A follow-up study of a genome-wide association scan identifies a susceptibility locus for venous thrombosis on chromosome 6p24.1.

To identify genetic susceptibility factors conferring increased risk of venous thrombosis (VT), we conducted a multistage study, following results of a previously published GWAS that failed to detect loci for developing VT. Using a collection of 5862 cases with VT and 7112 healthy controls, we identified the HIVEP1 locus on chromosome 6p24.1 as a susceptibility locus for VT. Indeed, the HIVEP1 rs169713C allele was associated with an increased risk for VT, with an odds ratio of 1.20 (95% confidence interval 1.13-1.27, p = 2.86 x 10(-9)). HIVEP1 codes for a protein that participates in the transcriptional regulation of inflammatory target genes by binding specific DNA sequences in their promoter and enhancer regions. The current results provide the identification of a locus involved in VT susceptibility that lies outside the traditional coagulation/fibrinolysis pathway.

Identification and functional analyses of molecular haplotypes of the human osteoprotegerin gene promoter.

OBJECTIVE: Osteoprotegerin (OPG) has been reported to be involved in the development of atherosclerotic disease, and OPG gene variation has been associated with plasma OPG levels and different cardiovascular disease phenotypes. However, the genetic architecture of the OPG promoter and its transcriptional regulation are poorly characterized. METHODS AND RESULTS: We identified 1008 bp of the OPG 5'-flanking region to be sufficiently transcriptionally active in osteosarcoma cell lines and generated serial promoter deletion constructs. Individual subcloning revealed the existence of 3 molecular haplotypes (MolHaps): [T(-960)-A(-946)-G(-900)-T(-864); MolHap1, wild type], [T(-960)-G(-946)-G(-900)-T(-864); MolHap2], [C(-960)-G(-946)-A(-900)-G(-864); MolHap4]. Compared to MolHap1, transcriptional activities of MolHaps 2 and 4 were significantly reduced (P=0.0018). Whereas introduction of the -159C allele reduced transcriptional activities of the full-length constructs (P=0.0014), it significantly increased activities of the deletion constructs (P=0.0005). Electrophoretic mobility shift, competition, and chromatin immunoprecipitation assays revealed specific DNA:protein interactions for the MolHaps with Sp1 and NF-1, and identified Egr1 interacting exclusively with the -159T allele. CONCLUSIONS: We propose new structural and transcriptional features within the OPG promoter region and identified MolHaps being differentially transcriptionally active and allele-dependently interacting with a proximal polymorphic site.

Osteopontin gene variation and cardio/cerebrovascular disease phenotypes.

We aimed at associating common osteopontin (OPN) gene variants with cardiovascular disease phenotypes.We scanned the OPN gene in 190 chromosomes from myocardial infarction (MI) patients and identified five variants in the promoter, three synonymous and one non-synonymous variant. All variants were investigated in case-control studies for MI (ECTIM: 990 cases, 900 controls) and brain infarction (BI) (GENIC: 466 cases, 444 controls). Promoter variants were functionally analyzed by bandshift assays, the coding D147D [T/C] by Western blot. Allele D147D C was independently and significantly associated with lower apoB levels (P=0.044 [ECTIM] P=0.03 [GENIC]), its allele frequency was significantly lower in patients with BI compared to controls (OR [95% CI] 0.39 [0.20-0.74], P=0.004), and C allele carriers had a significantly lower frequency of presence of carotid plaques (P=0.02). Bandshifts with HepG2 and Ea.hy926 nuclear proteins did not reveal any functionality of promoter variants, whereas the OPN-441C-containing construct resulted in reduced OPN protein expression in Western blots, complying with its potential protective effect on the phenotypes studied.We here provide evidence that a portion of the OPN locus is likely to associate with cardiovascular disease-related phenotypes. However, further experiments are warranted to clarify the functional role of OPN variants.

Left ventricular structure in relation to the human SAH gene in the European Project on Genes in Hypertension.

