Variations in angiotensin-converting enzyme gene insertion/deletion polymorphism in Indian populations of different ethnic origins

ACE Gene I/D Polymorphism and Cardiometabolic Risk Factors: A Cross Sectional Study of Rural Population

The D allele has been identified as being linked to cardiovascular disease since the discovery of an insertion/deletion (I/D) polymorphism in the ACE gene, this polymorphism has been found to have significant associations with a variety of cardiovascular risk factors. Recent findings indicate a rising prevalence of metabolic disorders among rural populations in developing nations. Research on health matters has been predominantly focused on urban populations, with relatively less attention given to their rural counterparts Hence, the present study attempts to estimate the prevalence of ACE gene I/D polymorphism and explore its association with various cardiovascular risk factors among Rural Yadav population from India. In the present study, 207 (Male 47, Female 160) members of the Yadav community participated in the cross-sectional study. All the socio-demographic factors, somatometric (anthropometric) variables, and the intravenous blood was collected and Physiological (blood pressure), and biochemical (fasting glucose and lipid profile) parameters were measured as recommended by the American Heart Association, allele-specific PCR of the ACE gene I/D polymorphism was carried out, the PCR products were genotyped on 2% agarose gel Electrophoresis and ACE gene polymorphism was analysed for its association with various cardiovascular risk factors. Among the analysed individuals, 34 (16.4%) were found to have the II genotype, 58 (28.0%) had the ID genotype, and 115 (55.6%) had the DD genotype. The allele frequency of the I allele was found to be 0.31, and the frequency of the D allele was 0.69. The frequency of the DD genotype was found to be significantly higher among individuals with high TC, high TG, and low non-HDL levels (p value < 0.05). When considered collectively, the findings of this study are consistent with the hypothesis that the DD genotype of ACE polymorphism represents a correlation with cardiovascular disease risk factors in this population.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in patients with laryngeal cancer

Objectives

The aim of this study was to compare the distribution of the angiotensin-converting enzyme (ACE) I/D polymorphism between patients with laryngeal cancer (LC) and a control group and to examine the distribution of this polymorphism with clinical parameters related to LC.

Methods

We enrolled 44 LC patients and 61 healthy controls. The ACE I/D polymorphism was genotyped with the PCR-RFLP method. The distribution of ACE genotypes (II, ID, and DD) and alleles (I or D) was evaluated with Pearson's chi-square test, and logistic regression analysis was performed for statistically significant parameters.

Results

There was no significant difference in ACE genotypes and alleles between LC patients and controls (p = 0.079 and p = 0.068, respectively). Among clinical parameters related to LC (extension of tumour, node metastasis, tumour stage and tumour location), only the presence of node metastasis was found to be significant in terms of ACE DD genotype (p = 0.137, p = 0.031, p = 0.147, p = 0.321 respectively). In the logistic regression analysis, the ACE DD genotype was increased 8.3 fold in nodal metastases.

Conclusions

The findings of the study suggest that ACE genotypes and alleles do not affect the prevalence of LC, but the DD genotype of ACE polymorphism may increase the risk of lymph node metastasis in LC patients.

Angiotensin-converting enzyme gene insertion/deletion polymorphism and hypertension disease

Background: The renin-angiotensin system (RAS), which is important for controlling haemostasis in the body, can increase the development of essential hypertension (HTN). Various surveys have shown that ACE I/D polymorphism that influences ACE activity, a key component of RAS, has been known to be associated with the risk of HTN. The goal of this study was to investigate the correlation between ACE (I/D) polymorphism and HTN.Methods: Blood samples were obtained from 102 patients and 104 healthy individuals. The two groups were matched by age and sex. Informed consent was prepared for the study. The demographic data were collected using a questionnaire. White blood cells (WBCs) and then DNA were extracted from whole blood. After this, the PCR test was performed using specific primers. PCR products were examined using 1% agarose gel. Individuals with genotype II having a band of 490 bp, ID two band of 490 bp and 190 bp, and individuals with DD genotype, have a band in region 190 bp.Results: The average age of the patients was 52.7 ± 7.5 years. A significant difference was seen in the distribution of DD, II and I/D genotypes of ACE polymorphism between the essential hypertensive patients (44.1, 10.8, and 45.1%) and their ethnically matched healthy control (61.5, 3.8, and 24.6%, respectively). Our study showed an increased risk of disease in people with II genotype in comparison to ID and DD genotypes (0.46 (0.1-1.75) and 0.26 (0.05-0.94), respectively).Conclusions: The present study demonstrated that ACEI/D polymorphism is characterised with greater risk of essential HTN in the Lorestan province. II genotype increased the relative risk of essential HTN in the population. In the future, more investigations with more samples size are recommended for the better study of genetic factors in hypertensive patients.

