Chromosome 9p21 rs10757278 polymorphism is associated with the risk of metabolic syndrome

Association of Genetic Polymorphisms with Abdominal Aortic Aneurysm in the Processes of Apoptosis, Inflammation, and Cholesterol Metabolism

Background and Objectives: This study aims to identify the minor allele of the single nucleotide polymorphisms (SNPs) DAB2IP rs7025486, IL6R rs2228145, CDKN2BAS rs10757278, LPA rs3798220, LRP1 rs1466535, and SORT1 rs599839 in order to assess the risk of abdominal aortic aneurysm (AAA) formation and define the linkage among these SNPs. Materials and Methods: A case-control study with AAA patients (AAA group) and non-AAA controls (control group) was carried out in a study population. DNA was isolated from whole blood samples; the SNPs were amplified using PCR and sequenced. Results: In the AAA group of 148 patients, 87.2% of the patients were male, 64.2% had a history of smoking, and 18.2% had relatives with AAA. The mean ± SD of age, BMI, and aneurysmal diameter in the AAA group were 74.8 ± 8.3 years, 27.6 ± 4.6 kg/m2, and 56.2 ± 11.8 mm, respectively. In comparison with 50 non-AAA patients, there was a significantly elevated presence of the SNPs DAB2IP rs7025486[A], CDKN2BAS rs10757278[G], and SORT1 rs599839[G] in the AAA group (p-values 0.040, 0.024, 0.035, respectively), while LPA rs3798220[C] was significantly higher in the control group (p = 0.049). A haplotype investigation showed that the SNPs DAB2IP, CDKN2BAS, and IL6R rs2228145[C] were significantly elevated in the AAA group (p = 0.037, 0.037, and 0.046) with minor allele frequencies (MAF) of 25.5%, 10.6%, and 15.4%, respectively. Only DAB2IP and CDKN2BAS showed significantly higher occurrences of a mutation (p = 0.028 and 0.047). Except for LPA, all SNPs were associated with a large aortic diameter in AAA (p < 0.001). Linkage disequilibrium detection showed that LPA to DAB2IP, to IL6R, to CDKN2BAS, and to LRP1 rs1466535[T] had D' values of 70.9%, 80.4%, 100%, and 100%, respectively. IL6R to LRP1 and to SORT1 had values for the coefficient of determination (r2) of 3.9% and 2.2%, respectively. Conclusions: In the investigated study population, the SNPs CDKN2BAS rs10757278, LPA rs3798220, SORT1 rs599839, DAB2IP rs7025486, and IL6R rs2228145 were associated with the development of abdominal aortic aneurysms. Individuals with risk factors for atherosclerosis and/or a family history of AAA should be evaluated using genetic analysis.

9p21 Locus Polymorphism Is A Strong Predictor of Metabolic Syndrome and Cardiometabolic Risk Phenotypes Regardless of Coronary Heart Disease

The world population is genetically predisposed to metabolic syndrome (MetS) and its components, also known as cardiometabolic risk phenotypes, which can cause severe health complications including coronary heart disease (CHD). Genetic variants in the 9p21 locus have been associated with CHD in a number of populations including Pakistan. However, the role of the 9p21 locus in MetS and cardiometabolic risk phenotypes (such as obesity, hypertension, hyperglycemia, and dyslipidemia) in populations with CHD or no established CHD has not been explored. Therefore, the present study was designed to explore the association of the minor/risk allele (C) of 9p21 locus SNP rs1333049 with MetS or its risk phenotypes regardless of an established CHD, in Pakistani subjects. Genotyping of rs1333049 (G/C) was performed on subjects under a case-control study design; healthy controls and cases, MetS with CHD (MetS-CHD⁺) and MetS with no CHD (MetS-CHD^-), respectively. Genotype and allele frequencies were calculated in all study groups. Anthropometric and clinical variables (Means ± SD) were compared among study groups (i.e., controls, MetS + CHD and MetS-CHD) and minor/risk C allele carriers (GC + CC) vs. non-carriers (Normal GG genotype). Associations of the risk allele of rs1333049 SNP with disease and individual metabolic risk components were explored using adjusted multivariate logistic regression models (OR at 95% CI) with a threshold p-value of ≤0.05. Our results have shown that the minor allele frequency (MAF) was significantly high in the MAF cases (combined = 0.63, MetS-CHD⁺ = 0.57 and MetS-CHD^- = 0.57) compared with controls (MAF = 0.39). The rs1333049 SNP significantly increased the risk of MetS, irrespective of CHD (MetS-CHD⁺ OR = 2.36, p < 0.05 and MetS-CHD^- OR = 4.04, p < 0.05), and cardiometabolic risk phenotypes; general obesity, central obesity, hypertension, and dyslipidemia (OR = 1.56-3.25, p < 0.05) except hyperglycemia, which lacked any significant association (OR = 0.19, p = 0.29) in the present study group. The 9p21 genetic locus/rs1333049 SNP is strongly associated with, and can be a genetic predictor of, MetS and cardiometabolic risks, irrespective of cardiovascular diseases in the Pakistani population.

