Genetic variations in ATP2B1, CSK, ARSG and CSMD1 loci are related to blood pressure and/or hypertension in two Korean cohorts

ATP2B1 gene polymorphisms associated with resistant hypertension in the Japanese population

Single-nucleotide polymorphisms (SNP) of ATP2B1 gene are associated with essential hypertension but their association with resistant hypertension (RHT) remains unexplored. The authors examined the relationship between ATP2B1 SNPs and RHT by genotyping 12 SNPs in ATP2B1 gene of 1124 Japanese individuals with lifestyle-related diseases. Patients with RHT had inadequate blood pressure (BP) control using three antihypertensive drugs or used ≥4 antihypertensive drugs. Patients with controlled hypertension had BP controlled using ≤3 antihypertensive drugs. The association between each SNP and RHT was analyzed by logistic regression. The final cohort had 888 (79.0%) and 43 (3.8%) patients with controlled hypertension and RHT, respectively. Compared with patients homozygous for the minor allele of each SNP in ATP2B1, a significantly higher number of patients carrying the major allele at 10 SNPs exhibited RHT (most significant at rs1401982: 5.8% vs. 0.8%, p = .014; least significant at rs11105378: 5.7% vs. 0.9%, p = .035; most nonsignificant at rs12817819: 5.1% vs. 10%, p = .413). After multivariate adjustment for age, sex, systolic BP, and other confounders, the association remained significant for rs2681472 and rs1401982 (OR: 7.60, p < .05 and OR: 7.62, p = .049, respectively). Additionally, rs2681472 and rs1401982 were in linkage disequilibrium with rs11105378. This study identified two ATP2B1 SNPs associated with RHT in the Japanese population. rs1401982 was most closely associated with RHT, and major allele carriers of rs1401982 required significantly more antihypertensive medications. Analysis of ATP2B1 SNPs in patients with hypertension can help in early prediction of RHT and identification of high-risk patients who are more likely to require more antihypertensive medications.

An individualized Bayesian method for estimating genomic variants of hypertension

BACKGROUND

Genomic variants of the disease are often discovered nowadays through population-based genome-wide association studies (GWAS). Identifying genomic variations potentially underlying a phenotype, such as hypertension, in an individual is important for designing personalized treatment; however, population-level models, such as GWAS, may not capture all the important, individualized factors well. In addition, GWAS typically requires a large sample size to detect the association of low-frequency genomic variants with sufficient power. Here, we report an individualized Bayesian inference (IBI) algorithm for estimating the genomic variants that influence complex traits, such as hypertension, at the level of an individual (e.g., a patient). By modeling at the level of the individual, IBI seeks to find genomic variants observed in the individual's genome that provide a strong explanation of the phenotype observed in this individual.

RESULTS

We applied the IBI algorithm to the data from the Framingham Heart Study to explore the genomic influences of hypertension. Among the top-ranking variants identified by IBI and GWAS, there is a significant number of shared variants (intersection); the unique variants identified only by IBI tend to have relatively lower minor allele frequency than those identified by GWAS. In addition, IBI discovered more individualized and diverse variants that explain hypertension patients better than GWAS. Furthermore, IBI found several well-known low-frequency variants as well as genes related to blood pressure that GWAS missed in the same cohort. Finally, IBI identified top-ranked variants that predicted hypertension better than GWAS, according to the area under the ROC curve.

CONCLUSIONS

The results support IBI as a promising approach for complementing GWAS, especially in detecting low-frequency genomic variants as well as learning personalized genomic variants of clinical traits and disease, such as the complex trait of hypertension, to help advance precision medicine.

Networks of placental DNA methylation correlate with maternal serum PCB concentrations and child neurodevelopment

BACKGROUND

Gestational exposure to polychlorinated biphenyls (PCBs) has been associated with elevated risk for neurodevelopmental disorders. Placental epigenetics may serve as a potential mechanism of risk or marker of altered placental function. Prior studies have associated differential placental DNA methylation with maternal PCB exposure or with increased risk of autism spectrum disorder (ASD). However, sequencing-based placental methylomes have not previously been tested for simultaneous associations with maternal PCB levels and child neurodevelopmental outcomes.

OBJECTIVES

We aimed to identify placental DNA methylation patterns associated with maternal PCB levels and child neurodevelopmental outcomes in the high-risk ASD MARBLES cohort.

METHODS

We measured 209 PCB congeners in 104 maternal serum samples collected at delivery. We identified networks of DNA methylation from 147 placenta samples using the Comethyl R package, which performs weighted gene correlation network analysis for whole genome bisulfite sequencing data. We tested placental DNA methylation modules for association with maternal serum PCB levels, child neurodevelopment, and other participant traits.

RESULTS

PCBs 153 + 168, 170, 180 + 193, and 187 were detected in over 50% of maternal serum samples and were highly correlated with one another. Consistent with previous findings, maternal age was the strongest predictor of serum PCB levels, alongside year of sample collection, pre-pregnancy BMI, and polyunsaturated fatty acid levels. Twenty seven modules of placental DNA methylation were identified, including five which significantly correlated with one or more PCBs, and four which correlated with child neurodevelopment. Two modules associated with maternal PCB levels as well as child neurodevelopment, and mapped to CSMD1 and AUTS2, genes previously implicated in ASD and identified as differentially methylated regions in mouse brain and placenta following gestational PCB exposure.

CONCLUSIONS

Placental DNA co-methylation modules were associated with maternal PCBs and child neurodevelopment. Methylation of CSMD1 and AUTS2 could be markers of altered placental function and/or ASD risk following maternal PCB exposure.

Exploring the Genetic Association between Obesity and Serum Lipid Levels Using Bivariate Methods

It is crucial to understand the genetic mechanisms and biological pathways underlying the relationship between obesity and serum lipid levels. Structural equation models (SEMs) were constructed to calculate heritability for body mass index (BMI), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and the genetic connections between BMI and the four classes of lipids using 1197 pairs of twins from the Chinese National Twin Registry (CNTR). Bivariate genomewide association studies (GWAS) were performed to identify genetic variants associated with BMI and lipids using the records of 457 individuals, and the results were further validated in 289 individuals. The genetic background affecting BMI may differ by gender, and the heritability of males and females was 71% (95% CI [.66, .75]) and 39% (95% CI [.15, .71]) respectively. BMI was positively correlated with TC, TG and LDL-C in phenotypic and genetic correlation, while negatively correlated with HDL-C. There were gender differences in the correlation between BMI and lipids. Bivariate GWAS analysis and validation stage found 7 genes (LOC105378740, LINC02506, CSMD1, MELK, FAM81A, ERAL1 and MIR144) that were possibly related to BMI and lipid levels. The significant biological pathways were the regulation of cholesterol reverse transport and the regulation of high-density lipoprotein particle clearance (p < .001). BMI and blood lipid levels were affected by genetic factors, and they were genetically correlated. There might be gender differences in their genetic correlation. Bivariate GWAS analysis found MIR144 gene and its related biological pathways may influence obesity and lipid levels.

A Review of Vascular Traits and Assessment Techniques, and Their Heritability

Various tools are available to assess atherosclerosis, arterial stiffening, and endothelial function. They offer utility in the assessment of hypertensive phenotypes, in cardiovascular risk prediction, and as surrogate endpoints in clinical trials. We explore the relative influence of participant genetics, with reference to large-scale genomic studies, population-based cohorts, and candidate gene studies. We find heritability estimates highest for carotid intima-media thickness (CIMT 35–65%), followed by pulse wave velocity as a measure of arterial stiffness (26–43%), and flow mediated dilatation as a surrogate for endothelial function (14–39%); data were lacking for peripheral artery tonometry. We furthermore examine genes and polymorphisms relevant to each technique. We conclude that CIMT and pulse wave velocity dominate the existing evidence base, with fewer published genomic linkages for measures of endothelial function. We finally make recommendations regarding planning and reporting of data relating to vascular assessment techniques, particularly when genomic data are also available, to facilitate integration of these tools into cardiovascular disease research.