Angiotensin-converting Enzyme Insertion/Deletion Polymorphism (rs4646994) and Susceptibility to Acute Lymphoblastic Leukemia: A Case–control Study

BACKGROUND: Angiotensin-converting enzyme (ACE) stimulates the proliferation of bone marrow hematopoietic progenitors and thought to be involved in pathological neoplastic hematopoiesis and leukemogenesis. AIM: This study aimed to investigate the association between ACE gene I/D polymorphism and the risk of acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: A total of 96 subjects were recruited for the study, 48 patients with ALL, and 48 apparently healthy volunteers as a control group. Genomic DNA was extracted from peripheral leukocytes and ACE I/D polymorphism was analysed using allele-specific polymerase chain reaction. RESULTS: In both study groups, the ACE D/D polymorphic genotype was the most frequent (52.1% and 54.2%, respectively), followed by the ID genotype (47.9% and 45.8% respectively), while the II genotype was completely absent in both study groups. The distribution of the polymorphic genotypes among the study groups was not significantly different (p = 0. 0.398). The frequency of the D allele was 0.76 in the patients and 0.77 in the control group, while the frequency of I allele was 0.24 in the patients and 0.23 in the control group. No deviation from Hardy–Weinberg equilibrium was observed (χ2 = 4.24, df = 1, p = 0.12). CONCLUSION: ACE I/D polymorphism is not associated with susceptibility to ALL among the Sudanese population.

Angiotensin-Converting Enzyme Gene Polymorphism Influences Gastrointestinal Motility in Type 2 Diabetes Mellitus

Uncontrolled diabetes mellitus may affect any part of the gastrointestinal tract (GIT) and impact negatively the quality of life. Angiotensin-converting enzyme (ACE) gene polymorphism can have direct effect on circulating level of ACE which further modifies the degradation of substance P and thus may influence the gut motility. Hence, it could be hypothesised that ACE gene polymorphism would influence the gut motility. An observational analytical study was conducted at PGIMER, Chandigarh. 300 Type2 diabetes mellitus (T2DM) and 200 age and sex matched healthy individuals were enrolled. After taking written consent, 5 ml blood sample was collected for measurement of substance P by ELISA method and for ACE gene polymorphism (insertion[I]/deletion[D]) by polymerase chain reaction. Orocecal transit time (OCTT) was measured using non-invasive lactulose breath test. Out of 300 diabetic patients, 32.7%, 44% and 23.3% belonged to II, ID and DD genotypes, respectively. The frequency of D allele (OR = 1.39) and DD genotype (OR = 2.17) was significantly higher in patients than in controls and was associated with increased risk. Moreover, more number of diabetes patients with constipation (90%) belonged to DD genotype and their OCTT was significantly delayed (166.7 ± 7.3 min) as compared to ID (143.5 ± 4.2 min) or II (121.8 ± 4.9 min) genotype. From this study, it could be concluded that ACE gene polymorphism could be an important contributing factor to influence the gut motility and thus giving rise to the GI symptoms for T2DM patients.

Link between ACE I/D Gene Polymorphism and Dyslipidemia in Diabetic Nephropathy: A Case-control Study from Hyderabad, India

Introduction:

Diabetic nephropathy (DN) is the commonest single cause of end-stage renal failure, and dyslipidemia is a critical risk factor in the occurrence of DN. In the light of recent reports emphasizing the importance of angiotensin I-converting enzyme (ACE) in the modulation of plasma lipids, we sought to evaluate the influence of ACE I/D gene polymorphism with dyslipidemia status among type 2 diabetic (T2D) patients with and without nephropathy in the genetic predisposition and the progression to DN.

Method:

This study comprised of 600 subjects, which include patients with DN, T2D, and healthy controls (HC). Polymerase chain reaction based genotyping of ACE I/D polymorphism was performed and appropriate statistical analysis was done.

Results:

Out of the 600 subjects, 20 (10%) of the HC, 73 (36.5%) of the T2D group, and 125 (62.5%) of the DN subjects had dyslipidemia. The D allele (0.62) and DD (42.5) genotype frequencies were higher in the DN group in comparison with T2D and HC (P < 0.05). The genotypes also varied among patients with dyslipidemia (χ² 5.04; P < 0.05) but not in the non-dyslipidemia group. Under the co-dominant model, DD genotype conferred a risk of 1.26 (P < 0.001) toward DN, whereas the ID genotype offered protection from DN among the dyslipidemic subjects (OR = 0.05; P < 0.01). In addition, genotype-dependent difference was seen in the plasma lipid levels among study groups. A multiple logistic regression analysis revealed male gender, BMI, HbA1c, TG, HDL, and ACE DD genotype as independent risk factors for the development of DN.

Conclusion:

The study showed a significant predisposing association of ACE DD genotype with DN and protective effect of ID genotype on DN in the dyslipidemia subgroup.