Dietary patterns interact with chromosome 9p21 rs1333048 polymorphism on the risk of obesity and cardiovascular risk factors in apparently healthy Tehrani adults

PURPOSE

Gene-dietary patterns may contribute to determining body composition and related biochemical indices. The aim of this study was to evaluate interactions between rs1333048 polymorphism and major dietary patterns on body fat percentage, general and central obesity, and related biochemical measurements.

METHODS

This cross-sectional study was conducted on 265 healthy Tehrani adults with mean age of 35 years (47.5% men, 52.5% women). Dietary patterns (DPs) were extracted by factor analysis. Bioelectrical impedance analysis was used for body analysis and rs1333048 was genotyped by the restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

Three DPs were extracted: restricted refined grains DP, legumes DP and healthy DP. AA genotype compared to CC genotype had greater odds for general obesity before (OR 3.14; 95% CI 1.008-9.60, P = 0.045) and after (OR 3.11; 95% CI 1.008-9.60, P = 0.048) adjusting for potential confounders. Individuals with AA genotype were more likely to be centrally obese before (OR 2.09; 95% CI 1.006-4.35, P = 0.048) and after (OR 2.63; 95% CI 1.12-6.17, P = 0.026) controlling for potential confounders. Significant interactions were observed between Legumes DP and rs1333048 SNP on waist circumference (P = 0.047), body fat % (BFP) (P = 0.048), hs-Crp (P = 0.042), BMI (P = 0.073), WHtR (P = 0.063) and odds for general obesity (P = 0.051). Following this DP reduced all these items for individuals with CC genotype, whereas increased them for people who carry CA or AA genotypes.

CONCLUSIONS

The findings indicate that there are significant associations between AA genotype of rs1333048 SNP and general and central obesity, and significant interaction between alleles of this SNP and major dietary patterns on the odds of general obesity, BFP, waist circumference, BMI, WHtR and hs-Crp.

The role of CDKN2B in cardiovascular risk in ethnic Saudi Arabs: A validation study

BACKGROUND

Genome-wide association studies (GWASs) have yielded a wealth of information furnishing support for the variability in genetic predisposition to disease. However, the actual impact of such findings on any particular ethnic population needs to be validated through replication studies. In the present study, we verified recent findings of a GWAS demonstrating a strong association for the cyclin-dependent kinase 4 inhibitor B (CDKN2B) genomic region with coronary artery disease (CAD)/myocardial infarction (MI) in ethnic Saudi Arabs.

METHODOLOGY

We genotyped 8 CDKN2B SNPs for cardiovascular risk in 4650 Saudi Arabs, comprising 2429 CAD cases (1860 males; 569 female) and 2221 controls (1189 male; 1032 female) by Taqman assay.

