No association of polymorphisms in the gene encoding 5-lipoxygenase-activating protein and myocardial infarction in a large central European population.

PURPOSE: Haplotypes based on polymorphisms in the gene encoding 5-lipoxygenase-activating protein have been linked with susceptibility to myocardial infarction in Iceland and the United Kingdom. We sought to replicate these association findings in a large case-control sample from Germany. METHODS: The case group included 3657 patients with myocardial infarction and the control group comprised 1211 individuals with angiographically normal coronary arteries and without clinical signs or symptoms of myocardial infarction. Nine different polymorphisms were genotyped with the use of the TaqMan technique. RESULTS: Genotype, allele, and haplotype analyses did not reveal significant associations between the polymorphisms and myocardial infarction. The negative results included a four-marker haplotype, termed HapA haplotype (odds ratio = 1.10; 95% confidence interval: 0.96-1.25), that was previously found to be related with myocardial infarction in a sample from Iceland, and a different four-marker haplotype, termed HapB haplotype (odds ratio = 0.94; 95% CI: 0.79-1.12), that was previously linked with myocardial infarction in a sample from the United Kingdom. Nine-marker haplotypes were not significantly associated with myocardial infarction in multiple logistic regression models adjusted for covariates (P >or= 0.38). CONCLUSION: In this sample from central Europe, specific polymorphisms in the gene for 5-lipoxygenase-activating protein were not associated with myocardial infarction, a result contrasting previous positive findings.     

Association of ALOX5AP gene single nucleotide polymorphisms and cerebral infarction in the Han population of northern China

ABSTRACT: BACKGROUND: To explore the association of ALOX5AP single nucleotide polymorphisms (SNPs) and haplotype with the occurrence of cerebral infarction in the Han population of northern China. METHODS: Blood samples were collected from 236 patients of Han ancestry with a history of cerebral infarction and 219 healthy subjects of Han ancestry with no history of cerebral infarction or cardiovascular disease. Applied Biosystems(R) TaqMan(R) SNP Genotyping Assays for SNP genotyping were used to determine the genotypes of 7 ALOX5AP SNP alleles (rs4073259, rs4769874, rs9315050, rs9551963, rs10507391, rs9579646, and rs4147064). RESULTS: One SNP allele (A) of rs4073259 was significantly associated with development of cerebral infarction (P = 0.049). In comparison to control groups, haplotype rs9315050&rs9551963 AAAC [OR (95 % CI) =1.53 (1.02-2.29)], and genotypes rs4147064 CT [OR (95 % CI) =1.872 (1.082-3.241)], and rs9551963 AC [OR (95 % CI) = 2.015 (1.165-3.484)] increased the risk of cerebral infarction in patients with hypertension. Genotype rs9579646 GG [OR (95 % CI) = 2.926 (1.18-7.251)] increased the risk of, while rs4073259 GG [OR (95 % CI) = 0.381 (0.157-0.922)] decreased the risk of cerebral infarction in patients with diabetes. CONCLUSION: These results suggest the ALOX5AP SNP A allele in rs4073259 and genotype rs9579646 GG, rs9551963 AC, and haplotype rs9315050 & rs9551963 AAAC were associated with an increased risk of ischemic stroke in the Han population, while rs4073259 GG was associated with a decreased risk.     

ALOX5 variants associated with susceptibility to human pulmonary tuberculosis

The 5-lipoxygenase (ALOX5)-derived lipid mediators leukotrienes and lipoxins have regulatory functions in inflammation by modulating activities of immune cells and cytokine production. Recently, it was shown in ALOX5-/- mice that host control of Mycobacterium tuberculosis is regulated by 5-lipoxygenase (5-LO). ALOX5 polymorphisms were genotyped in 1916 sputum-positive patients with pulmonary tuberculosis (TB) from Ghana and in 2269 exposed, apparently healthy controls. Polymorphisms of a variable number of tandem repeats (VNTR) of the ALOX5 promoter and of the exonic non-synonymous variant g.760G>A were analysed by fragment length determination and fluorescence resonance energy transfer, respectively, and DNA sequencing. Mycobacterial lineages of >1400 isolates were differentiated biochemically and genetically. Carriers of one variant (n repeats not equal 5) and one wild-type VNTR allele (n = 5) or of the exonic allele g.760A had a higher risk of TB [P(corrected) = 0.026, odds ratio (OR) 1.19 (95% CI 1.04-1.37) and P(corrected) = 0.026, OR 1.21 (95% CI 1.04-1.41), respectively]. The association of the exonic variant was stronger in infections caused by the mycobacterial lineage M. africanum West-African 2 [P(corrected) = 0.024, OR 1.70; (95% CI 1.2-2.6)]. Determination of haplotypes revealed the strongest associaton with TB for the 'non-5/760A' haplotype compared with the 'non-5/760G' haplotype (P = 0.003, OR 1.50). Our observation of an association of ALOX5 variants with susceptibility to TB contributes evidence of the importance of 5-LO products to the regulation of immune responses to M. tuberculosis.     

