Insertion /deletion (I/D) polymorphism at the locus for angiotensin I-converting enzyme and parental history of myocardial infarction

Bøhn M, Berge KE, Bakken A, Erikssen J, Berg K. Insertion/deletion (I/D) polymorphism at the locus for angiotensin I-converting enzyme and parental history of myocardial infarction.
Clin Genet 1993: 44: 298–301. © Munksgaard, 1993
One hundred and eighty-one male and 48 female myocardial infarction (MI) survivors and 172 male and 194 female controls were studied with respect to a possible association between premature parental MI (before age 61 years in mothers and/or before age 56 years in fathers) and an insertion/deletion (I/D) polymorphism in the gene encoding angiotensin I-converting enzyme (ACE). In the total series, the frequency of premature parental MI was 14% in the DD (homozygotes for the deletion (D) allele) genotypic group, 10.6% in the ID (heterozygotes) genotypic group and 6.1% in the II (homozygotes for the insertion (I) allele) genotypic group. In all males (male MI survivors and male controls combined), and in the total series, there was a significant excess of DD individuals as compared to II individuals among those with a parental history of premature MI (odds ratio 3.1 (p = 0.03) and 3.1 (p = 0.009), respectively). The ACE polymorphism may be an important genetic marker of MI risk and contribute to clustering of premature MI in families.     

Insertion/deletion (I/D) polymorphism at the locus for angiotensin I-converting enzyme and myocardial infarction

Bøhn M, Berge KE, Bakken A, Erikssen J, Berg K. Insertion/deletion (I/D) polymorphism at the locus for angiotensin I-converting enzyme and myocardial infarction.
Clin Genet 1993: 44: 292–297. © Munksgaard, 1993
Male (n = 185) and female (n = 49) survivors of myocardial infarction (MI) below 56 and 61 years of age, respectively, were compared to 366 controls with respect to distribution of genotypes in an insertion/deletion (ID) polymorphism at the angiotensin I-converting enzyme (ACE) locus. The frequency of the DD genotype (homozygosity for the deletion allele) was significantly lower among male patients than controls (22.7% versus 34.9%, p = 0.011). In a "low-risk" group, defined as having less than the sex-specific, age-adjusted median values of body mass index (BMI) and apolipoprotein B (apoB), respectively, and absence of treatment with lipid-lowering drugs, the prevalence of the DD genotype was not statistically different between male patients and controls. In a male "high-risk" group (those individuals who had not been defined as "low-risk" subjects), the prevalence of the DD genotype was 20.9% in patients and 38.3% in controls (p = 0.002). In women, no significant differences in genotype frequencies between patients and controls were found in the whole sample or in any subgroup. These results appear to be at variance with data reported recently by Cambien et al. (1992). The difference may be due to chance, undetected selection biases, different gene-environment interactions between Norway and France or Ireland, or to preferential loss of DD individuals in our male "high-risk" group.     

No effect of insertion/ deletion polymorphism at the ACE locus on normal blood pressure level or variability

Angiotensin I-converting enzyme (ACE) cleaves angiotensin I to angiotensin II, which is the active component in the renin-angiotensin system (RAS). We have studied an insertion/deletion polymorphism in DNA at the ACE locus. In three different series comprising 140, 90 and 136 unrelated individuals we found no evidence of association between genotypes in this insertion/deletion (I/D) polymorphism and level of systolic or diastolic blood pressure. In two series of 130 and 88 monozygotic (MZ) twin pairs, respectively, there was no difference between genotypes in within-pair variation in systolic or diastolic blood pressure. Thus, in these series of healthy people, neither "level gene" nor "variability gene" effects of this insertion/deletion polymorphism were observed.     

