Polymorphisms of the apolipoprotein and angiotensin converting enzyme genes in young North Karelian patients with coronary heart disease

The genes encoding apolipoproteins (apos) A-I, B, C-III and E as well as that encoding the angiotensin converting enyzme (ACE) have been proposed as candidate genes for coronary heart disease (CHD). We determined the common polymorphisms of the apo genes, previously found to influence serum lipid levels at the population level, and the insertion/deletion polymorphism of the ACE gene, recently reported to reflect the risk of myocardial infarction, in 82 very young (mean, 41 years) North Karelian Finns with symptomatic CHD and 50 controls of similar age. Patients with familial hypercholesterolemia had been excluded from this material. None of the polymorphisms examined, including the apo A-I promoter MspI, apo C-III SstI and apo B XbaI restriction fragment polymorphisms, a common variation of apo E (2, 3 and 4 alleles) and an ACE insertion/deletion (I/D) polymorphism, was significantly associated with the risk of premature CHD. Patients with CHD had a higher mean serum LDL cholesterol/HDL cholesterol ratio than controls (3.15±1.30 vs 2.72±0.98, P < 0.05), but no significant associations between the common apo gene polymorphisms and serum lipid levels were disclosed in either group. It is possible that other genetic loci than those proposed to be associated with accelerated atherosclerosis may be more important as risk factors of symptomatic CHD at the age of 40 years.     

Polymorphisms of apolipoproteins A-IV and E in a Turkish population living in Germany

Human apolipoproteins (apo) E and apo A-IV are polymorphic with significantly different allele frequencies among different ethnic groups. Whereas the variation at the apo E gene locus affects plasma cholesterol levels in all populations studied so far and is associated with longevity in Caucasians, the influence of the common apo A-IV polymorphism on plasma lipoproteins has not been unanimously accepted. We have therefore determined the common apo E and apo A-IV polymorphisms by isoelectric focusing, calculated the respective allele frequencies and studied their effects on plasma lipoproteins in a random sample of 240 nonrelated Turkish subjects (141 males, 99 females) living in Germany and originating from central and eastern Anatolia. When compared with the German population and other Caucasians in Europe a prominence of the apo ɛ3 allele frequency (0.885) was accompanied by a decrease in the frequencies of both the apo ɛ2 allele (0.048) and the apo ɛ4 allele (0.067). Thus, the Turkish population studied here clustered with populations mainly from southern Europe and Japan, which have low ɛ2 and ɛ4 allele frequencies. Also, the frequency of the A-IV-1 allele was higher (0.967) and that of the A-IV-2 allele lower (0.033) in the Turkish subjects studied than in other populations. At an average level of total cholesterol of 194.5 ± 45 mg/dl, no significant influence of the A-IV alleles on plasma lipoproteins was seen. However, apo E and apo B differed significantly between apo E phenotypes, with high levels of apo E and low levels of cholesterol and apo B in carriers of the ɛ2 allele, and vice versa for the ɛ4 allele. The average cholesterol excess for the ɛ2 allele was –7.95 mg/dl, for the ɛ3 allele, –1.34, and for the ɛ4 allele, +14.15 mg/dl. Thus, despite the unusual frequency distribution of the apo E alleles, their effects on plasma lipoproteins are within the range reported for other populations in Europe. Received: 10 April 1995 / Revised: 25 March 1996     

ACE I/D polymorphism in Alzheimer’s disease

Angiotensin-converting enzyme (ACE) has been reported to show altered activity in patients with neurological diseases. The recent studies found that a 287 bp insertion/deletion (I/D) polymorphism of the ACE gene may be associated with susceptibility to Alzheimer’s disease (AD) but the results have been heterogenous between studies in Europe. In the present study we examined for the first time the association of ACE I/D polymorphism along with APOE genotype in 70 sporadic AD and 126 control subjects in Slovak Caucasians (Central Europe). An increased risk for AD was observed in subjects with at least one APOE*E4 allele (OR=3.99, 95% CI=1.97–8.08). No significant differences for the genotype distribution or the allele frequency were revealed comparing controls and patients for ACE gene. Gene-gene interaction analysis showed increase of the risk to develop AD in subjects carrying both the ACE DD genotype and the APOE*E4 allele (OR=10.32, 95% C.I. 2.67–39.81).     

