Association of epistatic effects of MTHFR, ACE, APOB, and APOE gene polymorphisms with the risk of myocardial infarction and unstable angina in Egyptian patients

Despite remarkable discoveries in the genetic susceptibility of coronary artery disease (CAD), a large part of heritability awaits identification. Epistasis or gene-gene interaction has a profound influence on CAD and might contribute to its missed genetic variability; however, this impact was largely unexplored. Here, we appraised the associations of gene-gene interactions and haplotypes of five polymorphisms, namely methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, angiotensin converting enzyme (ACE) insertion/deletion (I/D), apolipoprotein B (APOB) R3500Q, and apolipoprotein E (APOE) ε4 with the risk of myocardial infarction (MI) and unstable angina (UA). Gene-environment interactions with traditional risk factors and clinical data were also scrutinized. This study recruited 100 MI, 50 UA patients, and 100 apparently healthy controls. Logistic regression models were employed in association analyses. We remarked that the single locus effect of individual polymorphisms was relatively weak; however, a magnified effect of their combination via gene-gene interaction may predict MI risk after adjustment for multiple comparisons. Only MTHFR C677T, ACE I/D, and APOB R5300Q were associated with the risk of UA, and the ACE I/D-R3500Q interaction posed a decreased UA risk. APOB R3500Q was in strong linkage disequilibrium with MTHFR C677T, ACE I/D, and APE ε4 polymorphisms. The TCDGε3, CADGε4, and TADGε4-C677T-A1298C-ACE I/D-R3500Q-APOE haplotypes were associated with escalating MI risk, while the CDG or CIG-C677T-ACE I/D-R3500Q haplotype was highly protective against UA risk compared to controls. Interestingly, the CADGε4 and CAIGε3 haplotypes were strongly associated with the presence of diabetes and hypertension, respectively in MI patients; both haplotypes stratified patients according to the ECHO results. In UA, the CDG haplotype was negatively associated with the presence of diabetes or dilated heart. Conclusively, our results advocate that a stronger combined effect of polymorphisms in MTHFR, ACE, APOB, and APOE genes via gene-gene and gene-environment interactions might help in risk stratification of MI and UA patients.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in Egyptian children with systemic lupus erythematosus: a possible relation to proliferative nephritis

Introduction Angiotensin-converting enzyme (ACE) is crucial in the pathogenesis of systemic lupus erythematosus through angiotensin II which regulates vascular tone and endothelial functions. Objectives To study the frequency of ACE insertion/deletion (I/D) gene polymorphism in Egyptian children with systemic lupus erythematosus and its possible relation to the renal pathology in cases with lupus nephritis. Subjects and methods The frequency of ACE gene insertion/deletion polymorphism genotypes was determined in 78 Egyptian children with systemic lupus erythematosus and compared to a matched group of 140 healthy controls using polymerase chain reaction. Results The DD genotype of the ACE gene was higher in systemic lupus erythematosus patients when compared to controls ( P<0.0001; odds ratio (OR) 2.4; 95% confidence interval (CI) 1.7-3.3) and the D allele was more frequent than the I allele in systemic lupus erythematosus patients in comparison to controls ( P < 0.0001; OR = 2.2; 95% CI = (1.6-3.1). In the lupus nephritis group, the DD genotype was significantly higher in those with proliferative lupus nephritis when compared to those with non-proliferative lupus nephritis ( P = 0.02; OR = 1.45; 95% CI = 1.4-1.6). Also, patients with proliferative lupus nephritis showed a higher frequency of the D allele ( P < 0.001; OR = 1.98; 95% CI = 1.3-2.9). Conclusion The D allele and DD genotype of the ACE gene appear to be a risk factor for the susceptibility of systemic lupus erythematosus and occurrence of proliferative nephritis in Egyptian children.

Prevalence of angiotensin converting enzyme (ACE) gene insertion/deletion polymorphism in South Indian population with hypertension and chronic kidney disease

Context:

Chronic Kidney Disease (CKD) is associated with a high risk of developing further severe complications such as, cardiovascular disease and eventually End Stage Renal Disease (ESRD) leading to death. Hypertension plays a key role in the progression of renal failure and is also a chief risk factor for the occurrence of End Stage Renal Disease (ESRD).

Aim:

This study investigates the possible association of insertion (I) and deletion (D) polymorphism of ACE gene in patients of Chronic Kidney Disease (CKD) with and without hypertension (HT).

Settings and Design:

Total 120 participants with 30 members in each group (Control, HT, CKD and CKD-HT) were chosen followed by informed consent.

