1、Gene Polymorphisms and Coronary Heart DiseaseFang ZhengClinic Lab,Zhongnan Hospital,Wuhan UniversityCoronary Heart Disease is still the No.1 killer in the world.GeneticsEnvironmentalLife styleThe prevention of CHD is based on the control of several factors associated with a disease or clinical condi
2、tion and suspected to play a pathogenetical role,defined as risk factors.The risk factors of CHD included:AgeClotting factorsSex Fibrinolytic factors Hypertension Hyperhomocysteinaemia SmokingInflammation factorsDiabetesEndothelium factorHyperlipidaemia Nutrition factorObesity Post-menopausal status
3、 Genetic factorsEmerged CHD Risk FactorsBut only in 5%of hereditary CHD,the gene background was clear.In the others,each genetic factor played a minor role in occurrence and development of the disease.Rare mutations(e.g.,in the LDLR and APOE genes)may have a major effect,whereas genes belonging to n
4、ormal polymorphism have only a moderate effect.But even genes with only a slight effect can be clinically important in combination with other genes.The importance of polymorphism analyses will increase significantly in the near future.Whats normal polymorphism?The occurrence in a population(or among
5、 populations)of several phenotypic forms associated with alleles of one gene or homologs of one chromosome.The occurrence together in the same population of more than one allele or genetic marker at the same locus with the least frequent allele or marker occurring more frequently than can be account
6、ed for by mutation alone.Polymorphism and Mutation They are both single nucleotide poly-morphism，SNP.npolymorphismnormal phenotypenmutationdiseasenpolymorphismmorenmutation less Cardiovascular disease is complex as a consequence of pleiotropy.These included environmental and genetics factors.Gene po
7、lymorphism played an important role in the occurrence and development of cardiovascular disease.And it can be applied on the prediction,diagnosis,treatment and prognosis.1.The gene polymorphisms as independent risk predictorsnAn HphI polymorphism in the E-selectin gene is associated with premature c
8、oronary artery disease.nApoE gene polymorphism is related to coronary heart disease.nE23K polymorphism in KCNJ11 gene has relationships with coronary heart disease.Every gene variants that contribute to CHD like tiny weights in balance.E-selectin belongs to a family of structurally related selectin
9、molecules including E-,P-and L-selectin and participates in the endothelial-leukocyte adhesion.Experiments using E-and P-selectin-double-knockout mice suggest that E-and P-selectin together play an important role in both early and advanced stages of the atherosclerotic lesion development.Several pol
10、ymorphisms in the E-selectin gene have been identified as new risk factors for the early atherosclerosis.1.1 The G98/T polymorphism in E-selectin gene and CHDThe transversion of G98T mutation abolishes the HphI recognition site.NT 92 TTGGGTGAAAAG103NT 92 TTGGGTTAAAAG103HphIHphIbp332194138Kb1.350.630
11、.310.190.12 The PCR product was digested by HphI and separated on 2%agarose gel electrophoresis.PCR amplification of the genomic DNA,subcloning and DNA sequencing were carried out.9898GG genotype:TT genotype:Table Frequency of the E-selectin G98T mutation in the angiographically documented premature
12、 CAD and controls(The original population:all males aged 50 yr.old,all females aged 60 yr.old;the subset:All males aged 45 yr.old,all females aged 55 yr.old)a:In control,32 males,39 females;in CAD,51 males,42 females.b:Chi-square statistical analysis was done using Sigma Stat(ver.2.0,SPSS Inc.,Chica
13、go,IL).c:In control,21 males,29 females;in CAD,28 males,23 females.d:Include 18 heterozygotes(GT)and two homozygotes(TT).N G-allele(%)T-allele (%)Total allelesThe populationa Control 71 128 (90.14)14 (10.93)142 CAD 93 160 (86.02)26(13.98)186 P b NSThe subsetc:Control 50 90 (90.00)10 (10.00)100 CAD 5
14、1 80 (78.43)22d(21.57)102 Pb 0.05)The concentrations of C-reactive protein in different genotype groups Gene typen CRP medianInter-quartile rangeCC121 2.05*0.67-3.64*CT93.98 1.69-6.68*(P0.05)The Taqpolymorphism of IL-1 was associated with the concentrations of CRP in normal peoplen The Taqpolymorphi
15、sm of IL-1 was not associated with with CHD nCRP,The first acute-phase protein to be described,its plasma concentration increases during inflammatory states.nRecently,CRP might have an important role in the pathogenesis and prediction of CHD.1.7 CRP gene and CHDnPolymorphism analysisFigure 1-1 Deter
16、mination of the+1444 C/T polymorphism in the CRP gene by PCR-RFLP.Lane M：DNA Marker;Lane A：PCR product;Lane B：homozygous CC;Lane C：heterozygous CT;nPolymorphism analysisFigure The chromatogram of homozygous CCnComparison of distribution of+1444 C/T genotypes and alleles between CHD group and control
