Association Of The Polymorphisms Of Apolipoprotein E Gene,Cholesterol 24S-hydroxylase Gene With Alzheimer's Disease

Objective: To explore the roles of the polymorphisms of apolipoprotein E (ApoE) gene,the cholesterol 24S-hydroxylase(CYP46) gene in the development of Alzheimer' s disease(AD) in Han people of ShanXi province.Methods: The gene polymorphism distribution of ApoE and CYP46 were detected in 40 AD patients (≥65 years old) and 36 normal controls with polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) . The detections of odd ratio and its chi-square significance were used.Results: 1,The frequency of alleleε4 in patients with AD increased significantly compared with that of the normal controls(χ2 =16.151,P< 0.001), Alleleε4 of the ApoE increased the risk of Alzheimer's disease (OR=9.281,95%CI(2.650-32.497), P=0.000),and the alleleε3 of ApoE gene was a protective factor for AD in chinese population(OR=0.314,CI 0.149-0.663) .2,The distribution of CYP46 three genotypes was significantly different in AD patients as compared to the normal controls(χ2=6. 863, P=0.032),The presence of at least one of CYP46 allele T was higher in AD patients than the normal controls (χ2=4.823 , P=0.028)。The presence of the ApoEε4 allele did not influence CYP46 genotypes or allele distribution.3. All the subjects were stratificatied by age, we found that there was significant difference in the allele frequency of ApoEε2,ε3,ε4 between the AD cases and controls groups(>70 years old)(χ2=15.343,P=0.000); while no significant difference was found in two groups(≤70 years old). Alleleε4 of the ApoE increased the risk of Alzheimer's disease when patients were beyond 70 years(OR=21.579,95%CI(2.761-168.680),P=0.000). But we didn't found the significant difference of CYP46 gene polymorphism in the stracification of age between AD and control groups (P>0.05).Conclusion: This study shows that alleleε4 of the ApoE is a major risk factor of sporadic AD and it has correlation with age. The alleleε3 of ApoE gene might be a protective factor;The allele T of CYP46 gene might be the risk factors for AD, the presence of the ApoEε4 allele did not influence CYP46 genotypes or allele distribution; A positive correlation is found between ApoE gene polymorphism, CYP46 gene polymorphism and AD .