Materials and Methods:

Blood samples were collected and subjected to biochemical analyses and nested PCR amplification was performed to genotype the DNA, for ACE I/D using specific primers.

Statistical Analysis:

Statistical analyses were performed using SPSS version 13. Allele and genotypic frequency was calculated by direct gene counting method. Comparison of the different genotypes was done by using Chi square test. Odd's ratios were calculated with a 95% confidence interval limit.

Results:

The ACE genotype were distributed as II, 27 (90%); DD, 2 (6.67%) and ID, 1 (3.33%) in control, II, 1 (3.33%); DD, 5 (16.67%) and ID, 24 (80%) in HT, II, 4 (13.33%); DD, 24 (80%) and ID, 2 (6.67%) in CKD and II, 0 (0%); DD, 2 (6.67%) and ID, 28 (93.33%) in CKD-HT group.

Conclusions:

D allele of ACE gene confers a greater role in genetic variations underlying CKD and hypertension. This result suggest that CKD patients should be offered analysis for defects in ACE I/D polymorphisms, especially if they are hypertensive.

The influence of angiotensin converting enzyme and bradykinin receptor B2 gene variants on voluntary fluid intake and fluid balance in healthy men during moderate-intensity exercise in the heat

Angiotensin converting enzyme (ACE) and bradykinin receptor B2 (B2R) genetic variation may affect thirst because of effects on angiotensin II production and bradykinin activity, respectively. To examine this, 45 healthy Caucasian men completed 60 min of cycle exercise at 62% ± 5% peak oxygen uptake in a room heated to 30.5 ± 0.3 °C with ad libitum fluid intake. Blood samples were collected pre-, mid-, and immediately post-cycle. Fluid intake, body mass loss (BML), sweat loss (determined via changes in body mass and fluid intake), and thirst sensation were recorded. All participants were genotyped for the ACE insert fragment (I) and the B2R insert sequence (P). Participants were homozygous for the wild-type allele (WW or MM), heterozygous (WI or MP) or homozygous for the insert (II or PP). No differences between genotype groups were found in mean (±SD) voluntary fluid intake (WW: 613 ± 388, WI: 753 ± 385, II: 862 ± 421 mL, p = 0.31; MM: 599 ± 322, MP: 745 ± 374, PP: 870 ± 459 mL, p = 0.20), percentage BML or any other fluid balance variables for both the ACE and B2R genes, respectively. Mean thirst perception in the B2R PP group, however, was higher (p < 0.05) than both MM and MP at 30, 45, and 60 min. In conclusion, the results of this study suggest that voluntary fluid intake and fluid balance in healthy men performing 60 min of moderate-intensity exercise in the heat are not predominantly influenced by ACE or B2R genetic variation.

Gender specificity of a genetic variant of angiotensin-converting enzyme and risk of coronary artery disease

Etiological factors for coronary artery disease (CAD) involve a wide range of gene and environmental interactions. One of the systems being implicated in the pathophysiology of CAD is the renin-angiotensin system (RAS). However, the genetic polymorphisms of this system have not been widely studied in Iranian patients diagnosed with CAD. The aim of this study was to assess the relationship between six gene polymorphisms of RAS components and CAD in a sample of Iranian population. A total of 374 participants were enrolled in a case/control study. The presence of CAD was determined by coronary angiography. Genotyping of six RAS gene polymorphisms was performed using a modified PCR-RFLP method. Our results revealed, for the first time, a significant independent association of angiotensin-converting enzyme (ACE) A-240T polymorphism and incidence of CAD among Iranian women (P=0.005, OR=20.4, 95% CI=2.49-41.2). There has also been a significant difference in genotype distribution of ACE A-240T (P=0.008) and angiotensin II receptor type 2 C3123A polymorphism (P=0.032) in Iranian female participants. In conclusion, TT genotype of ACE A-240T seems to be a genetic risk factor for CAD in Iranian women.

