Genetic analysis of mucopolysaccharidosis type VI in Taiwanese patients

BACKGROUND: Glutathione peroxidase 1 (GPX1), the key antioxidant enzyme in vascular endothelial cells, has been shown to exert a protective effect against the presence of coronary artery disease (CAD). The 198Pro/leu variant, located at codon 198 of GPX1 gene, has recently been linked to cardiovascular disease, but data were inconsistent. We investigated the association between the occurrence of CAD and the 198Pro/leu variant in a Chinese population. METHODS: A total of 265 unrelated CAD patients and 265 age- and sex-matched control subjects were recruited in this study. The GPX1 198Pro/leu genotype was determined using polymerase chain reaction-restriction fragment length polymorphism. RESULTS: Compared to the 198Pro/Pro carriers, subjects with the variant genotypes (198Pro/leu and 198Leu/leu) had a significantly higher risk of CAD (adjusted OR=2.02, 95%CI=1.27-3.22). In stratified analyses, the variant genotypes were significantly associated with increased CAD risk in subjects <64 y (adjusted OR=2.41, 95%CI=1.16-4.98), males (adjusted OR=1.86, 95%CI=1.09-3.18) and non-smokers (adjusted OR=2.40, 95%CI=1.15-5.01). However, no significant association was observed between this variant and the severity of CAD. CONCLUSION: These data provide evidence that GPX1 198Pro/leu variant genotypes are significantly associated with CAD risk in this Chinese population.     

亚甲基四氢叶酸还原酶基因多态性与急性淋巴细胞白血病患者甲氨蝶呤化疗毒副反应的研究

本研究旨在观察mthfr基因多态性分布对急性淋巴细胞白血病患者使用大剂量MTX化疗后毒副反应的影响。收集44例ALL患者外周血，提取基因组DNA，用PCR—RFLP技术检测mthfr基因型；观察经大剂量甲氨蝶呤化疗后所有患者的药后毒副作用。结果表明：mthfrC677T和A1298C各基因型间毒副反应差异显著，携带T突变基因患者发生毒副反应是携带CC基因型的3．75倍；携带AC＋CC基因型发生毒副反应是AA基因型携带者的0．12倍。mthfr677TT基因型联合1298AA基因型与677CC基因型同时携带1298C等位基因变异患者在毒副反应上差异显著，前者发生毒副作用的可能性是后者的16．5倍。结论：mthfr基因多态性分布与ALL患者HDMTX化疗后的毒副反应有关。     

Association between the eNOS (Glu298Asp) and the RAS genes polymorphisms and premature coronary artery disease in a Turkish population

BACKGROUND: The renin-angiotensin system (RAS) and endothelial nitric oxide (NO) affect the pathogenesis of atherosclerosis and prognosis of coronary artery disease (CAD). Previous epidemiologic data suggested that genetic factors are more likely to affect young rather than old people. Our objective was to investigate the association between the polymorphisms of eNOS (Glu298Asp) and the RAS genes and premature CAD in a Turkish population. METHODS: A total of 115 Turkish patients with premature CAD and 83 controls were included in the study. ACE I/D, AT1R A/C, AGT T/M and eNOS Glu298Asp gene polymorphisms were analysed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: It was found that increased premature CAD risk is associated with higher frequencies of the ACE DD [OR: 2.600 (CI 95% 1.395-4.847, p=0.002)], AGT MM [OR=2.407 (CI 95% 1.267-4.573, p=0.007)] and eNOS 894TT [OR=17.000 (CI 95% 3.952-73.125, p<0.001)] genotypes. Carriers of ACE DD+eNOS 894TT (p=0.002), AGT MM+eNOS 894TT (p=0.001), AT1R AA+eNOS 894TT and AT1R non-AA+eNOS 894TT (p=0.002) genotypes were significantly associated with the risk of premature CAD. CONCLUSIONS: This study indicates a synergistic contribution of RAS genes (ACE I/D, AGT T/M, AT1R T/C) and eNOS Glu298Asp polymorphisms to the development of the premature CAD.     

