Anyone who meets Hannah Carpenter would never know the 15-year-old has been managing a rare metabolic disorder since she was four years old.
That was around the time Hannah was diagnosed with a urea cycle disorder (UCD), a rare genetic condition that results in a deficiency of one of the six enzymes in the urea cycle, whose job is to remove ammonia from the bloodstream. Once ammonia accumulates it can be catastrophic, often leading to brain damage or death.
Hannah’s condition is the most common enzyme deficiency: OTC (ornithine transcarbamylase). Because her mutation is fairly moderate, she’s able to be stabilized through a daily regimen of medications (called ammonia scavengers), supplements, and a strict, protein-restricted diet.
Finding an answer
The Carpenters found out about Hannah’s condition in 2008 after she became ill and severely jaundiced. The local hospital in her native Dawson Creek, B.C., immediately sent her to a larger hospital in Grande Prairie, Alta., who then medivacked her to Edmonton.
When they failed to diagnose her right away, the family started to panic. “We were terrified,” recalls her mother, Catina. “She had every test known to man. They must have pulled 30 vials of blood in 24 hours. Then, several days after being admitted, one doctor asked if her ammonia levels had been tested.”
This test showed that her levels were above 200µmol/L (normal is around 35µmol/L or less). “The levels were so high they thought she would go into a coma,” says Catina. “Once they started her on medication and put her on a low-protein diet, the change was amazing. DNA testing later confirmed it was a UCD.”
Urea cycle disorders can be passed down when each parent gives a UCD gene to the child. One subtype, OTC deficiency, can also be inherited in an x-linked way, where the gene is passed down from the mother. In many cases the serious illness or death of a newborn child is a mother’s first indication that she is, in fact, a genetic carrier of OTC. Research into the Carpenters’ family history indicated that Hannah’s disease was a spontaneous mutation, meaning that Catina is unaffected.
Since her diagnosis, Hannah’s and her family’s lives have been redirected by her condition but neither she, nor her family, allow it to define them.
Because Hannah would always need to be within a two-hour drive of an appropriate hospital facility, the family was forced to move from their rural community to Chilliwack, B.C. to be closer to the BC Children’s Hospital in Vancouver.
Hannah’s condition also limits the places the family can travel, since she has to be within range of specific health care services and bring her own medical and food supplies.
That’s especially hard on a teenager longing for adventure. “I can’t go to Mexico because my medications aren’t approved there,” Hannah says. “I would love to visit the Philippines but that’s also one of the countries I can’t visit. It’s disappointing.”
Her restrictions will also limit her career choices. “I would love to be closer to the Rockies or a couple of hours north, living on a farm and working in agriculture. I don’t think my doctors would like that very much,” she says. “Not having those options is frustrating.”
One thing that Hannah hasn’t had to give up is her love of the outdoors. An active teenager with plenty of energy to spare, she can often be found going for weekend hikes with her father, Scott. She’s also an enthusiastic swimmer, dog walker and horseback rider. As of late Hannah has managed to overcome her earlier academic struggles as a result of complications that she suffered as a child, and is now an honour roll student.
Now that she’s 15, Hannah is learning to manage her own tracking and calculations, as well as to measure out her medications. “She understands she’ll have to be monitored by a physician her entire life,” says Catina. “Any stresses, such as pregnancy, will create more complications than it would for the average person.”
Unfortunately no Canadian-based, UCD-specific advocacy groups exist, and there are relatively few other patients to connect with. Because of this, Hannah and her parents often struggle with feelings of isolation—a feeling shared by many living with, or caring for a child with, a rare disease. “We had to ask the hospital if there were any other patients. We found out about one girl in Grande Prairie. That was the first and only connection we met in Canada,” says Catina.
Recently Hannah has been able to connect with other teens with a UCD via different Facebook groups and the Connecting Families UCD Foundation, through which she attends meet-ups with other girls her age. “The first time I met some girls at a conference, we spent three days ranting about mothers always telling us to take our medicine. Even being able to make jokes with others who have a UCD helps you deal with it,” she says.
For Hannah, awareness is best created through education and understanding. She’s working on a genetic disease research project at school and is equally eager to reach patients and healthcare professionals from coast to coast, well beyond the walls of her classroom. “I’d like to have people connect a bit more and for others like me and my family to know that they’re not alone,” she says.
Hannah is also teaming up with one of her new friends in the U.S. to start an Instagram account that will help spread their message further and provide a community to others like them.
“She’s amazing,” Catina says. “All that Hannah is able to do today came with a lot of hard work and diligence on her part.”
The Canadian Organization for Rare Disorders (CORD) is dedicated to advocating on behalf of the rare disease community in Canada. Please visit www.raredisorders.ca to seek additional resources and to support the fight for continued access to innovative treatments. To learn more about urea cycle disorders or to network with other North American patients, please visit www.ucdfamily.org.