Liver transplantation for late-onset ornithine transcarbamylase deficiency: A case report

BACKGROUND Ornithine transcarbamylase deficiency (OTCD) is an X-linked inherited disorder and characterized by marked elevation of blood ammonia. The goal of treatment is to minimize the neurological damage caused by hyperammonemia. OTCD can be cured by liver transplantation (LT). Post-transplant patients can discontinue anti- hyperammonemia agents and consume a regular diet without the risk of developing hyperammonemia. The neurological damage caused by hyperammonemia is almost irreversible. CASE SUMMARY An 11.7-year-old boy presented with headache, vomiting, and altered consciousness. The patient was diagnosed with late-onset OTCD. After nitrogen scavenging treatment and a protein-free diet, ammonia levels were reduced to normal on the third day of admission. Nevertheless, the patient remained in a moderate coma. After discussion, Li was performed. Following LT, the patient's blood ammonia and biochemical indicators stabilized in the normal range, he regained consciousness, and his nervous system function significantly recovered. Two months after LT, blood amino acids and urine organic acids were normal, and brain magnetic resonance imaging showed a decrease in subcortical lesions. CONCLUSION LT can significantly improve partial neurological impairment caused by late-onset OTCD hyperammonemic encephalopathy, and Li can be actively considered when early drug therapy is ineffective.