GNAS1 T393C polymorphism is associated with migraine

Migraineurs have an interictal sympathetic nervous system (SNS) hypofunctionality and hypersensitivity to adrenergic amines. The GNAS1 T393C polymorphism has been associated with a distinct SNS sensitivity in healthy subjects. We tested GNAS1 T393C variant in two independent sets of subjects. In the case-control subset, 365 migraine patients [194 with aura (MA)] vs. 347 healthy controls were studied. A significant excess of the CC genotype was found in migraneurs (31.2%) as opposed to controls (20.2%; P=0.003). Using a logistic regression model corrected for sex, the CC genotype conferred a general risk for migraine twice [odds ratio (OR) 1.79, 95% confidence interval (CI) 1.27-2.53; P=0.001] higher than CT/TT genotypes. Using parents from 117 migraine families, a marginally significant trend for association could be observed (P=0.025), but the transmission disequilibrium test for alleles maternally transmitted failed to demonstrate familial association. In this subgroup, CC genotype conferred a risk for migraine over twice (OR 2.20; 95% CI 1.14-4.40; P=0.019) higher than TT/TC genotypes. In conclusion, the GNAS1 T393C variant is associated with migraine, which suggests a genetic basis for its higher SNS sensitivity.     

金属蛋白酶2基因-1306C/T多态性与冠心病的关系

目的:研究金属蛋白酶2(MMP-2)基因-1306C/T多态性与冠心痛(CAD)发病的相关性.方法:采用基质辅助激光解吸电离飞行时间质谱技术(MALDI-TOF MS),检测283例冠心病患者与161例对照组人群MMP-2基因-1306C/T位点的基因型和等位基因的分布.结果:MMP-2基因-1306C/T位点基因型频率及等位基因频率在两组分布差异有统计学意义(P＜0.01),经Logistic回归分析后,CC基因型携带者患冠心病风险是T等位基因携带者(CT+TT)的2.038倍(OR=2.038,95％CI=1.193-3.481,P＜0.01).结论:MMP-2基因-1306C/T位点与冠心病发病的危险性相关,CC基因型可能是冠心病发病的遗传危险因素.     

Genetic variation in the rate-limiting enzyme in cholesterol catabolism (cholesterol 7alpha-hydroxylase) influences the progression of atherosclerosis and risk of new clinical events

CHD (coronary heart disease) is a complex disorder which is, in part, related to serum cholesterol levels. The rate-limiting enzyme in the catabolism of cholesterol into bile acids is CYP7A1 (cholesterol 7alpha-hydroxylase). The effect of the CYP7A1 A-278C promoter polymorphism on the progression of atherosclerosis, risk of a new clinical event and the influence of this variant on cholesterol-lowering therapy was investigated in 715 male patients with coronary atherosclerosis participating in REGRESS (Regression Growth Evaluation Statin Study). Genotype distributions were as follows: 283 with AA; 330 with AC and 102 with CC. There were no significant differences in baseline characteristics and serum lipids between genotypes. After 2 years, CC carriers had more progression of diffuse and focal atherosclerosis compared with AA carriers, as indicated by a larger decrease in MSD (mean segment diameter; 0.09 mm compared with 0.06 mm respectively; P=0.009) and MOD (minimum obstruction diameter; 0.09 mm compared with 0.05 mm respectively; P=0.024). Inclusion of risk factors for CHD in the model showed the same trend, although not significant for MOD (P=0.01 for MSD, and P=0.06 for MOD). In addition, CC carriers had an almost 2-fold higher risk of a new clinical event compared with AA carriers [RR (95% CI) 1.93 (1.11-3.36); P=0.02; where RR is relative risk and CI is confidence interval]. Inclusion of risk factors for CHD in the model showed the same trend, although not significant [RR (95% CI), 1.74 (0.96-3.12); P=0.06]. In conclusion, we present evidence that the CC variant of the A-278C polymorphism in the rate-limiting enzyme in the catabolism of cholesterol, CYP7A1, increases the progression of atherosclerosis and possibly the risk of a new clinical event.     

Myeloperoxidase -463 (G-->A) polymorphism associated with lower risk of lung cancer.

