The UCD Genetic Testing Program, sponsored by Horizon Therapeutics and performed by Invitae, provides access to genetic testing for patients in the US suspected of having a urea cycle disorder (UCD), and their family members, at no charge.

The UCD Genetic Testing Program provides testing to patients with a suspected diagnosis of a UCD or a family history of a UCD.

About urea cycle disorders

  • UCDs are a group of rare genetic diseases that affect about 1 in 35,000 births in the United States.

  • UCDs are characterized by potentially toxic elevations of ammonia levels in the blood and brain (hyperammonemia). In people living with UCDs, the liver is unable to metabolize ammonia so that it can be eliminated from the body in the urine. This results in elevated ammonia levels and leads to an accumulation of ammonia in the bloodstream. Excess ammonia can cross the blood–brain barrier and act as a neurotoxin in the brain. Left untreated, hyperammonemia can result in coma, brain damage, and, in some cases, even death.

  • Ornithine transcarbamylase (OTC) deficiency is the most common UCD subtype. It is passed on from a mother to her child via the X chromosome. In rare cases, OTC can also be passed down from a father to his daughter via the X chromosome. While a parent with the OTC gene is a carrier, they may not know they have OTC until their child is diagnosed. Approximately 20% of carrier females have symptoms of the disorder and rarely may be severely affected in childhood. Symptoms for adults who have OTC deficiency can range from migraines and nausea to confusion, ataxia, and even hallucinations.1


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Program eligibility

Available to patients in the US, who meet at least one of the following criteria:

  • A suspected diagnosis of a urea cycle disorder


  • A family history of urea cycle disorder

Genetic testing with Invitae

The UCD Genetic Testing Program offers testing with the Invitae Hyperammonemia Panel.
The Invitae Hyperammonemia Panel includes genes that are associated with the enzymes and transporter proteins responsible for the production and detoxification of ammonia. Deficiency of any of these proteins may result in an excess of ammonia in the blood; a condition known as hyperammonemia.
Once Invitae receives your patient’s blood or saliva specimen, their results will be available in 10 to 21 calendar days, on average.

View panel

How to order

1. Submit an order

To place your online order, click here and follow the on-screen prompts.

To place a paper-based order, download the paper order form and include it in the specimen box. 

2. Collect a specimen

If a specimen collection kit was not ordered during the online ordering workflow, order a blood, buccal, or saliva collection kit here
Please view specimen and shipping requirements for important information, and be sure to include the completed requisition form in the kit with the specimen. 

3. Receive results

On average, results are available 10-21 days after Invitae receives the specimen. You will receive a notification email once the test results are ready.
Log in to view the status of your online order. 

Next steps and additional services

Broaden your search with re-requisition

If you don’t find answers with your initial order, 
UCD includes one re-requisition within 90 days to genes within the original clinical area.

Simply log into your account, navigate to the order, and click "Add re-requisition”

Family variant testing for familial insights

If a positive result is identified, testing for your patient’s family members is available.

Simply follow the ordering instructions, selecting only the gene(s) you are interested in testing for the family member. The partner code will automatically be added with the order.

About Invitae

Invitae Corporation (NYSE: NVTA) is a leading medical genetics company, whose mission is to bring comprehensive genetic information into mainstream medicine to improve healthcare for billions of people. Invitae's goal is to aggregate the world's genetic tests into a single service with higher quality, faster turnaround time, and lower prices. For more information, visit the company's website at

About Horizon Therapeutics

Horizon Therapeutics is focused on researching, developing and commercializing innovative medicines that address unmet treatment needs for rare and rheumatic diseases. By fostering a growing pipeline of medicines in development and exploring all potential uses for currently marketed medicines, we strive to make a powerful difference for patients, their caregivers and physicians. For us, it’s personal: by living up to our own potential, we are helping others live up to theirs. For more information, please visit, follow us @HorizonNews on Twitter, like us on Facebook or explore career opportunities on LinkedIn.


While Horizon Therapeutics provides financial support for this program, tests and services are performed by independent third parties. Healthcare professionals must confirm that patients meet certain criteria to use the program. Horizon Therapeutics receives de-identified patient data from this program, but at no time does Horizon Therapeutics receive patient identifiable information. Horizon Therapeutics receives contact information for healthcare professionals who use this program. Genetic testing and counseling are only available in the US. Healthcare professionals and patients who use this program have no obligation to recommend, purchase, order, prescribe, promote, administer, use or support any Horizon Therapeutics product.


1. Ornithine transcarbamylase deficiency. National Organizations for Rare Disorders (NORD) website. Accessed March 20, 2019.