title: Association between apolipoprotein E gene polymorphism and the risk of multiple sclerosis: a meta-analysis of 6977 subjects.
abstract: Epidemiological studies have evaluated the association between apolipoprotein E (ApoE) gene polymorphism and multiple sclerosis (MS) risk. However, the results remain conflicting. Therefore, in order to derive a more precise association of ApoE gene polymorphism with MS risk, we performed this meta-analysis. Systematic searches of electronic databases PubMed, Embase and Web of Science, as well as hand searching of the references of identified articles were performed. Twenty studies were identified, covering a total of 4080 MS cases and 2897 controls. The results showed evidence for significant association between ApoE ε2 mutation and MS risk (for ε2/ε4 versus ε3/ε3: OR=1.74, 95% CI=1.12-2.71, p=0.01; for ε2 allele versus ε3 allele: OR=1.16, 95% CI=1.01-1.35, p=0.04). In the subgroup analysis by ethnicity, the similar results were obtained among Europeans (for ε2/ε4 versus ε3/ε3: OR=1.81, 95% CI=1.14-2.87, p=0.01; for ε2 allele versus ε3 allele: OR=1.19, 95% CI=1.02-1.38, p=0.03). After excluding the outlier studies by observing Galbraith plot, marginal association was found between ApoE ε3/ε4 genotype and the protective factor for MS (for ε3/ε4 versus ε3/ε3: OR=0.86, 95% CI=0.75-0.99, p=0.04). In summary, the present meta-analysis provides evidence that ApoE ε2 mutation is associated with MS risk. In addition, ApoE ε3/ε4 genotype appears to be a protective factor for MS.
authors.affiliation: Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing 400042, PR China.
authors.forename: Yan-Wei
authors.initials: YW
authors.lastname: Yin
authors.forename: Yun-Dong
authors.initials: YD
authors.lastname: Zhang
authors.forename: Jing-Zhou
authors.initials: JZ
authors.lastname: Wang
authors.forename: Bing-Hu
authors.initials: BH
authors.lastname: Li
authors.forename: Qing-Wu
authors.initials: QW
authors.lastname: Yang
authors.forename: Chuan-Qin
authors.initials: CQ
authors.lastname: Fang
authors.forename: Chang-Yue
authors.initials: CY
authors.lastname: Gao
authors.forename: Jing-Cheng
authors.initials: JC
authors.lastname: Li
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Zhang
mesh_terms: D001057:Apolipoproteins E / Q000235:genetics*; D016022:Case-Control Studies; D005787:Gene Frequency; D056726:Genetic Association Studies; D006801:Humans; D008957:Models, Genetic; D009103:Multiple Sclerosis / Q000235:genetics*; D011110:Polymorphism, Genetic; D017594:Publication Bias; D012307:Risk Factors
chemical_list: D001057:Apolipoproteins E