OBJECTIVE: To study the association of the myeloperoxidase (MPO) -463 (G-->A) polymorphism with lung cancer risk. PATIENTS AND METHODS: We performed a paired case-control analysis of 307 patients with primary lung cancer and an equal number of age-, sex-, and ethnicity-matched controls to evaluate the effect of the MPO -463 (G-->4A) polymorphism on disease susceptibility. We also performed conditional logistic regression analyses to evaluate the effect of the polymorphism adjusted for smoking status and chronic obstructive pulmonary disease, 2 established risk factors. We used 2 models for these analyses: one to compare homozygous (AA) genotypes with wild type (GG) and heterozygous (GA) genotypes and one to compare carriers (heterozygotes and AA homozygotes) with GG genotypes. Finally, we combined the results from the published studies of this putative association and performed a stratified analysis. RESULTS: The AA genotype was inversely associated with susceptibility to lung cancer (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.15-1.00). There was no association in heterozygotes. However, in the stratified analysis, we found an association between patients with the AA (OR, 0.44; 95% CI, 0.27-0.68) and GA (OR, 0.77; 95% CI, 0.64-0.93) genotypes vs the GG genotype. CONCLUSION: Our results are consistent with previous reports and show that homozygotes of the less common A allele of MPO -463 polymorphism have a 2.6-fold lower risk of lung cancer.     

Interleukin-17A gene variants and risk of coronary artery disease: a large angiography-based study

Recent studies have also revealed that interleukin (IL)-17A plays a key role in atherosclerosis and its complication, but the relationship of its common variants with coronary artery disease (CAD) has not been extensively studied. We systematically screened sequence variations in the IL17A gene and designed an angiography-based case-controlled study consisting of 1031 CAD patients and 935 control subjects to investigate the association between the selected polymorphisms of IL-17A gene and CAD risk in Chinese Han population. Frequencies of IL17A rs8193037 GG homozygote and G allele were significantly higher in the patient group than those in the control group (P<0.001; OR=0.68; 95% CI=0.54-0.85). Stratification analysis showed that the IL17A rs8193037 G allele significantly increased the risk of CAD only among male subjects (P=0.001; OR=0.63; 95% CI=0.47-0.83). After adjustment for conventional risk factors, binary logistic regression analysis showed that the G allele carriers (GG+AG) had significantly increased CAD risk compared with the AA homozygotes (adjusted P<0.001; OR 0.43; 95% CI, 0.33-0.58). ELISA showed augmented IL17A production in plasma of the AMI patients. Based on our data, we speculated that the SNP rs8193037 of IL17A gene is significantly associated with CAD risk in Chinese Han population and the rs8193037 G allele which is associated with increased expression of IL17A in AMI patients may be an independent predictive factor for CAD.     

Effect of paraoxonase-1 polymorphism on clinical outcomes in patients treated with clopidogrel after an acute myocardial infarction

Paraoxonase-1 (PON1) Q192R polymorphism was recently suggested to determine per se clopidogrel response on major cardiovascular events (MACEs). We assessed the impact of PON1, CYP2C19, and ABCB1 polymorphisms on MACE in clopidogrel-treated acute myocardial infarction (AMI) patients (N = 2,210), including those undergoing percutaneous coronary intervention (PCI) (n = 1,538). PON1 polymorphism was not associated with increased risk of in-hospital death and MACEs at 1 year (adjusted hazard ratio (HR) 1.03, 95% confidence interval (CI) 0.66-1.61 and adjusted HR 0.77, 95% CI 0.42-1.41 for QQ versus RR in all and PCI patients, respectively). The presence of two CYP2C19 loss-of-function (LOF) alleles was associated with the risk of in-hospital death and MACEs at 1 year in the overall population (adjusted odds ratio (OR) 3.67, 95% CI 1.05-12.80 and adjusted HR 1.96, 95% CI 1.08-3.54) and in PCI patients (adjusted OR 6.87, 95% CI 2.52-18.72 and adjusted HR 3.06, 95% CI 1.47-6.41). Unlike CYP2C19 polymorphism, PON1 (Q192R) polymorphism is not a major pharmacogenetic contributor of clinical response to clopidogrel in AMI patients.     

