载脂蛋白E基因多态性与散发性老年性痴呆病的关系

目的:探讨载脂蛋白E(apoE)外显子4和增强子元件基因多态性与散发性Alzheimer病(AD)的关系。方法:应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术分别检测apoE外显子4和内含子1内增强子元件(IE1)基因型。结果:(1)ApoE外显子4基因多态性:AD组ε3/4基因型频率(0.381)和ε4等位基因频率(0.226)显著高于对照组(P＜0.05)。(2)ApoEIE1基因多态性AD组G/G基因型频率(0.595)显著高于对照组(P＜0.05)。(3)有apoEε4个体患AD风险为无ε4个体的3倍,比值比为2.932,95%可信区间1.379~6.226;G/G基因型个体患AD风险为G/C、C/C个体的2倍,比值比为2.223,95%可信区间1.075~4.599;经统计分析发现apoEε4与IE1G/G呈非常显著性正相关(P＜0.01);排除apoEε4后发现IE1G/G与AD发病风险无关。结论:ApoEε4等位基因是个体发生AD的危险因素,IE1G/G增加AD发病风险是因其与ε4相关所致。

Relationship between apolipoprotein E gene polymorphism and sporadic Alzheimer's disease

AIM: To evaluate the association between apolipoprotein E(apoE) gene polymorphism and sporadic Alzheimer's disease (AD). METHOD: A case-control study was undertaken detecting the polymorphism of apoE by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).RESULTS:(1)The frequencies of 3/4 genotype and 4 al ele in AD were significant ly higher than that in age-matched controls(P<0.05).(2)The frequency of G/G genotype for apoE IE1 in AD was significantly higher than that in age-mat ched control(P<0.05).(3)The apoE 4 al ele was associated with a tripling of the risk for AD compared with no 4 allele(odd ratio 2.932, 95%CI 1.379~6.226);Homozygosity of the G allele in IE1 was associated with adoubling of the risk for AD compared with the G/C and C/C genotypes(odd rat io 2.223, 95%CI 1.075~4.599).However, the IE1 G al ele is also closely associated with apoE 4.When the sample was split on the basis of apo Egenotype, the associat ion between IE1 G/G genotype and AD was no longer statistically significant.CONCLUSION: ApoE ε4 was a risk factor of AD, and the apparent association between IE1 G/G and AD is a consequence of the association between the ε4 and IE1 G/G genotype.