RESULTS

Four SNPs, rs4977574_A [0.56(0.50-0.63); p < 0.0001], rs10757274_A [0.87(0.77-0.97); p = 0.014], rs10738607_A [0.89(0.80-1.00); p = 0.043] and rs1333045_T [0.54(0.48-0.61); p < 0.0001] residing on the CDKN2B gene were significantly associated with CAD following multivariate adjustments for MI, HTN and DM, while four others were weakly associated with the disease. Likewise, three SNPs, rs1412829_G [0.84(0.72-0.97); p = 0.019], rs564398_C [0.81(0.70-0.94); p = 0.006], rs4977756_G [0.87(0.76-0.99); p = 0.036] were significantly associated with MI after multivariate adjustments for CAD, HTN and DM, while the other five displayed borderline associations.

CONCLUSIONS

Our findings strongly support the notion of a critical role for the CDKN2B gene locus as a cardiovascular risk in ethnic Arabs. The study also demonstrates the importance of replication studies in ascertaining the role of a genomic sequence in disease.

Polymorphisms in the long non-coding RNA CDKN2B-AS1 may contribute to higher systolic blood pressure levels in hypertensive patients

OBJECTIVES

Hypertension (HT) is a complex disorder influenced by both genetic and environmental factors. Recent genome-wide association studies have identified a major risk locus for atherosclerosis on chromosome 9p21.3. SNPs within the coding sequences of CDKN2A/B and the long non-coding RNA CDKN2B-AS1 could potentially contribute to HT development. Thus, this study aimed to investigate whether the frequency of four SNPs on chromosome 9p21.3 affects blood pressure (BP) levels in Turkish HT patients, and to examine correlations between these SNPs, specific SNP haplotypes, and HT.

DESIGN AND METHODS

This is a case-control study comparing HT patients and healthy controls. Real-time polymerase chain reaction (RT-PCR) analysis was utilized to detect SNPs rs10757274, rs2383207, rs10757278, and rs1333049 in 170 HT patients and 180 healthy controls.

RESULTS

Each SNP was detected at significantly higher frequencies in HT patients than in controls (p values 0.001); however, there was no significant link between rs10757274, rs2383207, rs10757278, and rs1333049 SNPs and HT grades. Furthermore, there was a significant association between elevated systolic BP levels and rs1333049 GG genotype (p=0.047), while weight gain and increased fasting glucose levels were significantly associated with rs2383207 AA genotype (p=0.020 and p=0.009, respectively). Lastly, we detected a correlation between GG, GA, and AG haplotypes in block 1 (rs10757274, rs2383207) and GC and AG haplotypes in block 2 (rs10757278, rs1333049) and HT.

CONCLUSIONS

Our findings suggest that SNPs rs10757274, rs2383207, rs10757278, and rs1333049, particularly those within the CDKN2B-AS1 gene, and related haplotypes may confer increased susceptibility to HT development.

A genome-wide association study reveals susceptibility loci for myocardial infarction/coronary artery disease in Saudi Arabs

BACKGROUND

Multiple loci have been identified for coronary artery disease (CAD) by genome-wide association studies (GWAS), but no such studies on CAD incidence has been reported yet for any Middle Eastern population.

METHODS

In this study, we performed a GWAS for CAD and myocardial infarction (MI) incidence in 5668 Saudis of Arab descent using the Affymetrix Axiom Genotyping platform.

RESULTS

We describe SNPs at 16 loci that showed significant (P < 5 × 10(-8)) or suggestive GWAS association (P < 1 × 10(-5)) with CAD or MI, in the ethnic Saudi Arab population. Among the four variants reaching GWAS significance in the present study, the rs10738607_G [0.78(0.71-0.85); p = 2.17E-08] in CDNK2A/B gene was associated with CAD. Two other SNPs on the same gene, rs10757274_G [0.79(0.73-0.86); p = 2.98E-08] and rs1333045_C [0.79(0.73-0.86); p = 1.15E-08] as well as the rs9982601_T [1.38(1.23-1.55); p = 3.49E-08] on KCNE2 were associated with MI. These variants have been previously described in other populations. Several SNPs, including the rs7421388 (PLCL1) and rs12541758 (TRPA1) displaying a suggestive GWAS association (P < 1 × 10(-5)) with CAD as well as rs41411047 (RNF13), rs32793 (PDZD2) and rs4739066 (YTHDF3), similarly showing weak association with MI, were confirmed in an independent dataset. Furthermore, our estimation of heritability of CAD and MI based on observed genome-wide sharing in unrelated Saudi Arabs was approximately 33% and 44%, respectively.