Angiotensin Converting Enzyme Gene Insertion/Deletion Polymorphism Is Not Responsible for Antihypertensive Therapy Induced New Onset of Type 2 Diabetes in Essential Hypertension

Background:

Antihypertensive drug therapies have been reported to be associated with new onset of type 2 diabetes mellitus in some hypertensive patients after prolonged use. Angiotensin converting enzyme (ACE) gene has been found to affect essential hypertension, response of antihypertensive therapies, and glycemic disturbances. Therefore, ACE gene I/D polymorphism may be associated with risk of new onset of type 2 diabetes via metabolic disturbances, glycemic dysregulation, and insulin resistance.

Aim:

To assess the correlation between ACE gene I/D polymorphism and glycemic disturbance under influence of diuretic and other antihypertensive drug therapies.

Materials and methods:

We recruited 270 normotensive patients as control (150 men and 120 women), 270 hypertensive patients (95 men and 175 women), and 240 hypertensive with new onset of diabetes patients (80 men and 160 women). All samples were genotyped for ACE gene polymorphic alleles and relationship between different genotypes and anthropometric and clinical parameters along with drug therapies was established and analyzed.

Results:

Baseline clinical (systolic blood pressure, diastolic blood pressure, and fasting blood glucose level) and anthropometric parameters (height, weight, waist circumference, hip circumference, waist-hip ratio, and body mass index) of study populations were found highly statistically significant (P < .05) when compared among study groups. Furthermore, genotype wise comparison of all these parameters in essential hypertensive (EH) and essential hypertensive with onset of diabetes (EHNOD) patients found most of them nonsignificant and no variation was found with respect to different genotypes of ACE gene. The genotype wise comparison of clinical parameters among different antihypertensive drug therapy was found statistically nonsignificant in both EH and EHNOD patients.

Discussion:

Anthropometric parameters can be taken as the risk indicator factors for hypertension and diabetes. However, ACE gene polymorphism may not be a risk factor for development of diabetes in hypertensive patients.

Conclusion:

The present study suggested that ACE gene polymorphism did not show any significant association with the risk of new onset of diabetes in EH patients and more detailed studies with large population size are needed.

Association of Angiotensin-Converting Enzyme Gene Polymorphisms and Nephropathy in Diabetic Patients at a Tertiary Care Centre in South India

Background:

Genetic polymorphisms of the angiotensin-renin pathway have been thought to influence the development of diabetic nephropathy. However, there are conflicting results regarding this association in previous studies on populations with varying ethnicity.

Aims:

Primary aim was to compare the frequency of distribution of angiotensin-converting enzyme (ACE) gene (insertion/deletion [I/D]) polymorphism in Tamilian Indian type 2 diabetic individuals with and without microalbuminuria. Secondary objective was to compare the frequency of distribution of the 3 genotypes in diabetic patients with urinary albumin/creatinine ratio (ACR) < 30 mg/dL, urinary ACR = 30 to 300 mg/dL, and urinary ACR > 300 mg/dL.

Methods:

A total of 179 consecutive diabetic individuals between 40 and 70 years, from Puducherry and Tamilnadu of Dravidian descent participated in the study conducted from 2012 to 2014. Inclusion criteria were as follows: age ≥ 40 years and duration of type 2 diabetes mellitus for ≥5 years. Patients were divided into 2 groups based on ACR values. Group 1 consisted of 50 individuals with urinary ACR < 30 mg/g of creatinine, and group 2 consisted of 129 individuals with urinary ACR > 30 mg/g. Angiotensin I–converting enzyme (ACE) gene polymorphism was determined by allele-specific polymerase chain reaction method using a primer pair flanking the polymorphic region of its intron 16. Furthermore, group 2 patients were subdivided into those with urinary ACR = 30 to 300 mg/g of creatinine and those with urinary ACR > 300 mg/g of creatinine, and distribution of ACE gene polymorphism was compared in the three groups.

Statistics:

Statistical analysis was done using SPSS version 17.0. Independent Student t test was used to compare mean values between the 2 groups. Odds ratio was calculated for testing association between ACE gene (I/D) polymorphism and presence of microalbuminuria. P < .05 was considered significant. Comparison of ACE genotypes among 3 groups of patients (ACR < 30 mg/g, ACR = 30-300 mg/g, and ACR > 300 mg/g) was done using 1-way analysis of variance with Bonferroni multiple comparison test as post hoc analysis.

Conclusions:

Heterozygous I/D genotype was more frequent in the study population (45.8%) than the other genotypes. There was no difference in the genotype distribution in patients with varying levels of albuminuria.

