301-519-2100 • FAX 301-519-2892 • 207 PERRY PARKWAY GAITHERSBURG, MD 20877
SEARCH
Ornithine Transcarbamylase (OTC) Deficiency
OTC gene
Ornithine transcarbamylase (OTC) deficienty is an X-linked disorder of the urea cycle. The clinical features are highly variable ranging from an acute neonatal presentation with a high mortality rate to asymptomatic adult males. Males usually present in the neonatal period with massively elevated ammonia levels and hyperammonemic coma, encephalopathy and respiratory alkalosis. Approximately 20% of females who are heterozygous for mutations in the OTC are clinically symptomatic with disease severity similar to males with partial deficiency. Both symptomatic females and partially deficient males may present with late onset of symptoms, even into adulthood, with recurrent vomiting, history of protein avoidance, Reye-like syndrome, or with major neurologic impairment, neurobehavioral changes or seizures associated with hyperammonemia. Mutations are found in about 80% of patients with OTC deficiency; large deletions that would not be detectable by sequence analysis in females have been found in 8-15.7% of patients. The remaining patients may have mutations in either the regulatory regions or deep within the introns of the OTC gene.
Using genomic DNA, bi-directional sequence of the coding region and splice junctions of the OTC gene is analyzed. Deletion/duplication analysis is available to detect female carriers of a whole or partial gene deletion. Carrier testing and prenatal diagnosis is available one the mutation in the family has been defined.
Information Sheet, including prices and CPT codes
Consent Document
Genetic Test Sample Submission Form (Test Requisition Form) including Payment Options
Ornithine Carbamoyltransferase, ornithine carbamoyl transferase, ammonia, plasma amino acids, orotic acid, glutamine, NH3
© 2000 - 2012 GeneDx. All rights reserved.
