ORTHOTOPIC LIVER-TRANSPLANTATION FOR ORNITHINE TRANSCARBAMYLASE DEFICIENCY WITH HYPERAMMONEMIC ENCEPHALOPATHY

Ornithine transcarbamylase (OTC) deficiency is an X chromosome-linked disorder causing hyperammonemic encephalopathy with a very poor progno sis. We describe here two patients with OTC deficiency, one a late-ons et female patient (case 1) and the other a neonatal-onset male patient (case 2), who were successfully treated with orthotopic liver transpl antation (OLTx). The OTC activity in the excised liver was 10% and 0% of control, respectively. Hyperammonemic encephalopathy was controlled with medical therapy in case 1 until the age of 5 years. but the comp licated course in case 2 in which hyperammonemia required peritoneal d ialysis and hemodialysis in the neonatal period necessitated OLTx with a reduced-size liver at the age of 80 days. Both patients had restora tion of serum ammonia level to normal in 2 and 3 days after liver repl acement, and both patients have normal neurological and developmental status after 2 and 0.5 years of postoperative follow-up. These cases i llustrate not only the metabolic cure of this disorder, but also the n eed to preserve neurological integrity by aggressive medical managemen t of the hyperammonemia preoperatively and early surgical intervention when indicated, even if this is required very early in life. Copyrigh t (C) 1995 by W.B. Saunders Company