新生儿枫糖尿症二例报告并文献复习

Maple syrup urine disease of neonates：report of two cases and review of literature

目的 探讨新生儿枫糖尿症的临床特点及诊治经验,以提高认识,更好地预防和治疗该病.方法 报道新生儿枫糖尿症2例,并结合国内近15年来已报道的15例进行文献复习.结果 新生儿枫糖尿症的报道有增多趋势.17例发病年龄3 h～8 d,均有喂养困难,7例家族中有类似患儿,14例出现神经系统表现,8例伴特殊气味,13例血中支链氨基酸明显增高,6例利用串联质谱检测,12例尿中支链氨基酸及其代谢产物排泄增加,5例利用尿气相色谱-质谱分析,10例MRI/CT发现异常信号,12例死亡或放弃治疗,1例并发脑瘫,4例经特殊配方奶粉治疗者病情有不同程度好转.结论 新生儿枫糖尿症（maple syrup urine disease,MSUD）早期常出现喂养困难、反应差、嗜睡等非特异性症状,临床需要注意有无特殊气味和神经系统症状,疑诊者应及时进行血、尿氨基酸检测以便早期诊断,MRI（DWI）特异性水肿改变信号也有助于诊断,诊断后应立即干预治疗,同时应加强家长的配合,从而改善其预后.

Objective To analyze and summarize clinical manifestation of maple syrup urine disease（MSUD）of neonates.Methods Data of two cases with neonatal MSUD and the reports of 15 cases seen in the past 15 years in China were reviewed and analyzed.Results There was an increasing number of reports of cases with neonatal MSUD.All the 17 cases had the symptom of poor feeding between 3 h and 8 d after birth;7 cases had family history;14 cases showed progressive neurologic signs.Odor of maple syrup occurred in 8 cases.Blood levels of branched-chain amino acids（BCAA）significantly increased in 13 cases and 6 neonates were diagnosed using tandem mass spectrometry.Urinary levels of BCAA and metabolite elevated in 12 cases and 5 neonates were diagnosed using gas chromatography-mass spectrometry.MRI/CT demonstrated abnormal signal in 10 cases.Twelve cases died or their parents gave up treatment and one case had cerebral palsy;4 cases were treated with BCAA-free formula milk and showed improved outcome.Conclusion Newborns with MSUD often had early appeared non-specific symptoms with poor feeding and lethargy,most cases later showed an odor resembling maple syrup and neurologic signs.For patients who were suspected of having MSUD,blood and urine concentrations of BCAA should be tested for early diagnosis.Specific MRI edema signal from brain suggests the possibility of MSUD.Early intervention and treatment after diagnosis,with compliance of parents,would improve the patient＇s outcome.