Urea cycle disorders

Common Name(s)

Urea cycle disorders

A urea cycle disorder is a genetic disorder that results in a deficiency of one of the six enzymes in the urea cycle. These enzymes are responsible for removing ammonia from the blood stream. The urea cycle involves a series of biochemical steps in which nitrogen, a waste product of protein metabolism, is changed to a compound called urea and removed from the blood. Normally, the urea is removed from the body through the urine. In urea cycle disorders, nitrogen builds up in the blood in the form of ammonia, a highly toxic substance, resulting in hyperammonemia (elevated blood ammonia). Ammonia then reaches the brain through the blood, where it can cause irreversible brain damage, coma and/or death. The onset and severity of urea cycle disorders is highly variable. The severity correlates with the amount of urea cycle enzyme function.
 

Advocacy and Support Organizations

 

Condition Specific Organizations

Following organizations serve the condition "Urea cycle disorders" for support, advocacy or research.

Intermountain PKU and Allied Disorders Association

The mission of the Intermountain PKU and Allied Disorders Association is to provide education and resources to individuals and families, to encourage research, and to increase public awareness of these conditions.

Last Updated: 2 Mar 2013

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National Urea Cycle Disorders Foundation

The National Urea Cycle Disorders Foundation is the only organization solely dedicated to saving the lives of children and adults with urea cycle disorders and leading the search for a cure. NUCDF serves as a lifeline to families and medical professionals around the world seeking life saving information. NUCDF focuses on educating UCD patients, families and medical professionals on diagnosis and treatment, stimulating and supporting critical research, as well as providing guidance, information and support to all those affected by urea cycle disorders. The UCD International Patient Registry (www.ucdregistry.org), an IRB-approved research study, empowers UCD patients and caregivers to self-report their own unique experiences with UCD and compare them to others with UCD. Participants in the UCD Registry can help improve the understanding of UCDs, improve care, and accelerate research and development of new treatments.

Last Updated: 18 Mar 2013

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General Support Organizations

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Advocacy and Support Organizations

 

Condition Specific Organizations

Following organizations serve the condition "Urea cycle disorders" for support, advocacy or research.

Intermountain PKU and Allied Disorders Association

The mission of the Intermountain PKU and Allied Disorders Association is to provide education and resources to individuals and families, to encourage research, and to increase public awareness of these conditions.

http://www.go-ipad.org

Last Updated: 2 Mar 2013

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National Urea Cycle Disorders Foundation

The National Urea Cycle Disorders Foundation is the only organization solely dedicated to saving the lives of children and adults with urea cycle disorders and leading the search for a cure. NUCDF serves as a lifeline to families and medical professionals around the world seeking life saving information. NUCDF focuses on educating UCD patients, families and medical professionals on diagnosis and treatment, stimulating and supporting critical research, as well as providing guidance, information and support to all those affected by urea cycle disorders. The UCD International Patient Registry (www.ucdregistry.org), an IRB-approved research study, empowers UCD patients and caregivers to self-report their own unique experiences with UCD and compare them to others with UCD. Participants in the UCD Registry can help improve the understanding of UCDs, improve care, and accelerate research and development of new treatments.

http://www.nucdf.org

Last Updated: 18 Mar 2013

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Scientific Literature

Articles from the PubMed Database

Research articles describe the outcome of a single study. They are the published results of original research.
The terms "Urea cycle disorders" returned 16 free, full-text research articles on human participants. First 3 results:

Population pharmacokinetic modeling and dosing simulations of nitrogen-scavenging compounds: disposition of glycerol phenylbutyrate and sodium phenylbutyrate in adult and pediatric patients with urea cycle disorders.
 

Author(s): Jon P R Monteleone, M Mokhtarani, G A Diaz, W Rhead, U Lichter-Konecki, S A Berry, C Lemons, K Dickinson, D Coakley, B Lee, B F Scharschmidt

Journal: J Clin Pharmacol. 2013 Jul;53(7):699-710.

 

Sodium phenylbutyrate and glycerol phenylbutyrate mediate waste nitrogen excretion in the form of urinary phenylacetylglutamine (PAGN) in patients with urea cycle disorders (UCDs); rare genetic disorders characterized by impaired urea synthesis and hyperammonemia. Sodium phenylbutyrate ...

Last Updated: 24 Jun 2013

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Ammonia control in children ages 2 months through 5 years with urea cycle disorders: comparison of sodium phenylbutyrate and glycerol phenylbutyrate.
 

Author(s): Wendy Smith, George A Diaz, Uta Lichter-Konecki, Susan A Berry, Cary O Harding, Shawn E McCandless, Cindy LeMons, Joe Mauney, Klara Dickinson, Dion F Coakley, Tristen Moors, Masoud Mokhtarani, Bruce F Scharschmidt, Brendan Lee

Journal: J. Pediatr.. 2013 Jun;162(6):1228-34, 1234.e1.