C7基因调节区遗传变异对结直肠癌易感性的影响研究

目的 探讨补体7(C7)基因遗传变异与结直肠癌易感性的关系。方法 利用GEPIA数据库分析基因C7在结直肠癌组织与正常组织中的表达差异;利用TIMER数据库分析C7表达及拷贝数变异与结直肠癌免疫细胞浸润的相关关系。采用病例对照研究分析C7遗传变异对结直肠癌发病风险的影响。使用PCR-限制性片段长度多态性分析对C7 rs1061429和rs1376178单核苷酸多态性（SNP）进行基因分型。使用非条件logistic回归计算比值比（OR）和95%置信区间（CI）,分析C7rs1061429和rs1376178遗传变异与结直肠癌易感性的关系。结果 与结直肠正常组织相比,C7在结直肠癌组织中的表达显著降低（P<0.05）。C7表达及拷贝数变异可影响结直肠癌免疫细胞浸润。与C7 rs1061429 CC基因型携带者相比,CA基因型携带者可显著增加直肠癌发病风险（OR=1.42,95%CI:1.08～1.86）。与C7 rs1376178 CC基因型携带者相比,CA基因型携带者的结肠癌发病风险增加（OR=1.50,95%CI:1.06～2.10）,CA或AA基因型携带者有较高的直肠癌发病风...     

The Leu72Met polymorphism of the ghrelin gene is associated with a decreased risk for type 2 diabetes

BACKGROUND: Ghrelin is involved in several metabolic and cardiovascular processes. The Leu72Met polymorphism of its gene was associated with an increased risk of type 2 diabetes (DM2) in some, but not all studies. Its association with atherosclerosis is not known. METHODS: We investigated 420 Caucasian subjects with DM2 and 430 controls without diabetes (56.6% male, age 62+/-10 years). RESULTS: The Leu72Leu genotype frequencies were 89.76/84.65%, the Leu72Met 9.52/15.12% and the Met72Met 0.71/0.23% (P=0.029) in the DM2 and controls groups, respectively. In subjects with Met72+ genotypes the risk of DM2 was significantly decreased (univariate OR 0.63, 95% CI 0.42-0.95, P=0.026). In a logistic regression model, body mass index, hypertension and a positive family history for diabetes were predictors of diabetes while the polymorphism remained negatively associated with the disease (OR 0.62, 95% CI 0.40-0.97, P=0.036). After adjusting for known risk factors for atherosclerosis, the Met72+ variant was not associated with atherosclerotic disease (OR 1.41, 95% CI 0.78-2.54, P=0.25). Ghrelin concentrations were not associated with the polymorphism, DM2 or atherosclerotic disease. CONCLUSIONS: The Leu72Met polymorphism of the ghrelin gene is associated with a decreased risk for DM2. There is no association between the variant and atherosclerotic disease or ghrelin concentrations.     

ERCC1基因多态性与肝癌患者易感性分析

目的探讨切除修复交叉互补基因1(ERCC1)-4533/8092位点单核苷酸多态性(SNPs)与广西壮族人群肝癌易感性之间关系。方法通过聚合酶链反应限制性片段长度多态性(PCR-RFLP)方法检测88例原发性肝癌患者和82例健康对照者的ERCC1-4533/8092基因多态性。结果 ERCC1-4533位点的基因分型在病例组和对照组的频数分布差异无统计学意义(P0.05),ERCC1-8092位点的基因分型在病例组和对照组的频数分布差异具有统计学意义(P0.05)。与携带ERCC1-8092CC基因型的个体相比,携带ERCC1-C8092CA/AA基因型的个体具有更高的肝癌易感性(CA:OR=2.556,95%CI:1.345~4.855;AA:OR=8.667,95%CI:1.000~75.092)。以携带ERCC1-8092C等位基因作为参照,携带ERCC1-C8092A等位基因可以增加原发性肝癌的发病危险性(OR=2.387,95%CI:1.428~3.992)。结论 ERCC1-8092位点基因多态性与广西壮族人群肝癌易感性有关。     