Beneficial role of D allele in controlling ACE levels: a study among Brahmins of north India

India being a country with vast diversity is expected to have different dietary and life style patterns which in turn may lead to population-specific environmental risk factors. Further, the interaction of these risk factors with the genetic makeup of population makes it either susceptible or resistant to cardiovascular disease. One such candidate gene is angiotensin converting enzyme (ACE) for various cardiovascular mechanisms. ACE is the key enzyme of the renin angiotensin aldosterone system pathway which maintains homeostasis blood pressure in the body and any variation in the levels is reported to be associated with various complex diseases. The DD genotype is found to increase ACE levels, which is associated with cardiovascular diseases and decrease in ACE levels are associated with kidney diseases. The aim of this study was to understand the distribution of ACE I/D polymorphism and ACE levels among Brahmins of National Capital Region (NCR) north India, with respect to age and sex ratio distribution. In this study, 136 subjects of which 50 males and 86 females, who were unrelated up to first cousin, aged 25 to70 years were studied. ACE gene was found to be polymorphic with high frequency of heterozygote (ID) followed by II and DD genotypes. The studied population was found to be in Hardy-Weinberg equilibrium with respect to ACE I/D polymorphism (P = 0.55). I allele frequency was found to be higher (0.560) than the D allele (0.44). The median level of ACE was found to be 65.96 ng/mL (48.12-86.24) which is towards lower side of the normal range. ACE levels were found to be increased among individual having either of the homozygotes that is II or DD and higher frequency of heterozygote (ID) is indicative of advantage in the population by maintaining lower ACE levels. The limitation of the present study is low sample size, however, the merit is that the subjects belonged to a Mendalian population with a common gene pool.

Insertion/Insertion Genotype of Angiotensin I-Converting-Enzyme Gene Predicts Risk of Myocardial Infarction in North East India

Myocardial infarction (MI) is common in India and the disease occurs at a relatively younger age. We wanted to look for association of Angiotensin I-converting enzyme (ACE) gene with MI in North East India. We also wanted to examine possible environmental interaction of ACE gene with established cardiovascular risk factors in causation of MI. In the study carried out in Assam Medical College, 200 consecutive confirmed cases of MI were recruited. Equal numbers of age- and sex-matched control subjects from hospital workers and patients attending the hospital for diseases unrelated to cardiovascular disease were enrolled. Structured questionnaires were used to note demographic and clinical factors. Cardiovascular risk factors were determined from history, physical examination and biochemical investigations. ACE insertion/deletion (I/D) polymorphism was determined by PCR method. Interaction of ACE gene with other risk factors was noted. The study identified ACE II genotype (odds ratio = 3.02; 95% CI 1.40-6.51), smoking, hypertension, diabetes and serum triglyceride > 150 mg/dl as independent risk factors for MI. ACE II genotype showed greater risk in non-smokers, non-hypertensives, non-diabetics and in subjects with LDL-C < 130 mg/dl. Low HDL cholesterol enhanced the genetic risk. Subjects with ACE II genotype have an independent risk of developing MI, specially in low cardiovascular risk subjects.

Association of angiotensin converting enzyme gene insertion/deletion polymorphism and familial hypercholesterolemia in the Saudi population

BACKGROUND

The study of the association between genotype and phenotype is of great importance for the prediction of multiple diseases and pathophysiological conditions. The relationship between angiotensin converting enzyme (ACE) Insertion/Deletion (I/D) polymorphism and Familial Hypercholesterolemia (FH) has been not fully investigated in all the ethnicities. In this study we sought to determine the frequency of I/D polymorphism genotypes of ACE gene in Saudi patients with FH.

RESULTS

This is a case-control study carried out purely in Saudi population. Genomic DNA was isolated from 128 subjects who have participated in this study. ACE gene I/D polymorphism was analyzed by polymerase chain reaction in 64 FH cases and 64 healthy controls. There was no statistically significant difference between the groups with respect to genotype distribution. Furthermore, we did not find any significant difference in the frequency of ACE I/D polymorphism in FH subjects when stratified by gender (p = 0.43).

CONCLUSION

Our data suggest that ACE gene I/D polymorphism examined in this study has no role in predicting the occurrence and diagnosis of FH.

Role of the ACE ID and PPARG P12A Polymorphisms in Genetic Susceptibility of Diabetic Nephropathy in a South Indian Population

BACKGROUND

Diabetic nephropathy (DN) is one of the life-threatening disorders characterized by persistent albuminuria, raised arterial blood pressure, a lowered glomerular filtration rate, and high risk of cardiovascular morbidity and mortality. The vascular genes ACE (Angiotensin-converting enzyme), and PPARG (peroxisome proliferator activated receptor gamma) are involved in alterations in vascular endothelium, and are suggested to play a role in the susceptibility of diabetic nephropathy.

OBJECTIVES

The aim of our study was to find out the role of ACE ID and PPARG P12A polymorphisms in genetic susceptibility of diabetic nephropathy in south Indian population.

PATIENTS AND METHODS

A total of 54 cases with diabetic nephropathy and 67 control subjects with diabetes were enrolled for our study. DNA was isolated from peripheral blood leucocytes, and genotyped using PCR-electrophoresis (ACE ID) or PCR-RFLP (PPARG P12A) methods.