ACE基因I/D多态性在心血管疾病中的研究进展

血管紧张素转化酶（ACE）是肾素-血管紧张素-醛固酮系统（RAAS）的关键酶，在心血管疾病发生发展中起重要作用。近年来有多个研究探讨ACE基因插入/缺失（insertion/ deletion,I/D）多态性与心血管疾病之间的关系，然研究结果尚存争议。本文主要就ACE基因I/D的多态性及其与心血管疾病关系的研究进展做一综述。     

Association of angiotensin-converting enzyme insertion/deletion polymorphism with obesity,cardiovascular risk factors and exercise-mediated changes in Korean women

This study examined whether the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism is associated with obesity, cardiovascular risk factors and 12-week exercise-mediated changes in Korean women. A total of 105 subjects were divided into three groups as II, ID and DD genotype groups based upon ACE I/D genotypes. Body composition and cardiovascular risk factors were compared among the three groups, and the association of ACE I/D genotypes with obesity and hypertension was evaluated. Total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels were higher (P < 0.05) in the DD genotype than in II or ID genotypes. D allele frequency in ACE I/D gene had a higher (P = 0.063) trend in the hypertensive group than the normotensive group. The DD genotype had a trend to develop (odds ratio 4.032, P = 0.086) more hypertension than the II genotype. The II and ID genotypes showed a significant (P < 0.05) decrease in intima media thickness of the carotid artery after an exercise intervention, whereas the DD genotype showed an increase. In conclusion, there is a trend towards association of ACE I/D polymorphism with hypertension but not with obesity. Exercise-mediated changes did not differ significantly among genotypes except IMTCA.     

新疆哈萨克族隔离群血管紧张素转换酶基因I/D多态性与高血压病的关系

目的 探讨哈萨克族人群血管紧张素转换酶(angiotensin converting enzyme,ACE)基因第16内含子中的插入／缺失(insertion／deletion，I／D)多态性是否为高血压病(essential hypertension，EH)的遗传易患因素。方法 应用聚合酶链反应检测了新疆巴里坤县201例哈萨克族高血压病患者和151名正常人的ACE基因16内含子I／D多态性。结果 哈萨克族正常人群及高血压患者的ACE基因I／D多态性DD、ID、Ⅱ基因型频率分布分别为0．17、0．43、0．40和0．18、0．52、0．30，D和I等位基因分布频率分别为0．39和0．61和0．44、0．56，符合Hardy-Weinberg平衡。群体相关分析结果表明，ACE基因的D及I等位基因分布在高血压病组及正常血压组的差异无显著性(x^2＝1．98，P＝0.16)；基因型频率之间差异也无显著性(x^2＝4．0，P＝0．14)。结论 ACE基因16内含子I／D多态性可能与新疆巴里坤哈萨克族高血压病无关。     

Restriction site polymorphism at the LPA (Lp(a) apoliprotein; apoliprotein(a)) locus

A restriction site polymorphism in the Lp(a) apolipoprotein gene (the LPA gene) is reported. The basis for the polymorphism is presence or absence of an MspI restriction site that appears to be 3' to the last kringle IV structure of the gene. The "1" gene (presence of the restriction site) has a frequency of 0.316 and the "2" gene (absence of the restriction site) has a frequency of 0.684. Both members of each of 67 monozygotic (MZ) twin pairs had the same genotype and there was Mendelian segregation of the DNA variants in 40 families with a total of 75 children. There was a lower proportion of people with genotype 1-1 in the top quartile than in the 3 bottom quartiles of the population distribution of Lp(a) lipoprotein levels but the difference did not reach statistical significance.     

