线粒体脑肌病伴高乳酸血症和卒中样发作综合征与一种新的线粒体DNA基因突变

目的 检测1例线粒体脑肌病伴高乳酸血症和卒中样发作综合征(MELAS)患者脑组织和外周血线粒体DNA(mtDNA)的基因突变类型。方法 应用聚合酶链反应-限制性片段长度多态性(PCR—RFLP)方法对这例MELAS患者脑组织和外周血mtDNA的A3243G点突变进行检测，对检测过程中发现的异常扩增产物进行DNA测序分析。结果 该例MELAS患者脑组织和外周血白细胞PCR扩增产物行聚丙烯酰胺凝胶电泳时产生了两条带，一条为494bp，另一条为218bp。494bp的扩增产物是目的片段，而218bp的片段是一种异常扩增产物。我们对218bp的PCR扩增产物进行测序，发现在mtDNA3314—3589之间有276bp的碱基缺失。结论 mtDNA3314-3589位点之间276bp的碱基缺失可能是导致MELAs的一种新的基因突变类型。

A new mitochondrial DNA mutation related to the mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes

Objective To detect the mtDNA gene mutation of the brain tissue and peripheral blood cell from a MALAS patient. Methods A3243G point mutation in mtDNA of the brain tissue and white blood cells of the patient with MELAS was checked by using PCR-RFLP. A found new abnormal PCR product of 218 bp was sequenced. Results When running PCR products of the brain tissue and white blood cells on a polyacrylamide gel,we found two bands,one was 494 bp,the other was 218 bp. The latter was a new abnormal PCR product. A new gene mutation was assumed existing in this patient with MELAS that we sequenced the band of 218 bp and found that there was a 276-base pair deletion between the mtDNA 3314 and 3589. This kind of mtDNA mutation may be the factor making this patient suffer from MELAS. Conclusion The 276 bp deletion between the mtDNA 3314 and 3589 might be a new mtDNA mutation associated with MELAS.