<prompt> Hyperammonemia type I is due to deficiency ofCPS-ICPS-IIArginaseArginosuccinase  <response>: Deficiency of any of the urea cycle enzymes result in hyperammonemia. Carbamoyl phosphate synthetase1 deficiency or hyperammonemia type 1 is comparatively rare and is characterized by severe hyperammonemia.Ref: DM Vasudevan - Textbook of Biochemistry, 7th edition, page no: 205 