Fig. 4
From: Management of late onset urea cycle disorders—a remaining challenge for the intensivist?
![Fig. 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13613-020-00797-y/MediaObjects/13613_2020_797_Fig4_HTML.png)
diagnostic algorythm for late onset hyperammonemia. In case of hyperammonemia, the levels of citrulin and urinary orotic acid makes it possible to direct towards a specific analysis group leading to the final diagnosis. Unless indicated, with (U) to indicate urine. Ala: alanine, Arg: arginine, ARG1: arginase 1, 3-MGA: 3-methylglutaconic acid, NAGS: N-acetylglutamate synthase, CPS: carbamoylphosphate synthetase, Orn: ornithine, Pro: proline, P5CS: pyrroline-5-carboxyl synthetase, HHH: hyperornithinemia-hyperammonemia-homocitrullinuria, OAT: ornithine aminotransferase, OTC: ornithine transcarbamylase, Lys: lysine, LPI: lysinurix protein intolerance, ASA: arginosuccinic acid, ASS: arginosuccinate synthetase