C677T Methylentetrahydrofulate Reductase and Angiotensin Converting Enzyme Gene Polymorphisms in Patients with Alzheimer’s Disease in Iranian Population

In recent years numerous data suggest that vascular risk factors may be play a role in Alzheimer’s disease (AD). To determine the association of AD with methylentetrahydrofulate reductase (MTHFR) and angiotensin converting enzyme (ACE) as two main vascular risk factors, we examined MTHFR C677T and ACE insertion/deletion (I/D) gene polymorphism in 117 late-onset AD cases and 125 controls. We found no difference in ACE I/D genotype distribution between AD cases and control (P > 0.05) but there was a significant association between AD and the common MTHFR polymorphism C677T. The T allele conferred an increased risk of AD compared to carrying a C allele (P = 0.001, OR = 1.97, 95% CI: 1.3–2.09). Our result suggests a significant increase in risk of AD in cases with the MTHFR T allele, atleast in the Iranian population.     

Angiotensinogen and angiotensin-I converting enzyme gene polymorphisms and the risk of coronary artery disease in Chinese

The homozygous deletion allele (DD) of the angiotensin-I converting enzyme (ACE) gene and the T235 homozygote of the angiotensinogen (AGT) gene have been reported to be correlated with an increased prevalence of coronary artery disease (CAD) and myocardial infarction (MI). The importance of the DD genotype and T235 homozygote as genetic risk factors for CAD in Chinese remains uncertain. This study included 426 patients who underwent coronary angiography and 180 healthy subjects without clinical evidence of CAD. Coronary angiography identified 268 patients with CAD (CAD group) and 158 patients without CAD. The healthy subjects and patients without angiographic evidence of CAD constituted the control group. Three polymorphisms were studied: an insertion/deletion (I/D) polymorphism of the ACE gene and the T174 M and M235T polymorphisms of the AGT gene. No association was found between any of the three studied polymorphisms and the risk of CAD or MI in Chinese using univariate or multivariate analysis. In multivariate analysis, the relative risks were 1.20 (95% confidence interval = 0.91–1.61, P = 0.20) for the DD genotype, 1.05 (95% CI = 0.82–1.35, P = 0.69) for the T174 homozygote, and 1.19 (95% CI = 0.91–1.55, P = 0.20) for the T235 homozygote. Similarly, no significant difference was found in the frequencies of the DD genotype and the T174 and T235 homozygotes between the control group, the CAD group, the non-MI group, and the MI group when analyzed according to sex, age, or degree of risk. Our data suggest that neither the DD genotype of the ACE I/D polymorphism nor the T174 and T235 homozygotes of the AGT gene confer significant risk for CAD or MI in Chinese. Received: 18 December 1996 / Accepted: 27 February 1997     

Deletion/Deletion genotype of angiotensin-I converting enzyme gene is not associated with coronary artery disease in caucasians with type 2 diabetes

In this study we analyzed the contribution of genetic variability of the insertion/deletion (I/D) polymorphism of the angiotensin-I converting enzyme (ACE) gene to the predisposition for coronary artery disease (CAD) in a group of patients with type 2 diabetes. The I/D ACE gene polymorphism was tested in 366 Caucasians with type 2 diabetes: 148 cases with CAD and 218 subjects with no history of CAD. We failed to demonstrate that the ACE DD genotype was a risk factor for CAD in Caucasians with type 2 diabetes (OR 2.0, 95% CI 0.9-4.7; p = 0.1). In conclusion, we provide evidence that the ACE deletion/deletion genotype is not a risk factor for CAD in Caucasians with type 2 diabetes.     

Evidence, from combined segregation and linkage analysis, that a variant of the angiotensin I-converting enzyme (ACE) gene controls plasma ACE levels.

The hypothesis of a genetic control of plasma angiotensin I-converting enzyme (ACE) level has been suggested both by segregation analysis and by the identification of an insertion/deletion (I/D) polymorphism of the ACE gene, a polymorphism contributing much to the variability of ACE level. To elucidate whether the I/D polymorphism was directly involved in the genetic regulation, plasma ACE activity and genotype for the I/D polymorphism were both measured in a sample of 98 healthy nuclear families. The pattern of familial correlations of ACE level was compatible with a zero correlation between spouses and equal parent-offspring and sib-sib correlations (.24 +/- .04). A segregation analysis indicated that this familial resemblance could be entirely explained by the transmission of a codominant major gene. The I/D polymorphism was associated with marked differences of ACE levels, although these differences were less pronounced than those observed in the segregation analysis. After adjustment for the polymorphism effects, the residual heritability (.280 +/- .096) was significant. Finally, a combined segregation and linkage analysis provided evidence that the major-gene effect was due to a variant of the ACE gene, in strong linkage disequilibrium with the I/D polymorphism. The marker allele I appeared always associated with the major-gene allele s characterized by lower ACE levels. The frequency of allele I was .431 +/- .025, and that of major allele s was .557 +/- .041. The major gene had codominant effects equal to 1.3 residual SDs and accounted for 44% of the total variability of ACE level, as compared with 28% for the I/D polymorphism.(ABSTRACT TRUNCATED AT 250 WORDS)     

