[PDF] Hyperammonaemia: urea cycle disorders - citrullinaemia and argininosuccinic aciduria

British Inherited Metabolic Disease Group
British Inherited Metabolic Disease Group (BIMDG)
Publication date:
22 March 2012


The urea cycle converts ammonia into urea and defects of all the steps are now well documented. All cause hyperammonaemia, albeit to varying degrees, isĀ associated with other metabolic disturbances. All these disorders may cause severe neurological complications and treatment of acute illness is urgent. The disorders covered by this protocol are:

  • Citrullinaemia (argininosuccinate synthetase deficiency, CIT)
  • Argininosuccinic aciduria (argininosuccinate lyase deficiency, ASA)

Treatment is aimed at reducing the production of ammonia, patients are treated with a low protein diet and medicines that promote the removal of nitrogen by alternative pathways.

Sections of the guideline include: admission, initial plan and management in hospital, management, progress, re-introduction of oral feeds, going home.