Shared genetic etiology and antagonistic relationship of plasma renin activity and systolic blood pressure in a Korean cohorts

Despite extensive studies on blood pressure, its genetic risk factors remain uncertain. Even one of the most researched blood pressure-related traits - renin - is not fully understood genetically. Here, we determine the genetic relationship and associated predisposition between blood pressure and baseline renin. In 8840 Korean individuals, we observed a strong negative genome-wide genetic correlation (r_g = -0.484) between systolic blood pressure (SBP) and plasma renin activity (PRA), suggesting that antagonistic genetic signals explain the variance in the two traits. We found 51 significant pleiotropic SNPs affecting the two traits, which could contribute to the Renin-Angiotensin-Aldosterone System (RAAS). Our findings provide insight into studies on RAAS by identifying the genome-wide relationship and susceptibility loci of SBP and PRA.

Cataloging the potential SNPs (single nucleotide polymorphisms) associated with quantitative traits, viz. BMI (body mass index), IQ (intelligence quotient) and BP (blood pressure): an updated review

Background

Single nucleotide polymorphism (SNP) variants are abundant, persistent and widely distributed across the genome and are frequently linked to the development of genetic diseases. Identifying SNPs that underpin complex diseases can aid scientists in the discovery of disease-related genes by allowing for early detection, effective medication and eventually disease prevention.

Main body

Various SNP or polymorphism-based studies were used to categorize different SNPs potentially related to three quantitative traits: body mass index (BMI), intelligence quotient (IQ) and blood pressure, and then uncovered common SNPs for these three traits. We employed SNPedia, RefSNP Report, GWAS Catalog, Gene Cards (Data Bases), PubMed and Google Scholar search engines to find relevant material on SNPs associated with three quantitative traits. As a result, we detected three common SNPs for all three quantitative traits in global populations: SNP rs6265 of the BDNF gene on chromosome 11p14.1, SNP rs131070325 of the SL39A8 gene on chromosome 4p24 and SNP rs4680 of the COMT gene on chromosome 22q11.21.

Conclusion

In our review, we focused on the prevalent SNPs and gene expression activities that influence these three quantitative traits. These SNPs have been used to detect and map complex, common illnesses in communities for homogeneity testing and pharmacogenetic studies. High blood pressure, diabetes and heart disease, as well as BMI, schizophrenia and IQ, can all be predicted using common SNPs. Finally, the results of our work can be used to find common SNPs and genes that regulate these three quantitative features across the genome.

ATP2B1 genotypes rs2070759 and rs2681472 polymorphisms and risk of hypertension in Saudi population

This study examined an association of ATP2B1 gene polymorphism and hypertension in the Saudi population. The 246 hypertensive cases and 300 healthy human controls were genotyped. The results showed that genotypes rs.207075 (CA + AA) [p = 0.05; OR: 95% CI, 1.5:(1.0 to 2.4) and p = 0.001, OR: 95% CI, 2.4: (1.5 to 4.0) and rs2681472 (CT + TT) [p = 0.05; OR: 95% CI, 1.5 (1.0 to 2.4) and p = 0.006 OR: 95% CI, 2.0 (1.2 to 3.1) respectively] associated with the risk of hypertension. Cases carrying the recessive models: [(CA + AA)/(CT + TT)] and [(AA)/(TT)] genotypes confer a strong susceptibility risk of hypertension [p = 0.002; OR: (95%CI) 1.8 (1.2 to 2.6) and p = 0.001; OR: (95%CI) 2.6 (1.5 to 4.7) respectively]. However, cases with body-mass-index (BMI)<25, carrying homozygous mutant genotypes [AA, rs2070759, p = 0.007; OR: (95%CI) 2.75(1.37 to 5.5) and (TT, rs2681472, p = 0.05; OR: (95%CI) 1.96 (1.03 to 3.72)] as well as A allele of rs2070759 [p = 0.006; OR: (95%CI) 1.62 (1.16 to 2.25)] and T allele of rs2681472, p = 0.04, 1.43(1.03 to 1.98)] showed a significant association with high risk of hypertension. In short, a significant association between ATP2B1 gene polymorphism and risk of hypertension was noticed. In addition, individuals carrying recessive genotypes have greater risk in developing hypertension than those carrying dominant genotypes. Moreover, cases with high-risk BMI associated with ATP2B1 variants may play a critical role in developing hypertension.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1973034 .

Identifying the predictive effectiveness of a genetic risk score for incident hypertension using machine learning methods among populations in rural China

Current studies have shown the controversial effect of genetic risk scores (GRSs) in hypertension prediction. Machine learning methods are used extensively in the medical field but rarely in the mining of genetic information. This study aims to determine whether genetic information can improve the prediction of incident hypertension using machine learning approaches in a prospective study. The study recruited 4592 subjects without hypertension at baseline from a cohort study conducted in rural China. A polygenic risk score (PGGRS) was calculated using 13 SNPs. According to a ratio of 7:3, subjects were randomly allocated to the train and test datasets. Models with and without the PGGRS were established using the train dataset with Cox regression, artificial neural network (ANN), random forest (RF), and gradient boosting machine (GBM) methods. The discrimination and reclassification of models were estimated using the test dataset. The PGGRS showed a significant association with the risk of incident hypertension (HR (95% CI), 1.046 (1.004, 1.090), P = 0.031) irrespective of baseline blood pressure. Models that did not include the PGGRS achieved AUCs (95% CI) of 0.785 (0.763, 0.807), 0.790 (0.768, 0.811), 0.838 (0.817, 0.857), and 0.854 (0.835, 0.873) for the Cox, ANN, RF, and GBM methods, respectively. The addition of the PGGRS led to the improvement of the AUC by 0.001, 0.008, 0.023, and 0.017; IDI by 1.39%, 2.86%, 4.73%, and 4.68%; and NRI by 25.05%, 13.01%, 44.87%, and 22.94%, respectively. Incident hypertension risk was better predicted by the traditional+PGGRS model, especially when machine learning approaches were used, suggesting that genetic information may have the potential to identify new hypertension cases using machine learning methods in resource-limited areas. CLINICAL TRIAL REGISTRATION: The Henan Rural Cohort Study has been registered at the Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). http://www.chictr.org.cn/showproj.aspx?proj=11375 .

ATP2B1 gene polymorphisms rs2681472 and rs17249754 are associated with susceptibility to hypertension and blood pressure levels: A systematic review and meta-analysis

OBJECTIVE

The present study aimed to conduct a systematic review and meta-analysis to evaluate the relationships between ATP2B1 gene polymorphisms with blood pressure (BP) level and susceptibility to hypertension.

METHODS

PubMed, Web of Science, Embase and China National Knowledge Infrastructure (CNKI) Databases were systematically searched by 2 independent researchers to screen studies on ATP2B1 gene polymorphisms and BP related phenotypes. The records retrieval period was limited from the formation of the database to March 4, 2021. Pooled odds rations (ORs) or β and their 95% confidence intervals (95%CI) were calculated to assess the association between ATP2B1 gene polymorphisms and the risk of hypertension or BP levels. Publication bias and sensitivity analysis were conducted to find potential bias. All the statistical analysis were conducted with Stata version 11.0 software.

