Alzheimer病患者线粒体DNA点突变的研究

A study on point mutations of mitochondrial DNA in the patients with Alzheimer＇s disease

目的旨在观察Alzheimer病（Alzheimer disease,AD）患者线粒体DNA（mitochondrial DNA,mtDNA）上点突变的情况,并探讨mtDNA点突变与AD发生的关联性.方法入组了111例AD患者作为AD组和性别/年龄与之相匹配的正常老人117名组成对照组,应用PCR-RFLP的方法对被研究对象mtDNA上分别位于第4336、5460和8021三个位置的点突变情况进行检测.结果第4336位置上的碱基未发现存在突变的现象.第8021位置上的碱基仅在正常老人组内检测到1例突变型,其余均为野生型.在第5460位置上对照组突变率为2.6%（3/117）,AD老人组中突变率为6.3%（7/111）,显著性检验x^2=1.902,P=0.168.结论在我国上海汉族人群中线粒体DNA上第4336位置上可能不存在点突变的现象,第8021位置上突变也很少发生,在第5460位置上的碱基可能出现A或T的点突变,但这种突变的发生可能与AD的发生无直接关联.

Objective： To investigate the mutations of mitoehondrial DNA （mtDNA） in the patients with Alzheimer＇s disease （AD） and to detect the association between the mutations and AD. Methods： 111 patients with AD and 117 age -matched healthy comtrols were involved. The mutations at the positions of 4336, 5460 and 8021 in mtDNA were detected with PCR - RFLP. Results：The 4336G mutation was not present in our AD patients and the age- matched healthy samples. The 8021 A/G mutation was not present in any of our 111 AD samples but occurred in 1 individual of 117 （0.85%） controls. The 5460A or T mutation occurred in 7 of 111 （6.3%） AD patients and in 117 age- matched eontols,3 individuals （2.6%） bore the mutation. By statistical analysis, the difference between the two groups was not significant （ chisq = 1. 902, P = O. 168 ）. Conclusion ：In Chinese Han Populations, the 4336G mutation maybe does not exist, the 8021 A/G mutation seldom occurs, and at 5460 position, there is A or T mutation, but the mutation maybe does not associated with AD.