载脂蛋白E基因多态性与阿尔茨海默病

Apolipoprotein E Gene Polymorphisms and Alzheimer Disease

利用PCR RFLP方法分析了中国汉族人群中 16 0例散发性阿尔茨海默病 (Alzheimerdisease,AD)患者和 195例正常对照老年人中载脂蛋白E(APOE)基因多态性分布的差异。结果表明 ,APOE 3种等位基因ε2、ε3和ε4的频率在AD组和对照组分别为 0 0 5 6、0 713、0 2 31和 0 0 82、0 84 4、0 0 74。APOEε4等位基因携带个体患AD的危险为非携带个体的 3 82倍 (χ2 =2 8 7,P <0 0 0 1)。 6 5岁以上APOEε4携带个体患AD的危险为非携带个体的 5 38倍(χ2 =2 9 8,P <0 0 0 1) ,说明年龄因素可能影响ε4与AD间的相互作用。APOE等位基因和基因型频率在轻、中和重度痴呆病人间的分布无明显差异 (P >0 0 5 ) ,提示APOE基因多态性可能与AD患者的痴呆程度无关联。APOEε4基因型频率在女性AD病人中的分布略高于男性AD病人 (4 3 0 %对 36 5 % ) ,女性ε4携带个体患AD的危险也高于男性ε4携带个体 (4 3倍对 3 3倍 ) ,但统计学分析未检测到这些差异的显著性 (P >0 0 5 )。ε2等位基因频率在AD患者男性亚组明显低于女性亚组 ,也低于对照人群的男性亚组 (P <0 0 5 ) 。

PCR RFLP was used to investigate the distribution differences of apolipoprotein E ( APOE ) alleles and genotypes between sporadic Alzheimer disease (AD) patients (n=160) and healthy control individuals (n=195) in Chinese Han population.The results showed that the allelic frequencies of APOE ε2,ε3 and ε4 were 0 056,0 713 and 0 231 in AD group respectively,and 0 082,0 844 and 0 074 in control group respectively.The frequency of ε4 allele was significantly higher in AD cases than in control subjects and ε4 allele was associated with AD by an odds ratio (OR) of 3 82 (χ 2=28 70, P <0 001).The probability for APOE ε4 carriers to suffer from AD after 65 years old was 5 38 times of that for APOE ε4 non carriers (χ 2=29 76, P <0 001),suggesting that age might affect the interaction between APOE ε4 and AD.In addition,our results showed that the distributions of APOE alleles and genotypes were comparable among mild,moderate and severe dementia patients ( P >0 05),suggesting that APOE gene polymorphism was not likely to contribute to dementia severity of AD patients.The frequency of APOE ε4 genotype in female patients was higher than that in male patients(43 0% vs.36 5%)and females carrying APOE ε4 allele had higher OR value than corresponding males (4 3 vs.3 3),but the differences were not statistically significant ( P >0 05).As to ε2 allele,its frequency was significantly lower in male subgroup than in female subgroup of AD patients and also than in male subgroup of normal control ( P <0 05),suggesting that ε2 allele was possibly an AD protective factor in Chinese male population.