CAJ | 학술논문

目的研究线粒体DNA 1555A>G异质性突变大家系，异质性水平及其与耳聋临床表型的关系，以及异质性的代代传递情况。方法运用聚合酶链反应-限制性片段长度多态性技术、直接测序法及变性高效液相色谱技术（Denaturing High Performance Liquid Chromatography，DHPLC)检测家系成员的1555A>G突变异质性并定量，结合其临床表型进行分析。结果临床资料显示，该家系的临床表型从正常到重度、极重度耳聋，呈现多样化。实验室检测结果为：经酶切和测序共检测出6个异质性突变、10个同质性突变和2个野生型；DHPLC定量分析结果显示，异质性水平介于11.9%-97.9%之间，并且在酶切和测序结果显示为野生型或同质性突变的样品中又发现了4个异质性突变。结论异质性水平与耳聋程度/氨基糖甙类药物敏感度之间有很强的关联性（r=0.758，P<0.001）。此外，母亲的异质性水平控制或影响着子代的异质性，提示线粒体DNA异质性代代传递过程中可能存在一种规律。
목적연구선립체DNA 1555A>G이질성돌변대가계，이질성수평급기여이롱림상표형적관계，이급이질성적대대전체정황。방법운용취합매련반응-한제성편단장도다태성기술、직접측서법급변성고효액상색보기술（Denaturing High Performance Liquid Chromatography，DHPLC)검측가계성원적1555A>G돌변이질성병정량，결합기림상표형진행분석。결과림상자료현시，해가계적림상표형종정상도중도、겁중도이롱，정현다양화。실험실검측결과위：경매절화측서공검측출6개이질성돌변、10개동질성돌변화2개야생형；DHPLC정량분석결과현시，이질성수평개우11.9%-97.9%지간，병차재매절화측서결과현시위야생형혹동질성돌변적양품중우발현료4개이질성돌변。결론이질성수평여이롱정도/안기당대류약물민감도지간유흔강적관련성（r=0.758，P<0.001）。차외，모친적이질성수평공제혹영향착자대적이질성，제시선립체DNA이질성대대전체과정중가능존재일충규률。
Objective To study the relationship between mutation load and severity of hearing loss and to further ana-lyze the heteroplasmic mtDNA transmission in a large pedigree with heteroplasmy for 1555A>G. Methods Heteroplasmy was tested and quantified using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), direct sequencing and Denaturing High Performance Liquid Chromatography (DHPLC). Correlation was analyzed together with clinical data. Results The clinical phenotype varied from normal to severe or profound deafness. Six heteroplasmic sub-jects, ten homoplasmic subjects and two wild-type subjects were detected by PCR-RFLP and sequencing. The results of DHPLC revealed that the proportion of mutation load ranged from 11.9%to 97.9%, and four subjects who were considered as homoplasmic or wild-type subjects in previous testing were additionally identified as heteroplasmy. Conclusion There is a strong correlation between the mutation load and severity of hearing loss/sensitivity to aminoglycosides (r=0.758, P<0.001). In addition, the mutation level of offspring is associated with their mothers’in this pedigree, which indicates that there may exist a pattern in the process of heteroplasmic transmission.