XRCC1 polymorphism and lung cancer risk

DNA repair plays a critical role in protecting the genome of the cell from the insults of carcinogens or ionizing radiation. Reduced DNA repair capacity can increase the susceptibility to environmental- or occupational-induced cancers. Three coding polymorphisms at codon 194, codon 280 and codon 399 in the x-ray cross complementing group 1 (XRCC1) DNA repair gene have been identified, and it is possible that these polymorphisms may affect DNA repair capacity and thus modulate cancer susceptibility. In this review, we summarize the literature and discuss the relevance of XRCC1 polymorphisms and lung cancer risk. The frequency of genetic polymorphisms is dependent on the ethnic origins of a population. The frequency of the variant allele of codon 194 among Asians is on average 31.2% (95% confidence interval [CI]: 29.6-32.8), which is significantly higher than among Caucasians (6.6%; 95% CI: 5.9-7.4) or Africans (7.3%; 95% CI: 5.7-9.2). The variant allele in codon 399 occurs among Africans at a frequency of 15.5% (95% CI: 13.5-17.7), 34.7% in Caucasians (95% CI: 33.8-35.6) and 26.5% in Asians (95% CI: 25.6-27.4). Results regarding lung cancer risk are inconsistent. The lung cancer risk associated with polymorphisms of the XRCC1 codon 194 demonstrate an odds ratio (OR) of around 1.0. For the XRCC1 codon 280, lung cancer risk varied between ORs of 0.26 and 1.8; and for the XRCC1 codon 399 between 0.32 and 3.25. Only two studies showed significantly elevated risks (OR: 3.25; 95% CI: 1.2-10.7; OR: 1.3; 95% CI: 1.0-1.8, respectively), whereas one study showed a decreased lung cancer risk (OR: 0.60; 95% CI: 0.46-40.80). Lung cancer risk increased with cigarette smoking. A significant association was not observed between the single-nucleotide polymorphisms and tobacco-related cancers. Lung cancer risk increased significantly for the variant XRCC1 -77 genotypes (TC and CC) compared with the TT genotype (OR: 1.46; 95% CI: 1.18-1.82). The risk was more pronounced in smokers (OR: 1.63; 95% CI: 1.20-2.21) than in nonsmokers (OR: 1.28; 95% CI: 0.94-1.76). No association with polymorphisms were found for various histological tumor types. The XRCC1 399 Gln/Gln variant genotype was associated with a higher median survival time.     

EB病毒-MKK4基因遗传变异的交互作用与鼻咽癌危险性研究

目的:研究EB病毒感染与MKK4基因遗传变异的交互作用在鼻咽癌发病中的作用。方法:收集鼻咽癌病例和正常对照各500名,采用TAQMAN技术分析MKK4基因遗传变异-1304T>G与鼻咽癌发病的关联;并分析基因位点与EB病毒感染状态在鼻咽癌发生中的交互作用。结果:相对TT基因型携带者,G变异基因型鼻咽癌的发病风险下降(TG基因型adjustedOR=0.78,95%CI=0.61～0.94,P=0.02;GG基因型adjustedOR=0.64;95%CI=0.39～0.99;P=0.04),且存在显著的等位基因剂量—效应关联(Ptrend=0.02)。进一步交互作用分析发现EB病毒感染状态可改变G变异基因型降低鼻咽癌发病风险的作用(adjustedP交互作用=0.04)。结论:MKK4基因遗传变异可降低鼻咽癌的发病风险,但其对鼻咽癌的保护作用受EB病毒感染状态影响,提示EB病毒-MKK4基因交互作用可能是我国南方人群易患鼻咽癌的一个危险因素。     

PON1 L55M polymorphism is not a predictor of coronary atherosclerosis either alone or in combination with Q192R polymorphism in an Italian population