Association between NOD2/CARD15 polymorphisms and coronary artery disease: a case-control study

Inflammation and immune response play an important role in the pathogenesis of atherosclerosis. In this prospective study we tested the hypothesis of whether polymorphic variations in the NOD2/CARD15 gene may influence the risk of developing clinically evident coronary artery disease (CAD). ARG702TRP, GLY908ARG, and Leu1007fsinsC NOD2/CARD15 polymorphisms were analyzed in 109 consecutive patients with angiographically documented CAD and in 109 age- and sex-matched healthy controls. The ARG702TRP, GLY908ARG, and Leu1007fsinsC polymorphisms were analyzed by polymerase chain reaction followed by restriction digestion. The prevalence of the Leu1007fsinsC polymorphism was significantly increased in CAD patients compared with controls (11.9% vs 1.8%; odds ratios (OR) 7.2, 95% confidence interval (95% CI) 1.5-32.9; p = 0.01), especially in those presenting with an acute coronary syndrome (OR 5.7; 95% CI 1.1-39.7; p = 0.034 vs stable angina). In CAD patients the frequency of GLY908ARG polymorphism was significantly lower (1.8% vs 6.4% in controls; OR 0.05, 95% CI 0.01-0.69; p = 0.031, at multivariable analysis) and the prevalence of the ARG702TRP polymorphism was higher compared with controls (10.1% vs 3.7%; OR 2.9, 95% CI 0.91-9.6; p = 0.07). We report in a Caucasian population that NOD2/CARD15 polymorphisms influence the development of clinically evident and angiographically documented coronary artery disease. In particular, the Leu1007fsinsC polymorphism was associated with an increased risk of clinically evident and angiographically documented coronary atherosclerosis and clinical destabilization of coronary plaques, whereas the GLY908ARG polymorphism demonstrated a protective effect on coronary atherogenesis. These correlations were independent of cardiovascular risk factors at multivariable analysis. These findings may contribute to the identification of a novel genetic approach for the stratification of cardiovascular risk profile.     

Susceptibility to coronary artery disease and diabetes is encoded by distinct, tightly linked SNPs in the ANRIL locus on chromosome 9p

Genome-wide association studies have identified a region on chromosome 9p that is associated with coronary artery disease (CAD). The region is also associated with type 2 diabetes (T2D), a risk factor for CAD, although different SNPs were reported to be associated to each disease in separate studies. We have undertaken a case-control study in 4251 CAD cases and 4443 controls in four European populations using previously reported ('literature') and tagging SNPs. We replicated the literature SNPs (P = 8x10(-13); OR = 1.29; 95% CI: 1.20-1.38) and showed that the strong consistent association detected by these SNPs is a consequence of a 'yin-yang' haplotype pattern spanning 53 kb. There was no evidence of additional CAD susceptibility alleles over the major risk haplotype. CAD patients without myocardial infarction (MI) showed a trend towards stronger association than MI patients. The CAD susceptibility conferred by this locus did not differ by sex, age, smoking, obesity, hypertension or diabetes. A simultaneous test of CAD and diabetes susceptibility with CAD and T2D-associated SNPs indicated that these associations were independent of each other. Moreover, this region was not associated with differences in plasma levels of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fibrinogen, albumin, uric acid, bilirubin or homocysteine, although the CAD-high-risk allele was paradoxically associated with lower triglyceride levels. A large antisense non-coding RNA gene (ANRIL) collocates with the high-risk haplotype, is expressed in tissues and cell types that are affected by atherosclerosis and is a prime candidate gene for the chromosome 9p CAD locus.     