心肌梗死患者血管紧张素转换酶基因多态性与ACE、PAI-1活性的相关性

目的:研究心肌梗死(MI)患者血管紧张素转换酶(ACE)基因插入/缺失(I/D)多态性与ACE、PAI-1活性的关系。 方法: 应用PCR方法扩增93例MI患者及87例健康体检者ACE基因特异性片段，同时应用比色法测定血清ACE活性，发色底物法测定PAI-1活性，并对结果进行相关性分析。 结果:①MI组ACE DD基因型频率(32.3%)和D等位基因频率(54.3%)显著高于对照组(12.6%和37.4%)(均P<0.01)。②MI组血清ACE(216.00±58.26)U/L及血浆PAI-1活性(0.85±0.19)AU/mL均显著高于对照组(170.19±48.99)U/L, (0.66±0.20)AU/mL(均P<0.01)；MI组与对照组ACE与PAI-1活性均呈显著正相关(r分别为0.7108，0.7829,均P<0.01)；③MI组DD基因型血清ACE(251.64±57.76)U/L、血浆PAI-1活性(0.96±0.16)AU/mL显著高于ID基因型(211.47±51.87)U/L，(0.82±0.18)AU/mL及Ⅱ基因型(179.84±52.65)U/L，(0.71±0.17)AU/mL(均P<0.01)；ID基因型血清ACE、血浆PAI-1活性亦显著高于Ⅱ型(P<0.05)。对照组DD基因型血清ACE(195.53±54.76)U/L、血浆PAI-1活性(0.78±0.20)AU/mL，显著高于II基因型(154.98±52.74)U/L，(0.59±0.17)AU/mL(均P<0.05)。 结论:由ACE基因所决定的ACE活性，可能参与血浆PAI-1水平的调节；ACE基因I/D多态性与ACE、PAI-1水平相关，ACE基因种类影响纤溶平衡，这可能是其促使MI发病的重要机制之一。     

Apolipoproteins B and E, and angiotensin I-converting enzyme (ACE) genetic polymorphisms in Italian women with coronary artery disease (CAD) and their relationships with plasma lipid and apolipoprotein levels

The Xba I, Eco RI and the signal peptide insertion/deletion ( I/D ) polymorphic sites of APOB gene, the Cfo I polymorphic site of apolipoprotein E gene (APOE), and the insertion/deletion polymorphism of angiotensin I-converting enzyme (ACE) gene were studied using polymerase chain reaction (PCR) in 55 postmenopausal women with coronary artery disease (CAD) and in 119 control women of equivalent age. Patients and controls were recruited from the population of Rome, considered representative of Central and Southern Italy. There were no significant differences in allele frequencies between the two groups, though APOB X-, R- and I, APOE*3 , and ACE D alleles were slightly more frequent in the cases than in the controls. The patients did not differ from the controls for plasma total cholesterol (TC), HDL-cholesterol, LDL-cholesterol, and apoAI values, while they presented significantly higher levels of triglycerides and apoB, and lower apoE levels. TC, apoE, and apoB quantitative values, adjusted for age, varied significantly among APOB Xba I and APOE genotypes. APOB X-X-genotype was associated in patients with a significantly lower mean TC concentration than the other two genotypes pooled together. APOE 3–2 genotype in the controls had significantly lower TC levels with respect to the other two pooled genotypic classes and higher apoE levels compared to 3–3 and 4–3 genotypes. In the patients, 3–2 genotype had significantly lower apoB levels than the pooled 3–3 and 4–3 class. We conclude that in the Italian women the DNA polymorphisms studied in this work do not seem to be important risk factors for CAD occurrence; that apoE quantitation could be another useful parameter to identify subjects at risk of CAD; and that APOB X -and APOE*2 are the alleles that most influence the interindividual plasma lipid variation among CAD female patients.     

Homogeneous assay of rs4343, an ACE I/D proxy, and an analysis in the British Women's Heart and Health Study (BWHHS)

Current literature suggests that ACE SNP rs4343, ACE 2350A>G in exon 17, T202T, may be the best proxy for the ACE Alu I/D whereas rs4363 and rs4362 may be slightly stronger predictors of ACE levels. Considering reported difficulties in genotyping ACE I/D and stronger associations of rs4343 than ACE I/D with plasma ACE levels in Africans, and suitability of rs4343 for allelic mRNA (cDNA) studies, we developed and validated a liquid phase assay for rs4343, which has advantage on both functional and technical grounds. We confirmed that rs4343, is in near perfect linkage disequilibrium (D'=1, r2=0.88, n=64) with ACE I/D in Europeans (A and G alleles of rs4343 marking insertion and deletion alleles of ACE I/D respectively). We then studied its association with metabolic and cardiovascular traits in 3253 British women (60-79 years old). Apart from a nominal trend of association with diastolic blood pressure (p anova=0.08; p trend=0.05), no other associations were observed. A post-hoc vascular and general phenome scan revealed no further associations. We conclude that ACE I/D is not a major determinant of metabolic and cardiovascular traits in this population. Liquid phase genotyping of SNP rs4343 may be preferable to gel based ACE I/D genotyping both for technical and functional reasons.     

