α3—巨球蛋白基因多态性与Alzheimer病的关联研究

目的：观察α2-巨球蛋白基因（α2-macroglobulin,A2M) 内含子17一种五核苷酸缺失突变在广州地区汉族老年人中的分布，探讨其与晚发Alzheimer病（AD）的相关性。方法：以97例晚发AD患者和111名健康老年人为对照进行病例－对照研究。用聚合酶链反应－限制性片段长度多态性方法分析A2M缺失／插入多态性和载脂蛋白E（apolipoproteinE,apoE)基因多态性。结果：（1）A2M基因缺失突变在晚发AD患者中的频率为2．6％，在正常老年人中的频率为2．7％，在所有受试者中未检测到A2M突变纯合体，晚发AD患者和健康老年人之间不存在A2M等位基因和基因型分布的差异，A2M基因多态性与晚发AD无关联。（2）晚发AD患者中apoE等位基因ε4频率显著升高（Z＝3．32，P＜0．01）。晚发AD与ε3／ε4基因型正关联（RR＝2．62，χ^2=6.89,P＜0．01），和等位基因ε4正关联（RR＝2．67，χ^2=10.71,P＜0．01）。（3）晚发AD无论是否伴有apoE-ε4均与A2M不存在相关性。结论：广州汉族人群中A2M基因缺失突变多态性与晚发AD不具有关联。

No evidence for association between the

OBJECTIVE: To determine the effect of the pentanucleotide deletion polymorphism adjacent to a consensus splice site in intron 17 of alpha 2-macroglobulin(A2M) gene on the development of late-onset Alzheimer's disease (LOAD) in the Han Chinese in Guangzhou area. METHODS: A2M and apolipoprotein E genotypes were examined by polymerase chain reaction(PCR) and restriction fragment length polymorphism (RFLP) techniques in the patients(32 men and 65 women) with LOAD and age-matched healthy elderly Chinese subjects (57 men and 54 women). RESULTS: The A2M gene deletion allele frequency was 2.6% in the cases with LOAD and 2.7% in the controls. In the LOAD cases, the frequency of apoE-epsilon4 increased significantly (Z=3.32, P<0.01). ApoE-epsilon4 was associated with LOAD (RR=2.67, chi(2)=10.71, P<0.01) while the A2M deletion polymorphism was not associated with LOAD even the samples were stratified according to the presence of the apoE-epsilon4 allele. CONCLUSION: The above data demonstrate that there is no evidence for the association of A2M polymorphism with the development of LOAD in the Han Chinese population in Gaungzhou.