Outcome of Liver Transplantation for Neonatal-onset Citrullinemia Type I

Background: We evaluated the outcome of liver transplantation (LT) in neonatal-onset citrullinemia type I patients, especially its impact on neurological deficits and developmental retardation.

Methods: From October 2006 to October 2019, 5 of the 2003 children who received LT at Ren Ji Hospital had been diagnosed with citrullinemia type I. The primary indication for transplantation was repeated metabolic compensation and developmental retardation in 4 patients and prophylactic transplantation in the other. Among them, 3 patients received living donor LT and 2 received orthotopic LT.

Results: All recipients had successfully recovered within the median follow-up period of 32 months (range, 6-54 mo). Transplantation restored citrulline metabolism and liver function. Plasma ammonia and citrulline concentration decreased to normal levels with no further hyperammonemic episodes being reported, even after normal diet intake began. Meanwhile, uracil-2 and orotic acid were not detected in urinary excretion. Strikingly, patients suffered developmental retardation before LT showed improved psychomotor ability and significant catch-up growth during the follow-up period. Cognitive ability, including language skills and academic performance, also greatly improved. Three patients had sustained brain injuries and exhibited severe neurological deficits before transplantation, especially repeated generalized tonic-clonic seizures. LT halted neurological deterioration and controlled seizure episodes, which further facilitated the intellectual development and improvement of life quality.

Conclusions: LT is an effective treatment for neonatal-onset citrullinemia type I patients, which reverses metabolism decompensation and improves quality of life. For patients who have suffered severe hyperammonemic insults, LT should be conducted at an early age to avoid further neurological or developmental deficits.