Association of essential hypertension in elderly Japanese with I/D polymorphism of the angiotensin-converting enzyme (ACE) gene

Recent evidence suggests that an insertion/deletion (I/D) polymorphism of the gene encoding angiotensin-converting enzyme (ACE) is associated with myocardial infarction and related cardiovascular diseases. We investigated a possible association of the ACE polymorphism with essential hypertension in a total of 263 cases/controls from among the elderly (age, over 70 years) and middle-aged (age between 30 and 60 years) Japanese population. The frequency of the I/I homozygote was significantly higher in hypertensive subjects than in controls in the elderly age group (33/57 vs 16/46; P = 0.02), but no association was observed in the middle-aged group (25/75 vs 26/85; P = 0.71). Similarly, having at least one insertion allele was associated with essential hypertension in the elderly age group (83/114 vs 46/92 in controls; P = 0.001), but not in the middle-aged group (78/150 vs 94/170; P = 0.524). These data suggest that genetic variation at the ACE locus may be associated with some determinants for blood pressure in elderly persons, and imply the involvement of the ACE insertion/deletion polymorphism in the etiology of age-related essential hypertension in the Japanese population. Received: April 18, 2000 / Accepted: July 25, 2000     

Normal DNA polymorphism at the low density lipoprotein receptor (LDLR) locus associated with serum cholesterol level

A restriction fragment length polymorphism (RFLP) at the low density lipoprotein receptor (LDLR) locus detectable with the restriction enzyme PvuII exhibits association with total serum cholesterol level. People who are homozygous for absence of the PvuII restriction site have a significantly higher total cholesterol level than heterozygotes (the number of homozygotes for presence of the restriction site was too small to permit meaningful comparison). This difference is significant at the 2% level. Thus, this study of sex- and age-adjusted cholesterol levels in a sample of healthy people yields additional evidence and sustains our previous proposal that normal alleles at the LDLR locus contribute to the population variation in total cholesterol levels. Absence of the PvuII site appears to confer an odds ratio of approximately 2.7 for having a cholesterol level in the top quartile of the population distribution.     

No effect of a Taql polymorphism in DNA at the endothelin I (EDN1) locus on normal blood pressure level or variability

Endothelin is a peptide reported to be one of the most potent vasoconstrictors known. Presumably, endothelin could play a role in the physiological regulation of blood pressure in healthy or hypertensive people. We have studied a normal restriction fragment length polymorphism (RFLP) at the endothelin-I (EDN1) locus detected with the restriction enzyme TaqI. In three different series comprising 166, 120 and 207 unrelated individuals, we found no evidence for association between genotype in this polymorphism and level of systolic or diastolic blood pressure. In two series of 156 and 117 monozygotic (MZ) twin pairs, respectively, there was no difference between genotypes in within-pair variation in systolic or diastolic blood pressure. Thus neither "level gene" nor "variability gene" effects of normal genes at the EDN1 locus could be detected with the polymorphism analyzed, in healthy population samples.     

Angiotensin-I-converting enzyme (ACE) insertion/deletion polymorphism in Mexican patients with coronary artery disease. Association with the disease but not with lipid levels

Angiotensin-I-converting enzyme (ACE) insertion/deletion (ID) polymorphism has been associated with the genetic susceptibility to coronary artery disease (CAD) and also with the lipid profile in several populations. In the present work, we analyzed the distribution of ID polymorphism in 147 Mexican patients with CAD and 100 unrelated healthy controls. The correlation of this polymorphism with the lipid profile (cholesterol, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol, high density lipoprotein-cholesterol and triglycerides) in the patients group was determined. Increased frequency of D allele as well as DD genotype and decreased frequency of I allele and II genotype were found in CAD patients group (pC = 0.00058, OR = 1.96, pC = 0.021, OR = 2.5 and pC = 0.00058, OR = 0.51, pC = 0.0028, OR = 0.38). Correlation between ID genotypes and lipid profile in patients was carried out in total population and separately for females and males. After they had been adjusted for age, sex and BMI, there was no association among the three genotypes (II, ID and DD) and lipids and lipoproteins in none of the studied groups. Our data suggest that genetic variation at the ACE is a genetic factor related with the susceptibility to coronary artery disease in the Mexican Mestizo population.     