Angiotensin-converting enzyme insertion/deletion polymorphism and risk of myocardial infarction in an updated meta-analysis based on 34993 participants

The association between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and risk of myocardial infarction (MI) has been extensively studied. However, the results were in controversy. This study aimed to explore the association between ACE I/D polymorphism and risk of MI by using a meta-analysis. We retrieved the following databases to indentify eligible studies: Medline, Embase, ISI, VIP, CBM and Wan Fang database. The latest update was 10th May, 2012. Odds ratio and 95% confidence interval (95% CI) were used to present the strength of the association. A total of 40 case-control studies with 34993 participants were included. Overall, D allele of ACE I/D polymorphism was significantly associated with an increased risk of MI in genetic comparison models (OR (95% CI): 1.41 (1.22-1.64) for DD vs. II; 1.11 (1.01-1.21) for ID vs. II; 1.23 (1.10-1.37) for D carriers vs. II; 1.28 (1.15-1.43) for DD vs. I carriers and 1.06 (1.02-1.10) for D carriers vs. I carriers). Subgroup analyses, according to ethnicities and countries of participants also indicated that D allele was significantly associated with an increased risk of MI in Asians (especially for Chinese) and Caucasians (especially for English, French, Germans and Italians) (OR (95% CI) of DD vs. ID+II: 2.11 (1.65-2.70) for Asians and 1.15 (1.05-1.27) for Caucasians). In conclusion, this meta-analysis indicated that D allele of ACE I/D polymorphism was a possible risk factor for MI incidence for both Asians and Caucasians.

Meta-analysis of the relationship between ACE I/D gene polymorphism and end-stage renal disease in patients with diabetic nephropathy

AIMS

  Diabetic nephropathy (DN) is the major cause for end-stage renal disease (ESRD) and the pathogenesis for DN developing into ESRD is not clear at present. Results from published studies on the relationship between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and ESRD risk in DN patients are still conflicting. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and ESRD risk in DN patients.

METHODS

  Association studies were identified from the databases of PubMed, Embase and Cochrane Library on 1 October 2011, and eligible investigations were identified and synthesized using the meta-analysis method. Results were expressed using odds ratios (OR) for dichotomous data and 95% confidence intervals (CI) were also calculated.

RESULTS

  Twelve studies reporting the relation between ACE I/D gene polymorphism and ESRD risk in DN patients were identified. In overall populations, there was a notable association between D allele or DD genotype and ESRD susceptibility (D: OR = 1.32, 95% CI: 1.11-1.56, P = 0.002; DD: OR = 1.67, 95% CI: 1.25-2.21, P = 0.0004). In the sub-group analysis according to ethnicity, D allele or DD genotype was associated with ESRD risk in Asians. In Caucasians, the association of DD genotype with ESRD risk was observed, but the D allele was not. Furthermore, ACE I/D gene polymorphism was associated with ESRD risk in patients with DN due to diabetes mellitus type 2, but the association was not found for patients with DN due to diabetes mellitus type-1.

CONCLUSIONS

  Our results indicate that D allele or DD homozygous is associated with the ESRD susceptibility in DN patients. However, more investigations are required to further this association.

Relationship between angiotensin-converting enzyme insertion/deletion gene polymorphism and systemic lupus erythematosus/lupus nephritis: a systematic review and metaanalysis

OBJECTIVE

Results from studies of the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and systemic lupus erythematosus (SLE)/lupus nephritis (LN) are controversial. We performed this metaanalysis to evaluate the relationship between ACE I/D gene polymorphism and SLE/LN and to explore whether the ACE D allele or DD genotype could become a predictive marker for risk of SLE/LN.

METHODS

Association studies were identified from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database) as of May 1, 2011, and eligible investigations were synthesized using a metaanalysis method. Results were expressed with OR for dichotomous data, and 95% CI were calculated.

RESULTS

Sixteen investigations were identified for the analysis of association between ACE I/D gene polymorphism and SLE, consisting of 1959 patients with SLE and 2078 controls. In the overall populations, there was a marked association between D allele or DD genotype and SLE susceptibility (D: OR 1.29, 95% CI 1.04-1.58, p = 0.02; DD: OR 1.60, 95% CI 1.17-2.19, p = 0.003), and DD homozygous was associated with LN risk (OR 2.78, 95% CI 1.26-6.11, p = 0.01). In the subgroup analysis, DD genotype associated with SLE risk was observed in Asians; no other association was found in Asians, whites, Africans, and Brazilians.

CONCLUSION

D allele and DD homozygous are significant genetic molecular markers to predict SLE susceptibility, and DD genotype is a valuable marker to predict the LN risk. More investigations are required to clarify the association of the D allele or DD homozygous with SLE/LN susceptibility.

A meta-analysis of the association between angiotensin-converting enzyme insertion/deletion gene polymorphism and steroid-sensitive nephrotic syndrome in children

BACKGROUND AND OBJECTIVE

Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism correlates with circulating and cellular ACE concentration. Association between ACE I/D gene polymorphism and steroid-sensitive nephrotic syndrome (SSNS) risk in children is still controversial. This meta-analysis was performed to evaluate the relation between ACE I/D gene polymorphism and SSNS susceptibility in children.

