Diagnosis of UCD typically involves a combination of biochemical testing and genetic analysis. Elevated ammonia levels in the blood along with abnormal amino acid profiles, particularly elevated glutamine and decreased citrulline or arginine, can suggest a urea cycle defect. Urine orotic acid levels may also help identify specific subtypes. Definitive diagnosis is made through genetic testing to identify mutations in the genes responsible for UCD.
Treatment of Urea Cycle Disorder (UCD) involves two main goals: managing acute hyperammonemia and preventing future metabolic crises through long-term care.
During the acute phase, immediate intervention is critical. Protein intake is stopped, and high-calorie intravenous fluids are administered to reduce catabolism. Nitrogen-scavenging medications such as sodium benzoate or sodium phenylbutyrate are given to help remove excess ammonia. Arginine or citrulline may be added to support the urea cycle. If ammonia levels are very high or neurological symptoms appear, dialysis is used to rapidly lower ammonia levels. Close monitoring, often in an ICU, is necessary, especially in infants.
In the chronic phase, the focus is on preventing recurrence and supporting growth. A low-protein, high-calorie diet is carefully managed, with regular use of ammonia-scavenging drugs and amino acid supplements as needed. Patients require ongoing monitoring of ammonia levels, nutrition, and neurodevelopment. Families are trained to respond early during illness or stress. In severe cases, liver transplantation may be considered to restore normal metabolism.
Effective treatment requires a multidisciplinary team and close coordination with families to ensure adherence and long-term stability.