Liver transplantation in urea cycle disorders.

We report here our experience in the long-term management of 28 patients with citrullinaemia, 13 patients with carbamoyl phosphate synthase deficiency and 15 patients with argininosuccinic aciduria. In addition, we report a national French survey of 119 patients with ornithine transcarbamylase (OTC) deficiency enzymatically characterized in our laboratory. We also include in this report four personal patients (two with OTC and two with citrullinaemia) who were liver transplanted, and one OTC patient from the National French survey. Although this retrospective series is not really representative of the modern treatment combining low protein diet and arginine, sodium benzoate and sodium phenylbutyrate, it is obvious that the long-term outcome of all urea cycle disorders remains very guarded. We highlight the severity of the neonatal forms of such disorders, and mostly for OTC-deficient males. According to this evidence, our policy is not to treat such severely affected patients in the neonatal period who die anyway spontaneously within 2 to 3 days. At the present time, we only have three patients with neonatal citrullinaemia, aged 1, 6 and 10 years respectively, who are still doing well. One of them has been successfully liver transplanted at 5 years. Another transplanted patient died in the post-surgical phase. We emphasize the unexpected severity of argininosuccinic aciduria in which there is no one patient doing well. This is a rather surprising finding as this disorder is easy to manage and rarely presents with recurrent attacks of hyperammonaemia when it is treated by arginine supplementation. This consideration would suggest to extend the indication of orthotopic liver transplantation in this disorder. Finally, the most difficult indication is in the late onset symptomatic female OTC group. In this last group, despite a significant residual activity due to heterozygote status, even with a variable lyonisation, only seven girls are still mentally and neurologically normal. Interestingly, three of these seven were liver-transplanted before the constitution of irreversible neurological damage. These three girls and their family declare their well-being, their feeling to be cured and enjoy their normal life.