RESULTS

ACE ID genotypes followed Hardy-Weinberg equilibrium in both cases and controls. But P12A genotypes deviated from Hardy-Weinberg equilibrium in diabetic controls. Chi(2) test was applied for the analysis of genotypic distributions in genotypic and dominant models. Odds ratios were also calculated. No significant differences in genotype frequencies of ACE ID and PPARG P12A polymorphisms were found on comparing patients with diabetic nephropathy with diabetic controls. The synergistic role of ACE ID* PPARG P12A interaction, did not show any association in patients with diabetic nephropathy when compared to diabetic controls.

CONCLUSIONS

In conclusion, the ACE and PPARG genes do not have a key role in conferring risk for diabetic nephropathy.

Angiotensin-converting enzyme (ACE) gene II genotype protects against the development of diabetic peripheral neuropathy in type 2 diabetes mellitus

BACKGROUND

  Diabetic peripheral neuropathy (DPN) is one of the complications of type 2 diabetes mellitus (T2DM) that decreases the quality of life of T2DM patients. Very few studies have found an association between the development and progression of DPN in T2DM and angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphisms.

METHODS

  Using gene-specific primers in a polymerase chain reaction, the presence of ACE I/D polymorphisms was screened for in 276 T2DM patients with DPN, 496 T2DM patients without DPN, and 331 control (non-diabetic) subjects.

RESULTS

  The distribution of the I/D genotypes was in Hardy-Weinberg equilibrium. The II genotype was significantly more prevalent in T2DM patients without DPN than the DD genotype (P < 0.05); however, there was no significant difference in the prevalence of the II and DD genotypes in T2DM patients with DPN (P = 0.78).

CONCLUSION

  The II genotype of the ACE gene has a protective effect against the development of DPN in T2DM patients. This suggests a role for the renin-angiotensin system in modulating neuropathy in T2DM.

Polymorphism of ACE gene as the genetic predisposition of coronary artery disease in Eastern India

AIM

A case control study was designed to assess whether the prevalence of ACE gene polymorphism has any role in the development of CAD.

METHODS

The study included unrelated 217 cases with CAD and 255 healthy controls. PCR was done using primers followed by agarose gel electrophoresis for study of different ACE gene polymorphisms. Multiple logistic regression analysis was carried out to find association between studied genotypes and lifestyle as well as biochemical risk factors.

RESULTS

Both DD [OR: 2.16; 95%CI: (60.60-67.40)] and ID [OR: 1.48; 95%CI: (93.28-97.72)] genotypes of the ACE gene showed significant associations in the development of CAD. Coexistence of diabetes and hypertension found to be risk modifier of the disease. Tobacco intake in various forms elevates the risk of the disease among the cases with risk genotypes.

CONCLUSION

ID and DD genotypes of ACE gene came out to be predisposing factors for the CAD cases in our study population.

Molecular analysis of genetic variation in angiotensin I-converting enzyme identifies no association with sporting ability: First report from Indian population

INTRODUCTION:

A polymorphism in the angiotensin-converting enzyme (ACE) gene was the first performance enhancing polymorphisms (PEPs) to be identified and correlated with athletic abilities. This polymorphism (rs. 5186) is the absence (deletion; D allele), rather than the presence (insertion, I allele) of 287bp Alu repeat element in intron 16. However, the association of ACE I/D polymorphism in sports abilities have been contradicted and debated. No study has evaluated the ACE gene polymorphism in Indian athletes so far. Hence, the genotype distribution and allelic frequency of ACE gene in selected Indian athletic and non-athletic population was studied.

MATERIALS AND METHODS:

A total of 147 athletes and 131 controls were genotyped for the ACE gene polymorphism using PCR.

RESULTS:

No significant association was observed between the allelic frequencies of ACE gene in controls and athletes on a whole, as well as after sub-categorizing the athletes based on the type of sport they played (P > 0.1). However, a higher representation of I allele was observed in the athletes.

CONCLUSION:

ACE genotyping studies need to focus on truly elite athletes of a single sporting discipline, to be able to find an association. The ACE I/D polymorphism may not be considered a marker for human performance, but can be further studied in combination with other potent performance enhancing polymorphisms.

Preeclampsia in North Indian women: the contribution of genetic polymorphisms

AIM

To find association of angiotensin-converting enzyme (ACE) insertion/deletion (I/D), angiotensinogen (AGT) T704C, methylenetetrahydrofolate reductase (MTHFR) C677T and factor V Leiden (FVL) G1691A polymorphisms with pre-eclampsia (PE) in North Indian women.

MATERIAL & METHODS

In this prospective case-control study, genotyping of 200 pre-eclamptic women and 200 normotensive pregnant controls was performed for the ACE I/D, AGT T/C,MTHFR C/T and FVL G/A polymorphisms. Statistical analysis was carried out using SPSS and Epi Info to estimate their association with PE. The association of these polymorphisms with nonsevere PE and severe PE was separately assessed.