Epistatic interaction between haplotypes of the ghrelin ligand and receptor genes influence susceptibility to myocardial infarction and coronary artery disease

Data from both experimental models and humans provide evidence that ghrelin and its receptor, the growth hormone secretagogue receptor (ghrelin receptor, GHSR), possess a variety of cardiovascular effects. Thus, we hypothesized that genetic variants within the ghrelin system (ligand ghrelin and its receptor GHSR) are associated with susceptibility to myocardial infarction (MI) and coronary artery disease (CAD). Seven single nucleotide polymorphisms (SNPs) covering the GHSR region as well as eight SNPs across the ghrelin gene (GHRL) region were genotyped in index MI patients (864 Caucasians, 'index MI cases') from the German MI family study and in matched controls without evidence of CAD (864 Caucasians, 'controls', MONICA Augsburg). In addition, siblings of these MI patients with documented severe CAD (826 'affected sibs') were matched likewise with controls (n = 826 Caucasian 'controls') and used for verification. The effect of interactions between genetic variants of both genes of the ghrelin system was explored by conditional classification tree models. We found association of several GHSR SNPs with MI [best SNP odds ratio (OR) 1.7 (1.2-2.5); P = 0.002] using a recessive model. Moreover, we identified a common GHSR haplotype which significantly increases the risk for MI [multivariate adjusted OR for homozygous carriers 1.6 (1.1-2.5) and CAD OR 1.6 (1.1-2.5)]. In contrast, no relationship between genetic variants and the disease could be revealed for GHRL. However, the increase in MI/CAD frequency related to the susceptible GHSR haplotype was abolished when it coincided with a common GHRL haplotype. Multivariate adjustments as well as permutation-based methods conveyed the same results. These data are the first to demonstrate an association of SNPs and haplotypes within important genes of the ghrelin system and the susceptibility to MI, whereas association with MI/CAD could be identified for genetic variants across GHSR, no relationship could be revealed for GHRL itself. However, we found an effect of GHRL dependent upon the presence of a common, MI and CAD susceptible haplotype of GHSR. Thus, our data suggest that specific haplotypes of the ghrelin ligand and its receptor act epistatically to affect susceptibility or tolerance to MI and/or CAD.     

Association of angiotensinogen haplotypes with angiotensinogen levels but not with blood pressure or coronary artery disease: the Ludwigshafen Risk and Cardiovascular Health Study

Angiotensinogen and its cleaved forms angiotensin I and angiotensin II are important regulators of blood pressure. The gene for angiotensinogen (AGT) carries two common polymorphisms, T207M and M268T (previously described as T174M and M235T). To investigate the role of haplotypes formed by these polymorphisms for angiotensinogen levels we examined blood pressure, coronary artery disease (CAD), myocardial infarction (MI), and AGT genotypes and haplotypes in 2,575 patients with angiographically documented CAD and 731 individuals in whom CAD had been ruled out by angiography. Three haplotypes, designated as Hap1 (T207, M268), Hap2 (T207, T268) and Hap3 (M207, T268), accounted for more than 99% of alleles. The AGT Hap2 haplotype was significantly associated with angiotensinogen levels; one additional Hap2 allele accounted for an approx. 8% increase in angiotensinogen. This association was stronger than that of either single polymorphism. AGT genotypes or haplotypes were not related to hypertension, CAD or MI. We conclude that a common haplotype of the angiotensinogen gene is linked to angiotensinogen levels but has no major impact on blood pressure, hypertension, or cardiovascular risk.     

Ischaemic stroke in hypertensive patients is associated with variations in the PDE4D genome region