BACKGROUND: The present study evaluated the role of the PON1 L55M polymorphism independently and in conjunction with the Q192R polymorphism on the risk of coronary atherosclerosis in an Italian population. MATERIALS AND METHODS: Three hundred and ninety-one subjects with significant coronary stenosis (> 50%) (coronary artery disease-positive; CAD+), 196 subjects with normal coronary arteries (< 10% stenosis) (CAD-) and 178 healthy controls were screened using a combination of polymerase chain reaction and restriction enzyme digestion. RESULTS: In the pooled population, the frequencies of L and M alleles were 0.63 and 0.37, respectively; the most common haplotypes were QQ/LM (24.2%) and QR/LL (21.8%) and a strong linkage disequilibrium between L/55 and R/192 alleles was observed (D' = -0.91; P < 0.0001). CAD+ subjects did not show any significant differences in the distribution of PON1-55 genotypes as compared to CAD- subjects and population controls (chi2 = 1.5, P = 0.8). After controlling for other risk factors, the low-concentration M allele was not associated with a significant change of CAD risk (OR 1.02; 95% CI 0.80-1.29; P = 0.87). Moreover, the L55M polymorphism did not show any interaction with other risk factors such as smoking, diabetes, hypertension, low levels of high-density lipoprotein (HDL) or high ratios of low-density to high-density lipoproteins. The combination of L55M with the Q192R polymorphism did not show any effect on CAD risk. However, a marginal decrease in myocardial infarction risk was detected when QQ/MM carriers (OR 0.51; 95% CI 0.26-0.99; P = 0.048), but not LL/RR carriers, were compared with subjects not homozygous for an L or R allele. CONCLUSIONS: These findings did not indicate a major effect of the PON1 L55M polymorphism, either alone or in combination with the Q192R polymorphism, on CAD risk. Additional studies are needed for a better evaluation of the role of the 55/192 PON1 genotypes in combination on myocardial infarction risk.     

Interaction between smoking and PON2 Ser311Cys polymorphism as a determinant of the risk of myocardial infarction

BACKGROUND: Increased oxidative stress is thought to play a role in the pathogenesis of the atherothrombotic process. Paraoxonases (PONs) are closely related antioxidant enzymes encoded by clustered genes on chromosome 7q. We evaluated three PON polymorphisms (PON1 Leu55Met and Gln192Arg; PON2 Ser311Cys) as possible risk factors for coronary atherosclerotic disease (CAD) and/or its main thrombotic complication, myocardial infarction (MI). MATERIALS AND METHODS: We studied 890 subjects with angiographic documentation of coronary vessels (272=CAD-free; 618=CAD). In the CAD group, 341 subjects had a previous MI. RESULTS: Frequencies of various genotypes were not significantly different between CAD-free subjects and the entire CAD population. In the latter group, there were more carriers of the PON2 311Cys variation among those who had suffered a MI than among those who had not (P<0.01 by chi2). The adjusted OR for MI among PON2 311Cys carriers was 1.5 (95%CI, 1.03-2.19). A gene-environmental interaction was found between PON2 Ser311Cys and smoking. Smoking by itself was associated with an increased MI risk. Among smokers, however, the MI risk was related to PON2 genotype: Cys/Cys homozygotes (OR=5.3; 95%CI, 1.7-16.4) and Ser/Cys heterozygotes (OR=2.1; 95%CI, 1.3-3.6) were at greater risk than Ser/Ser subjects (OR=1.2; 95%CI, 0.8-1.8). The PON2 polymorphism did not influence the MI risk among nonsmokers. CONCLUSIONS: In CAD subjects, a proportion of the risk of MI may be influenced by the interaction between smoking and a polymorphism in the antioxidant enzyme PON2.     

Polymorphisms and haplotypes of the estrogen receptor-beta gene (ESR2) and cardiovascular disease in men and women