Earlier studies showed association of the human SAH (Spontaneously hypertensive rat-clone A-Hypertension associated) gene with hypertension and obesity. Left ventricular mass index (LVMI) increases with blood pressure and body mass index. In a family-based population study (54.5% women; mean age, 43.1 years), we measured LVMI, mean wall thickness (MWT) and the left ventricular internal diameter (LVID) at end-diastole in 699 non-Slavic and 493 Slavic participants. In multivariable-adjusted analyses, we investigated phenotype-genotype associations (SAH G-1606A and -962ins/del polymorphisms), while accounting for confounders and relatedness. Non-Slavic -1606GG homozygotes had a slightly greater LVID than -1606A allele carriers (48.6 vs. 48.0 mm; P=0.08). However, the between-family component of the variance in LVID was significant (P=0.005), suggesting that population stratification might explain the latter finding. Non-Slavic -962del carriers had higher LVMI (91.1 vs. 88.5 g m(-2); P=0.03) and MWT (9.61 vs. 9.44 mm; P=0.03) than -962ins homozygotes. Transmission of the -962del to non-Slavic offspring was also associated with higher MWT (P=0.03). In Slavic participants, in the absence of population stratification (P>or=0.69), -1606GG homozygotes had lower LVMI (96.5 vs. 102.3 g m(-2); P=0.004) and lower MWT (10.1 vs. 10.5 mm; P=0.003) than -1606A carriers. Sensitivity analyses showed that the latter associations were confined to founders. Transmission of the -962del allele to Slavic offspring was associated with lower MWT (P=0.007). In conclusion, LVMI and MWT, two phenotypes that are jointly influenced by blood pressure and obesity, might be related to variation in the human SAH gene.

Hypertension in mice lacking the CXCR3 chemokine receptor.

The CXC chemokine receptor 3 (CXCR3) has been linked to autoimmune and inflammatory disease, allograft rejection, and ischemic nephropathy. CXCR3 is expressed on endothelial and smooth muscle cells. Although a recent study posited that antagonizing of CXCR3 function may reduce atherosclerosis, the role of CXCR3 in controlling physiological vascular functions remains unclear. This study demonstrates that disruption of CXCR3 leads to elevated mean arterial pressures in anesthetized and conscious mice, respectively. Stimulation of isolated resistance vessels with various vasoconstrictors showed increased contractibility in CXCR3-/- mice in response to angiotensin II (ANG II) and a decreased vasodilatation in response to acetylcholine (ACh). The increased contractibility was related to higher ANG II type 1 receptor (AT1R) expression, whereas the decreased vasodilatation was related to lower M3-ACh receptor expression in the mesenteric arteries of CXCR3-/- mice compared with wild-type mice. The vasodilatatory response to ACh could be antagonized by the nonselective ACh receptor antagonist atropine and the selective M3 receptor antagonist 4-DAMP, but not by M1, M2, and M4 receptor antagonists. Additionally, EMSA studies revealed that transcription factors SP-1 and EGR-1 interact as a complex with the murine AT1R promoter region. Furthermore, we could show increased expression of SP-1 in CXCR3-/- mice indicating an imbalanced SP-1 and EGR-1 complex formation which causes increased AT1R expression and hypertension. The data indicate that CXCR3 receptor is important in vascular contractility and hypertension, possibly through upregulated AT1R expression.

Molecular genetic analysis of a human insulin-like growth factor 1 promoter P1 variation.

Insulin-like growth factor 1 (IGF1) exerts important endocrine and paracrine functions in the cardiovascular system. We identified the common variant -1411C>T in the IGF1 upstream promoter P1, located within several overlapping transcription factor binding sites. Using transient transfection assays, we identified this site as a functional enhancer. The T allele-carrying enhancer, compared with the C allelic portion, exerts significantly reduced or even abrogated activity, respectively, in SaOs-2 and HepG2 (all P<0.0001) as well as in differentiated THP-1 macrophages. Electrophoretic mobility shift assay and subsequent supershift experiments in HepG2 identified c-Jun as the binding partner exclusively to the T allele, whereas CCAAT/enhancer-binding protein delta and interferon consensus site-binding protein/interferon-regulating factor 8 interacted only with the C allelic promoter portion. Furthermore, genotyping in a case-control study for essential hypertension (n=745 hypertensive patients; n=769 normotensive control subjects) for this variant revealed an odds ratio for hypertension of 0.73 (95% confidence interval 0.58-0.91, P=0.006) associated with the T allele, and normotensive subjects carrying the protective T allele displayed a significant decrease in diastolic (P=0.036) and systolic (P=0.024) blood pressure levels. We here report detection of a functional enhancer module in the upstream IGF1 promoter region, which might play a key role in local IGF1 bioavailability. Whether -1411C>T is also associated with other IGF1-related disease phenotypes should be evaluated further in population studies.

Cardiovascular risk factors and mortality in patients with coronary heart disease.