Previous Icelandic studies reported that single nucleotide polymorphisms (SNPs) in the phosphodiesterase 4D (PDE4D) region and the 5-lipoxygenase activating protein ALOX5AP were associated with ischaemic stroke, whereas other studies reported ambiguous findings. We examined 932 ischaemic stroke patients from a Swedish population-based stroke register, and 396 control subjects. We assessed possible associations between ischaemic stroke and nine preselected SNPs in the chromosome regions of the PDE4D gene, including rs12188950 (SNP45) and rs3887175 (SNP39); the ALOX5AP gene, including rs17222814 (SG13S25) and the promoter region of the MHC class II transactivator, MHC2TA. The T allele of SNP45 showed negative association with ischaemic stroke (odds ratio, OR=0.72; 95% confidence interval (CI): 0.58-0.91; P=0.0055). Among hypertensive subjects, this influence of the T allele of SNP45, and the T allele of SNP39, were more pronounced (with OR=0.52; 95% CI: 0.37-0.73; P=0.0001 and OR=0.57; 95% CI: 0.41-0.79; P=0.0007, respectively). These SNPs also interacted with hypertension with a relative excess risk due to interaction of -1.66 (P=0.0002) for SNP45 and -1.65 (P=0.0005) for SNP39. The P-values remained significant after correction for multiple testing. Among nonhypertensives, the A allele of SG13S25 indicated increased stroke risk (OR=1.82; 95% CI: 1.21-2.74; P=0.0039; not significant after Bonferroni correction). SNP45 was associated with ischaemic stroke even when controlling for hypertension, diabetes, heart disease and smoking. Our meta-analysis of 13 studies (including ours) showed no overall influence of SNP45 on ischaemic stroke. However, the 13 studies may differ because of nonrandom causes, as suggested by the heterogeneity test (P=0.042). This might support previously undetected mechanisms causing fluctuating ischaemic stroke risk.European Journal of Human Genetics (2008) 16, 1117-1125; doi:10.1038/ejhg.2008.62; published online 9 April 2008.     

Factor VLeiden and prothrombin G20210A gene polymorphisms in patients with coronary artery disease

PURPOSE: The precise molecular mechanisms culminating in coronary artery disease (CAD) are not well understood, despite a wealth of knowledge on predisposing risk factors and pathomechanisms. CAD and myocardial infarction (MI) are complex genetic diseases; neither the environment alone, nor a single gene, cause disease, rather, a mix of environmental and genetic factors lead to atherosclerosis of the coronary arteries. MATERIALS AND METHODS: In the present study, our aim was to investigate the roles of prothrombin G20210A mutation and Factor VLeiden mutation in atherosclerotic coronary artery disease. 287 subjects (106 control subjects, who were angiographically normal, and 181 angiographically documented coronary atherosclerotic patients who exhibited coronary artery narrowing to a degree of >or=50%) were included in this study. The mutations were assessed with LightCycler Real-Time PCR mutation detection kits (Roche Diagnostics, GmbH, Germany). RESULTS: 6.6% of control subjects, and 6.1% of patients with (50% coronary artery narrowing were determined to have the Factor VLeiden heterozygote mutation. 6.6% of control subjects had the Prothrombin G20210A heterozygote mutation, while 7.7% of patients with (50% coronary artery narrowing had this mutation. The OR for Factor VLeiden was 1.52 (CI: 0.240-9.602) and for Prothrombin G20210A mutation, the OR was 1.415 (CI: 0.287-6.962). CONCLUSION: Although both the heterozygote Factor VLeiden and Prothrombin gene mutations were more frequent in patients with CAD than in control subjects, there was no statistical relationship found to exist between coronary artery disease and the Factor VLeiden and Prothrombin G20210A mutations.     

Human MHC region harbors both susceptibility and protective haplotypes for coronary artery disease

Aiming to study the role of human major histocompatibility complex (MHC) region on coronary artery disease (CAD), we enrolled two separate patient materials and controls. First, heart transplantation recipients (n = 276) were divided into three subgroups according to the severity of atherosclerosis. The human leukocyte antigen (HLA)-A-B-DR haplotype and gene frequencies were compared between groups. Second, patients with acute coronary syndrome (ACS) (n = 100) and healthy controls (n = 74) were assessed by nine genetic MHC markers (HLA-A, HLA-B, HLA-DRB1, LTA+253(a/g), LTA+496(C/T), LTA+633(c/g), LTA+724(C/A), C4A and C4B), and the frequencies were compared. In the heart transplantation recipients, HLA-DR1 was strongly associated with CAD [severe vs no evidence, odds ratio (OR) 2.37; 95% confidence interval (CI) 1.33-4.25; P = 0.003]. Similarly, in the patients with ACS, HLA-DRB1*01 was associated with CAD (patients vs controls, OR 2.36; 95% CI 1.25-4.44; P = 0.007). HLA-DRB1*01 was associated with low-density-lipoprotein cholesterol (OR 5.32; 95% CI 1.64-17.26; P = 0.005) and smoking habit (OR 3.13; 95% CI 1.09-9.03; P = 0.035) as risk factors. The strongest protective gene was HLA-B*07 alone (OR 0.46; 95% CI 0.24-0.88; P = 0.02) or together with the haplotype LTA+253a-LTA+633g-C4A3-C4B1 (OR 0.36; 95% CI 0.22-0.57; P = 0.00001). In conclusion, human MHC region harbors genes that protect from and predispose to CAD.     

