阿耳茨海默性痴呆与血管性痴呆的ApoE基因多态性研究

目的探讨ApoE基因在阿耳茨海默性痴呆（Alzheimer-typedementia，AD）与血管性痴呆（Vasculardementia，VD）患者当中的分布情况，以找出中国人的特点，评价ApoE基因检测在早期预测性诊断中的作用，比较AD与VD在ApoE基因多态性方面的异同。方法采用PCR-RFLP方法，对41例AD、35例VD和30例对照进行ApoE基因型测定。结果小于70岁的AD患者，其ε4等位基因频率大大高于同龄VD组患者和同龄对照组（P＜0.01和P＜0.05）。而≥70岁的AD患者ε4频率明显低于70岁以下AD患者（P＜0.01）。结论（1）ApoEε4与散发性AD之间具有明显相关性，其基因型以4/3为主，而ε4/4相对于国外文献报道要少。（2）AD组ε4等位基因频率高于VD组（P＜0.05）。（3）评价AD发病危险时，年龄因素不容忽视，70岁以下ε4携带者可能具有更高的AD发病危险性。

A study on ApoE genotype in Alzheimer-type dementia and vascular dementia

Objective　 To explore the frequency of ApoE genotype in Alzheimer-type dementia (AD) and vascular dementia (VD), to find Chinese features of these genotype in comparison with western reports，to evaluate the role of ApoE genotype examination in predicting diagnosis, and to compare the difference in ApoE genotype in AD and VD. Methods　 Using PCR-RFLP technique to examine ApoE genotype in 41 cases with AD, 35 cases with VD and 30 control. Results　 There was a higher ε4 allelic gene frequency (P<0.05) in AD than in VD and control in the groups of < 70 year old （P＜0.01 and P＜0.05）. However, a lower ε4 allelic gene frequency (P<0.01) in AD than in VD and control in the groups of 70 year old. Conclusion　 (1)This study indicates that there is a correlation between ApoE allelic gene ε4 and sporadic AD. The genotype is mainly 4/3, in which ε4/4 is lower than report in foreign countries. (2) The frequency of ApoE　ε4 genotype is higher in AD than in VD group (P<0.05). (3) When evaluating the correlation between ApoE ε4 and AD, the factor of age should be emphasized. The carrier of ε4 with age of <70-year-old is vulnerable to AD.