Molecular genetical analysis of human mitochondrial tRNA abnormality.

人类线粒体 tRNA 异常的分子遗传学分析。

基本信息

批准号：
07670923
负责人：
KOGA Yasutoshi
金额：
$ 1.34万
依托单位：
Kurume University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

We report the morphological, biochemical, and molecular genetic findings in a four-generation family with clinically and pathologically defined Leigh syndrome (LS) having an A-to-G transition at the nucleotide position 3243 (A3242G) in the mitochondrial tRNALeu (UUR) gene. The symptoms were not restricted to the CNS and muscle : the most severe features being LS with cardiomyopathy (CM), other severe features being mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) or non-insulin dependent diabetes mellitus (NIDDM), and milder features being muscle weakness, easy fatiguability and short stature without life-threatening symptoms. A 3-yewr-old floppy infant was died at the age of 10 years by cardiac failure. A muscle biopsy had revealed ragged-red fibers (RRF), scattered cytochrome c oxidase (COX) negative fibers and strongly SDH reactive vessels (SSVs), pathologically, and complex I plus IV deficiency, biochemically. Mitochondrial DNA (mtDNA) analys … More is in various tissues-including skeletal muscle, liver, heart, kidney and brain-showed a high percentage (>90%) of this mutation. Single fiber PCR analysis of muscle revealed that the percentage of mutation in muscle fibers with RRF-COX nagative (95.6(]SY.+-。[)1.7, mean(]SY.+-。[)SD) was significantly higher than that in fibers with RRF-COX positive (91.6(]SY.+-。[)2.9), and that with the non-RRF-COX positive (89.2(]SY.+-。[)3.3). The above findings suggested that the LS phenotype was a final common outcome for severe defect in the oxidative phosphorylation (OXPHOS) genes. 2) We report a patient with Leigh disease Having an A3243G mutation in the mitochondrial tRNALeu (UUR) gene. RNA analysis in muscle had shown a consistent increase in the steady state levels of RNA 19, polycistronic RNA precursor containing sequence for 16S rRNA,tRNALeu (UUR) and ND1. The above findings suggested that abnormal RNA processing may play an important role in the pathogenesis of human disease having this mutation.3) To investigate the prevalence of mitochondrial tRNALeu (UUR) gene mutation in diabetic children, we screened 115 diabetic patients in Japan, whose age at onset was under 15 years. Among 115 patients, 92 were diagnosed with insulin dependent diabetes mellitus (IDDM), 21 with non-insulin dependent diabetes mellitus (NIDDM), and 2 with abnormal glucose intolerance. All patients showed no sign of sensorineural hearing loss, no short stature, and no other symptom suggesting any mitochandrial disease. One IDDM patient was found to have an A to G substitution at position 3243 of mitochondrial tRNALeu (UUR) gene (A3243G), however this mutation did not demonstrate maternal inheritance in this family. In our study, the prevalence of the A3242G mutation among these diabetic children was 0.89%, suggesting that this mutation was a significant factor in the etiology of diabetes mellitus in children. Less

我们报告了一个四代家族中的形态学，生化和分子遗传发现，该家族具有临床和病理定义的利综合征（LS），在核毒性位置3243（A3242G）的A-to-G转变中，在线粒体trnaleu（uur）基因中。症状不仅限于CN和肌肉：最严重的特征是具有心肌病（CM）的LS，其他严重的特征是线粒体肌病，脑病，脑病，乳酸性酸中毒和中风样发作（Melas）（Melas）（Melas）或非胰岛素依赖性症状，而无效的效果（nIdids）和nIdiddmite（Nididdm）和niDds nidds nistrue（nidddm），以及三十脑的特征），并不适用于忙碌）威胁生命的症状。一名3岁大的软盘婴儿在10岁时因心力衰竭而死亡。肌肉活检揭示了破烂的红色纤维（RRF），散射的细胞色素C氧化酶（COX）阴性纤维以及强烈的SDH反应性视频（SSVS），病理学上，复杂的I和IV IV缺乏症。线粒体DNA（mtDNA）分析……在各种组织中，骨骼肌肉，肝脏，心脏，肾脏和脑显示了这种突变的高百分比（> 90％）。对肌肉的单纤维PCR分析表明，肌肉纤维中突变的百分比（95.6（]SY。+ - 。[）1.7，平均值（]SY。+ - 。[）SD显着高于带有RRF-COX阳性的纤维阳性的纤维（91.6（91.6（91.6（SY.SY。SY.+ - 。），以及那个and-cox，以及该and nontrf-cox和cox。（89.2（]SY。+ - 。[）3.3）。上面的发现表明，LS表型是氧化磷酸化（OXPHOS）基因中严重缺陷的最终共同结果。 2）我们报告了一名患有Leigh疾病的患者，其线粒体trnaleu（UUR）基因中有A3243G突变。肌肉中的RNA分析表明，RNA 19的稳态水平，含有16S rRNA，trnaleu（uur）和ND1的序列的稳态水平一致。以上发现表明，异常的RNA处理可能在具有这种突变的人类疾病的发病机理中起重要作用。3）研究糖尿病儿童中线粒体Trnaleu（UUR）基因突变的患病率，我们在日本的115名糖尿病患者中筛查了15岁以下年龄的115名糖尿病患者。在115例患者中，有92例被诊断为胰岛素依赖性糖尿病（IDDM），21例非胰岛素依赖性糖尿病（NIDDM）和2种异常葡萄糖肠内的患者。所有患者均未表现出感觉神经性听力损失，身材矮小的迹象，也没有其他症状表明任何线形疾病。发现一名IDDM患者在线粒体trnaleu（uur）基因（A3243G）的位置上具有A至G替代，但是该突变并未证明该家族中的母体遗传。在我们的研究中，这些糖尿病儿童中A3242G突变的患病率为0.89％，这表明这种突变是儿童糖尿病病因的重要因素。