National Urea Cycle Disorders Foundation leads the way in the fight against urea cycle disorders
Urea Cycle Disorder Families stand as a united voice for urea cycle disorder research

Urea cycle disorder UCD support and information

NUCDF is a key partner in the Urea Cycle Disorders Research Consortium
NUCDF is a member of NIH Rare Diseases Clinical Research Network, Guidestar, NORD Organization for Rare Diseases

We know Urea Cycle Disorders.  We live to conquer them. 

GET HELP AND SUPPORT:   Do you need support, information on diagnosis, or help learning how to manage a urea cycle disorder? Tell us your story. We're here to help with credible information and support. Network with other UCD patients and families in our vibrant private online community. Email or call us at (626)578-0833 (Pacific Standard Time)
GET INFORMATION: Learn more about UCD. We're here to answer your questions.

GET INVOLVED: Join the fight to conquer UCD. Learn more about supporting or participating in UCD research.

STAY INFORMED: Keep up with the latest information on treatments, management and research.

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News and Announcements

Jan 30, 2015 CLINICAL TRIAL FOR ASA/ASL TREATMENT OPEN FOR ENROLLMENT: The long awaited clinical trial "Nitric Oxide Supplementation as a Therapeutic Intervention in Argininosuccinic Aciduria (ASA)" is now open for enrollment at Baylor College of Medicine (one of the UCD Research Consortium clinical research sites) in Houston, Texas. A result of their pioneering discovery on the role of the urea cycle in regulating nitric oxide in the human body, the study is being conducted by Dr. Sandesh Nagamani and Dr. Brendan Lee to determine if supplementation of nitric oxide (NO) will lessen or correct the effects of NO deficiency in the arteries of individuals with ASA deficiency. The goal of the study is to better understand the role of NO deficiency in ASA and whether supplementation with NO is an effective treatment for ASA. DETAILS AND ELIGIBILITY

Jan 27, 2015 PHEBURANE RECEIVES APPROVAL FROM HEALTH CANADA AS TREATMENT FOR UCD: Pheburane is a tasteless oral formulation of sodium phenylbutyrate. The granular form masks the unpleasant taste of the active substance (sodium phenylbutrate). Pheburane will provide Canadians living with urea cycle disorder access to a lower-cost alternative solution for the treatment of UCD. In July 2013, Lucane Pharma, developer of Pheburane, was granted a marketing authorization valid throughout the European Union, and plans to apply for FDA approval in the United States in 2015.

Jan 9, 2015 NUCDF 2014 FELLOWSHIP AWARDEE LINDSAY BURRAGE, MD, PhD DEVELOPING ENZYME REPLACEMENT THERAPY FOR ARGINASE DEFICIENCY: A Phase I/II proof of concept clinical trial is being designed with the partnership of our National Institutes of Health Rare Diseases Clinical Research Network Urea Cycle Disorders Consortium (UCDC). The UCDC will be assist in study design as well as protocol review. Pre-clinical research has been completed and an Investigational New Drug filing will be submitted to the FDA in mid 2015 to enable initiation of the clinical trial. We will post updates as they become available. (See background).

Oct 8, 2014 NIH ANNOUNCES 5-YEAR $6.25 MILLION AWARD TO UREA CYCLE DISORDERS RESEARCH CONSORTIUM (UCDC):  The award marks the 3rd straight funding award for the UCDC from NIH's Rare Diseases Clinical Research Network.  Since its creation in 2003, the UCD Consortium has flourished into an international research network with 14 academic centers in the US, Canada and Europe providing state-of-the-art care and conducting cutting-edge UCD research. The UCDC is a collaboration between NIH, UCD physician-scientists and the National Urea Cycle Disorders Foundation to improve knowledge of UCDs and speed development of new treatments. Dr. Mark Batshaw, Physician-in-Chief and Chief Academic Officer at Children's National Medical Center will continue in his role as Principal Investigator. Dr. Mendel Tuchman, Chief Research Officer and Scientific Director of the Children's Research Institute will serve as Co-Principal Investigator and administrative director. NUCDF Executive Director, Cynthia Le Mons, has been chosen as Co-Principal Investigator in recognition of her leadership in the UCDC since its inception, extensive knowledge of urea cycle disorders, and advocacy role in the UCD community. The UCDC first received funding in 2003, and became a model for NIH's vision for rare disease research collaborations.  The 2014 UCDC grant application received a perfect score of 10, an exemplary score as "rare as hen's teeth." (UCDC has received the top score out of all grant applications for rare disorders in each of the 5-year funding rounds since 2003). (More about the UCDC's work).