Xbal polymorphism in DNA at the apolipoprotein B locus is associated with myocardial infarction (MI)

Bøhn M, Bakken A, Erikssen J, Berg K. Xbal polymorphism in DNA at the apolipoprotein B locus is associated with myocardial infarction (MI). Clin Genet 1993: 44: 241–248. © Munksgaard, 1993 High levels of low density lipoprotein (LDL) and its apolipoprotein B (apoB) are risk factors for atherosclerosis and myocardial infarction (MI). There is rich genetic polymorphism in apoB, first detected as the Ag allotypes of LDL, but today mostly examined at the DNA level. Genes contribute to the population variation in LDL and apoB levels and alleles in polymorphisms at the apoB locus are candidate genes with respect to control of lipid levels and susceptibility to atherosclerosis and MI. The Xbal polymorphism at the apoB locus, which involves the third base of threonin codon 2488 (ACC→ACT) without changing the amino acid sequence was examined in a case-control study comprising 238 survivors of myocardial infarction (MI) and 621 controls. In univariate analysis, frequencies of genotypes in this polymorphism were not statistically different between patients and controls of either sex. However, in multivariate logistic regression analysis, the odds ratio X - X - homozygotes (homozygotes for absence of restriction site) for having MI compared to the pooled group of heterozygotes and X + X + homozygotes (homozygotes for presence of restriction site) was 2.16 (p = 0.007), after adjustments for age, sex, and levels of apoB, high density lipoprotein (HDL) cholesterol (HDLC) and Lp(a) lipoprotein. It appeared that heterozygotes do not have increased risk, compared to the X + X + homozygotes. Stratification according to low or high levels of apoB, HDLC and Lp(a) lipoprotein, showed that the X - X - genotype was more common in patients than controls, in all subgroups. We conclude that the X - allele in double (but not in single) dose most probably increases the risk of MI. The increased risk is apparently not conferred by higher levels of total cholesterol, LDL or apoB, but through some variable or mechanism not closely related to traditional risk factors.     

The angiotensin-I converting enzyme I/D polymorphism is not associated with type 2 diabetes in individuals undergoing coronary angiography. (The Ludwigshafen Risk and Cardiovascular Health Study)

The deletion (D) allele of the angiotensin-I converting enzyme (ACE) is associated with higher ACE activity and has been implicated only recently in the pathogenesis of type 2 diabetes in Caucasian subjects. We have studied the ACE I/D polymorphism in 1054 patients with type 2 diabetes and in 2251 individuals without type 2 diabetes in Caucasians persons undergoing coronary angiography. Further parameters of glucose metabolism (fasting glucose, HbA1c, insulin, C-peptide, pro-insulin, and pancreatic beta-cell function) were analyzed according to the ACE I/D genotype in a subgroup of 2000 individuals in whom an oral glucose challenge was performed. The genotypes ACE II, ID, DD occurred at similar frequencies in patients with type 2 diabetes mellitus (21.0, 50.8, and 28.3%, respectively) compared to non-diabetic individuals (23.3, 49.2, and 27.5%, respectively). There was no association of the ACE D allele with all type 2 diabetes mellitus (OR 1.16, 95%CI, 0.94-1.43), nor with known (OR 1.28, 95% CI, 0.99-1.68) or newly diagnosed diabetes (OR 1.00, 95% CI, 0.75-1.32). These findings were not materially altered when we adjusted for age and gender, cardiovascular risk factors and anti-diabetic or cardiovascular medication. Further the ACE D-allele was not associated with angiographic coronary heart disease or myocardial infarction. The ACE I/D genotype is not associated with type 2 diabetes mellitus, glucose metabolism, coronary heart disease, or myocardial infarction.     