METHODS

The relevant investigations were screened from the search engines of PubMed, Cochrane Library and CBM-disc (China Biological Medicine Database) as of 1 March 2011, and eligible studies were synthesized using meta-analysis methods.

RESULTS

Ten studies were identified for the analysis of association between ACE I/D gene polymorphism and SSNS risk in children, including seven in Asians, one for Caucasians and two in Africans. There was no markedly positive association between D allele or DD genotype and SSNS susceptibility in Asians, Caucasians and Africans (D: Asians OR = 1.24, p = 0.28; Caucasians OR = 1.61, p = 0.15; Africans OR = 1.61, p = 0.53; DD: Asians OR = 1.72, p = 0.15; Caucasians OR = 1.39, p = 0.48; Africans OR = 1.80, p = 0.56). Furthermore, II homozygous seemed not to play a protective role against SSNS onset for Asians, Caucasians and Africans (Asians OR = 0.95, p = 0.85; Caucasians OR = 0.30, p = 0.11; Africans OR = 0.60, p = 0.65).

CONCLUSIONS

There was no association between ACE I/D gene polymorphism and SSNS susceptibility in Asians, Caucasians and Africans. However, the conclusions for Caucasians and Africans were less powerful.

Genetic polymorphism of ACE and the angiotensin II type1 receptor genes in children with chronic kidney disease

AIM AND METHODS

We investigated the association between polymorphisms of the angiotensin converting enzyme-1 (ACE-1) and angiotensin II type one receptor (AT1RA1166C) genes and the causation of renal disease in 76 advanced chronic kidney disease (CKD) pediatric patients undergoing maintenance hemodialysis (MHD) or conservative treatment (CT). Serum ACE activity and creatine kinase-MB fraction (CK-MB) were measured in all groups. Left ventricular mass index (LVMI) was calculated according to echocardiographic measurements. Seventy healthy controls were also genotyped.

RESULTS

The differences of D allele and DI genotype of ACE were found significant between MHD group and the controls (p = 0.0001). ACE-activity and LVMI were higher in MHD, while CK-MB was higher in CT patients than in all other groups. The combined genotype DD v/s ID+II comparison validated that DD genotype was a high risk genotype for hypertension .~89% of the DD CKD patients were found hypertensive in comparison to ~ 61% of patients of non DD genotype(p = 0.02). The MHD group showed an increased frequency of the C allele and CC genotype of the AT1RA1166C polymorphism (P = 0.0001). On multiple linear regression analysis, C-allele was independently associated with hypertension (P = 0.04).

CONCLUSION

ACE DD and AT1R A/C genotypes implicated possible roles in the hypertensive state and in renal damage among children with ESRD. This result might be useful in planning therapeutic strategies for individual patients.

ACE I/D gene polymorphism can't predict the steroid responsiveness in Asian children with idiopathic nephrotic syndrome: a meta-analysis

Background

The results from the published studies on the association between angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and the treatment response to steroid in Asian children with idiopathic nephrotic syndrome (INS) is still conflicting. This meta-analysis was performed to evaluate the relation between ACE I/D gene polymorphism and treatment response to steroid in Asian children and to explore whether ACE D allele or DD genotype could become a predictive marker for steroid responsiveness.

Methodology/Principal Findings

Association studies were identified from the databases of PubMed, Embase, Cochrane Library and CBM-disc (China Biological Medicine Database) as of September 1, 2010, and eligible investigations were synthesized using meta-analysis method. Five investigations were identified for the analysis of association between ACE I/D gene polymorphism and steroid-resistant nephrotic syndrome (SRNS) risk in Asian children and seven studies were included to explore the relationship between ACE I/D gene polymorphism and steroid-sensitive nephrotic syndrome (SSNS) susceptibility. Five investigations were recruited to explore the difference of ACE I/D gene distribution between SRNS and SSNS. There was no a markedly association between D allele or DD genotype and SRNS susceptibility or SSNS risk, and the gene distribution differences of ACE between SRNS and SSNS were not statistically significant. II genotype might play a positive role against SRNS onset but not for SSNS (OR = 0.51, P = 0.02; OR = 0.95, P = 0.85; respectively), however, the result for the association of II genotype with SRNS risk was not stable.

Conclusions/Significance

Our results indicate that D allele or DD homozygous can't become a significant genetic molecular marker to predict the treatment response to steroid in Asian children with INS.