Molecular Genetics Urea Cycle Disorders

The urea cycle is a metabolic process that is the main mechanism for clearance of excess nitrogen resulting from protein catabolism and the metabolism of nitrogenous compounds such as ATP from the cell.  It is also the only source for the endogenous production of arginine, citrulline, and ornithine.  The enzymes within the urea cycle, as well as an enzyme responsible for the production of a required cofactor, are the key components for this metabolic process. Detrimental effects occur when deleterious genetic defects occur within this process whose group of disorders are known as urea cycle disorders and can be categorized based on the specific enzyme deficiency that is present. Mutations in genes encoding the cellular machinery for this pathway can be clinically heterogeneous, but biochemical tests are carried out during newborn screening to assess sets of metabolic markers for urea cycle disorders. Patients may present with hypoglycemia, abnormality of liver, cardiomyopathy, and muscle weakness. These conditions are inherited in an autosomal recessive or X-linked manner.  This next-generation sequencing test targets the coding regions for 6 clinically significant genes associated with urea cycle disorders.

Reasons for Referral:

• Confirmation of a clinical diagnosis
• Carrier testing

For detailed information and ordering instructions, please refer to Full Gene Analysis (1240). Genes may be added or removed from the list below if clinically indicated.

Urea Cycle Disorders Panel (6 genes):
ARG1, ASL, ASS1, CPS1, NAGS, OTC