Longitudinal Study of Urea Cycle Disorders

Description

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.

Conditions

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

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Study Overview

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Study Details

Study overview

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.

Longitudinal Study of Urea Cycle Disorders

Longitudinal Study of Urea Cycle Disorders

Condition
Brain Diseases, Metabolic, Inborn
Intervention / Treatment

-

Contacts and Locations

Los Angeles

University of California, Los Angeles, Los Angeles, California, United States, 90095

Stanford

Stanford University Medical Center, Stanford, California, United States, 94305

Aurora

Children's Hospital Colorado, Aurora, Colorado, United States, 80045

Washington

Children's National Medical Center, Washington, District of Columbia, United States, 20010

Boston

Children's Hospital Boston (UCDC New England Center), Boston, Massachusetts, United States, 02115

Minneapolis

University of Minnesota, Minneapolis, Minnesota, United States, 55455

New York

Icahn School of Medicine at Mount Sinai, New York, New York, United States, 10029

Cleveland

Case Western Medical College, Cleveland, Ohio, United States, 44106

Portland

Oregon Health and Science University, Portland, Oregon, United States, 97239

Philadelphia

Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States, 19104

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

For general information about clinical research, read Learn About Studies.

Eligibility Criteria

  • * 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
  • * 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)

Ages Eligible for Study

to

Sexes Eligible for Study

ALL

Accepts Healthy Volunteers

No

Collaborators and Investigators

Andrea Gropman,

Andrea Gropman, MD, STUDY_CHAIR, Children's National Research Institute

Susan Berry, MD, STUDY_CHAIR, University of Minnesota Masonic Children's Hospital

Study Record Dates

2026-07