 

To examine ammonia levels, pharmacokinetics, and safety of glycerol phenylbutyrate (GPB; also referred to as HPN-100) and sodium phenylbutyrate (NaPBA) in young children with urea cycle disorders (UCDs).

Last Updated: 27 May 2013

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Urinary phenylacetylglutamine as dosing biomarker for patients with urea cycle disorders.
 

Author(s): M Mokhtarani, G A Diaz, W Rhead, U Lichter-Konecki, J Bartley, A Feigenbaum, N Longo, W Berquist, S A Berry, R Gallagher, D Bartholomew, C O Harding, M S Korson, S E McCandless, W Smith, J Vockley, S Bart, D Kronn, R Zori, S Cederbaum, N Dorrani, J L Merritt, Sandesh Sreenath-Nagamani, M Summar, C Lemons, K Dickinson, D F Coakley, T L Moors, B Lee, B F Scharschmidt

Journal: Mol. Genet. Metab.. 2012 Nov;107(3):308-14.

 

We have analyzed pharmacokinetic data for glycerol phenylbutyrate (also GT4P or HPN-100) and sodium phenylbutyrate with respect to possible dosing biomarkers in patients with urea cycle disorders (UCD).

Last Updated: 29 Oct 2012

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Reviews from the PubMed Database

Review articles summarize what is currently known about a disease. They discuss research previously published by others.
The terms "Urea cycle disorders" returned 7 free, full-text review articles on human participants. First 3 results:

Suggested guidelines for the diagnosis and management of urea cycle disorders.
 

Author(s): Johannes Häberle, Nathalie Boddaert, Alberto Burlina, Anupam Chakrapani, Marjorie Dixon, Martina Huemer, Daniela Karall, Diego Martinelli, Pablo Sanjurjo Crespo, René Santer, Aude Servais, Vassili Valayannopoulos, Martin Lindner, Vicente Rubio, Carlo Dionisi-Vici

Journal:

 

Urea cycle disorders (UCDs) are inborn errors of ammonia detoxification/arginine synthesis due to defects affecting the catalysts of the Krebs-Henseleit cycle (five core enzymes, one activating enzyme and one mitochondrial ornithine/citrulline antiporter) with an estimated incidence ...

Last Updated: 5 Nov 2012

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Brain imaging in urea cycle disorders.
 

Author(s): Andrea Gropman

Journal: Mol. Genet. Metab.. 2010 ;100 Suppl 1():S20-30.

 

Urea cycle disorders (UCD) represent a group of rare inborn errors of metabolism that carry a high risk of mortality and neurological morbidity resulting from the effects of accumulation of ammonia and other biochemical intermediates. These disorders result from single gene defects ...

Last Updated: 12 Apr 2010

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Establishing a consortium for the study of rare diseases: The Urea Cycle Disorders Consortium.
 

Author(s): Jennifer Seminara, Mendel Tuchman, Lauren Krivitzky, Jeffrey Krischer, Hye-Seung Lee, Cynthia Lemons, Matthias Baumgartner, Stephen Cederbaum, George A Diaz, Annette Feigenbaum, Renata C Gallagher, Cary O Harding, Douglas S Kerr, Brendan Lanpher, Brendan Lee, Uta Lichter-Konecki, Shawn E McCandless, J Lawrence Merritt, Mary Lou Oster-Granite, Margretta R Seashore, Tamar Stricker, Marshall Summar, Susan Waisbren, Marc Yudkoff, Mark L Batshaw

Journal: Mol. Genet. Metab.. 2010 ;100 Suppl 1():S97-105.

 

The Urea Cycle Disorders Consortium (UCDC) was created as part of a larger network established by the National Institutes of Health to study rare diseases. This paper reviews the UCDC's accomplishments over the first 6years, including how the Consortium was developed and organized, ...

Last Updated: 12 Apr 2010

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Symptoms, Diagnosis, and Treatment

There are currently no related results available in GeneReviews.

There are currently no related results available in Genetic Testing Registry.

 
 
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Clinical Trial Information This information is provided by ClinicalTrials.gov

Oxidative Stress, Inflammation and Acute Decompensation in Urea Cycle Disorders
 

Status: Recruiting

Condition Summary: Urea Cycle Disorders

 

Last Updated: 15 Apr 2013

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Human Heterologous Liver Cells for Infusion in Children With Urea Cycle Disorders
 

Status: Recruiting

Condition Summary: Urea Cycle Disorders

 

Last Updated: 25 Mar 2014

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Human Heterologous Liver Cells for Infusion in Children With Urea Cycle Disorders
 

Status: Recruiting

Condition Summary: Urea Cycle Disorders; Carbamoylphosphate Synthetase I Deficiency; Ornithine Transcarbamylase Deficiency; Citrullinemia

 

Last Updated: 16 Jul 2014

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