Abstract: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.