甲基丙二酸血症16例

目的 探讨甲基丙二酸血症的临床特征及治疗.方法 对本院通过气相色谱-质谱法尿有机酸分析确诊甲基丙二酸血症的患儿16例进行临床特征及诊疗分析.结果 本院16例患儿的发病年龄为出生5d～2岁,临床表现包括呕吐、喂养困难6例,发育落后/倒退6例,反应差5例,惊厥发作1例等.血气分析提示代谢性酸中毒8例,高血氨1例,11例头颅CT或MRI出现异常,2例视觉诱发电位均异常,3例查听觉脑干诱发电位2例异常.16例查尿有机酸均提示甲基丙二酸增高.2例确诊前死亡,6例确诊后放弃治疗,7例长期接受维生素B12、左旋肉碱治疗.对于接受治疗者进行随访,随访时间2个月～2 a(平均11个月),均存在发育落后,患儿进行一般神经发育评价,5例较治疗前有明显进步,但均存在发育落后,1例神经发育明显落后,1例治疗时间J短,现未复查,1例失访.结论 反应差、智力体格发育落后或倒退、惊厥、发作性呕吐、喂养困难、肌张力异常、代谢性酸中毒、高氨血症、头颅MRI出现基底核对称异常信号是甲基丙二酸血症的主要临床特征,不同年龄临床表现不同,气相色谱-质谱法尿有机酸分析是早期诊断的重要依据,确诊后坚持长期合理治疗是改善预后的有效方法.

Methylmalonic Acidemia in 16 Children

Objective To explore the clinical characteristics and treatment of methylmalonic acidemia(MMA). Methods Sixteen patients with MMA were confirmed by gas chromatography-mass spectrometry(GC/MS). Results The patients′ age of onset ranged from 5 days to 2 years.The main clinical manifestations were poor feeding and vomiting(6 cases),developmental retardation or retardation(6 cases),weak reaction(5 cases),convulsion(1 case).The laboratory findings showed metabolic acidosis in 8 cases,hyperammonemia in 1 case.Some abnormalities were noted by the brain CT or MRI in 11 cases.Two patients had abnormal findings in visual evoked potentials.Two patients were abnormal among 3 patients who received auditory brainstem response examination.There was remarkable elevation of urinary methylmalonic acid concentration in all the patients.Of the 8 cases without therapy,2 patients died before the diagnosis was made,6 cases died at home after giving up therapy.Seven cases received therapy of vitamin B12 and supplementation of L-carnitine with restricted-protein diet.The follow-up of 6 cases for a period ranging from 2 months to 2 years showed progress though developmental retardation could be found,only 1 case obviously fell behind the normal.One case was not to have follow-up due to short treatment time.One case failed to have follow-up. Conclusions The clinical manifestations of MMA are nonspecific,which include week reaction,developmental retardation or degradation,convulsion,poor feeding and vomiting,muscular dystonia,metabolic acidosis,hyperammonemia,abnormal signal in basal ganglia in the cranial MRI.GC/MS can be used to confirm the diagnosis.Early diagnosis and early treatment is the key to improve the prognosis.