Wada H, Woo M, Nishio H, Nagaki S, Yanagawa H, Imamura A, Yokoyama S, Ohbayashi C, Matsuo M, Itoh H, Nakamura H
Department of Pediatrics, Kobe University School of Medicine, Japan.
Brain Dev. 1996 Jul-Aug;18(4):263-8. doi: 10.1016/0387-7604(96)00017-4.
A 1-month-old Japanese girl had profound generalized weakness, hypotonia, and severe lactic acidosis. The infant improved gradually: she held her head at 9 months, learned to walk by 15 months. At the first muscle biopsy at 11 weeks of age, the specimen was characterized by numerous ragged-red fibers and decreased enzyme activity on cytochrome c oxidase (COX) staining. Electron microscopic findings were characterized by the presence of excessive abnormal mitochondria not only in skeletal muscle fibers but also in blood vessels. Vascular abnormalities consisted of an increased number of enlarged mitochondria in endothelial and smooth muscle cells of small arteries. Biochemical analysis showed an isolated defect of COX activity, which was only 16% of the mean control level. At the second biopsy at 44 months of age, the COX activity had increased to normal in the entire specimen. On electron microscopy, the abnormal mitochondria present on the first biopsy specimen had disappeared both in muscle fibers and blood vessels; nearly all mitochondria were morphologically normal at the second biopsy. Now at 5 years of age she can run and does not show muscle weakness. We report reversibility of abnormal mitochondria with age not only in skeletal muscle fibers but also in blood vessels in a patient, who had reversible COX deficiency with a benign clinical course.
一名1个月大的日本女孩出现严重的全身无力、肌张力减退和严重乳酸酸中毒。婴儿逐渐好转：9个月时能抬头，15个月时学会走路。在11周龄时首次进行肌肉活检，标本的特征是有大量破碎红纤维，细胞色素c氧化酶（COX）染色显示酶活性降低。电子显微镜检查结果的特征是不仅在骨骼肌纤维中，而且在血管中都存在过多异常线粒体。血管异常表现为小动脉内皮和平滑肌细胞中线粒体数量增加且增大。生化分析显示COX活性存在孤立缺陷，仅为平均对照水平的16%。在44个月龄时进行第二次活检，整个标本中的COX活性已恢复正常。电子显微镜检查显示，首次活检标本中存在的异常线粒体在肌肉纤维和血管中均消失；第二次活检时几乎所有线粒体形态正常。现在5岁的她能跑步，且无肌肉无力表现。我们报告了一名患有可逆性COX缺乏且临床病程良性的患者，其异常线粒体不仅在骨骼肌纤维中，而且在血管中随年龄增长具有可逆性。
