Abstract: Urea cycle disorders（UCDs）are a group of inborn errors caused by the deficiency of enzymes or transporters in the process of urea cycle metabolism，which causes ammonia detoxification or arginine synthesis disorder. The most significant clinical manifestation is increased blood ammonia，50% of the patients has neonatal hyperammonemia，and the mortality rate is as high as 25%-50%. Early diagnosis before clinical onset can reduce or even avoid the occurrence of complications of hyperammonemia. Newborn screening is the best way to achieve early diagnosis and treatment and to improve prognosis. More diseases have been diagnosed in the early stage，since tandem mass spectrometry was introduced to newborn screening，but UCDs has not been completely included in the newborn screening program，and there are always arguments in the selection of disease types，screening timing，follow-up and monitoring programs.

Key words: urea cycle disorders, newborn, screening

摘要： 尿素循环障碍（urea cycle disorders，UCDs）是一类遗传代谢病，由于尿素循环代谢过程中酶或转运体缺陷引起氨解毒或精氨酸合成障碍，以血氨增高为最显著的临床表现，50%的患者表现为新生儿高氨血症，病死率高达 25%~50%，临床发作之前及早诊断可减缓甚至避免高氨血症并发症的发生。新生儿筛查是实现早期诊治、改善预后的最佳方法。串联质谱技术引入新生儿筛查以来更多的病种得到早期诊断，UCDs一直没有完全被纳入新生儿筛查项目，且在疾病种类选择、筛查时机以及随访、监测方案方面一直存在争议。

关键词: 尿素循环障碍, 新生儿, 筛查