Upon clinical suspicion, diagnostic testing will often consist of measurement of amino acid concentrations in plasma, in search of a significantly elevated<unk>  concentration. Measurement of urine amino acid concentrations is sometimes necessary, particularly in neonatal onset cases to identify the presence or absence of homocitrulline for ruling out<unk>  translocase deficiency (hyperornithinemia, hyperammonemia, homocitrullinuria syndrome, HHH syndrome).<unk>  concentrations can be an unreliable indicator in the newborn period, thus newborn screening may not detect this condition, even if<unk>  is included in the screening panel. Enzyme assays to measure the activity of<unk><unk>  can be performed from fibroblasts or lymphoblasts for confirmation or during the neonatal period when the results of biochemical testing is unclear. Molecular genetic testing is also an option.
Ornithine aminotransferase deficiency
Glutaminase deficiency
Malonyl-CoA decarboxylase deficiency
Pyruvate kinase deficiency
Arginine:glycine amidinotransferase deficiency
3-Hydroxyisobutyryl-CoA deacylase deficiency
3-Methylcrotonyl-CoA carboxylase deficiency
Transaldolase deficiency