A priority in preventive cardiology is to reduce the number of recurrent events and to prolong survival in patients with established coronary heart disease (CHD). Aim of the present study was to examine risk factors for long-term mortality in CHD patients who entered routine secondary prevention after a coronary event or intervention. Such patients, from the EUROASPIRE (EUROpean Action on Secondary Prevention through Intervention to Reduce Events) I and II studies in the region of Münster, Germany, were followed over a mean period of 8.0 years up to the end of 2005. Patients were up to 70 years of age at baseline when they were interviewed and examined using standardised methods. Baseline examination was carried out at least 6 months and at a mean of 19.5 months after the coronary event or procedure. In 367 patients from EUROASPIRE I and 380 patients from EUROASPIRE II, a total of 125 deaths (16.7%) occurred during follow-up. Multivariate analyses, using Cox proportional hazards models, established diabetes mellitus and smoking as predictors for all-cause mortality with estimated hazard rate ratios (HRRs) of 2.24 (95% confidence interval (CI): 1.43-3.49) and 1.95 (95% CI: 1.23-3.10), respectively. Significant associations were found between diabetes mellitus and cardiovascular (HRR 2.36; 95% CI: 1.31-4.24) as well as CHD mortality (HRR 2.40; 95% CI: 1.25-4.59). Systolic blood pressure was significantly associated with increased cerebrovascular disease mortality (HRR 1.04; 95% CI: 1.01 and 1.08 for 1 mmHg increase). In conclusion, long-term mortality in coronary patients from routine secondary prevention is substantial. Diabetes mellitus and smoking represent key issues in patients with established CHD.

Molecular investigation of the functional relevance of missense variants of ICAM-1.

In genome-wide studies, the intercellular adhesion molecule-1 (ICAM-1) locus has been associated with cardiovascular and inflammatory bowel diseases. To determine the functional relevance of five missense ICAM-1 variants (G241R; I316V; P352L; K469E; R478W), we generated wild-type and variant proteins [M2(241R); M3(469E); M4(352L); M5(478W); M6(316V); M7(352L/469E)] and transiently transfected CV1 cells. Reverse transcription PCR, western blot, and ELISA did not reveal any differences in mRNA and protein expression levels for any construct. Conversely, in pulse-chase experiments, compared with wild-type (90-120 min), M3 and M5 possessed a prolonged half-life of approximately 150 min, whereas M2, M4, and M7 displayed a decreased half-life of approximately 60-75 min, implying differences in protein degradation. Our results do not indicate a major impact of missense variants on ICAM-1 biological function, even if G241R and K469E were functional in pulse-chase experiments. Whether these differences in protein stability exert measurable functional consequences needs to be elucidated further.

Characterization and functional analyses of the human G protein-coupled receptor kinase 4 gene promoter.

The G protein-coupled receptor kinase 4 is involved in renal sodium handling and blood pressure regulation. Missense variants have already been tested functionally and are associated with hypertension, but no data on promoter analyses are yet available. We scanned 94 hypertensive white subjects for genetic variation and performed promoter reporter gene analyses in HEK293T, COS7, and SaOs-2 cells. Transient transfections with various full lengths and wild-type deletion constructs revealed that 1851 bp of the flanking region and 275 bp of the 5'-untranslated region were sufficient for transcriptional activities and composed a powerful cis-active element in the distal 293 bp. The -1702T and +2T alleles resulted in drastic general reductions of promoter function, whereas an activity increasing effect of +268C was cell type specific. Electrophoretic mobility-shift assay, supershift, and cotransfection analyses of transcription factor binding sites predicted in silico (Alibaba2.1/Transfac7) resulted in allele-specific binding patterns of nuclear proteins and identified the participation of CCAAT/enhancer-binding protein transcription factor family members. The G protein-coupled receptor kinase 4 core promoter resides in the first 1851 bp upstream of its transcription start site. The 4 identified genetic variants within this region exert allele-specific impact on both cell type- and stimulation-dependent transcription and may affect the expression balance of renal G protein-coupled receptor kinase 4.

Functional and structural profiling of the human thrombopoietin gene promoter.

