NAGS deficiency:
The beginning of our diagnostic journey

This is 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.

When did you first start having symptoms?

MARY: My symptoms began at birth and were serious enough to admit me to the neonatal intensive care unit (NICU). The doctors thought maybe I had a head injury.

SLAVA: She wasn’t exactly in a coma, but she was kind of semi-conscious. Her symptoms improved, but the first year was uncertain. Mary still had unexplained symptoms, like sleepiness, and it was hard for us to wake her up. And she also had nausea and sometimes refused to eat.

What doctors did you take Mary to see during her first year of life?

SLAVA: At that time we lived in another country. We were able to consult a neurologist who told us that it was normal for babies to sleep and that we didn’t need to be able to wake Mary up. We were concerned that something was wrong with Mary, but her symptoms came and went, so they were difficult to observe. When we took her to doctor appointments, she appeared to be perfectly fine. I don’t think the neurologist we saw was equipped to work up Mary’s condition at that time.

What happened as Mary grew older?

SLAVA: After the first year, Mary’s symptoms disappeared for the next 9 years. Except for one thing.

MARY: I refused to eat foods that contained protein.

SLAVA: It seemed a little odd, but I just thought her aversion to protein was a personal choice, not some kind of disorder. So I didn’t force her to eat foods she didn’t want to eat.

Mary began having serious symptoms again at age 10. What happened?

SLAVA: One day when she was 10 years old, Mary appeared to be sleepy and confused. We were now living in the U.S., and we took Mary to our local hospital. The doctors thought maybe Mary’s symptoms were due to the flu since it was flu season. They let Mary go home. The next day she was so weak that she couldn’t walk. The 911 dispatcher recommended taking her to the children’s hospital in our metropolitan area.

What happened at the children’s hospital?

SLAVA: After Mary arrived at the hospital, her symptoms worsened. She became more and more unresponsive and appeared to be in a comatose state. The neurologist ran some toxicology tests, including blood ammonia level, which was high, and contacted a metabolic geneticist. A diagnosis was made: a urea cycle disorder. By the end of the hospitalization, we were told that Mary had presumed OTC (ornithine transcarbamylase deficiency) deficiency, the most common urea cycle disorder.

SLAVA: The doctors stabilized Mary and prescribed medicines and a low-protein diet to help keep her ammonia level low. Although the doctors cautioned that the treatment would only reduce some of Mary’s symptoms, not eliminate them, we had high hopes.


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.

Read part 2 of Mary’s story to find out how Mary responded to treatment and eventually had a lifechanging breakthrough