Liu C-S, Cheng W-L, Lee C-F, Ma Y-S, Lin C-Y, Huang C-C, Wei Y-H
Vascular and Genomic Research Center, Changhua Christian Hospital, Changhua, Taiwan.
Acta Neurol Scand. 2006 May;113(5):334-41. doi: 10.1111/j.1600-0404.2006.00586.x.
We investigated whether mutation of mitochondrial DNA (mtDNA) affects the copy number of the mitochondrial genome in patients with mitochondrial myopathy encephalopathy with lactic acidosis and stroke-like episodes (MELAS) and those with myoclonic epilepsy with ragged-red fiber (MERRF) syndromes.
Forty-eight Taiwanese patients with MELAS syndrome and 20 patients with MERRF syndrome were recruited in this study.
In relation to controls, the copy numbers of mtDNA in leukocytes of patients with MELAS or MERRF syndrome were significantly higher at a young age but lower at an advanced age. In addition, MELAS patients harboring higher proportions of mtDNA with A3243G transition had lower mtDNA copy numbers. The MELAS or MERRF patients with multi-system disorders had lower mtDNA copy numbers in leukocytes. Furthermore, higher proportions of mtDNA with 4977 bp deletion were found in leukocytes of MERRF patients with multi-system involvement.
In leukocytes, alteration in the copy number of mtDNA is related to the proportion of mtDNA with a point mutation or large-scale deletion, which may serve as a biomarker in the pathogenesis and disease progression of MELAS and MERRF syndromes.
我们研究了线粒体DNA（mtDNA）突变是否会影响线粒体脑肌病伴乳酸酸中毒和卒中样发作（MELAS）患者以及肌阵挛性癫痫伴破碎红纤维（MERRF）综合征患者的线粒体基因组拷贝数。
本研究招募了48例台湾MELAS综合征患者和20例MERRF综合征患者。
与对照组相比，MELAS或MERRF综合征患者白细胞中的mtDNA拷贝数在年轻时显著更高，但在老年时更低。此外，携带A3243G转换的mtDNA比例较高的MELAS患者的mtDNA拷贝数较低。患有多系统疾病的MELAS或MERRF患者白细胞中的mtDNA拷贝数较低。此外，在多系统受累的MERRF患者的白细胞中发现了更高比例的具有4977 bp缺失的mtDNA。
在白细胞中，mtDNA拷贝数的改变与具有点突变或大规模缺失的mtDNA比例有关，这可能作为MELAS和MERRF综合征发病机制和疾病进展的生物标志物。
