脂质沉积性肌病35例的临床特点及电子转移黄素蛋白脱氢酶基因突变分析

目的 探讨脂质沉积性肌病(LSM)的临床特点及电子传递黄素蛋白脱氢酶(ETFDH)基因突变所致的多种脂酰辅酶A脱氢酶缺乏症在该病中所占比例.方法 收集35例经病理明确诊断的LSM患者的临床资料,并对所有患者的ETFDH基因的全部13个外显子进行PCR扩增,产物纯化后直接测序.同时对来自50名健康对照的100条染色体进行检测,以验证发现的ETFDH新突变.结果 35例患者均存在不同程度的肌肉无力,包括10例存在咀嚼吞咽无力,28例存在抬头无力.在随访的32例患者中,29例患者经维生素B2及辅酶Q10治疗后症状明显改善.30例(86%)存在不同形式的ETFDH基因突变:8例为纯合突变,20例为复合杂合突变,2例患者仅存在1个杂合突变.本组患者共发现14个新突变:9个错义突变(c.3G>C、c.152G>A、c.191G>A、c.349G>C、c.433G>C、c.949C>A、c.1454C>G、c.1744A>T和c.1763A>G),1个无义突变(c.172G>T),2个缺失突变(c.1282_1283del和c.1773_1774del)和2个剪切位点突变(c.405+1G>T和c.1691-3C>G).所有患者中,9例存在c.250G>A突变,6例存在c.770A>G突变.结论 LSM可表现近端肌受累为主的肢体无力.基因分析发现本组KSM患者以ETFDH突变引起的多种酰基辅酶A脱氢酶缺乏为主.c.250G>A和c.770A>G是其最常见的突变位点.

Abstract：

Objective To investigate the clinical features and electron transfer flavoprotein dehydrogenase (ETFDH) gene mutations in 35 Chinese patients with lipid storage myopathy. Methods The clinical data of 35 cases with lipid storage myopathy confirmed by muscle biopsy were collected. The sequences of all 13 exons of ETFDH were analyzed. Results All 35 patients showed proximal weakness. Ten of them demonstrated masseter weakness and 28 of them showed weakness in neck flexion. Twenty-nine of 32 patients who were followed up showed improvement after treatment with VitB2 and CoQ10. Mutations of ETFDH were found in 30 of 35 patients,which included 8 homozygosises,20 compound heterozygosises and 2 single heterozygosises. Fourteen novel mutations were found, including 9 missense mutations ( c. 3G > C, c. 152G>A, c. 191G > A, c.349G>C, c.433G>C, c. 949C > A, c. 1454C > G, c. 1744A >T and c. 1763A>G), 1 nonsense mutation(c. 172G>T), 2 deletions(c. 1282_1283del and 1773_1774del) and 2 splice mutations (c. 405 + 1G > T and c. 1691 -3C > G). Nine of them showed c. 250G > A mutation and 6 of them showed c. 770A > G mutation. Conclusions Lipid storage myopathy is presented as proximal weakness. Multiple acyl-CoA dehydrogenase deficiency caused by mutations of ETFDH is the major cause of lipid storage disease in this group. ETFDH c. 250G > A and c. 770A > G mutations show a high frequency.

Clinical features and electron transfer flavoprotein dehydrogenase gene mutation analysis in 35 Chinese patients with lipid storage myopathy

Objective To investigate the clinical features and electron transfer flavoprotein dehydrogenase (ETFDH) gene mutations in 35 Chinese patients with lipid storage myopathy. Methods The clinical data of 35 cases with lipid storage myopathy confirmed by muscle biopsy were collected. The sequences of all 13 exons of ETFDH were analyzed. Results All 35 patients showed proximal weakness. Ten of them demonstrated masseter weakness and 28 of them showed weakness in neck flexion. Twenty-nine of 32 patients who were followed up showed improvement after treatment with VitB2 and CoQ10. Mutations of ETFDH were found in 30 of 35 patients,which included 8 homozygosises,20 compound heterozygosises and 2 single heterozygosises. Fourteen novel mutations were found, including 9 missense mutations ( c. 3G > C, c. 152G>A, c. 191G > A, c.349G>C, c.433G>C, c. 949C > A, c. 1454C > G, c. 1744A >T and c. 1763A>G), 1 nonsense mutation(c. 172G>T), 2 deletions(c. 1282_1283del and 1773_1774del) and 2 splice mutations (c. 405 + 1G > T and c. 1691 -3C > G). Nine of them showed c. 250G > A mutation and 6 of them showed c. 770A > G mutation. Conclusions Lipid storage myopathy is presented as proximal weakness. Multiple acyl-CoA dehydrogenase deficiency caused by mutations of ETFDH is the major cause of lipid storage disease in this group. ETFDH c. 250G > A and c. 770A > G mutations show a high frequency.