广州75岁以上老年人群中载脂蛋白E基因多态性与阿尔茨海默病关系的研究

目的：了解广州地区高龄老年人群中阿尔茨海默病（AD）患者载脂蛋白E（apoE）基因型的分布,探讨apoEε4等位基因和AD之间的关联性,方法：采用系统整群抽样方法获取样本进行社区横断面研究,调查广州市荔湾75岁以上的老年居民3825名,按DSM－Ⅲ-R和NINCDS／ADRDA的诊断,从中筛选出无血缘关系的散发性AD患者190例,其中110例接受抽血检查,并以该人群中518名接受抽 检查的健康老年人作为对照组,用PCR－RFLP技术,以测以上两组的apoE基因型。结果：AD组apoEε2、ε3、ε4等位基因频率分别为10．0％、83．2％、6．8％,对照组apoEε2、ε3、ε4等位基因频率分别为9．2％、84．3％、6．5％。AD组与对照组在apoE基因型频率及等位基因频率分布上的差异均无显著性（P＞0．05）。结论广州市荔湾区75岁以上老年人群中,未发现apoEε4等位基因与散发性AD之间有显著性关联。

Association between apolipoprotein E polymorphismand Alzheimer' s disease:Apopulation-based study in Guangzhou, China

OBJECTIVE: To investigate the distribution of apolipoprotein E (apoE) genotype of patients with Alzheimer's disease (AD) in the population aged 75 and older in Guangzhou and to determine whether there was an association between AD and apoE epsilon4 allele. METHODS: A systematic cluster sampling design, two-stage screening and field evaluations were used in a cross-sectional population-based study. Three thousand eight handred and twenty-five subjects aged 75 and above in Liwan district of Guangzhou were interviewed. Blood samples were collected from 110 cases and 518 normal controls. The criteria of DSM-III-R and NINCDS-ADRDA were used for clinical diagnosis of probable AD. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to determine apoE genotypes. RESULTS: There were 190 cases diagnosed as sporadic AD from this sample. The frequencies of the three apoE alleles were detected as follows: epsilon2 = 0.100, epsilon3 = 0.832, epsilon4 = 0.068 in AD patients; epsilon2 = 0.092, epsilon3 = 0.843, epsilon4 = 0.065 in normal controls. The frequencies of apoE genotype and allele in the AD patients were not significantly different from that in normal subjects (P > 0.05). CONCLUSION: No association between sporadic AD and apoE epsilon4 allele was found among the population aged 75 and above in Liwan district of Guangzhou.