NAGS deficiency:
The right diagnosis at last

This is part 2 of a true account of Mary, a woman in her twenties with NAGS deficiency, in the words of Mary and her mother, Slava. They share their story to help others who may have unexplained symptoms and no diagnosis or an unconfirmed diagnosis to understand the entirety of Mary’s diagnostic journey. Over the years, Mary had symptoms that were serious but unpredictable. She never knew when they would develop or when they would go away. As a result, she and her parents were frustrated. But they never gave up hope that Mary’s life could be much better.

This is an actual patient story, but the patient’s name has been changed and a stock photo has been used to protect her privacy.

How did you respond to the medicines and low-protein diet that your doctors prescribed for your high ammonia levels due to a urea cycle disorder after your hospitalization at age 10?

MARY: Some years I was in the hospital every couple of months, and other years it was less. I was still able to go to school and pass my exams and function okay. But I was on a very strict low-protein diet. I had to weigh my food and count my grams of protein. And I had to take around 40 pills a day!

SLAVA: The doctors told us the treatment would reduce, but not eliminate, the number of episodes Mary had. We thought changes in hormone levels might be contributing to her symptoms.

During your teenage years, what symptoms did you have that sent you to the hospital?

MARY: I had a variety of symptoms. Sometimes I would throw up. Sometimes I would have a headache. Sometimes I would be confused. Once I remember being in class and thinking the teacher seemed so far away from me physically. Another time I remember calling my mom, and the next thing I remember is being in the car and then waking up in the hospital. In the hospital after these episodes, I would remember bits and parts of things. So many memories are missing.

When you started having symptoms, what thoughts were running through your head?

MARY: I didn’t want to call attention to myself, but I knew I couldn’t ignore my symptoms. My doctors were very clear. They said, “If you even suspect that it could be a crisis, you need to come in.” So I knew that any time I felt off or something could be happening, I needed to go to the hospital.

How did you feel about being on so many medicines and a strict low-protein diet and still having symptoms that were so severe you needed to be in the hospital?

MARY: Sometimes I would think, “Why am I doing all of this when I still have to go to the hospital anyway?” But then I’d think, well, maybe it’s just the nature of my condition.

SLAVA: We saw Mary’s medical team regularly and followed her treatment plan. We were frustrated, and we sometimes felt discouraged. But we remained hopeful.

MARY: My parents were always open to new ideas and treatments, and they encouraged me to be open, too. Any study or test that was suggested, we agreed to do. We said yes to everything.

Did you ever wonder whether the diagnosis of OTC deficiency was incorrect?

SLAVA: When Mary was hospitalized at age 10, the doctors ran all the genetic tests for urea cycle disorders that were possible at the time. None of the tests came back positive. The doctors were certain Mary’s symptoms were caused by a disruption in the urea cycle. They informed us that OTC deficiency was a likely diagnosis, but not necessarily the only option, and they remained open to all possibilities.

What happened when you were hospitalized during your freshman year of college?

MARY: I was living in a dorm at my college, which I had chosen partly because it was close to my home and my doctors. I had a crisis, so I ended up back in the hospital. And this time the doctors told me about a study involving a new medication called carglumic acid.

SLAVA: The doctors explained that this medication might help Mary. They also told us about possible side effects. We considered the potential risks and benefits of the medication and decided she should try it.

How did you know that CARBAGLU® (carglumic acid) was effective in treating your symptoms?

SLAVA: The study showed that CARBAGLU reduced Mary’s ammonia level drastically. Because of her dramatic response to CARBAGLU, the doctors suspected that she might actually have NAGS deficiency. And at that time they were able to run additional tests on the regulatory part of Mary’s NAGS gene, and that’s where they discovered a problem that was disrupting her urea cycle.

MARY: Almost immediately I started feeling hopeful for a different future. Things like not having to miss school and not having to explain to people why I was in the hospital all the time. And being able to eat whatever I wanted, including a lot of protein, without having symptoms or a crisis! There was a short adjustment period as the doctors titrated down the medicine I was taking and determined the right dose of CARBAGLU, but in the 10 years since I started CARBAGLU, I haven’t had any cognitive or neurological symptoms, and I haven’t had to go to the hospital even once. I’m pleased with my progress since taking the medicine.


DISCLAIMER: These results are specific to this patient. Results may vary between patients. Some patients may experience side effects, including vomiting, abdominal pain, fever, inflammation of the tonsils, anemia, diarrhea, ear infection, infections, inflammation of the throat and nasal passages, protein molecules in red blood cells decreased, and headache. For more information, please see the CARBAGLU (carglumic acid) Full Prescribing Information, including Instructions for Use.This site contains medical information that is intended for residents of the United States only and is not meant to substitute for the advice provided by a medical professional. All decisions regarding patient care must be made with a healthcare provider, considering the unique characteristics of the patient. Always consult a physician if you have health concerns. Use and access of this site is subject to the terms and conditions as set out in our Privacy Policy and Terms of Use.

DISCLAIMER: This is an actual patient story as told in the patient’s words and the words of her mother, but names have been changed and a stock photo has been used to protect privacy.