CONCLUSIONS

Our study has identified susceptibility variants for CAD/MI in ethnic Arabs. These findings provide further insights into pathways contributing to the susceptibility for CAD and will enable more comprehensive genetic studies of these diseases in Middle East populations.

Evaluation of association between common genetic variants on chromosome 9p21 and coronary artery disease in Turkish population

Objective:

Coronary artery disease (CAD), which develops from complex interactions between genetic and enviromental factors, is a leading cause of death worldwide. Based on genome-wide association studies (GWAS), the chromosomal region 9p21 has been identified as the most relevant locus presenting a strong association with CAD in different populations. The aim of the present study was to investigate the association of two SNPs on chromosome 9p21 on susceptibility to CAD and the effect of these SNPs along with cardiovascular risk factors on the severity of CAD in the Turkish population.

Methods:

This study had an observational case-control design. We genotyped 460 subjects, aged 30-65 years, to investigate the association of 2 SNPs (rs1333049, rs2383207) on chromosome 9p21 and CAD risk in Turkish population. Real-time polymerase chain reaction (RT-PCR) was used to analyze the 2 SNPs in CAD patients and healthy controls. The genotype and allelic variations of these SNPs with the severity of CAD was also assessed using semi-quantitative methods such as the Gensini score. Student’s t test and multiple regression analysis were used for statistical analysis.

Results:

The SNPs rs1333049 and rs2383207 were found to be associated with CAD with an adjusted OR of 1.81 (95% Cl 1.05-3.12) and 2.12 (95% CI 1.19-4.10) respectively. After adjustment of CAD risk factors such as smoking, family history of CAD and diabetes, the homozygous AA genotype for rs2383207 increased the CAD risk with an OR 3.69. Also a very strong association was found between rs1333049 and rs2383207 and Gensini scores representing the severity of CAD (p<0.001).

Conclusion:

The rs2383207 and rs1333049 SNPs on 9p21 chromosome were significantly associated with the risk and severity of CAD in the Turkish population.

Association of polymorphisms on chromosome 9p21.3 region with increased susceptibility of abdominal aortic aneurysm in a Chinese Han population

OBJECTIVE

Several studies have reported that polymorphisms on chromosome 9p21.3, near the CDKN2A/2B gene, are strongly associated with increased susceptibility to abdominal aortic aneurysm (AAA). However, no convincing data has been reported on a relationship between AAA and these variants in the Chinese Han population. The aim of this study was to evaluate the role of rs10757278 and rs1333049 in determining genetic susceptibility to AAA.

METHODS

A total of 155 AAA patients and 310 controls, comparable in age and gender, were enrolled in this study. DNA samples were genotyped for rs10757278 and rs1333049 using the MassArray system. The association between these two single nucleotide polymorphisms and AAAs was tested using multivariate logistic regression. Stratified analysis was also performed by clinical and laboratory features.

RESULTS

Single nucleotide polymorphisms rs10757278 and rs1333049 were significantly associated with increased risk of AAA. The frequencies of rs10757278-G and rs1333049-C in AAA patients were significantly higher than in control subjects (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.11-2.11; P = .01, and OR, 1.48; 95% CI, 1.07-2.05; P = .02). Multiple logistic regression analysis indicated that, after adjusting for smoking habits, drinking habits, and histories of other chronic diseases, homozygosity of the risk allele for rs10758278-G and rs1333049-C also increased the likelihood of AAA (OR, 2.31; 95% CI, 1.22-4.36, and OR, 2.14; 95% CI, 1.13-4.05). The frequency of the GC haplotype was significantly higher in AAA patients than in control subjects (OR, 1.44; P = .038). Stratification analysis of clinical and laboratory features revealed no association between polymorphisms and aortic diameters in AAA patients. There was a significantly high frequency of the rs10757278 GG genotype in AAA patients with high serum total homocysteine compared with those control subjects with high serum total homocysteine (OR, 2.71; 95% CI, 1.12-6.58; P = .03) indicating that the genotype GG of rs10757278 might interact with the homocysteine biological pathway to stimulate the presence of AAA.

