老年人载脂蛋白E基因型与认知功能关系的研究

A study of the relationship between apolipoprotein E genotypes and cognitive function in elderly people

目的 研究老年人中载脂蛋白E(ApolipoproteinE ,ApoE)基因型的分布情况 ,分析ApoE基因型与认知功能的关系。 方法 用简易智能量表 (Mini MentalStateExamination ,MMSE)对 31 6例 60岁以上老龄人进行认知功能检查 ,根据MMSE得分将研究对象分为认知功能正常组和认知功能障碍组 ,分离其白血细胞基因组DNA ,用聚合酶链反应 (ploymerasechainreaction ,PCR)技术扩增ApoE带有多态性位点的第四外显子片段 ,根据限制性酶切片段长度多态性分析 (restrictionfragmentlengthpolymorphism ,RFLP)方法检测其基因型。结果 两组人群中ApoEε3/ 3基因型分布的百分比最大 ,其次为ApoEε3/ 4基因型 ,而ApoEε2 / 2基因型最小 ;ε2、ε3、ε4等位基因频率在认知功能障碍组和认知功能正常组分别为 :0 .0 95、0 .560、0 .345 ;0 .1 4 6、0 .699、0 .1 55。认知功能障碍组ε4携带者百分比大于对照组 (P <0 .0 1 ) ,ApoEε3/ 4基因型百分比也较认知功能正常组大 (P <0 .0 1 )。结论 老年人群中 ,ApoEε3/ 3为最常见的基因型 ,而ε2 / 2最少见 ;

Objective In order to explore the status of the distribution for Apo E genetypes frequency in older people and clarify the relationship between Apo E genetype and cognitive impairment onset. Methods A total of 316 residents aged 60 years and over were collected and tested with MMSE to inspect their cognitive function,and they were classified into the impaired group and the non impaired group according to MMSE scores;to isolate the genomic DNA from their peipheral blood lymphocytes. The exon 4 of ApoE gene with polymorphism sites was amplified by using PCR technique,;to determine the ApoE genotypes. by RFLP method.Results The most frequent genotype was Apo E ε3/3 ,the next was ApoE ε3/4 and the lest frequent genotype was Apo E ε2/2 in the two groups.The estimated ApoE allele frequencies in the sample of cognitive impairment subjects were 0.095,0.560 and 0.345 forε2,ε3 and ε4,respectively,and 0.146,0.699 and0.155 respectively in the sample of the non control impaired group.The percentage ofε4 allele carriers in the impaired group was bigger than in the non impaired group(P<0.01).The impaired group had distinctly higher percentage of ε3/4 genotype than the non impaired group.Conclusions Apo Eε3/3 was most common genetype for elderly people,but the Apo Eε2/2 was lowest, and Apo Eε4 has strong relation to development of cognitive impairment therefore, we consider that the Apo Eε4 may be a higher risk factor for cognitive impairment onset.