病理性近视线粒体DNA替代环区多态性研究

目的 对病理性近视线粒体DNA替代环（D-Loop）区进行测序,分析D-Loop区变异位点或多态性与病理性近视的关系.方法 实验研究.对127名病理性近视患者和104名正常对照者提取基因组DNA进行PCR扩增、双向测序,与修正的剑桥参照序列进行比对,分析变异位点.临床数据处理分析使用独立样本t检验,变异位点频率差异使用x^2检验和Bonferroni校正检验.结果 在127名病理性近视患者线粒体DNA D-Loop区中发现变异位点168个,3个为新的变异位点,其中有53个变异位点只在病理性近视中出现,经与正常对照组比较,差异无统计学意义.总的变异位点数目为1270个,平均每名病理性近视患者为10个；T152C在病理性近视中占19.7％（25/127）,在正常对照中占31.7％ （33/104）,两组差异存在统计学意义（x^2=4.412,P=0.036）,但经过Bonferroni校正后差异无统计学意义.结论 病理性近视线粒体D-Loop区为高度变异区域,为一个变异热点区域,线粒体D-Loop区变异位点是否与病理性近视有关还需进一步研究证实.

Study of single nucleotide polymorphism of mitochondrial DNA in the displacement loop region in pathological myopia

Objective To analyze mitochondrial DNA (mtDNA) in the displacement loop (D-Loop)region in pathological myopia subjects and controls.Methods Experimental study.Genomic DNA was extracted from 127 pathological myopia subjects and 104 controls.PCR-amplification of the D-Loop region and bidirectional sequencing was done according to the revised Cambridge reference sequence (rCRS) and all variants were analyzed.Data were analyzed using independent samples t test and frequency of variants using Chi-square test and Bonferroni correction.Results One hundred and sixty-eight variants were found in 127 pathological myopia subjects.Of these,3 were new variants and 53 variants were only found in the pathological myopia subjects and not in the controls.There were 1270 variants in 127 pathological myopia subjects,with an average of 10 variants in each subject.None of the variants was statistically associated with pathological myopia.The frequency of mtDNA T152C in pathological myopia subjects and controls was 19.7％(25/127) and 31.7％(33/104),respectively.Chi-square tests showed there were significant differences between the pathological myopia and control groups (x2=4.412,P=0.036),but Bonferroni correction did not show significant differences.Conclusion The displacement loop region of mitochondrial DNA in pathological myopia is a hot spot for mutations.Additional studies should be done on mitochondrial DNA D-Loop variants and pathological myopia.