The molecular basis of coronary artery disease (CAD) has been widely studied in the western world but there is no published work on the Malaysian population. This study looked at the global gene expression profiling of the peripheral blood of patients with CAD from the 3 main ethnic groups in Malaysia. Male subjects selected were based on angiographically confirmed CAD (≥50% stenosis) and normal control subjects (0% stenosis) with age range of 55.6±5.3 and 51.0±5.5 years, respectively. The global gene expression of 12 angiographically documented CAD patients and 11 matched control subjects were performed. The combined group samples identified 6 up regulated differential expression (DE) genes (GHRL, LTA, CBS, HP, ITGA2B, and OLR1) and 12 down regulated DE genes (IL18R1, ITGA2B, IL18RAP, HP, OLR1, SOD2 ITGB3, IL1B, MMP9, PLA2G7, UTS2, and CBS) to be involved in CAD at the fold change of 1.3 with fault discovery rate (FDR) of 1%. Three genes, MMP9, IL1B, and SOD2 were down regulated in all the 3 ethnic groups making them potential biomarker candidates for CAD across all three ethnicities. Further verification in a cohort study is needed.
Factor VII (FVII) is an independent risk factor for coronary artery disease. Three polymorphisms of the factor VII gene (F7) were studied in a group of healthy newborns comprising 561 Chinese, 398 Malays and 226 Asian Indians from Singapore. The allele frequencies of 3 polymorphisms (R353Q, Promoter 0/10bp Del/Ins and Intron 7) in the FVII gene were ascertained through genotyping by polymerase chain reaction and restriction digestion of amplified fragments. In Chinese the minor allele frequencies are Q: 0.04, Ins: 0.03, R7: 0.44; Malays, Q: 0.06, Ins: 0.10, R7: 0.41; and Indians, Q: 0.25, Ins: 0.23, R7: 0.43. Strong linkage disequilibrium (Delta > 0.7) is observed between the 0/10 bp and the R353Q sites in all ethnic groups. We conclude that: (i) the prevalence of the minor Q and Ins alleles of the R353Q and 0/10 bp polymorphisms are significantly higher in the Indian newborns than the Chinese and Malays; (ii) the Q allele is significantly associated (p = 0.01) with a lower plasma FVII coagulant level in the Indian and Malay neonates; and this polymorphism explains up to 3.8% of the variance in FVII coagulant levels; (iii) there is no significant difference in allele frequencies of the three polymorphisms between neonates with and without family histories of CAD.
A recent genome wide association study in the Chinese population has implicated rs6903956 within the ADTRP gene on chromosome 6p24.1 as a novel susceptibility locus for coronary artery disease (CAD). In this study, we evaluated the association of rs6903956 with CAD in the different ethnic groups of Singaporean population comprising Chinese, Malays and Asian Indians.
Genetic variants of cholesteryl ester transfer protein (CETP) and endothelial nitric oxide synthase (eNOS) influence high-density lipoprotein cholesterol (HDL-C) metabolism and nitric oxide (NO) synthesis, respectively, and might increase the risk of coronary artery disease (CAD). This study is to investigate the relationship between genetic polymorphisms and the risk of CAD and to evaluate their potential interactions. A total of 237 patients with CAD and 101 controls were genotyped. The association of the polymorphism with the risk of CAD varied among the ethnic groups. Moreover, the concomitant presence of both CETP B1 and eNOS 4a alleles significantly increased the risk of CAD in the Malay group (OR = 33.8, P < .001) and the Indian group (OR = 10.9, P = .031) but not in the Chinese group. This study has identified a novel ethnic-specific gene-gene interaction and suggested that the combination of CETP B1 allele and eNOS 4a allele significantly increases the risk of CAD in Malays and Indians.
Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. Although 58 genomic regions have been associated with CAD thus far, most of the heritability is unexplained, indicating that additional susceptibility loci await identification. An efficient discovery strategy may be larger-scale evaluation of promising associations suggested by genome-wide association studies (GWAS). Hence, we genotyped 56,309 participants using a targeted gene array derived from earlier GWAS results and performed meta-analysis of results with 194,427 participants previously genotyped, totaling 88,192 CAD cases and 162,544 controls. We identified 25 new SNP-CAD associations (P < 5 × 10-8, in fixed-effects meta-analysis) from 15 genomic regions, including SNPs in or near genes involved in cellular adhesion, leukocyte migration and atherosclerosis (PECAM1, rs1867624), coagulation and inflammation (PROCR, rs867186 (p.Ser219Gly)) and vascular smooth muscle cell differentiation (LMOD1, rs2820315). Correlation of these regions with cell-type-specific gene expression and plasma protein levels sheds light on potential disease mechanisms.
Methylenetetrahydrofolate reductase (MTHFR) C677T is involved in folate and homocysteine metabolism. Disruption in the activity of this enzyme will alter their levels in the body.
Identifying susceptible genes associated with the pathogenesis of atherosclerosis (ATH) may contribute toward better management of this condition. This preliminary study was aimed at assessing the expression levels of 11 candidate genes, namely tumor protein (TP53), transforming growth factor, beta receptor II (TGFBR2), cysthathionenine-beta-synthase (CBS), insulin receptor substrate 1 (IRS1), lipoprotein lipase (LPL), methylenetetrahydrofolate reductase (MTHFR), thrombomodulin (THBD), lecithin-cholesterol acyltransferase (LCAT), matrix metallopeptidase 9 (MMP9), low density lipoprotein receptor (LDLR), and arachidonate 5-lipoxygenase-activating protein (ALOX5AP) genes associated with ATH. Twelve human coronary artery tissues (HCATs) were obtained from deceased subjects who underwent post-mortem procedures. Six atherosclerotic coronary artery tissue (ACAT) samples representing the cases and non-atherosclerotic coronary artery tissue (NCAT) samples as controls were gathered based on predetermined inclusion and exclusion criteria. Gene expression levels were assessed using the GenomeLab Genetic Analysis System (GeXP). The results showed that LDLR, TP53, and MMP9 expression levels were significantly increased in ACAT compared to NCAT samples (p < 0.05). Thus, LDLR, TP53, and MMP9 genes may play important roles in the development of ATH in a Malaysian study population.
This study investigated the renin-angiotensin-aldosterone system (RAAS) gene polymorphisms as possible genetic risk factors for the restenosis development in patients with drug-eluting stents. 113 participants had coronary artery disease and underwent stenting. The control group consisted of 62 individuals with intact coronary arteries. Patients were divided into two groups: with in-stent restenosis (ISR) and without it. The patients with ISR were classified into subgroups by the terms of the restenosis development and age. Real-time PCR and Restriction Fragment Length Polymorphism-PCR were used to genotype the study participants for RAAS gene polymorphisms. We found that the development of restenosis is generally associated with the minor A allele for renin (REN) rs2368564 and the major TT genotype for angiotensinogen (AGT) rs699. The heterozygous genotype for AGT rs4762 acts as a protective marker. A minor A allele for angiotensin II type 2 receptor (AGTR2) rs1403543 is associated with a risk of restenosis in people under 65 years old. Among patients with the early ISR, heterozygotes for angiotensin II type 1 receptor (AGTR1) rs5186 are more frequent, as well as A allele carriers for AGTR2 rs1403543. A minor homozygous genotype for REN rs41317140 and heterozygous genotype for aldosterone synthase (CYP11B2) rs1799998 are predisposed to the late restenosis. Thus, to choose the effective treatment tactics for patients with coronary artery disease, it is necessary to genotype patients for the RAAS polymorphisms, which, along with age and clinical characteristics, will allow a comprehensive assessment of the risk of the restenosis development after stenting.