CITRULLINE ALERT: Although reputable suppliers of pharmaceutical grade L-citrulline have quality control procedures to ensure quality, due to the recent Medisca L-citrulline recall (see Feb 14 recall below), there are reasonable concerns about the potential for future issues with quality of supplements like L-citrulline that are not regulated by the FDA.  Quality issues could result in side effects, including but not limited to low citrulline levels, metabolic instability, hyperammonemia or other symptoms. Please notify your metabolic physician and pharmacy if you suspect any issues.  Adverse events should be reported to the FDA MedWatch HERE. 

Feb 14, 2014 URGENT DRUG RECALL - CITRULLINE: L-citrulline manfactured by Medisca, a supplier to pharmacies, has been recalled.  Lot#s 95482/A, 95482/B, 95482/C, 95482/D &96453/A, 96453/B, 96453/C, 96453/D contain ZERO citrulline. This could result in severe side effects including metabolic instability, hyperammonemia or other symptoms. The FDA has issued a warning HERE.  Manufacturer recall information is HERE. If you have other lot numbers of citrulline from Medisca, please email us at for further details, or call the FDA Drug Emergency Coordinating Center (FDA Center for Drug Evaluation and Research) at (301)796-9900.  Adverse events should be reported on FDA MedWatch HERE. Please notify your pharmacy and your metabolic physician immediately.


The purpose of the NUCDF's Fellowship Grant is to improve the quality of care for urea cycle disorder-affected individuals by attracting promising new clinicians and researchers with interest in biochemical genetics to the field of urea cycle disorders. The NUCDF Fellowship helps support postdoctoral fellows specialize and focus on research, clinical treatment and coordination of multidisciplinary care of UCDs, while advancing the understanding and treatment of our disorders.

Our 2014 Fellowship has been awarded to Dr. Lindsay Burrage of Baylor College of Medicine. Dr. Burrage will be working under the direction of preeminent UCD scientist and clinician, Dr. Brendan Lee.  Dr. Burrage is an outstanding candidate who will be conducting research studies to investigate whether a form of the arginase enzyme could be used to reduce blood arginine levels in an animal model of Arginemia. If her animal studies prove supportive, a clinical trial for enzyme replacement for arginase deficiency may be developed.  Previous NUCDF Fellowship awardees include Oleg Shchelockov, MD (2009), Ayelet Arez, MD PhD (2008) and Sandesh Nagamani MD(2011), resulting in transformational research on the role of nitric oxide in ASA and an upcoming clinical trial for a new treatment for ASA. For more about the NUCDF Fellowship awaredees and their commitment to UCD research and our UCD community click NUCDF Fellowship

UCD Dad takes on a dare to raise money for NUCDF

Update! Yair exceeds his fundraising goal. Thank you, Yair! Watch the video of his dare Here (click on Dare Video)

Do you need help or information on understanding or managing UCD? We're here to help you! Email us at

NUCDF Co-Hosts International Scientific Symposium Sept 2, 2013, Barcelona, Spain: NUCDF, the Urea Cycle Disorders Consortium and the EIMD co-hosted the 2013 International UCD Symposium, "Catalyzing New Therapeutic Approaches." Over 200 scientists, clinicians and trainees from around the globe attended. The symposium was a followup to NUCDF's 2009 International Scientific Symposium in La Jolla, CA. The goal of the Barcelona meeting was to serve as a catalyst for innovative collaborations and to provide stimulation for focused research over the coming years leading to new therapeutic approaches. Selected presentations will be published in the scientific journal, Molecular Genetics and Metabolism. To invest your support in accelerating research to develop therapeutic interventions to protect the brain from the effects of UCD, support NUCDF's Brain Project DONATE.

USA TODAY STORY: Weight loss surgery (gastric bypass) triggers undiagnosed fatal urea cycle disorder in Tennessee wife and teacher. Story. More information about bariatric surgery and the risk for urea cycle disorder Here.

UK TELEGRAPH STORY: Dukan high-protein diet triggers undiagnosed OTC, leading to coma and near death for UK man.

ABC NEWS STORY: Featuring Dr. Lee's ASA Research (see update below) and NUCDF Family that participated in the study.  Clinical trials being planned. Story  Stay updated by signing up for the NUCDF E-newsletter.