RESULTS

A total of 15 articles were ultimately included in the present study, including 15 polymorphisms of ATP2B1 gene. Nine articles (N = 65,362) reported the polymorphism rs17249754, and 7 articles(N = 91,997) reported rs2681472 (both loci were reported in 1 article). Meta-analysis showed that rs17249754 (G/A) and rs2681472 (A/G) were associated with the susceptibility to hypertension (rs17249754: OR = 1.19, 95%CI: 1.10-1.28; rs2681472: OR = 1.15, 95%CI: 1.12-1.17), and were positively associated with systolic BP (SBP) and diastolic blood pressure (DBP) (rs17249754: SBP, β=1.01, 95%CI: 0.86-1.16, DBP, β=0.48, 95%CI: 0.30-0.66; rs2681472: SBP, β=0.92, 95%CI: 0.77-1.07, DBP, β=0.50, 95%CI: 0.42-0.58) in the additive genetic model. Subgroup analysis stratified by race, population, sample size, and BP measurement method revealed that the association between A allele in rs2681472 polymorphism and risk of hypertension was slightly stronger in European (EUR) populations (OR = 1.16, 95%CI: 1.13-1.20) than in East Asians (OR = 1.14, 95%CI: 1.10-1.17). While in East Asians, relation between rs17249754 with risk of hypertension (OR = 1.19, 95%CI: 1.10-1.28) is stronger than rs2681472 (OR = 1.14, 95%CI: 1.10-1.17).

CONCLUSIONS

Our study demonstrated that ATP2B1 gene polymorphism rs2681472 and rs17249754 were associated with BP levels and the susceptibility to hypertension.

Rapid response to the alpha-1 adrenergic agent phenylephrine in the perioperative period is impacted by genomics and ancestry

The emergence of genomic data in biobanks and health systems offers new ways to derive medically important phenotypes, including acute phenotypes occurring during inpatient clinical care. Here we study the genetic underpinnings of the rapid response to phenylephrine, an α1-adrenergic receptor agonist commonly used to treat hypotension during anesthesia and surgery. We quantified this response by extracting blood pressure (BP) measurements 5 min before and after the administration of phenylephrine. Based on this derived phenotype, we show that systematic differences exist between self-reported ancestry groups: European-Americans (EA; n = 1387) have a significantly higher systolic response to phenylephrine than African-Americans (AA; n = 1217) and Hispanic/Latinos (HA; n = 1713) (31.3% increase, p value < 6e-08 and 22.9% increase, p value < 5e-05 respectively), after adjusting for genetic ancestry, demographics, and relevant clinical covariates. We performed a genome-wide association study to investigate genetic factors underlying individual differences in this derived phenotype. We discovered genome-wide significant association signals in loci and genes previously associated with BP measured in ambulatory settings, and a general enrichment of association in these genes. Finally, we discovered two low frequency variants, present at ~1% in EAs and AAs, respectively, where patients carrying one copy of these variants show no phenylephrine response. This work demonstrates our ability to derive a quantitative phenotype suited for comparative statistics and genome-wide association studies from dense clinical and physiological measures captured for managing patients during surgery. We identify genetic variants underlying non response to phenylephrine, with implications for preemptive pharmacogenomic screening to improve safety during surgery.

Characterization of Hepatitis B Virus Integrations Identified in Hepatocellular Carcinoma Genomes

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality. Almost half of HCC cases are associated with hepatitis B virus (HBV) infections, which often lead to HBV sequence integrations in the human genome. Accurate identification of HBV integration sites at a single nucleotide resolution is critical for developing a better understanding of the cancer genome landscape and of the disease itself. Here, we performed further analyses and characterization of HBV integrations identified by our recently reported VIcaller platform in recurrent or known HCC genes (such as TERT, MLL4, and CCNE1) as well as non-recurrent cancer-related genes (such as CSMD2, NKD2, and RHOU). Our pathway enrichment analysis revealed multiple pathways involving the alcohol dehydrogenase 4 gene, such as the metabolism pathways of retinol, tyrosine, and fatty acid. Further analysis of the HBV integration sites revealed distinct patterns involving the integration upper breakpoints, integrated genome lengths, and integration allele fractions between tumor and normal tissues. Our analysis also implies that the VIcaller method has diagnostic potential through discovering novel clonal integrations in cancer-related genes. In conclusion, although VIcaller is a hypothesis free virome-wide approach, it can still be applied to accurately identify genome-wide integration events of a specific candidate virus and their integration allele fractions.

AHR canonical pathway: in vivo findings to support novel antihypertensive strategies

Essential hypertension (HTN) is a disease where genetic and environmental factors interact to produce a high prevalent set of almost indistinguishable phenotypes. The weak definition of what is under the umbrella of HTN is a consequence of the lack of knowledge on the players involved in environment-gene interaction and their impact on blood pressure (BP) and mechanisms. The disclosure of these mechanisms that sense and (mal)adapt to toxic-environmental stimuli might at least determine some phenotypes of essential HTN and will have important therapeutic implications. In the present manuscript, we looked closer to the environmental sensor aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor involved in cardiovascular physiology, but better known by its involvement in biotransformation of xenobiotics through its canonical pathway. This review aims to disclose the contribution of the AHR-canonical pathway to HTN. For better mirror the complexity of the mechanisms involved in BP regulation, we privileged evidence from in vivo studies. Here we ascertained the level of available evidence and a comprehensive characterization of the AHR-related phenotype of HTN. We reviewed clinical and rodent studies on AHR-HTN genetic association and on AHR ligands and their impact on BP. We concluded that AHR is a druggable mechanistic linker of environmental exposure to HTN. We conclude that is worth to investigate the canonical pathway of AHR and the expression/polymorphisms of its related genes and/or other biomarkers (e.g. tryptophan-related ligands), in order to identify patients that may benefit from an AHR-centered antihypertensive treatment.

Genomic Association of Single Nucleotide Polymorphisms with Blood Pressure Response to Hydrochlorothiazide among South African Adults with Hypertension

This study described single nucleotide polymorphisms (SNPs) in hydrochlorothiazide-associated genes and further assessed their correlation with blood pressure control among South African adults living with hypertension. A total of 291 participants belonging to the Nguni tribes of South Africa on treatment for hypertension were recruited. Nineteen SNPs in hydrochlorothiazide pharmacogenes were selected and genotyped using MassArray. Uncontrolled hypertension was defined as blood pressure ≥140/90 mmHg. The association between genotypes, alleles and blood pressure response to treatment was determined by conducting multivariate logistic regression model analysis. The majority of the study participants were female (73.19%), Xhosa (54.98%) and had blood pressure ≥140/90 mmHg (68.73%). Seventeen SNPs were observed among the Xhosa tribe, and two (rs2070744 and rs7297610) were detected among Swati and Zulu participants. Furthermore, alleles T of rs2107614 (AOR = 6.69; 95%CI 1.42–31.55; p = 0.016) and C of rs2776546 (AOR = 3.78; 95%CI 1.04–13.74; p = 0.043) were independently associated with uncontrolled hypertension, whilst rs2070744 TC (AOR = 38.76; 95%CI 5.54–270.76; p = 0.00023), CC (AOR = 10.44; 95%CI 2.16–50.29; p = 0.003) and allele T of rs7297610 (AOR = 1.86; 95%CI 1.09–3.14; p = 0.023) were significantly associated with uncontrolled hypertension among Zulu and Swati participants. We confirmed the presence of SNPs associated with hydrochlorothiazide, some of which were significantly associated with uncontrolled hypertension in the study sample. Findings open doors for further studies on personalized therapy for hypertension in the country.

Primary Active Ca2+ Transport Systems in Health and Disease

Calcium ions (Ca²⁺) are prominent cell signaling effectors that regulate a wide variety of cellular processes. Among the different players in Ca²⁺ homeostasis, primary active Ca²⁺ transporters are responsible for keeping low basal Ca²⁺ levels in the cytosol while establishing steep Ca²⁺ gradients across intracellular membranes or the plasma membrane. This review summarizes our current knowledge on the three types of primary active Ca²⁺-ATPases: the sarco(endo)plasmic reticulum Ca²⁺-ATPase (SERCA) pumps, the secretory pathway Ca²⁺- ATPase (SPCA) isoforms, and the plasma membrane Ca²⁺-ATPase (PMCA) Ca²⁺-transporters. We first discuss the Ca²⁺ transport mechanism of SERCA1a, which serves as a reference to describe the Ca²⁺ transport of other Ca²⁺ pumps. We further highlight the common and unique features of each isoform and review their structure-function relationship, expression pattern, regulatory mechanisms, and specific physiological roles. Finally, we discuss the increasing genetic and in vivo evidence that links the dysfunction of specific Ca²⁺-ATPase isoforms to a broad range of human pathologies, and highlight emerging therapeutic strategies that target Ca²⁺ pumps.