Human thrombopoietin (TPO) is involved in cardiovascular disease as it regulates megakaryocyte development and enhances platelet adhesion/aggregation. The THPO promoter structure is still controversial. By reverse transcription-PCR, we confirm that THPO transcription is cell line-dependently initiated at two alternative promoters, which we newly designated P1a and P1. We subsequently electrophoretically scanned and resequenced these portions in 95 and 57 patients with cardiovascular disease, respectively, and identified seven variants (-1450/del58bp, C-920T [rs2855306], A-622G, C-413T [rs885838], C+5A, G+115A, and C+135T). After subcloning of 1032 bp of THPO P1 in pGL3-basic vector, five molecular haplotypes (MolHaps1-5) were observed: [A(-622)-C(-413)-C(+5)-G(+115); wild type (wt)], [A(-622)-T(-413)-C(+5)-G(+115)], [G(-622)-T(-413)-C(+5)-G(+115)], [A(-622)-C(-413)-A(+5)-G(+115)], [A(-622)-C(-413)-C(+5)-A(+115)], and analyzed in reporter gene assays in HEK293T and HepG2 cells. MolHaps 2, 4, and 5 were significantly more active than wt (all p values < or =0.01) in HEK293T cells, MolHap3 exerted a substantial loss of promoter activity (p < 0.0001 in HEK293T and p < 0.01 in HepG2, compared with wt). Electrophoretic mobility shift assays revealed that A-622G and C-413T individually differed from MolHaps in their DNA-protein interaction patterns. Supershift and chromatin immunoprecipitation assays identified CCAAT/enhancer-binding protein delta as the binding protein exclusively for the -622A allelic portion.

G/T substitution in intron 1 of the UNC13B gene is associated with increased risk of nephropathy in patients with type 1 diabetes.

OBJECTIVE: Genetic and environmental factors modulate the susceptibility to diabetic nephropathy, as initiating and/or progression factors. The objective of the European Rational Approach for the Genetics of Diabetic Complications (EURAGEDIC) study is to identify nephropathy susceptibility genes. We report molecular genetic studies for 127 candidate genes for nephropathy. RESEARCH DESIGN AND METHODS: Polymorphisms were identified through sequencing of promoter, exon, and flanking intron gene regions and a database search. A total of 344 nonredundant SNPs and nonsynonymous variants were tested for association with diabetic nephropathy (persistent albuminuria >/=300 mg/24 h) in a large type 1 diabetes case/control (1,176/1,323) study from three European populations. RESULTS: Only one SNP, rs2281999, located in the UNC13B gene, was significantly associated with nephropathy after correction for multiple testing. Analyses of 21 additional markers fully characterizing the haplotypic variability of the UNC13B gene showed consistent association of SNP rs13293564 (G/T) located in intron 1 of the gene with nephropathy in the three populations. The odds ratio (OR) for nephropathy associated with the TT genotype was 1.68 (95% CI 1.29-2.19) (P = 1.0 x 10(-4)). This association was replicated in an independent population of 412 case subjects and 614 control subjects (combined OR of 1.63 [95% CI 1.30-2.05], P = 2.3 x 10(-5)). CONCLUSIONS: We identified a polymorphism in the UNC13B gene associated with nephropathy. UNC13B mediates apopotosis in glomerular cells in the presence of hyperglycemia, an event occurring early in the development of nephropathy. We propose that this polymorphism could be a marker for the initiation of nephropathy. However, further studies are needed to clarify the role of UNC13B in nephropathy.

Blood pressure and renal sodium handling in relation to genetic variation in the DRD1 promoter and GRK4.

Activation of type-1 dopamine receptors (DRD1) reduces renal sodium reabsorption. In a family-based random sample of 611 untreated whites (women, 45.0%; mean age, 38.6 years), we measured blood pressure (BP). We used the endogenous lithium clearance to assess fractional sodium excretion (FE(Na)) and proximal (RNa(prox)) and distal (RNa(dist)) tubular sodium reabsorption. We investigated multivariate-adjusted associations with the DRD1 promoter (A-48G, G-94A, and C-800T) and GRK4 (Ala142Val). The frequent DRD1 haplotypes were AGC (48.2%), GGT (34.4%), and AAC (14.3%). While standardizing to mean sodium excretion (8.7 mmol/h) and adjusting for covariates and relatedness, RNa(dist) was lower in DRD1 -94GG homozygotes than -94A allele carriers (effect size, -0.94%; P=0.005) with opposite findings for FE(Na) (+0.084%; P=0.014). AGC carriers (-0.88%; P=0.012) and AAC carriers (+1.00%; P=0.004) had different RNa(dist) compared to corresponding noncarriers. Furthermore, FE(Na) was lower in AAC carriers than in noncarriers (-0.082%; P=0.019). The family-based analyses identified a significant between-family component in the variance of the renal phenotypes associated with the DRD1 polymorphisms. Transmission of the DRD1 AGC haplotype was also associated with lower systolic (-3.54 mm Hg; P=0.016) and diastolic (-2.80 mm Hg; P=0.0064) BPs without significant between-family variance component. Plasma renin activity and urinary aldosterone excretion were not associated with DRD1 variation. The GRK4 Ala142Val polymorphism did not contribute to the phenotypes under study. In conclusion, renal sodium handling and BP were associated with genetic variation in the DRD1 promoter. The between-family variance component excluded population stratification for BP, but not for the renal phenotypes.

