早发性帕金森病患者线粒体DNA部分点突变的研究

Mitochondrial DNA partly point mutations in praecox Parkinson's disease

目的 验证线粒体DNA点突变与早发性帕金森病 (PPD)的相关性 ,并了解中国人线粒体DNA点突变特点。方法 用聚合酶链反应 (PCR)、斑点杂交、放射显影定性方法对 4 0例PPD患者及 4 8名健康对照组A4 336C、G5 4 6 0A、A10 398G、A13780G突变点进行检测 ,对 2 0例PPD组和 2 0例对照组碱基位点 10 2 5 6～ 10 5 77线粒体DNA片段测序。结果 PPD组A10 398G、G5 4 6 0A、A4 336C、A13780G ,4个位点的突变率均高于对照组 ,而且PPD组A10 398G突变率 (5 0 0 % )显著高于对照组 (14 6 % ) (P =0 0 0 0 1) ;其他 3个突变点PPD组的突变率与对照组比较差异无显著意义 ;新发现碱基位点 10 4 0 0C/T多态性。结论 线粒体DNA突变与PPD的发病存在相关性 ,A10 398G突变很可能是PPD发病的一个重要原因 ;中国人线粒体DNA存在 10 4 0 0C/T多态性和PPD患者A10 398G高突变率 (5 0 0 % )

Objective To test the association between mitochondrial DNA(mtDNA) point mutations and praecox Parkinson's disease (PPD),and to investigate the characteristics of mtDNA mutations in Chinese patients with PPD. Methods Screening mtDNA A4336C, G5460A,A10398G,A13780G point mutations in 40 patients with PPD and 48 in control group was carried out by using Polymerase Chain Reaction (PCR), dot blotting, radiant developing. And sequencing was given to the nucleotide position (np)10256～np10577mtDNA of 20 patients with PPD and 20 subjects in control group.Results Out of the 40 patients with PPD, 20 (50%)had A10398G mutation. 6 (15%) had G5460A, 5(12.5%) had A13780G, 2 (5%)had A4336C, 19 (47.5%)had C10400T mutation. Out of the 48 controls, 7(14.6%) had A10398G, 24.2% had G5460A, 1 (2.1%)had A13780G and 20 (41.7%)had C10400T, but no any A4336C mutation was found in the controls. Thus, the ratios of A10398G,G5460A,A4336C,A13780G in patients with PPD were separately higher than those in the control group. Moreover significant difference was found in A10398G point mutation (P<0.01) . No significant differences were found in the other 3 point mutations; and a new synonymous mutation--C10400T was found in the study,showing that the np10400C/T single-nucleotide polymorphism (SNP) of mtDNA could be found in Chinese.Conclusions Our results suggest there exists association between mtDNA missense mutations and PPD: the A10398G missense mutation might possibly be one of the contributing factors leading to PPD. The high ratios of A10398G in PPD and the np10400C/T SNP should be two characteristics of Chinese mtDNA.