Urea cycle disorders: Clinical features and diagnosis
- Brendan Lee, MD, PhD
Brendan Lee, MD, PhD
- Baylor College of Medicine
- Texas Children's Hospital
The urea cycle is the metabolic pathway that transforms nitrogen to urea for excretion from the body (figure 1). Deficiency of an enzyme in the pathway causes a urea cycle disorder (UCD). The UCDs  are:
●Carbamyl phosphate synthetase I (CPSI) deficiency (MIM #237300)
●Ornithine transcarbamylase (OTC) deficiency (MIM #311250)
●Argininosuccinate synthetase (ASS) deficiency  (also known as classic citrullinemia or type I citrullinemia, CTLN1, MIM #215700)
●Argininosuccinate lyase (ASL) deficiency  (also known as argininosuccinic aciduria, MIM #207900)
Subscribers log in hereLiterature review current through: Jul 2017. | This topic last updated: Oct 21, 2015.References
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- CLINICAL FEATURES
- Typical presentation
- Atypical presentation
- LABORATORY FINDINGS
- Plasma amino acid/urine orotic acid analyses
- Enzyme analysis
- Specialized testing
- DNA mutation analysis
- Prenatal testing
- Newborn screening
- DIFFERENTIAL DIAGNOSIS