Effect Of Polymorphisms Of ALOX5AP And IL-1A Gene On Ischemic Stroke

ObjectiveCerebrovascular disease(CVD)is one of the three major causes of death,and is harmful to human health.Ischemic stroke(IS)of incidence of cerebrovascular disease accounted for 80%.IS is a heterogeneous multifactorial disorder.Epidemiological data provide substantial evidence for a genetic component to the disorder,but the extent of predisposition is unknown.Genetic variance determines IS genetic predisposition. Although the exact mechanisms are not clarified,in recent years through polymorphisms linkage analysis some new susceptible genes have been reported such as apolipoproteinE(ApoE),phosphodiesterase 4D(PDE4D),Interleukin-1A(IL-1A), and arachidonate 5-lipoxygenase-activating protein(ALOX5AP)gene.However the association results of these candidate genes in different regions and for different ethnic population have not been effectively reapeated and confirmed.In view of northern Chinese population with higher incidence of IS,it is necessary to carry out an association study of candidated susceptible genes aimed at northern China region Han population IS.Atherosclerosis is an important pathophysiological basis of IS,and inflammatory reaction process is of great significance in atherosclerosis formation,so our study selected inflammation-related ALOX5AP and IL-1A gene.By introducing candidate genes case-control association analysis,we mesured ALOX5AP gene haplotype HapA four SNPs(SG13S25A/G,SG13S32A/C,SG13S89A/G,SG13S114A/T)and IL-1A-889 C/T SNP genotype and allele frequencies between IS group,IS subgroups and control group,and evaluated the association between these two genes SNPs and IS.So we can provide IS molecular epidemiology data for comprehensively understanding IS potential genetic mechanisms and more early IS molecular biology diagnosis indicators.Materials and methods A case-control design was introduced.The subjects of IS group were consecutively recruited from northern China region patients with a total of 472 cases male 283,female 189,aged 40-80 years old,Han nationality,no consanguinity with each other.The controls matched by age,sex,and ethnic orign were recruited from the same patients geographic region,with a total of 312 cases,male 183,female 129. Accordting to the different causes the patients were divided into two subgroups:the large vessels group(thrombotic cerebral infarction group) and the small vessels group(lacunar infarction group).ALOX5AP gene SG13S32,SG13S89,and IL-1A-889 SNPs were genotyped by polymerase chain reaction and restriction fragment length polymorphism(PCR-RFLP) analysis.ALOX5AP SG13S114 and SG13S25 SNPs were genotyped by means of Matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF) primer extension reaction.Genotyping results were confirmed by dideoxy termination squencing method.SPSS 13.0 statistical software was used for data processing.Continuous variables were expressed as mean±SE and were assessed by One-Way ANOVA.Genotype and allele frequencies were calculated for control group and each of the patient groups.Univariate comparisons of allele and genotype distributions were done using x~2 test.The x~2 goodness of fit test was used to test for deviation of genotype distribution from Hardy-Weinberg equilibrium. Conditional Logistic Regression adjusted for IS traditional risk factors including age, blood pressure,blood sugar,blood lipids and smoking.The influence of AlOX5AP and IL-1A gene polymorphisms on IS was indicated by odds ratio(OR) and 95% confidenc(CI) with P＜0.05 as significant criteria.Haplotype-based analysis was infered by using Shesis online-software.The synergistic action of ALOX5AP gene and IL-1A gene for IS was analysed by UNPHASED 3.0.7 version software.Results1.The genotype frequencies of all SNPs conformed to the expectations of Hardy-Weinberg equilibrium(P>0.05).It was suggested that the selected samples could represent the population and were suitable for genetic analysis.2.ALOX5AP gene SNPs frequencies distributions among the patients and the controls:SG13S32 C allele frequencies of the IS group were higher than the control group(OR=1.271;95%CI:1.027-1.572;P=0.028);SG13 S 114 AA genotyp frequencies of the large vessels group were higher than the control group(OR=1.987;95%CI: 1.138-3.471;P=0.014),and after conditional logistic regression the differece was still significant(OR=1.479;95%CI:1.024-2.135;P=0.037).3.ALOX5AP gene haplotype frequencies among the patients and the controls: ALOX5AP gene HapA haplotype frequencies were normal among the patients and the controls;GCGA haplotype frequencies of the IS group were higher than the control group(OR=1.683;95%CI:1.138-2.487;P=0.008),the frequencies of the large vessels were higher than the control group(OR=1.629;95%CI:1.047-2.532;P=0.029),and the frequencies of the small vessels group were remarkably higher than the control group(OR=1.806;95%CI:1.156-2.822;P=0.009);GAGA haplotype frequencies of the IS group were lower than the control group(OR=0.763;95%CI:0.583-0.988; P=0.048),and the frequencies of the large vessels group were lower than the control group(OR=0.719;95%CI:0.522-0.99;P=0.042)4.ALOX5AP gene haplotype gender-specific frequencies distributions: Significant differences of all the haplotypes were not observed in the male and female IS group and control group.5.L-1A-889 SNPs frequencies distributions among the patients and the controls: IL-1A-889 TT frequencies of the IS group were higher than the control group (OR=2.473;95%CI:1.129-5.42;P=0.02),and after conditional logistic regression the difference was still significant(OR=1.581;95%CI:1.003-2.493;P=0.047); IL-1A-889 T allele frequencies of the large vessels group were higher than the control group(OR=1.540;95%CI:1.075-2.204;P=0.018).IL-1A-889 gene polymorphisms distributions were not different among male and female.6.ALOX5AP gene and IL-1A gene synergistic reaction:The individuals who carried the haplotype GCGA and IL-1A-889 C allele suffered IS with the 1.608 folds risk(OR=1.608;95%CI:1.067-2.423;P=0.022).Conclusions1.ALOX5AP gene SG13S114 AA genotype might be the independent risk factors of northern China region han population thrombotic cerebral infarction,and its risk mainly came from T allele.2.SG13S32 C allele can increase genetic susceptibilty of thrombotic cerebral infaction.3.The association ofALOX5AP gene HapA haplotype with IS was not identified.4.ALOX5AP gene GCGA haplotype might be at-risk haplotype of IS,and GAGA haplotype might be protective haplotype of IS.5.The association of ALOX5AP gene with IS was not related with male and female sex.6.IL-1A-889 TT genotype could be independent risk factor of thrombotic cerebral infarction,and its genetic susceptibility mainly came from T allele.7.The association of IL-1A-889 with IS was not related with male and female sex.8.ALOX5AP and IL-1A gene polymorphisms can synergistically confer higher risk for IS of northern China region population.