ABSTRACT
Objective To investigate whether metabolic pathway-related gene polymorphisms are associated with arterial plaque stability and their gene-gene interactions increase the risk of cerebral infarctions.Methods Totally 294 patients with atherothrombosis stroke admitted to the Department of Neurology, the Third Affiliated Hospital of Wenzhou Medical University from September 2010 to December 2012 were divided into a carotid vulnerable plaque group ( n=69 ) and a stable plaque group ( n=225 ) according to the results of carotid B-mode ultrasonography.A total of 282 healthy volunteers excluded carotid plaque and stroke were enrolled as well.Genetic polymorphisms of ALOX5AP and CYP3A5, CYP2C9*2, CYP2C9*3 and EPHX2 were genotyped using polymerase chain reaction and mass spectrometry analysis.The SPSS16.0 software was used to compare genotype frequencies and the generalized multifactor dimensionality reduction ( GMDR ) method was applied for gene-gene interaction analyses.Results The results showed that EPHX2 GG genotype might protect against stroke ( OR =0.520, 95% CI 0.288 -0.940, P=0.030).The distribution of CYP3A5 genotypes showed statistically significant differences (χ2 =7.284, P=0.026) between the vulnerable plaque ( AA: 5 cases, AG: 36 cases, GG: 28 cases) and stable plaque ( AA: 26 cases, AG: 77 cases, GG: 122 cases ) groups.Multivariate Logistic regression analysis showed that the GG genotype of CYP3A5 was protective factor for unstable plaques ( OR=0.405, 95%CI 0.178 -0.920, P =0.031 ).Differences in other SNPs did not reach statistical significance between the two groups.The GMDR analysis showed a significant gene-gene interaction between SG13S114 and A6986G, with scores of 10 for cross-validation consistency and 9 for the sign test (P=0.011).The best model for ischemic stroke was found to be SG13S114 AA and A6986G AA.Adjusting for age, hypertension and diabetes, the certain gene-gene interaction predicted a significantly higher risk of cerebral infarction (OR=1.804, 95%CI 1.180-2.759, P=0.006).Conclusions The EPHX2 G860A gene might be linked with the incidence of cerebral infarctions.Only a CYP3A5 gene polymorphism might be associated with carotid plaque instability in patients with stroke.The gene-gene interaction predicts a significantly higher risk of cerebral infarction.There is a 1.804-fold increased risk for ischemic stroke in individuals with these combined genetic factors.