A multi-ancestry genome-wide study incorporating gene-smoking interactions identifies multiple new loci for pulse pressure and mean arterial pressure

Elevated blood pressure (BP), a leading cause of global morbidity and mortality, is influenced by both genetic and lifestyle factors. Cigarette smoking is one such lifestyle factor. Across five ancestries, we performed a genome-wide gene-smoking interaction study of mean arterial pressure (MAP) and pulse pressure (PP) in 129 913 individuals in stage 1 and follow-up analysis in 480 178 additional individuals in stage 2. We report here 136 loci significantly associated with MAP and/or PP. Of these, 61 were previously published through main-effect analysis of BP traits, 37 were recently reported by us for systolic BP and/or diastolic BP through gene-smoking interaction analysis and 38 were newly identified (P < 5 × 10-8, false discovery rate < 0.05). We also identified nine new signals near known loci. Of the 136 loci, 8 showed significant interaction with smoking status. They include CSMD1 previously reported for insulin resistance and BP in the spontaneously hypertensive rats. Many of the 38 new loci show biologic plausibility for a role in BP regulation. SLC26A7 encodes a chloride/bicarbonate exchanger expressed in the renal outer medullary collecting duct. AVPR1A is widely expressed, including in vascular smooth muscle cells, kidney, myocardium and brain. FHAD1 is a long non-coding RNA overexpressed in heart failure. TMEM51 was associated with contractile function in cardiomyocytes. CASP9 plays a central role in cardiomyocyte apoptosis. Identified only in African ancestry were 30 novel loci. Our findings highlight the value of multi-ancestry investigations, particularly in studies of interaction with lifestyle factors, where genomic and lifestyle differences may contribute to novel findings.

Positive association between ATP2B1 rs17249754 and essential hypertension: a case-control study in Burkina Faso, West Africa

Background

Genetic and environment play a significant role in the etiology of essential hypertension (EH). Recently STK39 rs3754777, ATP2B1 rs2681472 and rs17249754 have been associated with BP variation and hypertension. In this study we aimed to determine firstly whether index variants were associated with the risk of developing EH in Burkina Faso and secondly to characterize cardiovascular risk markers.

Methods

We conducted a case-control study with 380 participants including 180 case subjects with EH and 200 control subjects with normal BP. We used TaqMan genotyping assays with probes from Applied Biosystems to genotype polymorphisms using the 7500 Real-Time PCR System. Biochemical parameters were measured using chemistry analyzer COBAS C311.

Results

T-test showed that cardiovascular risk markers such as body mass index, waist circumference, blood sugar, total cholesterol and triglycerides were significantly higher in hypertensive compared to normotensive (all p <  0.05). Binary logistic regression analysis revealed in decreasing order that overweight, family history of hypertension, central obesity and alcohol intake increased the risk of developing EH (all OR > 3.8; all p <  0.001).

In genetic level we observed that individuals carrying the AA+AG genotype of ATP2B1 rs17249754 had a low risk of developing EH than those carrying the GG genotype (OR = 0.48 [95% CI: 0.31–0.75] p = 0.001) and the A allele frequency in the cases was significantly lower than that of the controls (OR = 0.56 [95% CI: 0.38–0.82] p = 0.003). We also observed that ATP2B1 rs17249754 was significantly associated with higher SBP and DPB in case and control groups (GG versus AG + AA; p <  0.05), ATP2B1 rs2681472 was significantly associated with higher SBP only in case and control group (AA versus AG + GG; p <  0.05), STK39 rs3754777 was not significantly associated with any of the BP traits (CC versus CT + TT; p > 0.05).

Conclusion

Our results confirmed the significant association of ATP2B1 rs17249754 with the risk of developing EH in Burkinabe and showed an increase of cardiovascular risk markers levels in subjects with EH.

Electronic supplementary material

The online version of this article (10.1186/s12872-019-1136-x) contains supplementary material, which is available to authorized users.

Update on Chronic Kidney Disease Mineral and Bone Disorder in Cardiovascular Disease

Chronic kidney disease mineral and bone disorder (MBD) encompasses changes in mineral ion and vitamin D metabolism that are widespread in the setting of chronic kidney disease and end-stage renal disease. MBD components associate with cardiovascular disease in many epidemiologic studies. Through impacts on hypertension, activation of the renin-angiotensin-aldosterone system, vascular calcification, endothelial function, and cardiac remodeling and conduction, MBD may be a direct and targetable cause of cardiovascular disease. However, assessment and treatment of MBD is rife with challenges owing to biological tensions between its many components, such as calcium and phosphorus with their regulatory hormones fibroblast growth factor 23 and parathyroid hormone; fibroblast growth factor 23 with its co-receptor klotho; and vitamin D with control of calcium and phosphorus. These complex interactions between MBD components hinder the simple translation to clinical trials, which ultimately are needed to prove the benefits of treating MBD. Deeper investigation using precision medicine tools and principles, including genomics and individualized risk assessment and therapy, may help move the field closer toward clinical applications. This review provides a high-level overview of conventional and precision epidemiology in MBD, potential mechanisms of cardiovascular disease pathogenesis, and guiding therapeutic principles for established and emerging treatments.

Association between ATP2B1 and CACNB2 polymorphisms and high blood pressure in a population of Lithuanian children and adolescents: a cross-sectional study

OBJECTIVES

Recently, genome-wide associated studies have identified several genetic loci that are associated with elevated blood pressure and could play a critical role in intracellular calcium homeostasis. The aim of this study was to assess the associations of ATP2B1 rs2681472 and CACNB2 rs12258967 gene polymorphisms with high blood pressure (HBP) among Lithuanian children and adolescents aged 12-15 years.

STUDY DESIGN AND PARTICIPANTS

This was a cross-sectional study of a randomly selected sample of 646 12-15-year-old adolescents who participated in the survey 'The Prevalence and Risk Factors of HBP in 12-15 Year-Old Lithuanian Children and Adolescents (from November 2010 to April 2012)'. Anthropometric parameters and BP were measured. The participants with HBP were screened on two separate occasions. Subjects were genotyped ATP2B1 rs2681472 and CACNB2 rs12258967 gene polymorphisms using real-time PCR method.

RESULTS

The prevalence of HBP was 36.7%, significantly higher for boys than for girls. In the multivariate analysis, after adjustment for body mass index and waist circumference, boys with CACNB2 CG genotype, CACNB2 GG genotype and CACNB2 CG +GG genotype had higher odds of having HBP in codominant (adjusted OR (aOR)=1.92; 95% CI 1.16 to 3.18, p=0.011; and aOR=2.64; 95% CI 1.19 to 5.90, p=0.018) and in dominant (aOR=2.05; 95% CI 1.27 to 3.30, p=0.003) inheritance models. Girls carrying CACNB2 CG genotype and CACNB2 CG +GG genotype had increased odds of HBP in codominant (aOR=1.82; 95% CI 1.02 to 3.24, p=0.044) and in dominant (aOR=1.89; 95% CI 1.09 to 3.28, p=0.023) inheritance models. Furthermore, significant associations were found in additive models separately for boys (aOR=1.72; 95% CI 1.20 to 2.46, p=0.003) and girls (aOR=1.52; 95% CI 1.05 to 2.20, p=0.027). No significant association was found between ATP2B1 gene polymorphism and the odds of HBP.