No association of ALOX5AP polymorphisms with risk of MRI-defined brain infarcts

The arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene has been associated with stroke. The majority of the reported ALOX5AP associations have considered non-radiologically confirmed infarcts as the stroke phenotype. We assessed the association of genetic variants in ALOX5AP with stroke defined by the presence of infarcts on brain magnetic resonance imaging (MRI). We studied 202 persons with MRI-defined brain infarcts and 487 healthy individuals of Caribbean Hispanic ancestry. Another sample of European ancestry comprised 1823 persons with MRI-defined brain infarct and 7578 control subjects. Subjects were genotyped for the 4 single nucleotide polymorphisms (SNPs) that define ALOX5AP HapA haplotype. No association was found between SNPs and MRI-defined brain infarcts. Our data do not support the hypothesis that variants in ALOX5AP are associated with risk of MRI-defined brain infarcts.     

A genetic risk score predicts coronary artery disease in familial hypercholesterolaemia: enhancing the precision of risk assessment

Familial hypercholesterolaemia (FH) is associated with increased risk of coronary artery disease (CAD); however, risk prediction and stratification remain a challenge. Genetic risk scores (GRS) may have utility in identifying FH patients at high CAD risk. The study included 811 patients attending the lipid disorders clinic at Royal Perth Hospital with mutation-positive (n = 251) and mutation-negative (n = 560) FH. Patients were genotyped for a GRS previously associated with CAD. Associations between the GRS, clinical characteristics, and CAD were assessed using regression analyses. The average age of patients was 49.6 years, and 44.1% were male. The GRS was associated with increased odds of a CAD event in mutation-positive [odds ratio (OR) = 3.3; 95% confidence interval (CI) = 1.3-8.2; P = .009] and mutation-negative FH patients (OR = 1.8; 95% CI = 1.0-3.3; P = .039) after adjusting for established predictors of CAD risk. The GRS was associated with greater subclinical atherosclerosis as assessed by coronary artery calcium score (P = .039). A high GRS was associated with CAD defined clinically and angiographically in FH patients. High GRS patients may benefit from more intensive management including lifestyle modification and aggressive lipid-lowering therapy. Further assessment of the utility of the GRS requires investigation in prospective cohorts, including its role in influencing the management of FH patients in the clinic.     

Association between arachidonate 5-lipoxygenase-activating protein (ALOX5AP) and lung function in a Korean population

Arachidonate 5-lipoxygenase-activating protein (ALOX5AP) plays a role in the 5-lipoxygenase (LO) pathway, which includes the LTC(4), LTD(4), LTE(4) and LTB(4). These leukotrienes are known causative factors of asthma, allergy, atopy and cardiovascular diseases. ALOX5AP lacks enzyme activity and acts by helping 5-LO function. In this study, healthy and general subjects who live in rural and urban areas of Korea were tested for the association of ALOX5AP polymorphisms with lung function. Lung function was also estimated by calculating the predicted values for forced expiratory volume in one second (FEV(1) _%PRED) and the proportion of the forced vital capacity exhaled in the first second (FEV(1) /FVC_PRED). The linear regression was adjusted for residence area, gender, age, height and smoking status. The analysis revealed associations between FEV(1) and the single-nucleotide polymorphism (SNP) rs9506352 and the haplotype TCAC (permuted P-value < 0.05). The linkage disequilibrium block that included the significant SNPs overlapped with SNPs that were revealed previously to associate with myocardial infarction and asthma and to affect lung function. This study is the first to demonstrate the association between lung function and ALOX5AP polymorphisms in a healthy and general population.     

