Uziel G, Carrara F, Granata T, Lamantea E, Mora M, Zeviani M
Division of Child Neurology, 'C. Besta' National Neurological Institute, 20133, Milan, Italy.
Neuromuscul Disord. 2000 Aug;10(6):415-8. doi: 10.1016/s0960-8966(99)00115-7.
A mutation was found in an Italian child affecting the gene encoding the mitochondrial transfer RNA for leucine (codon UUR). This mutation (3291T-->C) had previously been reported in a single Japanese patient. In contrast with the original patient, who suffered from early-onset mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), our patient presented an apparently isolated mild myopathy. Mutational analysis in the proband and her family showed that the mutation was heteroplasmic, and that its relative amount was positively correlated with the severity of the phenotype. These findings lead to the definitive confirmation that the 3291T-->C is indeed pathogenic. As commonly found in mitochondrial-DNA related disorders, also for this mutation different clinical manifestations can be associated with the same genetic abnormality.
在一名意大利儿童中发现了一种突变，该突变影响编码亮氨酸线粒体转运RNA（密码子UUR）的基因。这种突变（3291T→C）此前仅在一名日本患者中报道过。与最初患有早发性线粒体脑肌病、乳酸酸中毒和卒中样发作（MELAS）的患者不同，我们的患者表现为明显孤立的轻度肌病。对先证者及其家族的突变分析表明，该突变是异质性的，其相对含量与表型严重程度呈正相关。这些发现最终证实3291T→C确实具有致病性。正如线粒体DNA相关疾病中常见的那样，对于这种突变，相同的基因异常也可能与不同的临床表现相关。