CONCLUSIONS

Our results indicate that CACNB2 gene polymorphism was significantly associated with higher odds of HBP in Lithuanian adolescents aged 12-15 years.

Association of ATP2B1 common variants with asymptomatic intracranial and extracranial large artery stenosis in hypertension patients

BACKGROUND AND AIMS

Genetic factors play an important role in the cervico-cerebral large-artery atherosclerotic stenosis (LAS), and ATP2B1 gene has been associated with the process of atherosclerosis disorders, such as coronary artery disease and arterial stiffness. But there is little information about the relationship between ATP2B1 gene and atherosclerosis in the intracranial arteries. We hereby investigated the association of common variants in ATP2B1 gene with LAS in asymptomatic Chinese hypertension patients.

METHODS

The stenosis of intracranial and extracranial arteries were evaluated in 899 subjects through computerized tomography angiography from the aortic arch to the skull base. A total of 11 ATP2B1 common variants were genotyped. Multivariate logistic regression was carried out in a dominant model with confounding factors adjusted.

RESULTS

rs17249754-A (OR = 0.43, p = 0.0002) and rs1401982-G (OR = 0.47, p = 0.0007) were associated with decreased susceptibility of concurrent extra and intracranial stenosis even after Bonferroni correction. These two minor alleles were also significantly associated with less stenotic arteries and moderate-to-severe stenosis.

CONCLUSION

rs17249754 and rs1401982 were associated with asymptomatic LAS in stroke-free Chinese hypertension patients and might benefit early recognition of LAS patients in clinical practice.

Expression level of fibroblast growth factor 5 (FGF5) in the peripheral blood of primary hypertension and its clinical significance

OBJECTIVE

To explore the expression level of FGF5 in the peripheral blood of primary hypertension patients and its clinical significance.

METHODS

The 34 patients with primary hypertension treated in this hospital from June 2012 to June 2014 were selected as the observation group, while the 25 patients at this hospital who had physical exam with heathy results were selected as control group. Venous blood was drawn early in the morning after an overnight fast. FGF5, mRNA and protein level changes in the peripheral blood cells and peripheral blood serum were analyzed by real-time fluorescence based quantitative PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). FGF5 gene SNP (rs16998073) were amplified by PCR and inserted into T vector, and its genetic variation were analyzed by sequencing. The relationship of FGF5 protein levels and genetic variation with diastolic/systolic blood pressure was also analyzed.

RESULTS

Comparing with the control group, the observation group's FGF5 mRNA and protein levels significantly increased in the peripheral blood cells and peripheral blood. The difference was statistically significant (P < .05). Correlation analysis showed that FGF5 protein level and systolic/diastolic blood pressure were positively correlated (P < .05). T/A genetic variation of FGF5 gene SNP (rs16998073) and diastolic/systolic blood pressure were positively correlated (P < .05).

CONCLUSION

The FGF5 mRNA and protein expression levels of the patients with primary hypertension were abnormal and had genetic variation, which were associated with blood pressure of the patients with primary hypertension.

The Plasma Membrane Calcium ATPases and Their Role as Major New Players in Human Disease

The Ca²⁺ extrusion function of the four mammalian isoforms of the plasma membrane calcium ATPases (PMCAs) is well established. There is also ever-increasing detail known of their roles in global and local Ca²⁺ homeostasis and intracellular Ca²⁺ signaling in a wide variety of cell types and tissues. It is becoming clear that the spatiotemporal patterns of expression of the PMCAs and the fact that their abundances and relative expression levels vary from cell type to cell type both reflect and impact on their specific functions in these cells. Over recent years it has become increasingly apparent that these genes have potentially significant roles in human health and disease, with PMCAs1-4 being associated with cardiovascular diseases, deafness, autism, ataxia, adenoma, and malarial resistance. This review will bring together evidence of the variety of tissue-specific functions of PMCAs and will highlight the roles these genes play in regulating normal physiological functions and the considerable impact the genes have on human disease.

Genomic Approaches to Hypertension

Genomic insights and analyses of Mendelian hypertension (HTN) syndromes and Genome-Wide Association study (GWAS) on essential hypertension have contributed to the depth of understanding of the genetics origins of hypertension. Mendelian syndromes are important for the field, since such knowledge leads to specific insights about disease pathogenesis and the potential for precision medicine. The clinical impact of findings of on essential hypertension is continuously evolving, and the insights accrued will refine efforts to combat the societal impact of hypertension. Comprehensive identification of all genomic variants of hypertension, along with their individual associated mechanisms, is paving the way forward in the era of personalized medicine. The overriding challenge for care providers is to reduce health inequities through improved compliance and, perhaps, new paradigms for implementation science that incorporate genomic medicine.

Exploration of haplotype research consortium imputation for genome-wide association studies in 20,032 Generation Scotland participants

Background

The Generation Scotland: Scottish Family Health Study (GS:SFHS) is a family-based population cohort with DNA, biological samples, socio-demographic, psychological and clinical data from approximately 24,000 adult volunteers across Scotland. Although data collection was cross-sectional, GS:SFHS became a prospective cohort due to of the ability to link to routine Electronic Health Record (EHR) data. Over 20,000 participants were selected for genotyping using a large genome-wide array.

Methods

GS:SFHS was analysed using genome-wide association studies (GWAS) to test the effects of a large spectrum of variants, imputed using the Haplotype Research Consortium (HRC) dataset, on medically relevant traits measured directly or obtained from EHRs. The HRC dataset is the largest available haplotype reference panel for imputation of variants in populations of European ancestry and allows investigation of variants with low minor allele frequencies within the entire GS:SFHS genotyped cohort.

Results

Genome-wide associations were run on 20,032 individuals using both genotyped and HRC imputed data. We present results for a range of well-studied quantitative traits obtained from clinic visits and for serum urate measures obtained from data linkage to EHRs collected by the Scottish National Health Service. Results replicated known associations and additionally reveal novel findings, mainly with rare variants, validating the use of the HRC imputation panel. For example, we identified two new associations with fasting glucose at variants near to Y_RNA and WDR4 and four new associations with heart rate at SNPs within CSMD1 and ASPH, upstream of HTR1F and between PROKR2 and GPCPD1. All were driven by rare variants (minor allele frequencies in the range of 0.08–1%). Proof of principle for use of EHRs was verification of the highly significant association of urate levels with the well-established urate transporter SLC2A9.

Conclusions

GS:SFHS provides genetic data on over 20,000 participants alongside a range of phenotypes as well as linkage to National Health Service laboratory and clinical records. We have shown that the combination of deeper genotype imputation and extended phenotype availability make GS:SFHS an attractive resource to carry out association studies to gain insight into the genetic architecture of complex traits.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-017-0414-4) contains supplementary material, which is available to authorized users.

Interaction between Single Nucleotide Polymorphism and Urinary Sodium, Potassium, and Sodium-Potassium Ratio on the Risk of Hypertension in Korean Adults

Hypertension is a complex disease explained with diverse factors including environmental factors and genetic factors. The objectives of this study were to determine the interaction effects between gene variants and 24 h estimated urinary sodium and potassium excretion and sodium-potassium excretion ratios on the risk of hypertension. A total of 8839 participants were included in the genome-wide association study (GWAS) to find genetic factors associated with hypertension. Tanaka and Kawasaki formulas were applied to estimate 24 h urinary sodium and potassium excretion. A total of 4414 participants were included in interaction analyses to identify the interaction effects of gene variants according to 24 h estimated urinary factors on the risk of hypertension. CSK rs1378942 and CSK-MIR4513 rs3784789 were significantly modified by urinary sodium-potassium excretion ratio. In addition, MKLN rs1643270 with urinary potassium excretion, LOC101929750 rs7554672 with urinary sodium and potassium excretion, and TENM4 rs10466739 with urinary sodium-potassium excretion ratio showed significant interaction effects. The present study results indicated that the mutant alleles of CSK rs1378942 and CSK-MIR4513 rs3784789 had the strongest protective effects against hypertension in the middle group of 24 h estimated urinary sodium-potassium excretion ratio. Further studies are needed to replicate these analyses in other populations.