DNA polymorphism at the locus for human cholesteryl ester transfer protein (CETP) is associated with high density lipoprotein cholesterol and apolipoprotein levels

Cholesteryl ester transfer protein (CETP) is a protein involved in "reverse cholesterol transport" and it could play an important role in facilitating the removal of cholesteryl esters from peripheral tissues for transport to the liver or for transfer of cholesterol between plasma lipoprotein particles. Both functions may be relevant to susceptibility or resistance to atherosclerotic disease. We have studied 149 and 146 unrelated persons, respectively, for the A and B polymorphism at the CETP locus detectable with the restriction enzyme TaqI. The B system is by far the more polymorphic. A search for association with risk or "anti-risk" factor levels was conducted with the following quantitative parameters: total cholesterol, HDL cholesterol, triglycerides, apolipoprotein AI (apoA-I), apolipoprotein B (apoB) and Lp(a) lipoprotein levels. Highly significant differences in apoA-I concentration were found between the two categories of homozygotes in the B polymorphism. The association observed remained significant after multiplying the p value by the number of quantitative parameters used for the association tests. There was a dosage effect on the apoA-I level of genes in the B polymorphism. We conclude that the associations observed are likely to reflect true biological phenomena. The effect of CETP genes appeared to be limited to non-smokers.     

Ongoing hypermutation in the Ig V(D)J gene segments and c-myc proto-oncogene of an AIDS lymphoma segregates with neoplastic B cells at different sites: implications for clonal evolution

To investigate the role of somatic Ig hypermutation in the evolution of AIDS-associated B cell lymphomas, we analyzed the Ig V(D)J and c-myc genes expressed by neoplastic B cells in two extranodal sites, testis and orbit, and clonally related cells in the bone marrow. Testis and orbit B cells expressed differentially mutated but collinear V_HDJ_H, VκJκ and c-myc gene sequences. Shared mutations accounted for 10.2%, 8.4%, and 4.3% of the overall V_HDJ_H, VκJκ, and c-myc gene sequences. Tumor-site specific V_HDJ_H, VκJκ, and c-myc mutations were comparable in frequency, and a single point-mutation gave rise to an EcoRI site in the testis c-myc DNA. Both shared and tumor site-specific V_HDJ_H, VκJκ, and c-myc mutations displayed predominance of transitions over transversions. The “neoplastic” V_HDJ_H sequence was expressed by about 10⁻⁵ cells in the bone marrow, and contained two of the three orbital, but none of the testicular V_HDJ_H mutations. The nature and distribution of the Ig V(D)J mutations found in the κ chain suggested a selection by antigen in testis and orbit. Our data suggest that, in AIDS-associated B cell lymphomas, the Ig hypermutation machinery targets V_HDJ_H, VκJκ, and c-myc genes with comparable efficiency and modalities.     

Ongoing hypermutation in the Ig V(D)J gene segments and c-myc proto-oncogene of an AIDS lymphoma segregates with neoplastic B cells at different sites: implications for clonal evolution

To investigate the role of somatic Ig hypermutation in the evolution of AIDS-associated B cell lymphomas, we analyzed the Ig V(D)J and c-myc genes expressed by neoplastic B cells in two extranodal sites, testis and orbit, and clonally related cells in the bone marrow. Testis and orbit B cells expressed differentially mutated but collinear V_HDJ_H, VκJκ and c-myc gene sequences. Shared mutations accounted for 10.2%, 8.4%, and 4.3% of the overall V_HDJ_H, VκJκ, and c-myc gene sequences. Tumor-site specific V_HDJ_H, VκJκ, and c-myc mutations were comparable in frequency, and a single point-mutation gave rise to an EcoRI site in the testis c-myc DNA. Both shared and tumor site-specific V_HDJ_H, VκJκ, and c-myc mutations displayed predominance of transitions over transversions. The “neoplastic” V_HDJ_H sequence was expressed by about 10⁻⁵ cells in the bone marrow, and contained two of the three orbital, but none of the testicular V_HDJ_H mutations. The nature and distribution of the Ig V(D)J mutations found in the κ chain suggested a selection by antigen in testis and orbit. Our data suggest that, in AIDS-associated B cell lymphomas, the Ig hypermutation machinery targets V_HDJ_H, VκJκ, and c-myc genes with comparable efficiency and modalities.