The frequency of factor V Leiden mutation,ACE gene polymorphism,serum ACE activity and response to ACE inhibitor and angiotensin II receptor antagonist drugs in Iranians type II diabetic patients with microalbuminuria

The aim of present study was to determine if factor V Leiden (FVL) mutation and angiotensin converting enzyme insertion/deletion (ACE I/D) polymorphism are associated with diabetic nephropathy (DN) among Kurdish population from Western Iran. This case–control study comprised 144 unrelated adult type 2 diabetic mellitus patients (T2DM) including 72 patients with microalbuminuria and 72 age and sex matched patients without nephropathy. The ACE I/D polymorphism and FVL mutation were detected by polymerase chain reaction (PCR) and PCR–RFLP, respectively. The frequency of FVL G1691A and ACE D allele in T2DM patients with microalbuminuria were 1.6 and 57%, respectively and in normoalbuminuric T2DM patients were 4.9 and 58.3%, respectively (P > 0.05). ACE genotypes affected on serum ACE activity and a better response to ACE inhibitor therapy (captopril) compared to angiotensin II receptor antagonist (losartan) was obtained with significant reduction of ACE activity in diabetic patients without nephropathy carrying DD genotype. However, the beneficial effect of losartan therapy was observed in microalbuminuric patients with II genotype compared to ID and DD genotypes.     

Angiotensin-converting enzyme gene polymorphisms and T2DM in a case�Ccontrol association study of the Bahraini population

Bahrain has one of the highest incidence rates of type 2 diabetes mellitus (T2DM). Development of diabetic nephropathy (DN) as a complication was noticed in some patients while absent in others. This interesting observation raises the role of certain genetic risk factors for the development of DN. Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism was found to be associated with T2DM. While some patients have predisposition to DN in the population, others have negative association. The present case-control association study was designed to investigate the association of ACE I/D polymorphism in T2DM patients in Bahrain especially in those who developed DN. A total of 360 T2DM patients (110 with DN and 250 without DN) and 360 healthy (non-diabetic) age-matched subjects were recruited for this study for comparison. The presence (insertion)/absence (deletion) (I/D) polymorphism of a 287-bp Alu1 element inside intron 16 of the ACE gene was investigated using PCR-gel electrophoresis. The results show that the distribution of the homozygote DD genotype of the ACE gene was high among Bahraini T2DM patients compared to the healthy non-diabetic subjects. In addition, the distribution of the deletion (D) allele was high among Bahraini T2DM patients with DN when compared to the healthy non-diabetic subjects. However, there was no significant difference in the distribution of ACE I/D allele and genotypes between DN patients when compared to those T2DM patients without DN. The results obtained in this study are in closely agreement with some previous reports which show a strong association of ACE polymorphism with T2DM patients, yet not a risk factor for development of DN.     

Association of APOE genotype with carotid atherosclerosis in men and women: the Framingham Heart Study

The aim of this study was to determine the association between APOE genotype and carotid atherosclerosis, defined as intimal-medial thickness (IMT) and stenosis, and to assess if other cardiovascular risk factors modify this association. A total of 1,315 men and 1,408 women from the Framingham Offspring Study underwent carotid ultrasound during examination cycle 6 and had complete data on APOE genotype. Three APOE genotype groups were defined: APOE2 (including E2/E2, E3/E2 genotypes), APOE3 (E3/E3), and APOE4 (including E4/E3, E4/E4 genotypes). Carotid IMT and the presence of carotid stenosis > 25% were determined by ultrasonography. In women, the APOE2 group was associated with lower carotid IMT (0.67 vs. 0.73 mm) and lower prevalence of stenosis (odds ratio = 0.49; 95% confidence interval = 0.30-0.81) compared with the APOE3 group. In men, APOE genotype was not associated with carotid IMT or stenosis in the whole group; however, diabetes modified the association between APOE genotype and carotid IMT (P for interaction = 0.044). Among men with diabetes, the APOE4 group was associated with a higher internal carotid artery IMT (1.22 mm) than the APOE3 group (0.90 mm) or the APOE2 group (0.84 mm). The E2 allele was associated with lower carotid atherosclerosis in women, and the E4 allele was associated with higher internal carotid IMT in diabetic men.     

