Abstract: 　Objective　To explore the diagnosis and treatment of recurrent hyperammonemia caused by argininosuccinic aciduria. Method　The diagnosis, treatment and follow-up of argininosuccinic aciduria in a child were retrospectively analyzed, and the related literature was reviewed. Results　A 13-month-old boy was admitted to hospital for vomiting, sleepiness and poor reaction. The results showed elevated blood ammonia (138.02 μmol/L), abnormal liver function, hypokalemia, elevated blood citrulline (65.64 Umol/L), and abnormal electroencephalogram. The second generation gene sequencing was performed on hyperammonia-related genes, and the compound heterozygous mutation of argininosuccinate lyase (ASL) gene was found. After the treatment with protein restriction diet and arginine supplementation, the children's hyperammonia still recurred and the liver was progressively enlarged. One year after the diagnosis, liver transplantation was performed. At present, 1 year after transplantation, the liver function, blood ammonia, growth and development of the child were normal. Conclusion　The clinical manifestations of argininosuccinic aciduria are complex, and hyperammonia is an important manifestation. Gene examination is helpful for diagnosis and liver transplantation is effective.

Key words: hyperammonemia;　argininosuccinate lyase;　argininosuccinic aciduria;　argininosuccinate lyase gene; liver transplantation