Kleinle S, Schneider V, Moosmann P, Brandner S, Krähenbühl S, Liechti-Gallati S
Department of Pediatrics, University of Berne, Switzerland.
Biochem Biophys Res Commun. 1998 Jun 9;247(1):112-5. doi: 10.1006/bbrc.1998.8729.
We have identified a novel mitochondrial (mt) DNA mutation in the tRNA(Phe)-gene in a patient with an isolated mitochondrial myopathy. This T to C transition at position 618 disrupts a strictly conserved base pair within the anticodon stem of tRNA(Phe). Computer analysis showed that the affected base pair is essential for anticodon stem formation of tRNA(Phe). The mutant mtDNA was heteroplasmic in skeletal muscle (95% mutant) and peripheral blood cells (20% mutant) from the patient but was undetectable in blood cells from his healthy sister. The patient presented with ragged red fibers and reduced activities of complex I and complex III in skeletal muscle. The T618C mutation described here is the second found in this region. Both mutations affect the same base pair of the tRNA(Phe) anticodon stem substantiating the pathogenic nature of both mutations.
我们在一名患有孤立性线粒体肌病的患者中，鉴定出了tRNA（Phe）基因中的一种新型线粒体（mt）DNA突变。该突变发生在第618位，由T突变为C，破坏了tRNA（Phe）反密码子茎内一个严格保守的碱基对。计算机分析表明，受影响的碱基对对于tRNA（Phe）反密码子茎的形成至关重要。该患者骨骼肌中的突变mtDNA呈异质性（95%为突变型），外周血细胞中也有20%为突变型，但在其健康妹妹的血细胞中未检测到。该患者骨骼肌出现破碎红纤维，且复合体I和复合体III的活性降低。此处描述的T618C突变是该区域发现的第二个突变。两种突变均影响tRNA（Phe）反密码子茎的同一碱基对，证实了两种突变的致病性。
