A successful liver transplantation in a patient with neonatal-onset carbamoyl phosphate synthetase-1 deficiency

Objectives Carbamoyl phosphate synthetase 1 (CPS-1) deficiency is a rare urea cycle disorder with an estimated prevalence of one in 150,000-200,000 live births. Patients often present with hyperammonemia shortly after protein feeding in the early days of life, and early-onset type is associated with high mortality rate.Case presentation We present here a case of a newborn male with a history of two deceased siblings whose ammonium level exceeded 200 mu mol/L on the first day after birth, and who was started on dextrose infusion and ammonia-scavenging therapy after oral feeding was discontinued. Peritoneal dialysis was initiated after the patient's ammonia level exceeded 500 mu mol/L. At the age of five months, the patient underwent hemodialysis due to elevated ammonia levels accompanied by lethargy. The patient's ammonia levels were successfully brought under control, and the patient underwent a liver transplantation at the age of six month, donated by the father.Conclusions We present this case to emphasize the efficacy of liver transplantation from a parent carrying a CPS-1 deficiency. The authors believe that, with further support from future studies, the use of carglumic acid can improve the prognosis in the chronic management of CPS-1 deficiency.