Longitudinal Study of Urea Cycle Disorders

Status unconfirmed

Conditions studied: Brain Diseases, Metabolic, Inborn, Amino Acid Metabolism, Inborn Errors, Urea Cycle Disorders

In brief

Urea cycle disorders (UCD) are a group of rare inherited metabolism disorders. Infants and children with UCD commonly experience episodes of vomiting, lethargy, and coma. The purpose of this study is to perform a long-term analysis of a large group of individuals with various UCDs. The study will focus on the natural history, disease progression, treatment, and outcome of individuals with UCD.

Key facts

Study ID

NCT00237315

Run by

Andrea Gropman

People needed

1500

Starts

2006-02-01

Expected to finish

2026-07-01

Last updated by the study team

2024-02-13

Who can join

Age: any. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• Diagnosis of NAGS deficiency, defined as the detection of a pathogenic mutation, and/or decreased (less than 20 % of control) NAGS enzyme activity in liver ,and/or hyperammonemia and first degree relative meets at least one of the criteria for NAGS deficiency
• Diagnosis of CPS I deficiency, defined as decreased (less than 20 % of control) CPS I enzyme activity in liver, and/or an identified pathogenic mutation, and/or hyperammonemia and first degree relative meets at least one of the criteria for CPS I deficiency
• Diagnosis of OTC deficiency, defined as the identification of a pathogenic mutation, and/or less than 20% of control of OTC activity in the liver, and/or elevated urinary orotate (greater than 20 uM/mM) in a random urine sample or after allopurinol challenge test, and/or hyperammonemia and first degree relative meets at least one of the criteria for OTC deficiency
• Diagnosis of AS deficiency (Citrullinemia), defined as a greater than or equal to 10-fold elevation of citrulline in plasma, and/or decreased AS enzyme activity in cultured skin fibroblasts or other appropriate tissue, and/or identification of a pathogenic mutation in the AS gene, and/or hyperammonemia and first degree relative meets at least one of the criteria for AS Deficiency
• Diagnosis of AL deficiency (Argininosuccinic Aciduria, ASA), defined as the presence of argininosuccinic acid in the blood or urine, and/or decreased AL enzyme activity in cultured skin fibroblasts or other appropriate tissue, and/or identification of a pathogenic mutation in the AL gene, and/or hyperammonemia and first degree relative meets at least one of the criteria for AL Deficiency
• Diagnosis of ARG deficiency (Hyperargininemia), defined as a greater than or equal to 5-fold elevated arginine levels in the blood, and/or decreased arginase enzyme levels in red blood cells or other appropriate tissue, and/or identification of a pathogenic mutation in the ARG gene, and/or hyperammonemia and first degree relative meets at least one of the criteria for ARG Deficiency
• Diagnosis of HHH Syndrome or ORNT deficiency, defined as a greater than or equal to 5-fold elevated plasma ornithine and homocitrulline levels in the urine, and/or a pathogenic mutation, and/or less than 20% residual labeled ornithine incorporation into protein in cultured fibroblasts, and/or hyperammonemia and first degree relative meets at least one of the criteria for HHH Syndrome or ORNT Deficiency
• Diagnosis of CITR deficiency (Citrullinemia Type II), defined as elevated citrulline levels in the blood and a pathogenic mutation and/or hyperammonemia and first degree relative meets criteria for CITR Deficiency
• Pending diagnosis of a UCD (UCD highly likely), defined as laboratory values highly suggestive of a UCD with symptomatic hyperammonemic episodes but without a verifiable diagnosis

You may not qualify if…

• Hyperammonemia caused by an organic academia, lysinuric protein intolerance, mitochondrial disorder, congenital lactic academia, fatty acid oxidation defects, or primary liver disease
• Rare and unrelated comorbidities (e.g., Down's syndrome, intraventricular hemorrhage in the newborn period, and extreme prematurity)

Where it is running

• University of California, Los Angeles — Los Angeles, California, United States (enrolling)
• Stanford University Medical Center — Stanford, California, United States (enrolling)
• Children's Hospital Colorado — Aurora, Colorado, United States (enrolling)
• Children's National Medical Center — Washington D.C., District of Columbia, United States (enrolling)
• Children's Hospital Boston (UCDC New England Center) — Boston, Massachusetts, United States (enrolling)
• University of Minnesota — Minneapolis, Minnesota, United States (enrolling)
• Icahn School of Medicine at Mount Sinai — New York, New York, United States (enrolling)
• Case Western Medical College — Cleveland, Ohio, United States (enrolling)
• Oregon Health and Science University — Portland, Oregon, United States (enrolling)
• Children's Hospital of Philadelphia — Philadelphia, Pennsylvania, United States (enrolling)
• Baylor College of Medicine — Houston, Texas, United States (enrolling)
• Children's Hospital and Regional Medical Center — Seattle, Washington, United States (enrolling)
• The Hospital for Sick Children — Toronto, Ontario, Canada (enrolling)
• University of Heidelberg — Heidelberg, Germany (enrolling)
• University Children's Hospital — Zurich, Switzerland (enrolling)

Full record on ClinicalTrials.gov

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