Abstract: Objective   To study the muscular pathological characteristics in riboflavin-responsive lipid storage myopathy before and after treatment.  Methods  A 10-year follow-up visit was made on a patient with riboflavin-responsive lipid storage myopathy, and the changes of serum enzymes, and both histological and ultrastructural data acquired by general muscular pathology, immunohistochemistry and electron microscope were observed before and after treatment by using levocarnitine. ETFDH gene were detected in the patient and his family. Results  The patient presented limb weakness, difficulty in raising head and dysphagia, which were typical clinical features of lipid storage myopathy (LSM). The serum creatine kinase (CK) level and lactic dehydrogenase (LDH) level elevated evidently. EMG showed myogenic abnormality, and muscular pathology revealed numerous lipid droplets deposited in the fibers. ATPase staining showed predominant atrophy of typeⅠ fibers and relative increasing of the portion of typeⅡ fibers. Modified Gomori trichrome (MGT) staining did not observe ragged red fibers. Immunohistochemical staining showed positive expression of dystrophin. Sultan Ⅲ staining revealed multiple vacuolated myofibers. ETFDH gene test showed two heterozygous mutations in the patient. After treating with levocarnitine for several years, the patient could live a normal life. The muscular pathological result returned to normal. Conclusions  After appropriate therapy, patient with lipid storage myopathy can not only gain complete remission clinically, but also the reversion of lesion pathologically.

Key words: Lipidoses, Electron-transferring flavoproteins, Carnitine, Mutation

摘要： 目的  观察核黄素反应性脂质沉积性肌病治疗前后肌肉组织变化。 方法 对1 例核黄素反应性脂质沉积性肌病患者随访10 年，比较左卡尼汀治疗前后临床表现和肌肉病理变化，并行电子转移黄素蛋白脱氢酶（ETFDH）基因突变分析。结果 患者具有脂质沉积性肌病的主要表现，四肢乏力、抬头费力、吞咽困难等；血清肌酸激酶和乳酸脱氢酶水平明显升高；肌电图呈肌源性损害；肌肉病理观察可见大量脂质沉积；ETFDH 基因突变分析呈杂合突变。经左卡尼汀治疗数年后恢复正常生活和工作，肌肉组织活检呈正常形态。结论脂质沉积性肌病患者经适当治疗后，不仅临床症状可完全缓解，而且可逆转肌肉病理改变。

关键词: 脂质贮积病, 电子转移黄素蛋白质类, 肉碱, 突变