Lack of association of the common TaqIB polymorphism in the cholesteryl ester transfer protein gene with angiographically assessed coronary atherosclerosis

The anti-atherogenic effect of cholesteryl ester transfer protein (CETP) genetic variants associated with lowered enzyme activity is controversial. Moreover, in a few studies, this effect has been evaluated in the presence of a certain risk factor constellation. We addressed this issue in a case-control study, where 415 subjects with angiographically documented coronary artery disease (CAD +), 397 subjects without CAD (in 215, CAD was excluded by coronarography (CAD-)), and 188 healthy population controls, were screened for the CETP TaqIB polymorphism. The prevalence of the low-activity TaqIB2 allele was 0.396 in CAD+, and 0.428 and 0.416 in CAD- and population controls, respectively (p = 0.40). Its presence was significantly associated with increased high-density lipoprotein cholesterol (HDL-C) in population controls (1.40 +/- 0.40 mmol/l in B1B1, 1.52 +/- 0.39 mmol/l in B1B2 and 1.58 + 0.46 mmol/l in B2B2; p < 0.03 for trend), but not in the other groups. The CETP TaqIB polymorphism accounted for < 1% of the HDL-C variance in the whole cohort (p = 0.048). After adjustment for other risk factors, the CETP TaqIB2 allele was found not to be associated with significant changes in CAD risk independently of an assumed either dominant (odds ratio (OR) 0.97; 95% confidence interval (CI) 0.66-1.44; p = 0.89) or recessive effect (OR 0.68; 95% CI 0.42-1.12; p = 0.13). The CETP TaqIB polymorphism did not show a significant interaction with other risk factors in influencing CAD risk. Our findings do not support the hypothesis that a genetic variant resulting in lowered CETP activity is associated with reduced risk of coronary atherosclerosis.     

The role of LTA4H and ALOX5AP polymorphism in asthma and allergy susceptibility

Background: Leukotrienes (LTs) have been identified as central mediators in asthma and allergy. Pharmacological inhibition of cysteinyl‐LT activity improves asthma symptoms and control. Accumulating evidence suggests a role for the dihydroxy leukotriene LTB₄ in airway disease. LTA₄ hydrolase and 5‐lipoxygenase activating protein have key roles in LTB₄ production. Single nucleotide polymorphism (SNPs) and haplotypes spanning the LTA4H and ALOX5AP genes have been associated with LTB₄ production and myocardial infarction (MI). Objective: To assess the contribution of LTA4H and ALOX5AP polymorphism to asthma and allergy susceptibility. Methods: Three hundred and forty‐one Caucasian families (two asthmatic siblings) were genotyped for eight SNPs spanning ALOX5AP and five SNPs spanning LTA4H. Association analyses of asthma and related phenotypes (total IgE, atopy, bronchial hyper‐responsiveness, FEV₁) were undertaken using the Family Based Association Test. Results: Single point analyses identified association (P < 0.05) between SNPs SG13S114, SG13S89, SG13S41 (ALOX5AP), rs1978331 (LTA4H) and asthma and/or related phenotypes. Haplotype analyses using all LTA4H SNPs identified a single key risk haplotype for the development of asthma (P = 0.006) and related phenotypes (P = 0.042–0.005). Haplotype analyses using all ALOX5AP SNPs identified several asthma and atopy risk and protective haplotypes. There was limited correlation with previously identified MI risk haplotypes in both genes. Carriers of both ALOX5AP SG13S41 and LTA4H rs1978331 alleles had an increased risk of developing asthma (OR 2.17, CI 1.41–3.32). Conclusions: These data provide evidence for the role of SNPs spanning the ALOX5AP and LTA4H genes in asthma and atopy susceptibility in the Caucasian population and support a role for LTB₄ in disease pathogenesis.     

Association between lipoprotein-associated phospholipase A2 gene polymorphism and coronary artery disease in the Chinese Han population

The role of the lipoprotein-associated phospholipase A(2) gene (PLA2G7) in atherosclerosis remains controversial. We investigated the frequency of single-nucleotide polymorphisms (SNPs) of PLA2G7 (rs16874954 and rs1051931) and their association with coronary artery disease (CAD) in a cohort of CAD patients (n= 806) and age-matched healthy controls (n= 482) in the Chinese Han population. The VF and FF genotype of rs16874954 was significantly more frequent in the CAD patients (13.5%) than in the controls (9.3%, P= 0.024). The association remained after adjustment for age, gender, body mass index, smoking status, history of diabetes, positive family history of CAD, high-density lipoprotein cholesterol, and triglyceride (OR = 1.922; 95% CI [1.146-3.224]; P= 0.013). There was no significant difference in the frequency of any genotype of rs1051931 between the two groups. However, the frequency of the allele V379 was significantly greater in CAD patients with a history of myocardial infarction (MI) than in those without a history of MI (18.7% and 14.8%, P= 0.038). We conclude that there is significant association between the rs16874954 mutation and CAD in the Chinese Han population. The expression of rs1051931 variant in CAD patients may entail increased risk of MI.     

