The I allele of the angiotensin converting enzyme I/D polymorphism confers protection against coronary artery disease

Genetic variations of renin-angiotensin and fibrinolytic systems and susceptibility to coronary artery disease: a population genetics perspective

BACKGROUND

Genetic predisposition is an important risk factor in coronary artery disease (CAD).This study was conducted to determine the polymorphism frequencies of the plasminogen activator inhibitor-1(PAI-1) gene 4G/5G, angiotensin-converting enzyme (ACE) gene I/D, and angiotensin II type 1 receptor (AT1) gene A1166C genotypes and to examine the role of these polymorphisms in CAD.

METHODS

Genomic DNAs obtained from 260 subjects (130 CAD patients and 130 control) were used in the study. ACE I/D and PAI-1 4G/5G polymorphism genotypes were determined using polymerase chain reaction (PCR) and electrophoresis. AT-1 A1166C polymorphism was determined using the PCR, restriction fragment length polymorphism (RFLP) and electrophoresis. The products amplified from AT1 gene by PCR were cut with HindIII restriction endonuclease and then analyzed by 2% agarose gel electrophoresis. The results were statistically analyzed with the chi-square test, Mann-Whitney U test, and independent two-sample t-test.

RESULTS

Allele frequencies showed statistically significant differences between the patient and control groups. There was no statistically significant difference in ACEI/D genotype frequencies between the twogroups. Likewise, no statistically significant difference was found in the AT1 A1166C genotype frequencies; however, a statistically significant difference was found in allele frequencies. The PAI-1 4G/5G genotype frequency was significantly higher in the patient group.

CONCLUSIONS

While there is a relationship between of PAI-1 gene 4G/5G polymorphism and CAD, ACE gene I/D and AT1 gene A1166C polymorphisms are not related. PAI-1 gene homozygous genotypes may be considered as a prognostic marker for CAD patients.

The Effect of ACE I/D Polymorphisms Alone and With Concomitant Risk Factors on Coronary Artery Disease

BACKGROUND

Coronary artery disease (CAD), also known as atherosclerotic heart disease, is a leading cause of mortality and morbidity throughout the world. The role of insertion/deletion (I/D) polymorphisms of the angiotensin-converting enzyme (ACE) gene in the etiology of CAD remains to be more completely clarified. The aim of this study was to determine the role of the ACE I/D polymorphism in patients with CAD and to study the association together with traditional risk factors in assessing the risk of CAD.

METHODS

Our study population included 145 Tunisian patients with symptomatic CAD and a control group of 300 people matched for age and sex. All participants in the study were genotyped for the ACE I/D polymorphisms obtained by polymerase chain reaction amplification on genomic DNA.

RESULTS

Our analysis showed that the ACE D allele frequency ( P < 10^-3; odds ratio [OR] = 5.2; 95% confidence interval [CI] = 3.6-7.6) and DD genotype ( P < 10^-3; OR = 6.8; 95% CI = 4.4-10) are significantly more prevalent among patients with CAD than in controls and may be predisposing to CAD. We further found that the risk of CAD is greatly potentiated by several concomitant risk factors (smoking, diabetes, hypertension, dyslipidemia, and a family history of CAD).

CONCLUSION

The ACE D allele may be predictive in individuals who may be at risk of developing CAD. Further investigations of these polymorphisms and their possible synergisms with traditional risk factors for CAD could help to ascertain better predictability for CAD susceptibility.

The frequency of 4 common gene polymorphisms in nonagenarians, centenarians, and average life span individuals

Single nucleotide polymorphisms of angiotensin-converting enzyme (ACE) such as rs1799752, nuclear factor kappa B (NFkB) such as rs28362491 and cholesteryl ester transport protein (CETP) such as rs708272 (TaqB1) and rs5882 (I405V) were evaluated in nonagenarians, centenarians, and average life span individuals (controls). The study population (n = 307; 190 nonagenarians, 12 centenarians and 105 middle-aged controls) was genotyped for ACE, NFkB, and CETP genetic variants. The age of nonagenarian and centenarian group ranged between 90 and 111 years; centenarians and controls age ranged from 99 to 111, and from 18 to 80 years, respectively. The I carriers of ACE I/D gene were fewer in nonagenarians compared to centenarians (37.6% vs 62.5%, P = .016). The I carriers of ACE gene were more frequent in centenarians compared to controls (62% vs 41%, P = .045). No differences in frequency of common NFkB and CETP genotypes between patients with exceptional longevity and middle-aged patients were observed.

The relationship between three well-characterized polymorphisms of the angiotensin converting enzyme gene and lung cancer risk: a case-control study and a meta-analysis

BACKGROUND AND OBJECTIVE

The gene encoding angiotensin converting enzyme (ACE) is a promising candidate for lung cancer. We aimed to assess three well-characterized polymorphisms of the ACE gene (A-240T, I/D, A2350G) and lung cancer in Chinese people, and complete a meta-analysis of the association of I/D polymorphism with lung cancer.

METHODS AND RESULTS

In our case-control study, a total of 684 patients with lung cancer and 602 age-matched controls were recruited. Genotyping was performed using polymerase chain reaction (PCR) and ligase detection reactions (LDR) techniques. Single-locus analysis indicated that carriers of the A-240T allele had a significantly increased risk for lung cancer under additive (odds ratio (OR)=1.2; 95% confidence interval (CI): 1.02-1.42; P=0.027) and recessive (OR=1.8; 95% CI: 1.24-2.63; P=0.002) models, and that DD genotype carriers were 1.97 times more likely to develop lung cancer (95% CI: 1.25-3.11; P=0.004) compared with those with the I allele under the recessive model. However, no significance was observed in further haplotype analysis (P>0.05). In a meta-analysis of ACE gene insertion-deletion (I/D) polymorphism from six studies with 1183 lung cancer patients and 1065 controls, we failed to detect any significant association (overall OR=1.09; 95% CI: 0.84-1.41). A low probability of publication bias was observed.

CONCLUSIONS

Our results suggest that ACE gene A-240T polymorphism might be a genetic marker for the development of lung cancer in Chinese people.