DALLAS – May 9, 2018 – Something was wrong with Jessica Hitt.

She’d given birth four days earlier to her first child, Olivia. The birth had gone well and Jessica had gloried in the skin-to-skin time of those first minutes after her baby was born, in getting to know her perfect daughter.

Jessica Hitt, left, with her 2-year-old daughter, Olivia, is now expecting a second child after she was successfully treated for a rare genetic disorder by Dr. McNutt.

But now Jessica was sleepy. Not new-mother tired, but sunk inside an overwhelming, can’t-wake-up fog.

The hospital near Jessica’s Arlington home determined that her ammonia level was high – but why? After ruling out the most obvious causes of elevated ammonia, they reached out to Dr. Markey McNutt, a clinical genetics specialist at UT Southwestern Medical Center, for advice.

“The idea that she could have a genetic disease arose and we’re one of the few places in North Texas that has a genetics department, and so we helped manage her by phone initially. When her condition deteriorated, they decided to move her here because of the breadth of the different specialties that we have available at UT Southwestern,” said Dr. McNutt, an Assistant Professor with the Eugene McDermott Center for Human Growth and Development who specializes in treating adult patients with metabolic diseases of genetic origin.

When the young new mother arrived at UT Southwestern, she was critically ill, Dr. McNutt said. Her red blood cells had started to break down, so that not only were her ammonia levels ominously high, but her blood levels were also dangerously low.

Jessica’s problem was a defect in the urea cycle, which is the way that the body deals with excess nitrogen created by the breakdown of protein. Depending on the specific genetic error, a urea cycle defect might cause problems in early childhood or the problem might not be revealed until a major stress occurs later in life.

“There’s a broad spectrum of how these diseases can present clinically,” said Dr. McNutt, also Assistant Professor of Internal Medicine and Pediatrics at UT Southwestern, which is recognizing its 75^th year in 2018. “In the mild cases, they do fine until they encounter a serious stress. That could be something like a car accident or a severe infection. And then there are the most severe cases, children who present in the first couple of days of life with very high ammonias.”

Jessica’s crisis had been brought on by childbirth. After days of intensive treatment, including dialysis and blood transfusions, her condition stabilized. The fog she’d been living in lifted.

“Finally, I started feeling better and they allowed my mother-in-law, who’d been taking care of my daughter, to bring her up to see me. I was able to hold her and see her and that really helped me,” Jessica said.

With her status much improved, Jessica was able to go home with medication. But Dr. McNutt explained it would be better if they could pinpoint the particular enzyme that was the source of her problem, so Jessica agreed to take part in a genetic research study to identify the faulty enzyme.

The Genetic and Metabolic Disease Program is part of Children’s Research Institute at UT Southwestern, a joint program of UT Southwestern and Children’s Health, and Jessica’s DNA was scrutinized in its lab. Eventually, Dr. McNutt was able to contact Jessica with some very good news: She had a rare recessive genetic condition called N-acetylglutamate synthase deficiency. More important, there was an easy fix for it – a medication she’d take twice a day.

“It doesn’t even taste bad. It’s like a citrusy sand water and immediately my ammonia levels went to normal,” Jessica said. “The medication will help me lead a normal lifestyle, so taking pills twice a day is nothing.”

Doctors detected elevated ammonia in Jessica Hitt, right, and referred her to Dr. Markey McNutt, an adult clinical genetics specialist at UT Southwestern, who was able to determine a gene mutation was causing her symptoms.

Dr. McNutt said Jessica is lucky in a way. “The problem she has is one for which we have, essentially, a curative medicine. When I see her now, she seems like a completely different person. She is cheerful, always full of energy. She’s always been a very positive person, but to see her have the energy, the brightness to really go with her personality has been fantastic.”

The good control of her ammonia levels opened the door for something else Jessica and her husband, Marshall, wanted very much: the possibility of a second child. Olivia, who just turned 2, will become a big sister in October.

Jessica sees high-risk pregnancy specialists at UT Southwestern, and everything is looking good.

“I’m feeling great. I’m really happy with everything,” she said. “I’m just thankful that we were able to overcome all the obstacles that we went through as a family, begin to grow, and put this past us."

About UT Southwestern Medical Center

UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty has received six Nobel Prizes, and includes 22 members of the National Academy of Sciences, 16 members of the National Academy of Medicine, and 14 Howard Hughes Medical Institute Investigators. The faculty of more than 2,700 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide care in about 80 specialties to more than 100,000 hospitalized patients, 600,000 emergency room cases, and oversee approximately 2.2 million outpatient visits a year.