The detoxification of ammonia to urea requires a functional hepatic urea cycle, which consists of six enzymes and two mitochondrial membrane transporters. The initial step of the urea cycle is catalyzed by carbamyl phosphate synthetase 1 (CPS1). CPS1 deficiency (CPS1D) is a rare autosomal recessive disorder. N-Carbamylglutamate (NCG), a deacylase-resistant analogue of N-acetylglutamate, can activate CPS1. We describe the therapeutic course of a patient suffering from neonatal onset CPS1D with compound heterozygosity for the c.2359C > T (p.Arg787*) and c.3559G > T (p.Val1187Phe) variants in CPS1, treated with NCG. She presented with hyperammonemia, which reached 944 μmol/L at the age of 2 days. The ammonia concentration decreased after treatment with continuous hemodiafiltration, NCG, sodium benzoate, sodium phenylbutyrate, L-arginine, vitamin cocktail (vitamin B1, vitamin B12, vitamin C, vitamin E, biotin), l-carnitine, coenzyme Q10, and parenteral nutrition. Her ammonia and glutamine levels remained low; thus, protein intake was increased to 1.2 g/kg/day. Furthermore, the amount of sodium benzoate and sodium phenylbutyrate were reduced. She remained metabolically stable and experienced no metabolic crisis following treatment with oral NCG, sodium benzoate, sodium phenylbutyrate, citrulline, vitamin cocktail, l-carnitine, and coenzyme Q10 until she underwent liver transplantation at 207 days of age. She had no neurological complications at the age of 15 months. Ammonia and glutamine levels of the patient were successfully maintained at a low level via NCG treatment with increased protein intake, which led to normal neurological development. Thus, undiagnosed urea cycle disorders should be treated rapidly with acute therapy including NCG, which should be maintained until a genetic diagnosis is reached. It is essential to prevent metabolic crises in patients with CPS1D until liver transplantation to improve their prognoses.

将氨解毒为尿素需要一个功能性肝素尿素循环，该循环由六个酶和两个线粒体膜转运蛋白组成。尿素循环的起始步骤由氨基甲酸酯磷酸合成酶1（CPS1）催化。CPS1缺乏症（CPS1D）是一种罕见的常染色体隐性遗传疾病。Ñ -Carbamylglutamate（NCG），的耐脱酰酶-类似物Ñ -acetylglutamate，可以激活CPS1。我们描述了从新生儿发病CPS1D的患者与化合物杂合子的c.2359C的疗程> T（p.Arg787 *）和c.3559G> T（p.Val1187Phe）在变体CPS1，用NCG处理。她出现高氨血症，在2天时达到了944μmol/ L。连续性血液透析滤过，NCG，苯甲酸钠，苯丁酸钠，L-精氨酸，维生素鸡尾酒（维生素B1，维生素B12，维生素C，维生素E，生物素），1-肉碱，辅酶Q10和肠胃外营养治疗后，氨浓度降低。她的氨和谷氨酰胺水平仍然很低。因此，蛋白质摄入量增加到1.2 g / kg /天。此外，减少了苯甲酸钠和苯丁酸钠的量。口服NCG，苯甲酸钠，苯基丁酸钠，瓜氨酸，维生素鸡尾酒，L，-肉碱和辅酶Q10，直到她在207天大时接受肝移植。她在15个月大时没有神经系统并发症。通过增加蛋白质摄入量的NCG治疗，可成功将患者的氨和谷氨酰胺水平维持在较低水平，从而导致正常的神经系统发育。因此，应通过包括NCG在内的急性治疗迅速治疗未确诊的尿素循环紊乱，并应保持这种治疗直至获得遗传诊断。在肝移植之前，必须预防CPS1D患者的代谢危机，以改善其预后。