5112: Urea Cycle Disorders Practice Patterns and Outcomes Assessment

Status: No Longer Recruiting



This study consists of online surveys developed and chosen by researchers from the Urea Cycle Disorders Consortium and sent to those enrolled in the RDCRN Contact Registry.


For Diseases

  • N-Acetylglutamate Synthase (NAGS) Deficiency
  • Carbamyl Phosphate Synthetase (CPS) Deficiency
  • Ornithine Transcarbamylase (OTC) Deficiency
  • Argininosuccinate Synthetase Deficiency (Citrullinemia I)
  • Argininosuccinate Lyase Deficiency (Argininosuccinic Aciduria)
  • Arginase Deficiency (Hyperargininemia)
  • Ornithine Translocase Deficiency (HHH) Syndrome
  • Citrin Deficiency (Citrullinemia II)
  • or urea cycle disorder highly likely/diagnosis pending


The UCDC RDCRN Contact Registry (CR) is a vehicle through which patients (and their families) can register with the RDCRN to obtain information about the activities of the UCDC and learn about new studies in which they might be interested in participating. The RDCRN has developed surveys to be sent to the CR registrants to assess disease outcomes (patient reported outcomes) and more detailed diagnostic data.


About this Study

Patients with urea cycle disorders will be recruited via the RDCRN UCDC Contact Registry. The UCDC contact registry consists of over 300 participants with urea cycle disorders.

Participants enrolled in the RDCRN UCDC Contact Registry will receive an email inviting them to participate in the study. Interested participants will be directed to the informed consent document. After agreeing to participate, participants will be directed to the study web portal. The study web portal will be developed and maintained by the Data Management and Coordinating Center at the University of South Florida (USF).

Participants will complete several questionnaires about their urea cycle disorder including diagnosis and treatment information and quality of life.


Target Enrollment: 100

To be eligible to participate, you must be an individual with one of the following:

  • Be an individual with one of the following urea cycle disorders:
    • NAGS Deficiency
    • CPS I deficiency
    • OTC deficiency
    • AS deficiency (Citrullinemia),
    • AL deficiency (Argininosuccinic Aciduria, ASA)
    • ARG Deficiency (Hyperargininemia)
    • HHH Syndrome or ORNT Deficiency
    • CITR Deficiency (Citrullinemia Type II)
    • or urea cycle disorder highly likely/diagnosis pending
  • Be enrolled in the Urea Cycle Disorders Consortium Contact Registry

You are not eligible to participate if you have:

  • Hyperammonemia caused by another disorder
  • Rare and unrelated serious comorbidities (e.g. genetic syndrome effecting brain development, such as Down Syndrome, intraventricular hemorrhage in the newborn period and extreme prematurity (<1500 g)
  • Inability to provide informed consent and complete survey

How to participate

You can only join this study through a personalized link. This link has been sent to the email address you provided upon joining the Urea Cycle Disorders Contact Registry.

If you have any questions about this study, please contact Amy Holbert

Study Principal Investigators:

Jeffrey Krischer, PhD
University of South Florida


Total Enrolled