患儿，男，11岁，间断乏力、行走困难6年，发作性意识不清4年；辅助检查提示严重代谢性酸中毒、低血糖、肝功能异常，CT示肝脏明显增大、呈脂肪密度影。给予补液、纠酸、纠正低血糖，以及左卡尼汀、复合维生素B、辅酶Q₁₀等治疗，患儿持续昏迷、代谢性酸中毒及低血糖难以纠正，患儿死亡。血、尿有机酸筛查和基因检测证实为电子转运黄素蛋白脱氢酶编码基因 （ETFDH）缺陷所致的迟发型戊二酸尿症Ⅱ型 （GA Ⅱ c型）。GA Ⅱ c型是一种发病率很低的遗传性代谢病，易误诊误治。对于反复乏力或活动耐力下降、低血糖、肝脏明显增大伴肝功能异常的患儿，应考虑GA Ⅱ型的可能，尿有机酸分析和血串联质谱分析可提供诊断线索， ETFDH基因分析可提供确诊依据。

A boy aged 11 years was admitted due to intermittent weakness and diffculty in walking for 6 years,and hepatomegaly,glycopenia and unconsciousness for 4 years.The laboratory examinations showed severe metabolic acidosis,hypoglycemia,and abnormal liver function.CT scan showed marked liver enlargement with fat density shadow. The boy was given fluid infusion,correction of acidosis,intravenous injection of glucose,L-carnitine,compound vitamin B,and coenzyme Q₁₀,but he was in a persistent coma and it was difficult to correct refractory metabolic acidosis and hypoglycemia.The boy died.Blood and urinary organic acid screening and gene detection confrmed that the boy had late-onset glutaric aciduria type Ⅱ (GAⅡc) caused by electron-transferring-flavoprotein dehydrogenase (ETFDH) gene defect.GAⅡc is an inherited metabolic disease with a low incidence,resulting in a high misdiagnosis rate.GAⅡc should be considered for children with recurrent weakness or reduced activity endurance,hypoglycemia, and marked liver enlargement with abnormal liver function.Urinary organic acid analysis and blood tandem mass spectrometry can help with the early diagnosis of GAⅡc,and ETFDH gene analysis helps to make a confirmed diagnosis.