Angiotensin-converting enzyme (ACE) gene polymorphisms in patients characterised by coronary angiography

The angiotensin converting enzyme (ACE) gene is implicated as a risk factor for coronary artery disease and myocardial infarction (MI). An insertion/deletion (I/D) polymorphism is believed to be in linkage disequilibrium with a functional site elsewhere. Ten polymorphisms have recently been identified in the ACE gene. We screened patients undergoing coronary angiography (n = 258) for six of these polymorphisms (T-5491C, T-93C, A-240T, T1237C, D/I and 4656(CT)_2/3), and identified a further two rare polymorphisms. ACE levels were associated with genotype for all polymorphisms analysed individually by one way ANOVA (P < 0.0005). The polymorphisms occurring in the 5′ region were in negative linkage disequilibrium with the exonic and 3′ region polymorphisms. The A-240T polymorphism had the greatest association with ACE levels (R² = 14%); none of the others were significantly associated with levels when adjustment was made for A-240T. None of the polymorphisms were associated with the extent of coronary atheroma. Two of the promoter polymorphisms (A-240T and T-93C) were weakly related to the occurrence of MI (P = 0.03 and P = 0.05, respectively, by χ² analysis). The TT genotype of A-240T appeared to be protective against MI with an odds ratio of 0.31 (95% confidence interval, 0.12, 0.83). These findings indicate that polymorphisms in the ACE gene promoter region may have a stronger association with disease than the I/D polymorphism. Received: 16 February 1997 / Accepted: 13 May 1997     

飞行员中血管紧张素转换酶基因插入或缺失多态性研究

为了解飞行员血管紧张素转换酶(ACE)基因插入或缺失（I/D）多态性情况,探讨ACE基因多态性与飞行员耐力可能的关系,用聚合酶链反应（PCR）扩增技术检测118例飞行员和96例健康对照者的ACE基因I/D多态性。 结果位于ACE基因内含子16的I/D多态性经PCR扩增后呈三种基因型：纯合子插入型（II）、纯合子缺失型（DD）和杂合子插入或缺失型（I/D）。飞行员组II基因型（44.07%）和I等位基因频率（0.65）显著高于健康对照组(分别为31.25%和0.52)。 结果表明ACE I基因有可能在飞行员的飞行耐力中起重要作用。 Abstract:In order to understand insertion/delation (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene in pilots,and to explore the relationship between ACE gene I/D polymorphism and the perfomance of the pilots,the polymerase chain reaction (PCR) was used to determine the genotypes for an I/D polymorphism in intron 16 of the ACE gene in 118 pilots and 96 healthy subjects as controls.The result showed that the I/D polymorphism in intron 16 of the ACE gene was categorized into three genotypes: two deletion alleles (genotype DD),heterozygous alleles (genotype ID),and two insertion alleles (genotype II).The genotype II and I allele frequency were significantly higher in pilots (44.07% and 0.65) than that in healthy subjects (31.25% and 0.52).It is suggested that I gene of ACE may play a role in perfomance of the pilots.     

The apolipoprotein E polymorphism in Greenland Inuit in its global perspective

Apolipoprotein E (apoE) genotypes were determined in Inuit population samples from Nuuk on the south-west coast of Greenland (n = 100) and from the Ammassalik region on the south-east coast (n = 78). The ɛ2 allele was absent in the latter sample, and the ɛ4 allele frequency was relatively high, about 23%. As in most other populations, mean plasma lipoprotein-related variables, except high-density lipoprotein (HDL) cholesterol, were higher in both Inuit men and women with ɛ4 than in ɛ3ɛ3 genotypes (P < 0.05 for triglycerides in men, and for non-HDL cholesterol and apolipoprotein B in women). The estimated apoE allele frequencies were combined with data from other studies of aboriginal peoples to outline a world map of apoE allele frequencies. A recent study of non-human primates suggests that ɛ4, and not ɛ3, is the ancestral allele in humans and we have used the map to generate additional hypotheses regarding the history of the apoE polymorphism in humans. Received: 30 November 1995 / Revised: 15 June 1996     

Association between the Insertion/Deletion Polymorphism of the Angiotensin-Converting Enzyme Gene and Angiopathy in Patients with Non-Insulin Dependent Diabetes Mellitus in Chuvash Republic

Insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene was analyzed in patients with non-insulin-dependent diabetes mellitus (NIDDM) and in the control group consisting of healthy subjects. The insertion allele (I) and genotype II were found to be associated with NIDDM. The frequencies of diabetic retinopathy and nephropathy in NIDDM patients were not associated with this polymorphism. However, an association was found between the DD genotype of the ACE gene and diabetic angiopathy in lower extremities.     