17、 groupGroupsnGenotype Distribution(%)Allele Distribution(%)CCCT+TTCTCHD128114(89.1)14(10.9)242(94.5)14(5.5)Control119107(89.9)12(10.1)226(95.0)12(5.0)20.0480.045P0.8270.832OR(95%CI)0.913(0.4042.063)*0.918(0.4162.027)*:genotype CC vs CT+TT；：；：allele C vs TnThe concentrations of C-reactive protein in
18、different groups GroupsnmedianInter-quartile rangeCHD1281.210.632.58CC1141.210.672.48CT+TT141.520.513.73Control1190.770.591.22CC1070.750.591.15CT+TT121.420.663.05nThe+1444 C/T polymorphism of CRP was associated with the basal concentrations of CRP in normal people.nThe+1444 C/T polymorphism of CRP w
19、as not associated with CHD.1.8 Conclusion for the study on polymorphisms as predictors of CHDnWe found the polymorphisms of E-selectin,ApoE gene and KCNJ11 gene were related to CHD disease.nThe polymorphisms in LDL-R gene and ApoE gene effected the level of lipid.nThe polymorphisms of IL-1and CRP ge
20、nes influenced the CRP baseline.nWe didnt find any association between polymorphism in fibronectin gene and CHD.n Patients with an acute myocardial infarction are of high risk to develop ischemia induced ventricular arrhythmias,leading to sudden cardiac death in about one third of all AMI patients.n
21、The individual susceptibility to ischemia-induced arrhythmias may be modified by polymorphisms in genes encoding ion channels.nA.Jeron studied the Kir6.2 gene.Opening of the KATP channel during ischemia results in action potential shortening in various studies and may therefore influence the outcome
22、 of AMI patients.nHowever they didnt find any significant influence of Kir6.2 gene polymorphism on the risk of SCD in patients with CHD.But they identified two novel missense mutations in a highly conserved region of the Kir6.2 gene.2.Gene polymorphism and prognosisFrom:Johnson J.A.TRENDS in Genetic
23、s 2019 Vol.19 No.11:660-6663.Gene polymorphism and pharmacogenomicsqThe new pharmacogenetics uses powerful experimental and data-handling techniques in DNA analysis to discover and assemble a comprehensive list of the variations within the human genome specifically,SNPs and then defines complex gene
24、tic profiles of these SNPs that predict the use of new or existing therapeutic agents with maximal efficacy and minimal toxicity.nA genetic test for certain single nucleotide polymorphisms(SNP)will predict you that:You should suffer a severe adverse reaction to it.You are expected to shown an excell
25、ent response to a different medication with little chance of side effects.nThis is the promise of pharmacogenetics The optimization of drug therapy based on the individual genetic profile.n The HMG-CoA reductase is the rate-limited enzyme in the biosynthesis of cholesterol.n Statins,the HMG-CoA redu
26、ctase inhibitors,are widely designed to reduce de novo cholesterol biosynthesis.n The efficacy and toxicity of Statins are different in different individuals.For Example:n Recently,investigation in the relationship of statins effects and gene polymorphisms related to the lipoprotein metabolism has b
27、een developed.n These genes included the apolipoprotein E gene,hepatic lipase gene,lipoprotein lipase gene and CETP gene.n In 2000,Siest G et al used different HMG-CoA reductase inhibitors to detect the relationship of apo E polymorphisms and LDL-C level.It showed the best effects to reduce LDL-C in
28、2 carriers.n The4 carriers has elevated level of plasma cholesterol.And the affinity of LDL particles to LDL receptor was increased,the activity of HMG-CoA reductase was decreased.The effect of statins in4 carriers was poor may be due to the low base level of HMG-CoA reductase activity.n In 2019,Car
29、lquist et al had concluded that the Taq1B polymorphism in the CETP gene is associated with CETP activity,HDL concentration,atherosclerosis progression,and response to statins.n Their findings suggested,for the first time,the potential of CETP Taq1B genotyping to enable more effective,pharmacogenetic
30、ally directed therapy.From:Johnson J.A.TRENDS in Genetics 2019 Vol.19 No.11:660-666Identification of all gene variants that contribute to CHD appears possible;this may considerably improve our understanding of the aetiology and mechanisms of this disease.Furthermore,simultaneous analysis of several
31、predisposing alleles may help to identify high-risk individuals and assess prognosis.And the treatment of CHD could be guided by screening certain SNP using pharamcogenetic methods.In a word,.From:Pfost D R et al.TIBTECH,2000(Vol.18):334-338Aknowlegement！Aknowlegement！Aknowlegement！Aknowlegement！Prof.Xin ZhouProf.Li XiaYin ZhangChenling XiongXiaobo Sun
