目的:总结以血栓性微血管病为突出表现的甲基丙二酸血症的临床特点。方法:收集2014年9月至2019年12月中国医科大学附属盛京医院收治的以血栓性微血管病为突出表现的甲基丙二酸血症6例患儿的病例资料，分析临床表现及实验室检查、影像学、肾脏组织病理学检查结果，治疗及预后情况。结果:6例患儿中，男5例，女1例，年龄1个月～7岁。6例均确诊为甲基丙二酸血症合并高同型半胱氨酸血症。入院前6例患儿均有前驱感染史，均有水肿表现，5例伴有高血压，4例伴有神经系统表现。1例有家族史。6例患儿确诊后均给予维生素Bn 12、左卡尼汀、叶酸、甜菜碱等治疗。3例患儿精神神经症状较前明显改善、溶血控制、肾功能好转，随访2.5～4.5年，其中2例智力运动发育基本接近同龄儿，肾功能正常，血压控制良好，尿蛋白正常；另1例智力发育较前明显好转，但仍稍差于同龄儿，口服抗癫痫药治疗中，近1年无抽搐发作，血压维持在135/90～160/110 mmHg(1 mmHg＝0.133 kPa)，24 h尿量2 000 mL左右，肌酐维持在150 μmol/L左右，离子水平正常，尿蛋白2+。1例中途退院。2例多器官功能衰竭于住院期间死亡。n 结论:对于不明原因血栓性微血管病应早期完善血尿遗传代谢病筛查，提倡尽早同型半胱氨酸筛查，早期发现、及时治疗尤为重要。“,”Objective:To summarize the characteristics of methylmalonic acidemia(MMA) with thrombotic microangiopathy as the prominent manifestation.Methods:Clinical data was collected from MMA patients with thrombotic microangiopathy as the prominent manifestation, who were treated at Shengjing Hospital of China Medical University from September 2014 to December 2019.The clinical manifestations, laboratory results, imaging results, histopathological examination, treatment and prognosis were analyzed.Results:Six children aged 1 month to 7 years old were included in our study, including 5 males and 1 female.Six cases were all MMA complicated hyperhomocysteinemia.All patients had a history of prodromal infection before admission.All cases had edema.Five patients were hypertenson and 4 patients accompanied neurologic presentation.One patient had a family history.All patients were treated with Vitamin Bn 12, levocarnitine, folic acid and betaine.Three patients′ psychiatric symptoms and renal function were improved and hemolysis were controlled.Two of them were similar with the same age children in intelligence and motor development, with normal renal function, good blood pressure control and normal urine protein.The third one was significantly improved in intelligence development, but still slightly worse than that of the children with the same age.He had no convulsions occurred in recent one year with antiepileptic drugs in oral.His blood pressure was maintained between 135/90-160/110 mmHg(1 mmHg=0.133 kPa), 24-hour urine volume was about 2 000 mL, creatinine was maintained at about 150 μmol/L, ionic level was normal, and urinary protein was 2 + .One case discharged from hospital.Two patients died of multiple organ failure.n Conclusion:An early screening of metabolic diseases should be achieved for thrombotic microangiopathy of unknown etiology.Early screening of homocysteine is important for early detection and treatment.