Angiotensin-converting enzyme gene polymorphism is associated with anemia in non small-cell lung cancer

The angiotensin-converting enzyme (ACE) plays an important role not only in the regulation of vascular homeostasis but also in stimulation of hematopoiesis. We aimed to evaluate the association between insertion/deletion (I/D) polymorphism of the ACE gene and anemia at the time of the diagnosis. We enrolled 75 patients with non-small-cell lung cancer (NSCLC) and 85 age- and sex-matched healthy control participants. The I/D polymorphism of ACE was identified by using polymerase chain reaction from peripheral blood samples. Statistical analyses were performed with SPSS for Windows. The distributions of the ACE genotypes and alleles are similar in patients and in healthy participants (P=0.29 and P=0.08, respectively). In patients with NSCLC, 34 (45.3%) had anemia; of whom 3 (8.8%) had genotype II, 24 (70.6%) had genotype ID, and 7 (20.6%) had genotype DD (P=0.001). The patients with the II and ID genotypes had more frequent anemia at the time of the diagnosis (odds ratio = 6.02; P=0.001). Our findings suggest that I/D polymorphism of the ACE gene may influence the development of anemia in patients with NSCLC.     

Polymorphism of the Angiotensin-Converting Enzyme Gene in Patients with Coronary Heart Disease from the Moscow Population

The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene was studied in patients with coronary heart disease (CHD) and healthy individuals randomly sampled from the Moscow population. The ACE gene proved to be associated with the plasma apolipoprotein B (ApoB) content in CHD patients, but not associated with HCD development in individuals with elevated serum cholesterol and triglycerides. An association was not revealed between the alleles of the ACE gene and hypertension in CHD patients.     

Association between insertion-deletion polymorphism of the angiotensin-converting enzyme gene and development of angiopathies in patients with non-insulin dependent diabetes mellitus from the Chuvash Republic

Insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene was analyzed in patients with non-insulin-dependent diabetes mellitus (NIDDM) and in the control group consisting of healthy subjects. The insertion allele (I) and genotype II were found to be associated with NIDDM. The frequencies of diabetic retinopathy and nephropathy in NIDDM patients were not associated with this polymorphism. However, an association was found between the DD genotype of the ACE gene and diabetic angiopathy in lower extremities.     

Polymorphism of the angiotensin-converting enzyme gene in patients with coronary heart disease from Moscow population]

The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene was studied in patients with coronary heart disease (CHD) and healthy individuals randomly sampled from the Moscow population. The ACE gene proved to be associated with the plasma apolipoprotein B (ApoB) content in CHD patients, but not associated with HCD development in individuals with elevated serum cholesterol and triglycerides. An association was not revealed between the alleles of the ACE gene and hypertension in CHD patients.     

Identification of new polymorphisms of the angiotensin I-converting enzyme (ACE) gene, and study of their relationship to plasma ACE levels by two-QTL segregation-linkage analysis.

Plasma angiotensin I-converting enzyme (ACE) levels are highly genetically determined. A previous segregation-linkage analysis suggested the existence of a functional mutation located within or close to the ACE locus, in almost complete linkage desequilibrium (LD) with the ACE insertion/deletion (I/D) polymorphism and accounting for half the ACE variance. In order to identify the functional variant at the molecular level, we compared ACE gene sequences between four subjects selected for having contrasted ACE levels and I/D genotypes. We identified 10 new polymorphisms, among which 8 were genotyped in 95 healthy nuclear families, in addition to the I/D polymorphism. These polymorphisms could be divided into two groups: five polymorphisms in the 5' region and three in the coding sequence and the 3' UTR. Within each group, polymorphisms were in nearly complete association, whereas polymorphisms from the two groups were in strong negative LD. After adjustment for the I/D polymorphism, all polymorphisms of the 5' group remained significantly associated with ACE levels, which suggests the existence of two quantitative trait loci (QTL) acting additively on ACE levels. Segregation-linkage analyses including one or two ACE-linked QTLs in LD with two ACE markers were performed to test this hypothesis. The two QTLs and the two markers were assumed to be in complete LD. Results supported the existence of two ACE-linked QTLs, which would explain 38% and 49% of the ACE variance in parents and offspring, respectively. One of these QTLs might be the I/D polymorphism itself or the newly characterized 4656(CT)2/3 polymorphism. The second QTL would have a frequency of approximately .20, which is incompatible with any of the yet-identified polymorphisms. More extensive sequencing and extended analyses in larger samples and in other populations will be necessary to characterize definitely the functional variants.