SAH gene variants revisited in the European Project On Genes in Hypertension.

OBJECTIVE: Previous studies found significant association of hypertension and hypertension-related phenotypes with genetic variation in SAH (Spontaneously hypertensive rat-clone A-Hypertension-associated). We sought independent confirmation of these findings in the European Project On Genes in Hypertension. METHODS AND RESULTS: We randomly recruited 2603 relatives from 560 families and 31 unrelated subjects from six European populations (mean age 38.8 +/- 15.7 years; 52.1% women). We measured systolic/diastolic blood pressure (mean, 122.4/76.6 mmHg), body mass index (24.9 kg/m2), triceps skinfold (1.7 cm), waist-to-hip ratio (0.83 units), serum total and high-density lipoprotein (HDL) cholesterol (5.14 and 1.33 mmol/l), serum triglycerides (1.95 mmol/l) and blood glucose (4.90 mmol/l). We genotyped the G-1606A and -962del/ins polymorphisms. In all subjects, the allele frequencies were 11.8 and 29.5% for -1606A and -962del, respectively. Lewontin's D' was 0.97 (P < 0.0001). Haplotype frequencies were 58.8% for -1606G plus -962ins, 29.5% for -1606G plus -962del, and 11.7% for -1606A plus -962ins. Both before and after adjustment for covariates, none of the phenotype-genotype associations approached statistical significance. Our study had 80% power to detect on two-sided tests (P = 0.05), effect sizes of 1.8/1.3 mmHg for systolic/diastolic blood pressure, 0.52 kg/m2 for body mass index, 0.01 units for the waist-to-hip ratio, 0.96 mm for the triceps skinfold, 0.13 and 0.05 mmol/l for total and HDL cholesterol, 0.18 mmol/l for serum triglycerides, and 0.11 mmol/l for blood glucose. The family-based analyses did not reveal population stratification (P > or = 0.67). CONCLUSION: The evidence supporting an association of hypertension or hypertension-related phenotypes with the SAH gene remains equivocal in human studies.

Neutrophil elastase gene variation and coronary heart disease.

AIMS: Identification and functional characterization of variants in the neutrophil elastase (ELA2) gene in cardiovascular disease. METHODS: From participants of the ECTIM (Etude Cas-Témoins sur l'infarctus du Myocarde) Study with myocardial infarction (MI) 2082 chromosomes were genetically scanned; 990 patients with MI and 904 controls were genotyped for the common polymorphisms G-761A and S173S (C4890A). Expression vectors for Ela2 variants were transiently transfected, followed by Northern and Western blot analyses. Promoter variants were analyzed by transfection/reporter gene assays. RESULTS: We identified 11 genetic variants, two in the 5'-flanking (G-761A, -852/del53 bp), six in exons (R49H, N81N, G93V, S173S, D222Y, P228L) and three in introns (C+29/in3T, C+149/in3T, C+137/in4T). In Belfast, 4890A allele carriers had a risk for MI with an odds ratio (OR) of 1.44 (95% CI 1.12-1.86; P=0.005), the OR for MI associated with the -761G/-4890A haplotype with reference to -761G/-4890C amounting to 2.38 (95% CI 1.23-4.57; P=0.01). Transcript or protein expression of both allelic constructs (4890A and 4890C) did not, however, differ. Conversely, transcriptional activity was significantly elevated (<35%) by -852/del53 bp in THP-1 monocytes compared with the nondeleted promoter (P=0.001); the deletion was observed in one patient with premature MI at the age of 28 years, whose mother had had an MI at the age of 48 years. CONCLUSIONS: The association of C4890A with MI in Belfast exclusively, and the presumed absence of its functionality, provides little support for a substantial implication of common ELA2 gene variants in overall MI risk. Whether -852/53del plays a role in cardiovascular pathophysiology or not should be evaluated further.

Polymorphisms in 33 inflammatory genes and risk of myocardial infarction--a system genetics approach.

