argininosuccinate lyase deficiency; argininosuccinic aciduria; argininosuccinic acidemia

Etiology

• deficiency in urea cycle enzyme argininosuccinate lyase

Pathology

• hyperammonemia due to malfunction of the urea cycle

Clinical manifestations

• see hyperammonemia

Laboratory

• plasma ammonia is elevated
• elevated urine argininosuccinate
• elevated serum argininosuccinate
• low serum argininosuccinate lyase

Management

• immediate: see hyperammonemia
• long-term:
  • low-protein diet
  • arginine supplementation
• liver transplantation
• donor cell engraftment
• consults
  • pediatric critical care (as needed)
  • medical geneticist
  • dietician

More general terms

• urea cycle disorder

Additional terms

• argininosuccinate lyase (argininosuccinase, ASAL, ASL)