A Longitudinal HbA1c Model Elucidates Genes Linked to Disease Progression on Metformin

One-third of type-2 diabetic patients respond poorly to metformin. Despite extensive research, the impact of genetic and nongenetic factors on long-term outcome is unknown. In this study we combine nonlinear mixed effect modeling with computational genetic methodologies to identify predictors of long-term response. In all, 1,056 patients contributed their genetic, demographic, and long-term HbA1c data. The top nine variants (of 12,000 variants in 267 candidate genes) accounted for approximately one-third of the variability in the disease progression parameter. Average serum creatinine level, age, and weight were determinants of symptomatic response; however, explaining negligible variability. Two single nucleotide polymorphisms (SNPs) in CSMD1 gene (rs2617102, rs2954625) and one SNP in a pharmacologically relevant SLC22A2 gene (rs316009) influenced disease progression, with minor alleles leading to less and more favorable outcomes, respectively. Overall, our study highlights the influence of genetic factors on long-term HbA1c response and provides a computational model, which when validated, may be used to individualize treatment.

TET2 and CSMD1 genes affect SBP response to hydrochlorothiazide in never-treated essential hypertensives

BACKGROUND

Thiazide diuretics have been recommended as a first-line antihypertensive treatment, although the choice of 'the right drug in the individual essential hypertensive patient' remains still empirical. Essential hypertension is a complex, polygenic disease derived from the interaction of patient's genetic background with the environment. Pharmacogenomics could be a useful tool to pinpoint gene variants involved in antihypertensive drug response, thus optimizing therapeutic advantages and minimizing side effects.

METHODS AND RESULTS

We looked for variants associated with blood pressure response to hydrochlorothiazide over an 8-week follow-up by means of a genome-wide association analysis in two Italian cohorts of never-treated essential hypertensive patients: 343 samples from Sardinia and 142 from Milan. TET2 and CSMD1 as plausible candidate genes to affect SBP response to hydrochlorothiazide were identified. The specificity of our findings for hydrochlorothiazide was confirmed in an independent cohort of essential hypertensive patients treated with losartan. Our best findings were also tested for replication in four independent hypertensive samples of European Ancestry, such as GENetics of drug RESponsiveness in essential hypertension, Genetic Epidemiology of Responses to Antihypertensives, NORdic DILtiazem intervention, Pharmacogenomics Evaluation of Antihypertensive Responses, and Campania Salute Network-StayOnDiur. We validated a polymorphism in CSMD1 and UGGT2.

CONCLUSION

This exploratory study reports two plausible loci associated with SBP response to hydrochlorothiazide: TET2, an aldosterone-responsive mediator of αENaC gene transcription; and CSMD1, previously described as associated with hypertension in a case-control study.

Plasma membrane calcium ATPases (PMCAs) as potential targets for the treatment of essential hypertension

The incidence of hypertension, the major modifiable risk factor for cardiovascular disease, is increasing. Thus, there is a pressing need for the development of new and more effective strategies to prevent and treat hypertension. Development of these relies on a continued evolution of our understanding of the mechanisms which control blood pressure (BP). Resistance arteries are important in the regulation of total peripheral resistance and BP; changes in their structure and function are strongly associated with hypertension. Anti-hypertensives which both reduce BP and reverse changes in resistance arterial structure reduce cardiovascular risk more than therapies which reduce BP alone. Hence, identification of novel potential vascular targets which modify BP is important. Hypertension is a multifactorial disorder which may include a genetic component. Genome wide association studies have identified ATP2B1, encoding the calcium pump plasma membrane calcium ATPase 1 (PMCA1), as having a strong association with BP and hypertension. Knockdown or reduced PMCA1 expression in mice has confirmed a physiological role for PMCA1 in BP and resistance arterial regulation. Altered expression or inhibition of PMCA4 has also been shown to modulate these parameters. The mechanisms whereby PMCA1 and 4 can modulate vascular function remain to be fully elucidated but may involve regulation of intracellular calcium homeostasis and/or comprise a structural role. However, clear physiological links between PMCA and BP, coupled with experimental studies directly linking PMCA1 and 4 to changes in BP and arterial function, suggest that they may be important targets for the development of new pharmacological modulators of BP.

Gene Silencing and Haploinsufficiency of Csk Increase Blood Pressure

Objective

Recent genome-wide association studies have identified 33 human genetic loci that influence blood pressure. The 15q24 locus is one such locus that has been confirmed in Asians and Europeans. There are 21 genes in the locus within a 1-Mb boundary, but a functional link of these genes to blood pressure has not been reported. We aimed to identify a causative gene for blood pressure change in the 15q24 locus.

Methods and Results

CSK and ULK3 were selected as candidate genes based on eQTL analysis studies that showed the association between gene transcript levels and the lead SNP (rs1378942). Injection of siRNAs for mouse homologs Csk, Ulk3, and Cyp1a2 (negative control) showed reduced target gene mRNA levels in vivo. However, Csk siRNA only increased blood pressure while Ulk3 and Cyp1a2 siRNA did not change it. Further, blood pressure in Csk^+/- heterozygotes was higher than in wild-type, consistent with what we observed in Csk siRNA-injected mice. We confirmed that haploinsufficiency of Csk increased the active form of Src in Csk^+/- mice aorta. We also showed that inhibition of Src by PP2, a Src inhibitor decreased high blood pressure in Csk^+/- mice and the active Src in Csk^+/- mice aorta and in Csk knock-down vascular smooth muscle cells, suggesting blood pressure regulation by Csk through Src.

Conclusions

Our study demonstrates that Csk is a causative gene in the 15q24 locus and regulates blood pressure through Src, and these findings provide a novel therapeutic target for the treatment of hypertension.

The Role of DNA Methylation in Hypertension

DNA methylation is the covalent modification of DNA that affects its function, without altering DNA sequences. Three important roles of DNA methylation include intrauterine programming, acquired predisposition, and transgenerational inheritance. A wide variety of factors can affect DNA methylation. Intrauterine programming involves drastic changes in DNA methylation patterns during cellular development and differentiation, which have a long-lasting effect on the predisposition of offspring. Influences from the mother, including maternal nutritional status, modify intrauterine epigenetic programming. In contrast to the rapid and drastic changes in utero, postnatal factors in daily life can also continue to slowly and dynamically change DNA methylation patterns in both somatic and germ cells. Epigenetic changes occurring in germ cell DNA exert a transgenerational impact on the phenotype of future generations, thus providing a means for ancestral transmission of environmental experiences. Despite adaptive ability, mismatch effect of transgenerational inheritance could be potentially harmful to health if environment has changed, and the acquired acclimatization is no longer beneficial. Increasing evidence from both human and animal studies indicates that DNA methylation exerts a causal impact on the development of hypertension. Therefore, an adverse outcome of maternal malnutrition could be the development of hypertension in offspring, whereby nutritional factors or disease conditions could induce phenotypes susceptible to hypertension through alteration of DNA methylation patterns. These factors are likely to alter DNA methylation patterns in all tissues including germ cells, and despite no direct evidence of an association between transgenerational epigenetic inheritance and hypertension, it is likely to play a role.

Pharmacogenomics of hypertension and heart disease

Heart disease is a leading cause of death in the United States, and hypertension is a predominant risk factor. Thus, effective blood pressure control is important to prevent adverse sequelae of hypertension, including heart failure, coronary artery disease, atrial fibrillation, and ischemic stroke. Over half of Americans have uncontrolled blood pressure, which may in part be explained by interpatient variability in drug response secondary to genetic polymorphism. As such, pharmacogenetic testing may be a supplementary tool to guide treatment. This review highlights the pharmacogenetics of antihypertensive response and response to drugs that treat adverse hypertension-related sequelae, particularly coronary artery disease and atrial fibrillation. While pharmacogenetic evidence may be more robust for the latter with respect to clinical implementation, there is increasing evidence of genetic variants that may help predict antihypertensive response. However, additional research and validation are needed before clinical implementation guidelines for antihypertensive therapy can become a reality.