The hypothesis of a causal link between inflammation and atherosclerosis would be strengthened if variants of inflammatory genes were associated with disease. Polymorphisms of 33 genes encoding inflammatory molecules were tested for association with myocardial infarction (MI). Patients with MI and a parental history of MI (n = 312) and controls from the UK (n = 317) were genotyped for 162 polymorphisms. Thirteen polymorphisms were associated with MI (P values ranging from 0.003 to 0.041). For three genes, ITGB1, SELP, and TNFRSF1B haplotype frequencies differed between patients and controls (P values < 0.01). We further assessed the simultaneous contribution of all polymorphisms and relevant covariates to MI using a two-step strategy of data mining relying on Random Forest and DICE algorithms. In a replication study involving two independent samples from the UK (n = 649) and France (n = 706), one interaction between the ITGA4/R898Q polymorphism and current smoking status was replicated. This study illustrates a strategy for assessing the joint effect of a large number of polymorphisms on a phenotype that may provide information that single locus or single gene analysis may fail to uncover. Overall, there was weak evidence for an implication of inflammatory polymorphisms on susceptibility to MI.

Apolipoprotein E interrupts interleukin-1beta signaling in vascular smooth muscle cells.

OBJECTIVES: Apolipoprotein E (apoE) exerts antiatherogenic effects but precise mechanisms remain unclear. We here investigated the effect of apoE on intracellular signaling by interleukin-1beta (IL-1beta), a proinflammatory cytokine present in atherosclerotic lesions. METHODS AND RESULTS: IL-1beta-induced expression and activation of inducible nitric oxide synthase and cyclooxygenase-2 were inhibited by apoE in vascular smooth muscle cells (VSMCs). These inhibitory effects were linked to the suppression of both NF-kappaB and activating protein-1 (AP-1) transactivation, suggesting that the interruption of IL-1beta signaling occurs upstream of transcription factors. Studies in VSMCs overexpressing IL-1beta signaling intermediates revealed that NF-kappaB transactivation was inhibited by apoE in MyD88- and IRAK1- but not in TRAF6-transfected cells. Furthermore, apoE prevented IRAK1 phosphorylation and IRAK1-TRAF6 but not MyD88-IRAK1 complex formation. Inhibitory effects of apoE on IL-1beta signaling were abolished after silencing LDL receptor-related protein-1 (LRP1) expression with siRNA. In addition, inhibitors of adenylyl cyclase and protein kinase A (PKA) restored IL-1beta signaling in apoE-treated VSMCs, whereas apoE stimulated PKA activity. ApoE inhibited VSMC activation in response to IL-18 but not to tumor necrosis factor-alpha or polyinosinic:polycytidylic acid. CONCLUSION: ApoE targets IRAK-1 activation and thereby interrupts IL-1beta and IL-18 signaling in VSMCs. This antiinflammatory effect represents a novel antiatherogenic activity of apoE.

SAH gene variants are associated with obesity-related hypertension in Caucasians: the PEGASE Study.

OBJECTIVE: The SAH gene locus has recently been proposed to be involved in obesity-related hypertension in Japanese individuals. METHODS: To replicate independently the initial findings in another ethnic group, we scanned the entire SAH gene in 190 Caucasian chromosomes. A total of 651 patients with essential hypertension and 776 controls (PEGASE Study) were genotyped for all identified variants using allele-specific oligonucleotides, and single nucleotide polymorphism as well as haplotype analyses were carried out. We also performed transient transfection experiments, northern and western blots, immunoprecipitation, and acyl-coenzyme A synthetase activity assays. RESULTS: We identified five polymorphisms in the promoter region (C-1808T, G-1606A, -962ins/del, G-451A, T-67C), two in introns 5 and 7 (T+9/In5C, A+20/In7T), and one missense variant (K359N). Carriage of the -1606A allele was significantly associated with hypertension [odds ratio (OR) 1.28, P = 0.049] as was 359N (OR 1.35, P = 0.048) compared with non-carriers. Conversely, for -962del, the OR for hypertension was 0.80 (P = 0.042). The SAH alleles -1606A and 359N, but not -962ins/del, displayed a raising effect on body mass index (BMI; P = 0.004 and P = 0.030, respectively) in hypertensive as well as in control individuals. After adjustment for BMI in hypertensive individuals, only the OR associated with -962ins/del remained significant (OR 0.77, P = 0.028). Functional analyses in BHK did not reveal differences for SAH 359N or 359K-containing constructs, formally excluding K359N as the functional variant. CONCLUSION: We confirm recent evidence that the SAH locus is associated with obesity-related hypertension, in which pathophysiological context SAH variants affecting blood pressure remain, however, to be shown.