A Case of Citrullinemia

ABSTRACT

Citrullinemia is one of the five urea cycle defects and is caused by argininosuccinic acid synthetase deficiency ; conversion of citrulline to argininosuccinic acid is blocked. Severe hyperammonemia typically develops in the neonate within a few days and symptoms such as vomiting, lethargy, convulsion, coma follows rapidly. The diagnosis is supported by high citrulline level in serum, urine, CSF and decreased activity of argininosuccinic acid synthetase in liver biopsy. We experienced a 3-day-old male neonate with poor activity, lethargy, convulsion, and coma who was diagnosed as citrullinemia by markedly elevated plasma and urine citrulline level with hyperammonemia. We report this case with brief review of the related literature.