Trans-ancestry genome-wide association study identifies 12 genetic loci influencing blood pressure and implicates a role for DNA methylation

We carried out a trans-ancestry genome-wide association and replication study of blood pressure phenotypes among up to 320,251 individuals of East Asian, European and South Asian ancestry. We find genetic variants at 12 new loci to be associated with blood pressure (P = 3.9 × 10(-11) to 5.0 × 10(-21)). The sentinel blood pressure SNPs are enriched for association with DNA methylation at multiple nearby CpG sites, suggesting that, at some of the loci identified, DNA methylation may lie on the regulatory pathway linking sequence variation to blood pressure. The sentinel SNPs at the 12 new loci point to genes involved in vascular smooth muscle (IGFBP3, KCNK3, PDE3A and PRDM6) and renal (ARHGAP24, OSR1, SLC22A7 and TBX2) function. The new and known genetic variants predict increased left ventricular mass, circulating levels of NT-proBNP, and cardiovascular and all-cause mortality (P = 0.04 to 8.6 × 10(-6)). Our results provide new evidence for the role of DNA methylation in blood pressure regulation.

Plasma membrane calcium ATPases: From generic Ca(2+) sump pumps to versatile systems for fine-tuning cellular Ca(2.)

The plasma membrane calcium ATPases (PMCAs) are ATP-driven primary ion pumps found in all eukaryotic cells. They are the major high-affinity calcium extrusion system for expulsion of Ca(2+) ions from the cytosol and help restore the low resting levels of intracellular [Ca(2+)] following the temporary elevation of Ca(2+) generated during Ca(2+) signaling. Due to their essential role in the maintenance of cellular Ca(2+) homeostasis they were initially thought to be "sump pumps" for Ca(2+) removal needed by all cells to avoid eventual calcium overload. The discovery of multiple PMCA isoforms and alternatively spliced variants cast doubt on this simplistic assumption, and revealed instead that PMCAs are integral components of highly regulated multi-protein complexes fulfilling specific roles in calcium-dependent signaling originating at the plasma membrane. Biochemical, genetic, and physiological studies in gene-manipulated and mutant animals demonstrate the important role played by specific PMCAs in distinct diseases including those affecting the peripheral and central nervous system, cardiovascular disease, and osteoporosis. Human PMCA gene mutations and allelic variants associated with specific disorders continue to be discovered and underline the crucial role of different PMCAs in particular cells, tissues and organs.

The Role of Genetic Risk Score in Predicting the Risk of Hypertension in the Korean population: Korean Genome and Epidemiology Study

Hypertension is regarded as a multifactorial disease with a modest contribution of genetic factors and strongly affected by environmental factors. Recent genome-wide association studies have identified specific loci associated with high blood pressure (BP) and hypertension. This study aimed to examine the association between the genetic risk score (GRS), a linear function of multiple single nucleotide polymorphisms (SNPs) associated with hypertension, and high BP and prevalent hypertension at baseline examination and to evaluate the efficacy of the GRS for predicting incident hypertension with longitudinal data in Korean subjects. Data for 8,556 participants, aged 40 to 69, in a community-based cohort study were analyzed. Unweighted GRS (cGRS) and weighted GRS (wGRS) were constructed from 4 SNPs related to high BP or hypertension in previous genome-wide association and its replication studies for the Korean middle-aged population. Cross-sectional analysis (n=8,556) revealed that cGRS was significantly associated with prevalent hypertension (odds ratio=1.15 per risk allele; 95%CI, 1.09-1.20). Additionally, the odds ratios (ORs) of prevalent hypertension for those who in medium and the highest tertile compared with those who in the lowest tertile of wGRS were 1.31 (95% CI, 1.15-1.50) and 1.59 (95%CI, 1.38-1.82), respectively. In a longitudinal analysis (n=5,632), participants in the highest tertile of wGRS had a 1.22-fold (OR=1.22, 95%CI, 1.02‒1.46) greater risk of incident hypertension relative to those in the lowest tertile, after adjusting for a number of confounding factors. However, wGRS topped with traditional risk factors had no significant effect on discrimination ability (c-statistics with and without wGRS were 0.811 and 0.810, P=0.1057). But, reclassification analysis showed that the addition of GRS to the model with conventional risk factors led to about 9% significant increment in category-free net reclassification improvement. GRSs based on 4 SNPs were independently associated with hypertension and may provide a statistically significant improvement over the existing model for prediction of incident hypertension.

The African Genome Variation Project shapes medical genetics in Africa

Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa.

Effects of established blood pressure loci on blood pressure values and hypertension risk in an Algerian population sample

Genome-wide association studies and subsequent replication studies have pinpointed 29 genetic variants associated with blood pressure (BP). None of these studies included North African populations. We therefore looked at whether or not these genetic variants modulated BP and hypertension (HTN) risk in an Algerian population sample. Twenty-nine single-nucleotide polymorphisms (SNPs) were genotyped in a representative sample of 787 subjects from the InSulino-résistance à ORan (ISOR) study (378 men and 409 women aged between 30 and 64 years and recruited from within the city of Oran, Algeria). Genetic variants were considered both individually and when combined as genetic predisposition scores (GPSs) for systolic BP (SBP), diastolic BP (DBP) and HTN risk. The SNPs in CYP1A1-ULK3, HFE and SH2B3 were significantly associated with BP and/or HTN. The SBP-GPS, DBP-GPS and HTN-GPS were associated with higher levels of DBP (+0.24 mm Hg P=0.05, +0.23 mm Hg P = 0.05 and +0.26 mm Hg P = 0.03, respectively). Moreover, the three GPSs tended to be associated with a 6% higher risk of HTN. Our study is the first to show that some of the BP loci validated in subjects of European descent were associated (either individually or when combined as GPSs) with BP traits and/or the HTN risk in an Algerian population, but to a lesser extent than in European populations. Although larger studies and meta-analyses of North African populations are needed to confirm the present results, our data contribute to a better understanding of genetic susceptibility to HTN.

Identification of a genetic variant at 2q12.1 associated with blood pressure in East Asians by genome-wide scan including gene-environment interactions

Background

Genome-wide association studies have identified many genetic loci associated with blood pressure (BP). Genetic effects on BP can be altered by environmental exposures via multiple biological pathways. Especially, obesity is one of important environmental risk factors that can have considerable effect on BP and it may interact with genetic factors. Given that, we aimed to test whether genetic factors and obesity may jointly influence BP.

Methods

We performed meta-analyses of genome-wide association data for systolic blood pressure (SBP) and diastolic blood pressure (DBP) that included analyses of interaction between single nucleotide polymorphisms (SNPs) and the obesity-related anthropometric measures, body mass index (BMI), height, weight, and waist/hip ratio (WHR) in East-Asians (n = 12,030).

Results

We identified that rs13390641 on 2q12.1 demonstrated significant association with SBP when the interaction between SNPs and BMI was considered (P < 5 × 10 ^-8). The gene located nearest to rs13390641, TMEM182, encodes transmembrane protein 182. In stratified analyses, the effect of rs13390641 on BP was much stronger in obese individuals (BMI ≥ 30) than non-obese individuals and the effect of BMI on BP was strongest in individuals with the homozygous A allele of rs13390641.

Conclusions

Our analyses that included interactions between SNPs and environmental factors identified a genetic variant associated with BP that was overlooked in standard analyses in which only genetic factors were included. This result also revealed a potential mechanism that integrates genetic factors and obesity related traits in the development of high BP.