STUDIES BEGIN TO UNRAVEL THE MYSTERIES OF THE EFFECTS OF UCD ON BRAIN FUNCTION: NUCDF'S "Brain Project" stimulates and funds expansion of research - how does the brain respond to the effects of hyperammonemia? Are the effects reversible? Can we find ways to protect the brain from damage that could result in developmental delay or other neurological damage? Support NUCDF's Brain Project DONATE.


NUCDF is proud to announce that the work of Dr. Lee and three NUCDF Fellows has resulted in a major discovery in ASA deficiency that transforms human science. The research has been published in Nature Medicine, a preeminent scientific journal, and challenges long-held theories about the role of nitric oxide in the human body as a regulator of cardiovascular health. The discovery is the result of research spanning several years conducted by three consecutive NUCDF Fellowship awardees, Ayelet Erez, MD, PhD, Oleg Shchelochkov, MD, and Sandesh Nagamani, MD.  Dr. Stephen Cederbaum says of Dr. Lee's work, "He has transformed treatment of this rare condition and illustrates what one creative mind in the hands of an excellent and persistent scientist can do." NUCDF and our families are delighted beyond words that our investment in these three promising young scientists and Dr. Lee's work has resulted in this life-changing discovery.

"These findings open a door into ways to explore the effect of nitric oxide on a host of disorders.  We hope it transforms the field,” said Dr. Lee in a recent press release.  A renowned UCD expert, beloved champion of UCD families, and member of NUCDF's Medical Advisory board for over a decade, Dr. Lee has received the prestigious NIH Director's Award for Transformative Research.


Urea Cycle Disorder Consortium research conducted by Dr, Brendan Lee at Baylor suggests low-dose arginine combined with sodium phenylbutyrate may decrease liver dysfunction in patients with ASA. Details

HELP MOVE RESEARCH FORWARD FOR NEWBORN SCREEN FOR OTC AND CPS1 DEFICIENCIES: A study to validate a newborn screen for OTC deficiency, CPS1, and potentially NAGS is being conducted to help identify infants affected with the disorders at birth. The pilot study has been successful in identifying cases, but more samples are needed to fully validate the screen.  If your child is affected with OTC, CPS1 or NAGS, please consider releasing their newborn screening card to this research study. Most states store the NBS cards for several months; many store indefinitely and these samples can be accessed with your consent. Newborn screening is already available in most states for ASA lyase, citrullinemia and arginase deficiency, making it possible to identify and treat affected children early, resulting in significantly improved outcomes. Imagine the lives that would be saved and the neurological disabilities that could be avoided if all newborns were screened at birth for all the urea cycle disorders. Your help can make the difference!

UPDATE: NUCDF has formed a Task Force of experts in UCD to prepare the application required for submission to the Health and Human Services Secretary's Advisory Committee on Heritable Disorders in Newborns to request the addition of OTC deficiency to the HHS recommended newborn screening panel.  After a ten-year struggle to find a way to screen newborns for OTC, we have light at the end of the tunnel. The above study is ongoing for OTC, CPS1 and NAGS screens, so please consider participating.

For more study details and consent forms, please contact Cindy Le Mons, NUCDF Executive Director at OTC/CPS/NAGS Screen Study


National Urea Cycle Disorders Foundation receives 2010 Child Neurology Foundation Advocacy Award


NUCDF was chosen to receive the prestigious Child Neurology Foundation 2010 Advocacy Award of Merit. This national award recognizes a patient support organization making outstanding achievements on behalf of patients and families with neurologic and developmental disorders. We are proud to have been recognized for our efforts and humbled to have been chosen from among over 20 outstanding organizations representing childhood epilepsy, autism and other neurodevelopmental disorders.

Our deep appreciation to Child Neurology Foundation for this award, and to all our NUCDF families and friends who so passionately and generously support our fight to conquer urea cycle disorders.

Donate Now To End Urea Cycle Disorders

Help Move Research Forward - Participate in a Research Study

NUCDF President Tresa Warner (family with OTC deficiency) talks about her family's participation in the Longitudinal Study of Urea Cycle Disorders, and thanks the National Institutes of Health for its support of the Urea Cycle Disorders Consortium

We can make a difference and help end the devastating effects of urea cycle disorders.

Please support NUCDF and participate in UCD research!

