Guo Y, Guo Z, Chen L, Zhang J, Wang W, Liu X, Ren H, Gao S
Department of Neurology, Peking Union Medical College Hospital, Beijing, China.
Chin Med J (Engl). 1997 Nov;110(11):851-5.
To study the clinical, pathological and genetic characteristics of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS).
Eight cases of MELAS (6 of them were from 2 families) underwent clinical study, muscle biopsy, autopsy on one patient, brain biopsy on one patient and genetic research.
In clinical report the average age of onset was 10-22 years old. Four cases from one family were 3 brothers and their nephew (sister's son). The death age of the three brothers was 16-20 years. Two cases from another family were a brother and a sister. The six patients of the two families showed the typical inherited characters of MELAS. The symptoms were myoclonic epilepsy, stroke-like episodes, paralysis of limbs, progressive mental retardation and neurological deaf. CT showed calcification in globus pallidus and MRI demonstrated clearly the abnormal prolongation of T2-weighed signals that distributed in frontal, parietal, occipital and temporal cortex as multiple focal, cystic and laminar necrotic areas. Pathological studies on brain showed multi-focal, cystic, and laminar or spongy necrotic abnormality primarily in gray matter of frontal, parental, temporal and occipital cortex. Decrease and loss of nerve fibers of the sub-cortical white matters of the lesion areas of cortex and calcification of globus pallidus were also observed. Red ragged fibers (RRF) and abnormal mitochondron were found by muscle biopsies. A point mutation (A-G transition) at nt 4243 in the mitochondrial tRNA Leu (UUR) was confirmed by using PCR and Southern Blot.
Although great progress has been made in the clinical, pathological and genetic research of MELAS, the pathogenesis of the disease remains further research.
研究线粒体肌病、脑病、乳酸酸中毒伴卒中样发作（MELAS）的临床、病理及遗传学特征。
8例MELAS患者（其中6例来自2个家系）接受了临床研究、肌肉活检、1例患者尸检、1例患者脑活检及遗传学研究。
临床报告显示平均发病年龄为10 - 22岁。一个家系的4例患者为3兄弟及其侄子（姐妹之子）。3兄弟的死亡年龄为16 - 20岁。另一个家系的2例患者为1兄弟和1姐妹。两个家系的6例患者均表现出典型的MELAS遗传特征。症状包括肌阵挛性癫痫、卒中样发作、肢体瘫痪、进行性智力减退及神经性耳聋。CT显示苍白球钙化，MRI清晰显示T2加权信号异常延长，分布于额叶、顶叶、枕叶及颞叶皮质，呈多发局灶性囊性及层状坏死区。脑病理研究显示多灶性、囊性、层状或海绵状坏死异常，主要位于额叶、顶叶、颞叶及枕叶皮质灰质。还观察到皮质病变区域皮质下白质神经纤维减少和缺失以及苍白球钙化。肌肉活检发现红色破碎样纤维（RRF）和异常线粒体。通过PCR和Southern印迹法证实线粒体tRNA亮氨酸（UUR）基因第4243位核苷酸存在点突变（A - G转换）。
尽管在MELAS的临床、病理及遗传学研究方面取得了很大进展，但该病的发病机制仍有待进一步研究。