RESULTS

The FVL mutation was found in 4% of women and increased the risk of PE twofold (odds ratio [OR] 2.08, P-value 0.03). The MTHFR mutant allele was found to be protective (OR 0.59, P-value 0.01). Both these polymorphisms showed similar association with nonsevere PE (OR 2.149, P-value 0.038 and OR 0.565, P-value 0.222, respectively) but not with severe PE. The ACE I/D and AGT T/C polymorphisms were not found to be associated with PE overall (OR 1.26, P-value 0.11 and OR 1.15, P-value 0.35, respectively), but ACE I/D polymorphism was found to increase the risk of severe PE (OR 1.53, P-value 0.019).

CONCLUSION

FVL mutation is more common in North Indians than previously believed and it predisposes the women to PE. MTHFR mutant allele is paradoxically protective. ACE polymorphism appears to predispose to severe PE but not nonsevere PE. No significant contribution of AGT polymorphism to PE is found.

Association of angiotensin-converting enzyme gene insertion/deletion polymorphism with high-altitude pulmonary oedema: a meta-analysis

Background and objective: High-altitude pulmonary oedema (HAPE) is a non-cardiogenic hydrostatic oedema involving a genetic component. Considering the low incidence of HAPE, sample sizes in current reports are relatively limited. We aimed to assess the association between the angiotensin-converting enzyme (ACE) I/D polymorphism and HAPE via a meta-analysis of published and unpublished data.

Materials and methods: We searched PubMed, CBM, CNKI, and Cochrane Library Database before 20 November 2010. A random-effects model was applied (STATA) and study quality was assessed in duplicate.

Results: A total of five studies including 305 cases and 662 controls were meta-analysed. The summary odds ratio (OR) indicated that no significant differences in risk of developing HAPE were found between carriers of ACE D and I alleles (OR = 1.20; 95% confidence interval (CI), 0.98–1.48; p = 0.084). Lack of association persisted for genotypes under the recessive mode. However, genotype association under the dominant mode showed D allele carriers significantly conferred a 1.55-fold increased HAPE risk compared with II genotype carriers (95% CI, 1.15–2.08; p = 0.004). Funnel plot and Egger’s test suggested no evidence of publication bias.

Conclusions: Our results supported the notion that ACE D allele carriers were at significant increased risk of developing HAPE.

Angiotensin-converting enzyme gene polymorphism in hypertensive rural population of Haryana, India

BACKGROUND

Essential hypertension is a complex genetic disorder influenced by diverse environmental factors. Of the various physiological pathways affecting the homeostasis of blood pressure, the renin-angiotensin system (RAS) is known to play a critical role. Angiotensin-I converting enzyme (ACE) is a significant component of RAS and an insertion/deletion (I/D) polymorphism in its gene has been implicated in predisposition to hypertension.

OBJECTIVE

The present study is aimed to determine the association, if any, of ACE I/D polymorphism with essential hypertension in a rural population of Haryana, India.

MATERIALS AND METHODS

The blood samples were collected from the patients visiting M. M. Institute of Medical Sciences, Mullana, Haryana. DNA from the patients (106) and control (110) specimens were isolated, amplified by PCR and analyzed employing agarose gel electrophoresis.

RESULTS

There was no significant difference in the distribution of DD, II and I/D genotypes of ACE polymorphism in essential hypertensive patients (28.8, 25.5, and 46.2%) and their ethnically matched normal control (24.5, 30, and 45.5), respectively. The two groups also presented with very similar allelic frequencies and were also found to be in Hardy-Weinberg equilibrium.

CONCLUSIONS

The present study demonstrates that ACE I/D polymorphism is not a risk factor for essential hypertension in the hitherto unstudied rural population of Haryana.

Association of the insertion/deletion polymorphism of the angiotensin-converting enzyme gene with type 2 diabetes in two ethnic groups of Jerba Island in Tunisia

Introduction.The aim of the current study was to evaluate the role of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism on the prediction of type 2 diabetes in two ethnic populations from Jerba Island,Tunisia.

Methods. In this study, we analysed the genotypic and the allelic distributions of the ACE I/D polymorphism and conducted a case/control association study between healthy normoglycaemic controls and diabetic patients in the two studied groups.ACE gene polymorphism was analysed by polymerase chain reaction in 272 individuals consisting of 172 diabetic subjects and 100 controls.

Results.The genotype frequencies for DD, ID and II were 75.50%, 19.60% and 4.89% inArabs and 76.66%, 16.66% and 6.67% in Berbers, respectively, in the case group, and 42.85%, 35.71% and 21.43% inArabs and 57.50%, 22.50% and 20.00% in Berbers, respectively, in the control group.The DD frequency was significantly higher in the case group than in the control group (p<0.001), suggesting that the DD genotype is associated with an increased susceptibility to type 2 diabetes in our study populations.