BACKGROUND: Cohort studies suggest an association between variation in the estrogen receptor-alpha gene (ESR1) and cardiovascular disease (CVD), but data are lacking for the effect of variation in the estrogen receptor-beta gene (ESR2). METHODS: Three polymorphisms of the ESR2 gene, and their associated haplotypes, were evaluated in 296 white women from the Women's Health Study and 566 white men from the Physicians' Health Study who developed CVD [myocardial infarction (MI) or ischemic stroke], each matched 1:1 to a member of the cohort study who remained free from CVD. Blood samples and cardiovascular risk information were collected at baseline. RESULTS: Women, but not men, who developed CVD or MI, but not ischemic stroke, were more likely to have the rs1271572 polymorphism variant T allele (P = 0.05 and 0.02) and less likely to have the rs1256049 polymorphism variant A allele (P = 0.003 and 0.004). No associations were observed for rs4986938. In conditional logistic multivariate regression, the rs1271572 variant was associated with increased odds of CVD [odds ratio (OR) = 1.49, 95% CI: 1.10-2.01] and MI (OR = 1.46, 95% CI: 0.96-2.23), whereas the rs1256049 variant was associated with decreased odds of CVD (OR = 0.37, 95% CI: 0.17-0.79) and MI (OR = 0.25, 95% CI: 0.09-0.73) in women. A common haplotype that included the rs1271572 variant was associated with a 7-fold increased risk of MI in women. CONCLUSIONS: Two tightly linked polymorphisms of ESR2 were associated with risk of CVD, particularly MI, in women but not men. Additional studies of ESR2 genetic variation and risk of CVD are warranted.     

Independent risk factor for moderate to severe internal carotid artery stenosis: T786C mutation of the endothelial nitric oxide synthase gene

BACKGROUND: NO synthesized from L-arginine by the constitutive endothelial NO synthase (eNOS) plays a key role in the atherosclerotic process. We investigated whether common variants in the NOS3 gene (a T786C mutation in the 5' flanking region and the polymorphism on exon 7 that produced the Glu298Arg polymorphism in the protein) are associated with an increased risk of moderate to severe internal carotid artery (ICA) stenosis. METHODS: We studied 88 patients consecutively operated for ICA stenosis and 133 healthy controls. A T786C mutation in the 5' flanking region and the polymorphism in exon 7 that produces the Glu298Asp polymorphism in the protein were explored by PCR and fluorescent probe analysis. RESULTS: Genotype distribution was significantly different between patients and controls only for T786C, the CC genotype frequency being 26% and 13%, respectively [odds ratio (OR), 2.26; 95% confidence interval (CI), 1.14-4.46; P = 0.018]. Moreover, the CC genotype was significantly more frequent in a subgroup of patients with ulcerative plaques compared with patients with nonulcerative lesions (44% vs 17%; OR, 3.82; 95% CI, 1.79-8.14; P = 0.003). Multiple logistic regression analysis using the most frequent risk factors and the eNOS gene variant showed that the CC genotype is an independent risk factor for ICA stenosis (P = 0.023). CONCLUSION: C allele homozygosity in position 786 of the eNOS promoter seems to be an independent risk factor for the development of moderate to severe ICA stenosis, especially ulcerative lesions.     

A prospective evaluation of apolipoprotein M gene T-778C polymorphism in relation to coronary artery disease in Han Chinese

OBJECTIVES: Apolipoprotein M (apoM) is important for the formation of pre-beta-high-density lipoprotein (HDL) and cholesterol efflux in macrophages. It is demonstrated that single-nucleotide polymorphism (SNP) T-778C of apoM gene is related to type 2 diabetes in Han Chinese. In the present study, we investigated the possible association of apoM polymorphism in relation to coronary artery disease (CAD) in Han Chinese. DESIGN AND METHODS: This case-controlled study consisted of 118 CAD patients who were diagnosed angiographically to have at least 30% stenosis, and 255 unrelated subjects who were used as control. ApoM gene polymorphism in the proximal promoter region was analyzed by PCR-RFLP and serum lipid levels were also measured. RESULTS: It is indicated that CAD patients had increased frequency of C allele on apoM T-778C compared to the controls (14.8% vs. 6.9%, P=0.0008). Multivariable logistic regression analysis indicated that odds ratios (ORs) for all subjects with apoM CC+CT genotypes and C allele were 1.9 (95% CI=1.1-2.9, P<0.0001) and 1.9 (95% CI=1.3-3.2, P<0.0001), respectively. The plasma total cholesterol (TC) levels were significantly higher in individuals with CC or CT genotype than those with TT genotype in both CAD patients and controls. CONCLUSIONS: The present findings suggest that the C allele at nucleotide -778 in the apoM gene is a risk factor for genetic susceptibility to CAD and is also associated with TC levels in Han Chinese.