Tumor necrosis factor receptor 2 gene (TNFRSF1B) in genetic basis of coronary artery disease

Tumor necrosis factor (TNF)-alpha has been implicated in pathophysiological processes in coronary artery disease (CAD). TNF receptor 2 is of particular interest in mediating such effects. The gene for this receptor (TNF-RSF1B) has, moreover, been implicated in hypertension, elevated cholesterol and insulin resistance. TNFRSF1B is thus a worthy candidate in studies of the genetic basis of CAD. We therefore conducted a case-control study of a microsatellite marker with five alleles (CA13-CA17) in intron 4 of TNFRSF1B in 1006 well-characterized white patients with angiographically confirmed CAD and a control group of 183 healthy subjects. We found a strong association of the TNFRSF1B marker with CAD (chi2=40, P=0.00000069). The frequency of the CA16 allele was 33% in CAD vs. 21% in control (odds ratio, OR, to have CAD for presence vs. absence of CA16 allele in CA16 homozygotes was 4.5, 95% CI 2.1-9.4, P<0.0001; in CA16 heterozygotes OR was 1.3, 95% CI 0.94-1.89, P=0.10). The frequency of the major allele (CA15) was 43% in CAD vs. 56% in controls (in CA15 homozygotes OR 0.33, 95% CI 0.20-0.52, P<0.0001; in heterozygotes OR 0.41, 95% CI 0.26-0.63, P<0.0001). In a stepwise logistic regression model the CA16 allele was significantly associated with overweight (OR 1.44, 95% CI 1.0-1.9, P=0.027). Apolipoprotein A-I was elevated (P<0.0001), as was high-density lipoprotein (P=0.098), and severity of angina was decreased (P=0.024) as a function of genotype. Plasma soluble (s) TNF-R2 was 5.1 +/- 0.1 ng/ml in CAD vs. 3.2 +/- 0.1 in control (P<0.0001), 5.2 +/- 0.1 in the presence vs. 4.6 +/- 0.2 in the absence of vessel disease (P=0.009), and rose with increasing severity of angina: 4.2 +/- 0.2 (no angina), 5.0 +/- 0.1 (stable angina), 5.4 +/- 0.2 (unstable angina; P=0.003). sTNF-R2 was correlated with age, cholesterol, creatinine, fibrinogen, transforming growth factor beta and homocysteine and was influenced by TNFRSF1B genotype. Thus genetic variation in or near the TNFRSF1B locus may predispose to CAD.     

Inducible nitric oxide synthase gene (NOS2A) haplotypes and the outcome of hepatitis C virus infection

Inducible nitric oxide synthase (iNOS) is an important molecule involved in the host defense against infectious agents. iNOS is encoded by the NOS2A gene and well-defined haplotypes exist with respect to this gene. We examined whether these haplotypes were associated with the outcome of hepatitis C virus (HCV) infection in 619 Caucasian patients from seven European liver centres. We observed five major haplotypes: (-277A)+(-1026G)+(-1659C): haplotype 1; (-277G)+(-1026T)+(-1659C): haplotype 2; (-277G)+(-1026G)+(-1659C): haplotype 3; (-277G)+(-1026T)+(-1659T): haplotype 4; and (-277A)+(-1026T)+(-1659C): haplotype 5. Distributions of these haplotypes are comparable with those of previous studies. Homozygotes for haplotype 2 or those with haplotypes 2/4 were more likely than those with the 1/1 (wild type) combination to have self-limiting infections (odds ratios (OR)=3.43; 95% confidence intervals (95% CI): 1.10-8.0; P=0.0206 and OR=5.15; 95% CI: 1.32-14.32; P=0.0018, respectively). Conversely, carriage of haplotype 1 was associated with the lack of self-limiting disease (OR=0.48; 95% CI: 0.27-0.83; P=0.009). The effect was mainly among males (OR=0.41; 95% CI: 0.182-0.942; P=0.031 for males, and OR=0.55; 95% CI: 0.24-1.37; P=0.136 for women). Carriage of haplotype 1 was not associated with initial response (P=0.268) or sustained response (P>0.171). Combinations of haplotypes 1/4 were more likely to respond to interferon monotherapy in comparison of initial responders to nonresponders (OR=2.25; 95% CI: 1.05-5.68; P=0.0275).