Conclusions.The current investigation provides new evidence regarding the role of the ACE I/D polymorphism in the pathogenesis of type 2 diabetes in Jerbian populations. Furthermore, it underlines the importance of ethnicity, which should be considered in all studies aiming to test the genetic effects on the susceptibility to type 2 diabetes.

Relationship of angiotensin-converting enzyme gene polymorphism with nephropathy associated with Type 2 diabetes mellitus in Asian Indians

OBJECTIVE

Diabetic nephropathy (DN) has become the leading cause of end-stage renal disease, but the pathogenesis of this condition is not exactly understood. Several studies from different parts of the world have examined angiotensin-converting enzyme (ACE) gene polymorphism as a candidate for DN. Two studies yielding controversial results have been reported from India. To rule out this discrepancy, we carried out a hospital-based study on a cohort from our population to determine whether ACE gene polymorphism is associated with DN.

RESEARCH DESIGN AND METHODS

ACE gene polymorphism was analyzed by polymerase chain reaction in 460 individuals consisting of 174 cases of DN, 175 cases of Type 2 diabetes mellitus (DM), and 111 controls. The DN cases included in the study were Type 2 DM cases with serum creatinine >1.5 mg/dl and serum albumin >30 mg/dl in a 24-h urine sample.

RESULTS

ACE insertion/deletion genotyping analysis showed DD genotype in 22.75% of DN cases, 15.42% of Type 2 DM cases, and 21.62% of controls. Chi-square test between the DN group and the control group did not show a significant difference in D allele. However, the difference was significant at P<.05 between the DN group and the DM group. The odds ratio was 2.0953 (95% confidence interval=1.35-3.2522), indicating a significant association of DD genotype and D allele with DN.

CONCLUSION

Our data enable us to conclude that Asian Indians with D allele and Type 2 DM are at greater risk for developing DN.

Association of APOE (Hha1) and ACE (I/D) gene polymorphisms with type 2 diabetes mellitus in North West India

Familial and epidemiological studies have shown that genetic factors play a role in the development and progression of type 2 diabetes mellitus (T2DM). Asian Indians have shown an increasing prevalence of T2DM. Apolipoprotein E (APOE) and Angiotensin-1 converting enzyme (ACE) I/D polymorphisms have been associated with T2DM. This study examined the association of APOE and ACE genes with T2DM patients of Punjab, India. APOE (HhaI) and ACE (I/D) genotypes analysed by polymerase chain reaction were available from 90 patients and 97 random healthy controls. All loci and populations are in Hardy-Weinberg equilibrium. There is no significant association of APOE vis-à-vis T2DM, however APOE*4 allele frequency is low in diabetics (3.9% and 8.8%). DD genotype and *D allele of ACE are associated with T2DM (OR=1.90, p<0.05, and OR=1.58, p<0.05, respectively). Recessive and multiplicative mode of inheritance for *D allele provided the strongest support for the association. Height, weight and BMI did not reveal any significant association with APO or ACE. DD-33 and ID-23 combinations (ACE-APOE) showed higher odds of 2.01 and 2.14, respectively. ACE but not APOE polymorphism is positively associated with T2DM in Indian population, however, the synergistic effects of DD-33 and ID-23 are also evident.

Association of polymorphisms in pulmonary surfactant protein A1 and A2 genes with high-altitude pulmonary edema

STUDY OBJECTIVES

A potential pathogenetic cofactor for the development of high-altitude pulmonary edema (HAPE) is an increase in capillary permeability, which could occur as a result of an inflammatory reaction and/or free-radical-mediated injury to the lung. Pulmonary surfactant protein A (SP-A), the most abundant surfactant protein, has potent antioxidant properties and protects unsaturated phospholipids and growing cells from oxidative injury. Single-nucleotide polymorphisms (SNPs) in SP-A1 and SP-A2, genes encoding SP-A, have been associated with susceptibility to respiratory distress syndrome, COPD, and pulmonary infections. In view of the protective role of SP-A against inflammatory reactions and oxidative damage, the two underlying mechanisms in development of HAPE, we examined the association of constitutional susceptibility to HAPE with polymorphisms in SP-A1 and SP-A2.

DESIGN

A cross-sectional case-control study.

SETTING

Blood samples were collected at an altitude (> or = 3,500 m).

PARTICIPANTS

Twelve low-altitude native (LAN) subjects with a history of HAPE, 15 healthy LAN sojourners without a history of HAPE (LAN control subjects), and 19 healthy high-altitude natives (HANs) without a history of HAPE (HAN control subjects).

MEASUREMENTS

The SNPs in four exons and intermediate introns of the SP-A1 and SP-A2 were screened by polymerase chain reaction and sequencing. Biochemical parameters related to oxidative stress (malondialdehyde and reduced glutathione in RBC) and membrane permeability (circulating levels of lactate dehydrogenase) were measured in plasma.