The common single-nucleotide polymorphism rs2681472 is associated with early-onset preeclampsia in Northern Han Chinese women

Preeclampsia, characterized by hypertension and proteinuria, remains a leading cause of maternal morbidity and mortality. Recently, a genome-wide association study (GWAS) identified the single-nucleotide polymorphism, rs2681472, as a new hypertension susceptibility genetic variant. The purpose of this study was to evaluate the association between preeclampsia and rs268172 in a Northern Han Chinese population. We genotyped 1218 unrelated Northern Han Chinese women, including 515 patients with preeclampsia and 703 healthy controls. No significant differences were detected in the allele frequencies between patients and controls (P = .23). When patients were divided into early-onset and late-onset preeclampsia according to gestational age of disease onset, the allele frequencies significantly differed between controls and patients with early-onset preeclampsia (P = .02). Genotype frequencies also were significantly different between controls and patients early-onset preeclampsia when data were analyzed under additive (P = .03) and dominant (P = .009) models. We replicated this association in an independent Northern Han Chinese population and observed a significant difference in the allele frequencies between patients with early-onset preeclampsia and controls (P = .011). We report that rs2681472 is associated with early-onset preeclampsia in Northern Han Chinese women.

Interaction between a CSK gene variant and fish oil intake influences blood pressure in healthy adults

Blood pressure is a heritable determinant of cardiovascular disease (CVD) risk. Recent genome-wide association studies have identified several single-nucleotide polymorphisms (SNPs) associated with blood pressure, including rs1378942 in the c-Src tyrosine kinase (CSK) gene. Fish oil supplementation provides inconsistent protection from CVD, which may reflect genetic variation. We investigated the effect of rs1378942 genotype interaction with fish oil dosage on blood pressure measurements in the MARINA (Modulation of Atherosclerosis Risk by Increasing doses of N-3 fatty Acids) study, a parallel, double-blind, controlled trial in 367 participants randomly assigned to receive treatment with 0.45, 0.9, and 1.8 g/d eicosapentaenoic acid [EPA (20:5n-3)] and docosahexaenoic acid [DHA (22:6n-3)] (1.51:1) or an olive oil placebo for 12 mo. A total of 310 participants were genotyped. There were no significant associations with blood pressure measures at baseline; however, the interaction between genotype and treatment was a significant determinant of systolic blood pressure (SBP) (P = 0.010), diastolic blood pressure (DBP) (P = 0.037), and mean arterial blood pressure (MABP) (P = 0.014). After the 1.8 g/d dose, noncarriers of the rs1378942 variant allele showed significantly lower SBP (P = 0.010), DBP (P = 0.016), and MABP (P = 0.032) at follow-up, adjusted for baseline values, than did carriers. We found no evidence of SNP genotype association with endothelial function (brachial artery diameter and flow-mediated dilatation), arterial stiffness (carotid-femoral pulse wave velocity and digital volume pulse), and resting heart rate. A high intake of EPA and DHA could help protect noncarriers but not carriers of the risk allele. Dietary recommendations to reduce blood pressure in the general population may not necessarily benefit those most at risk. This trial was registered at controlled-trials.com as ISRCTN66664610.

Multivariate generalized multifactor dimensionality reduction to detect gene-gene interactions

Background

Recently, one of the greatest challenges in genome-wide association studies is to detect gene-gene and/or gene-environment interactions for common complex human diseases. Ritchie et al. (2001) proposed multifactor dimensionality reduction (MDR) method for interaction analysis. MDR is a combinatorial approach to reduce multi-locus genotypes into high-risk and low-risk groups. Although MDR has been widely used for case-control studies with binary phenotypes, several extensions have been proposed. One of these methods, a generalized MDR (GMDR) proposed by Lou et al. (2007), allows adjusting for covariates and applying to both dichotomous and continuous phenotypes. GMDR uses the residual score of a generalized linear model of phenotypes to assign either high-risk or low-risk group, while MDR uses the ratio of cases to controls.

Methods

In this study, we propose multivariate GMDR, an extension of GMDR for multivariate phenotypes. Jointly analysing correlated multivariate phenotypes may have more power to detect susceptible genes and gene-gene interactions. We construct generalized estimating equations (GEE) with multivariate phenotypes to extend generalized linear models. Using the score vectors from GEE we discriminate high-risk from low-risk groups. We applied the multivariate GMDR method to the blood pressure data of the 7,546 subjects from the Korean Association Resource study: systolic blood pressure (SBP) and diastolic blood pressure (DBP). We compare the results of multivariate GMDR for SBP and DBP to the results from separate univariate GMDR for SBP and DBP, respectively. We also applied the multivariate GMDR method to the repeatedly measured hypertension status from 5,466 subjects and compared its result with those of univariate GMDR at each time point.

Results

Results from the univariate GMDR and multivariate GMDR in two-locus model with both blood pressures and hypertension phenotypes indicate best combinations of SNPs whose interaction has significant association with risk for high blood pressures or hypertension. Although the test balanced accuracy (BA) of multivariate analysis was not always greater than that of univariate analysis, the multivariate BAs were more stable with smaller standard deviations.

Conclusions

In this study, we have developed multivariate GMDR method using GEE approach. It is useful to use multivariate GMDR with correlated multiple phenotypes of interests.

Male-specific genetic effect on hypertension and metabolic disorders

Genetic risk factors for hypertension may have age or gender specificity and pleiotropic effects. This study aims to measure the risk of genetic and non-genetic factors in the occurrence of hypertension and related diseases, with consideration of potential confounding factors and age-gender stratification. A discovery set of 352,228 genotyped plus 1.8 million imputed single-nucleotide polymorphisms were analyzed for 2,886 hypertensive cases and 3,440 healthy controls obtained from two community-based cohorts in Korea, and selected gene variants were replicated in the Health Examinee cohort (665 cases and 1,285 controls). Genome-wide association analyses were conducted in 12 groups stratified by age and gender after adjusting for potential covariates under three genetic models. Age, rural area residence, body mass index, family history of hypertension, male gender, current alcohol drinking status, and current smoking status were significantly associated with hypertension (P = 4 × 10(-151) to 0.011). Five gene variants, rs11066280 (C12orf51), rs12229654 and rs3782889 (MYL2), rs2072134 (OAS3), rs2093395 (TREML2), and rs17249754 (ATP2B1), were found to be associated with hypertension mostly in men (P = 4.76 × 10(-14) to 4.46 × 10(-7) in the joint analysis); three SNPs (rs11066280, rs12229654, and rs3782889) remained significant after Bonferroni correction in an independent population. Three gene variants, rs12229654, rs17249754, and rs11066280, were significantly associated with metabolic disorders such as hyperlipidemia and diabetes (P = 0.00071 to 0.0097, respectively). Careful consideration of the potential confounding effects in future genome-wide association studies is necessary to uncover the genetic underpinnings of complex diseases.

Advances in blood pressure genomics

The elucidation of genes implicated in Mendelian forms of hypertension demonstrates rare variants with substantial effects are responsible, and often these genes lie within pathways managing sodium homeostasis. More recently with advances in affordable high-throughput genotyping strategies, multiple common genetic variants with modest effects on blood pressure (<1 mmHg systolic) have been discovered in the population. In aggregate, these common variants explain <3% of the variance of blood pressure. Although these findings may offer new mechanistic insights into the biology of blood pressure, a key question is can these findings translate into patient benefit? It is timely to reflect on recent advances in genomics, and the use of new resources, such as the 1000 Genomes Project and the Encyclopedia of DNA Elements, to annotate likely causal variants, and their relevance to cardiovascular disease. In this review, we discuss the advances in relation to our knowledge of the genetic architecture of blood pressure, and whether gene discoveries might influence cardiovascular risk assessment, help to stratify patient response to medicine, or identify new biological pathways for novel therapeutic targets.