be reliably associated with differences in angiotensin-converting enzyme (ACE) activity. However, previous studies of the ACE-I/D variant and preeclampsia have been individually underpowered to detect plausible genotypic risks.

METHODS AND FINDINGS

A prospective case-control study was conducted in 1,711 unrelated young pregnant women (665 preeclamptic and 1,046 healthy pregnant controls) recruited from five Colombian cities. Maternal blood was obtained to genotype for the ACE-I/D polymorphism. Crude and adjusted odds ratio (OR) and 95% confidence interval (CI) using logistic regression models were obtained to evaluate the strength of the association between ACE-I/D variant and preeclampsia risk. A meta-analysis was then undertaken of all published studies to February 2006 evaluating the ACE-I/D variant in preeclampsia. An additive model (per-D-allele) revealed a null association between the ACE-I/D variant and preeclampsia risk (crude OR = 0.95 [95% CI, 0.81-1.10]) in the new case-control study. Similar results were obtained after adjusting for confounders (adjusted per-allele OR = 0.90 [95% CI, 0.77-1.06]) and using other genetic models of inheritance. A meta-analysis (2,596 cases and 3,828 controls from 22 studies) showed a per-allele OR of 1.26 (95% CI, 1.07-1.49). An analysis stratified by study size showed an attenuated OR toward the null as study size increased.

CONCLUSIONS

It is highly likely that the observed small nominal increase in risk of preeclampsia associated with the ACE D-allele is due to small-study bias, similar to that observed in cardiovascular disease. Reliable assessment of the origins of preeclampsia using a genetic approach may require the establishment of a collaborating consortium to generate a dataset of adequate size.

Searching for genetic clues to the causes of pre-eclampsia

Pre-eclampsia and its related syndromes are significant causes of maternal and fetal death, but much remains unclear about the underlying disease mechanisms. Epidemiological research has consistently demonstrated a familial predisposition to pre-eclampsia, which has encouraged genetic research in this area. The goal is the discovery of susceptibility genes which will inform understanding of the pathophysiology of pre-eclampsia, and may prove to be targets for therapeutic or preventative strategies. This review examines the application of molecular technologies to the search for genetic clues in pre-eclampsia and emphasizes the importance of integrative approaches. The results of recent genome-wide linkage studies have been particularly encouraging, identifying a number of loci which merit closer examination. Candidate gene studies have proved less fruitful, generating conflicting and inconclusive results. Possible explanations and remedies for this deficiency are discussed with a view to stimulating closer collaboration between researchers in this field.

A sister's risk: family history as a predictor of preeclampsia

OBJECTIVE

The purpose of this study was to determine if women with preeclampsia are more likely to have a sister who also had preeclampsia.

STUDY DESIGN

This was a population-based case-control study using data from Washington (WA) state birth certificates linked to hospital discharge records. Cases were women with gestational hypertension (n = 1611) or preeclampsia (n = 1071); controls (n = 8041) had normotensive pregnancies. All women delivered their first child between 1987 to 2002 and had a sister with a previous delivery in WA.

RESULTS

Women with preeclampsia were 2.3 times (95%CI 1.8-2.9) more likely to have a sister who had preeclampsia; those with gestational hypertension were 1.6 times (95%CI 1.3-2.0) more likely to have a sister with gestational hypertension. Similar results were obtained following stratification by age, race, smoking status, or body mass index.

CONCLUSION

The greater likelihood of preeclampsia among sisters of women with a previous preeclamptic pregnancy is consistent with a pathophysiologic role for genetic and/or behavioral factors that cluster in families.

Genetic thrombophilia has pleiotropic effects in pregnancy

Genetic thrombophilia has been established as a risk factor for pregnancy-associated disorders, such as thrombosis, early and late miscarriage, and pre-eclampsia. Associations between the factor V (F5) Leiden G1691A and the prothrombin/factor II (F2) G20210A SNPs and pre-eclampsia have been evaluated in over 50 association studies. A pooled analysis of 23 and 11 studies demonstrates that carriage of the F5 Leiden G1691A (p < 0.001; odds ratio [OR] 2.0; 95% confidence interval [CI] 1.6-2.5) and the F2 G20210A (p < 0.001; OR 1.8; 95% CI 1.1-2.9) SNPs is significantly associated with pre-eclampsia. Besides pre-eclampsia, genotyping for the F5 Leiden G1691A and the F2 G20210A SNPs is also useful for individual risk assessment regarding pregnancy-associated thrombosis. Carriers of the F5 Leiden G1691A SNP will develop this condition in 6.4% of heterozygotes and in 8.9-16.7% of homozygotes. A total of 6.2% of women with the F2 G20210A SNP and 17.8% of women with simultaneous carriage of the F5 Leiden G1691A and F2 G20210A SNPs will develop pregnancy-associated thrombosis. Both the F5 Leiden G1691A and F2 G20210A SNPs are also risk factors of early recurrent, late recurrent and late spontaneous miscarriage based on a published meta-analysis of 31 studies. These women may benefit from prophylactic heparinization. Six case-control and cohort studies of 687 women with genetic thrombophilia document live birth rates of 82% (181/221) using low-molecular-weight heparin or fractionated heparin compared with 20% (95/466) without therapy (p < 0.001, OR 17.7; 95% CI 12.2-25.5). Based on the data in the literature, including association studies and meta-analyses of these association studies, it can be concluded that genetic thrombophilia due to carriage of the F5 Leiden G1691A and F2 G20210A SNPs is a significant and clinically relevant risk factor for pre-eclampsia, pregnancy-associated thrombosis, and early and late miscarriages.