RESULTS

Allele frequencies of three loci in SP-A1 and one in SP-A2 were significantly different between LAN HAPE patients (SP-A1 C1101T: C allele, 36.4% and T allele, 63.6%; SP-A1 T3192C: T allele, 61.1% and C allele, 38.9%; SP-A1 T3234C: T allele, 61.1% and C allele, 38.9%; and SP-A2 A3265C: A allele, 21.4% and C allele, 78.6%) and LAN control subjects (SP-A1 C1101T: C allele, 8.3% and T allele, 91.7%; SP-A1 T3192C: T allele, 15% and C allele, 85%; SP-A1 T3234C: T allele, 15% and C allele, 85%; and SP-A2 A3265C: A allele, 37.5% and C allele, 62.5%) [C1101T odds ratio [OR], 6.3 with 95% confidence interval (CI), 2.8 to 14.3; T3192C OR, 8.9 with 95% CI, 4.5 to 17.6; T3234C OR, 8.9 with 95% CI, 4.5 to 17.6; and A3265C OR, 2.2 with 95% CI, 1.2 to 4.1 (p < or = 0.01)]. Heterozygous individuals, with respect to SP-A1 C1101T and SP-A2 A3265C, showed less severity in oxidative damage in comparison with homozygous subjects (SP-A1 T1101 and SP-A2 C3265).

CONCLUSION

The polymorphisms in SP-A1 (C1101T, T3192C, and T3234C) and SP-A2 (A3265C) might be one of the genetic factors contributing to susceptibility to HAPE.

The Indian Genome Variation database (IGVdb): a project overview

Indian population, comprising of more than a billion people, consists of 4693 communities with several thousands of endogamous groups, 325 functioning languages and 25 scripts. To address the questions related to ethnic diversity, migrations, founder populations, predisposition to complex disorders or pharmacogenomics, one needs to understand the diversity and relatedness at the genetic level in such a diverse population. In this backdrop, six constituent laboratories of the Council of Scientific and Industrial Research (CSIR), with funding from the Government of India, initiated a network program on predictive medicine using repeats and single nucleotide polymorphisms. The Indian Genome Variation (IGV) consortium aims to provide data on validated SNPs and repeats, both novel and reported, along with gene duplications, in over a thousand genes, in 15,000 individuals drawn from Indian subpopulations. These genes have been selected on the basis of their relevance as functional and positional candidates in many common diseases including genes relevant to pharmacogenomics. This is the first large-scale comprehensive study of the structure of the Indian population with wide-reaching implications. A comprehensive platform for Indian Genome Variation (IGV) data management, analysis and creation of IGVdb portal has also been developed. The samples are being collected following ethical guidelines of Indian Council of Medical Research (ICMR) and Department of Biotechnology (DBT), India. This paper reveals the structure of the IGV project highlighting its various aspects like genesis, objectives, strategies for selection of genes, identification of the Indian subpopulations, collection of samples and discovery and validation of genetic markers, data analysis and monitoring as well as the project's data release policy.

ALU-ring elements in the primate genomes

Elucidation of complete nucleotide sequence of the human has revealed that coding sequences that store the information needed to synthesize functional proteins, occupy only 2% of the genomic region. The remaining 98%, barring few regulatory sequences, has been referred to as non-functional or junk DNA and consists of many kinds of repeat elements. In fact, human genome is the most repeat rich genome sequenced so far, in which more than half of the region is occupied by such sequences. Determination of significance of these repeats in the human genome has become the focus of many studies all over the world, especially after genome sequencing did not reveal any significant difference in coding regions between lower eukaryotes and human. In this article, we have focused on Alu repeats that are primate specific elements with many interesting biological properties. Moreover, these are the repeats with highest copy number in the human genome. We have highlighted different facets of their interaction with the genome and changing paradigms regarding their role in genome organization.

ACE genotype and cognitive decline in an African-Caribbean population

The insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme (ACE) gene is believed to influence risk of cerebrovascular disease. However, associations with cognitive outcomes remain controversial. As far as we are aware, all studies to date have been carried out in white American or European populations. African-Caribbean populations have high prevalence rates of hypertension, diabetes and cerebrovascular disease but risk factors for cognitive outcomes remain under-researched. In a UK community sample of 148 African-Caribbean people aged 55-75 years, we investigated the association between ACE genotype and cognitive decline over 3 years using a battery of repeated tests. No direct association was found between ACE genotype and decline. However, the association between increased age and cognitive decline was significantly stronger in people with the ACE DD genotype (odds ratio 3.6 per 5-year increase, 95% CI: 1.9-6.7) compared to those with ID/II genotype (odds ratio 0.7, 95% CI 0.4-1.2). This interaction was particularly strong for decline in verbal memory and was not apparently mediated by vascular risk factors measured at baseline.