CONCLUSIONS

Present data demonstrate that rs10757278 and rs1333049 on chromosome 9p21.3 are significantly associated with increased risk of AAA in the Chinese population and emphasize the need to further study the role of these markers in AAA.

Effects of Pro12Ala polymorphism in peroxisome proliferator-activated receptor-γ2 gene on metabolic syndrome risk: a meta-analysis

BACKGROUND

Associations between peroxisome proliferator-activated receptor γ2 (PPARγ2) gene polymorphism and metabolic syndrome risk remained controversial and ambiguous. Thus, we performed a meta-analysis to assess the association between Pro12Ala polymorphism in PPARγ2 gene and metabolic syndrome susceptibility.

METHODS

An electronic literature search was conducted on Medline, OVID, Cochrane Library database, and the China National Knowledge Internet up to March 2013. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the strength of association in the fixed or random effects model.

RESULTS

Ten studies involving a total of 4456 cases and 10343 controls were included in this meta-analysis. No statistical evidence of association was found between Pro12Ala polymorphism and metabolic syndrome risk in all genetic models (homozygote model: OR=0.83, 95% CI=0.62-1.12; heterozygote model: OR=1.04, 95% CI=0.94-1.14; dominant model: OR=1.02, 95% CI=0.93-1.12; recessive model: OR=0.83, 95% CI=0.62-1.11). No statistical evidence of significant association was observed when stratified by ethnicity, definition of metabolic syndrome, source of control groups and quality score of the selected articles. All in all, the results did not support a major role of the Pro12Ala variant of the PPARγ2 gene in metabolic syndrome risk.

CONCLUSIONS

This meta-analysis suggested that the effect of Pro12Ala polymorphism in PPARγ2 gene may not be related to metabolic syndrome as an entity. However, Pro12Ala may affect the single component of metabolic syndrome. A large, well designed study is required to more adequately assess the role for Pro12Ala polymorphism on metabolic syndrome.

Endothelin Type A Receptor Genotype is a Determinant of Quantitative Traits of Metabolic Syndrome in Asian Hypertensive Families: A SAPPHIRe Study

Co-heritability of hypertension and insulin resistance (IR) within families not only implies genetic susceptibility may be responsible for these complex traits but also suggests a rational that biological candidate genes for hypertension may serve as markers for features of the metabolic syndrome (MetS). Thus we determined whether the T323C polymorphism (rs5333) of endothelin type A (ETA) receptor, a predominant receptor evoking potent vasoconstrictive action of endothelin-1, contributes to susceptibility to IR-associated hypertension in 1694 subjects of Chinese and Japanese origins. Blood pressures (BPs) and biochemistries were measured. Fasting insulin level, insulin-resistance homeostasis model assessment (HOMAIR) score, and area under curve of insulin concentration (AUCINS) were selected for assessing insulin sensitivity. Genotypes were obtained by methods of polymerase chain reaction-restriction fragment length polymorphism. Foremost findings were that minor allele frequency of the T323C polymorphism was noticeable lower in our overall Asian subjects compared to multi-national population reported in gene database; moreover both the genotypic and allelic frequencies of the polymorphism were significantly different between the two ethnic groups we studied. The genotype distributions at TT/TC/CC were 65, 31, 4% in Chinese and 51, 41, 8% in Japanese, respectively (p < 0.0001). Additionally, carriers of the C homozygote revealed characteristics of IR, namely significantly higher levels of fasting insulin, HOMAIR score, and AUCINS at 29.3, 35.3, and 39.3%, respectively, when compared to their counterparts with TT/TC genotypes in Chinese. Meanwhile, the CC genotype was associated with a higher level of high density lipoprotein cholesterol in Japanese. No association of the polymorphism with BP was observed. This study demonstrated for the first time that T323C polymorphism of ETA receptor gene was associated with an adverse insulin response in Chinese and a favorite atherogenic index in Japanese.