Liver transplantation in urea cycle disorders

Area of Science:

• Biochemistry
• Genetics
• Pediatrics

Background:

• Urea cycle disorders (UCDs) are genetic conditions affecting nitrogen metabolism.
• Long-term management strategies for UCDs have evolved, but outcomes remain challenging.
• Ornithine transcarbamylase (OTC) deficiency is the most common UCD.

Purpose of the Study:

• To report on the long-term management and outcomes of patients with various UCDs.
• To evaluate the effectiveness of liver transplantation in specific UCD cases.
• To highlight the challenges and potential improvements in UCD treatment.

Main Methods:

• Retrospective analysis of 28 patients with citrullinaemia, 13 with carbamoyl phosphate synthase deficiency, and 15 with argininosuccinic aciduria.
• Inclusion of a national French survey of 119 patients with OTC deficiency.
• Review of four personal liver transplant cases (2 OTC, 2 citrullinaemia) and one OTC patient from the survey.

Main Results:

• Long-term outcomes for UCDs are generally guarded, with severe neonatal forms having a poor prognosis.
• Neonatal citrullinaemia patients showed variable outcomes, with some benefiting from liver transplantation.
• Argininosuccinic aciduria patients exhibited unexpected severity, suggesting broader transplantation indications.
• Late-onset female OTC deficiency cases had challenging prognoses, with liver transplantation improving neurological outcomes in some.

Conclusions:

• The long-term prognosis for urea cycle disorders remains guarded, necessitating careful management.
• Liver transplantation should be considered for severe argininosuccinic aciduria and selected cases of late-onset OTC deficiency.
• Early intervention and transplantation may prevent irreversible neurological damage in high-risk UCD patients.