Donate Now To End UCDs

Participate in a UCD Research Study

Educational Videos:

NUCDF Conference Presentation Series

Baby Steps - Learn the Signs, Act Early

Put Your Hands Together: Learn how to help stop the spread of colds and flu and stay healthy.

Plate Full of Color: Teaches kids the value of eating a variety of colorful and healthy foods.

In The News!

Napa Register: 2011 Cure the Cycle Challenge event inspired in memory of fire captain Jim Stavas

Stavas family is committed to helping NUCDF raise awareness that UCDs affect both children and adults. 55-year-old firefighter Jim Stavas fell into hyperammonemic coma from undiagnosed CPS1 deficiency after a simple sinus surgery and receiving medication, prednisone.


Unaware of an underlying urea cycle defect, ornithine transcarbamylase deficiency (OTC deficiency), 20-year-old hockey player Ben Pearson died after engaging in a high-protein diet. Our NUCDF families extend our heartfelt sympathies to the Pearson Family.

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Make A Donation in Memory or Honor of
a Loved One

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in Memory of
          Elaine Stiller

Help Conquer UCD

Urea Cycle Disorder Support

In Memory of
Anne Laree Jenkins

June 16, 2004 - August 3, 2010

Anne loved butterflies, and
they loved her.

"We love you and miss you very much! Thank you, God, for 6 of the most precious years with my little Anne Angel." Love, Mommy


July 10-12, 2015

NUCDF Annual Family &

Scientific Conference

Cleveland, Ohio

Info & Registration coming soon.

UCD Families and Friends are invited to join us for the 2015 Cure the Cycle Challenge to raise UCD awareness and funds to accelerate UCD research. Registration coming in the Spring!

Get info

Thank you to all our generous donors, Challenge and Virtual Riders for raising over $85,000 for critical UCD research!

We had an awesome

2014 Annual Family Conference!

July 11-13, 2014

Hilton San Diego Resort & Spa

Rare and Precious Benefit

Dinner and Auction

April 25, 2014

Burlingame, CA

Over $90K was raised to benefit NUCDF's Brain Project and research to prevent the effects of UCD on brain function!

Did you miss our first
Virtual Conference?

For the first time, our 2013 NUCDF Annual Conference was held online - virtually! Over 200 families and medical professionals from around the world spent the day online with our UCD experts learning the latest info about UCD treatment and research. Nobody had to travel, no expenses, no stress!  Details


Our event raised over $86,000 for UCD research.

Thank you to all our cyclists, "virtual riders," donors, sponsors, and volunteers for rising to the challenge and making our event a success!

About the Challenge Events

4th UCD International Scientific Symposium

for Clinical and Research Scientists

Barcelona, Spain

September 2, 2013

Over 200 researchers and clinicians from around the globe were in attendance to learn about the latest UCD research developments and what's on the horizon.

Three NCAA Basketball Tournaments Raise UCD Awareness

Hoops for Hope Classic

Hardwood Tournament of Hope

Basketball Challenge-San Diego


"OUR DREAM IS FOR A CURE" Shopping Totes

NUCDF Cure Urea Cycle Disorders Support

Urea Cycle Disorder Awareness Bracelet

¡Folletos del conocimiento de UCD en español!

Help Move  Research Forward by participating in critical research studies.

UCD International Patient Registry: By reporting your own unique experiences with UCD, you can help improve the understanding of UCD. Details

Neuroimaging Studies:

   1) Studies using MRI techniques are being conducted to investigate the effects of UCD on brain function.  Details HERE.  For more information or how to participate contact NUCDF.

   2) Study of past MRIs: If your child (or an affected adult) has had an MRI or EEG in the past, sign a consent to release the data to Dr. Andrea Gropman at Children's National Medical Center for reinterpretation by new software in a special study of effects of UCD on brain function. For more information contact NUCDF or Study Coordinator Details HERE

Newborn Screen for OTC & CPS deficiencies: If your child was diagnosed with OTC or CPS1 deficiencies, release their state newborn screening card to help validate a test to screen newborns at birth for OTC and CPS deficiencies. Read more

Urea Cycle Nutrition and Immunity Study at National Institutes of Health to investigate the effects of the UCD diet on immune response. Peter McGuire, MD, Principal Investigator.

Contact Janet Shiffer, Study Coordinator

Download Study Flyer

Watch Video here



urea cycle disorder treatment and support urea cycle disorder support