Citrullinemia FAQ: What exactly does Jacob eat? Also, why do you have a gram scale in your kitchen?

Every day, I mix up Jacob’s formula according to the recipe provided by Erika, his metabolic dietician and guardian angel. It is Erika that maintains Jacob’s delicate balance of enough protein for growth and not enough to hurt him. Although Jacob’s medical progress is supervised by Dr. S, Erika is the one who I email or call on nearly a daily basis with questions about Jacob’s various needs. In Jacob’s two months of life, she has probably adjusted his formula recipe at least five times to account for his growth and answered, oh, about 4,733 of my questions. (I exaggerate, but not by much.) I also can tell that she genuinely cares about him. We are so lucky to have her on our team.

Erika’s recipes are carefully calculated mixtures of two different infant formulas, Pro-Phree and Cyclinex-1, both made by Abbott Nutrition, added to my breast milk and water. I have already discussed in detail my experiences as an exclusive pumper, so we won’t revisit that here.

Pro-Phree is described on Abbott’s website as a “protein free energy module” (doesn’t that sound appetizing?). Basically it provides calories and some vitamins but no protein, hence the name. Cyclinex-1 makes up the bulk of his formula. It is specially designed for children with urea cycle disorders. It does not contain the non-essential amino acids, that is, the ones that our bodies are capable of producing. Since Jacob can only have a limited amount of protein, this formula allows him to get a higher concentration of the essential amino acids that he cannot make on his own.

Each day, I measure his formula and arginine medication on a gram scale and my breast milk in 80 mL test-tube-like vials. It’s like Breaking Bad in my kitchen. pro-phree cyclinex-1 gram scale breast milk arginine

He gets more breast milk than is shown in the picture, but you get the idea. His recipe is taped to the wall and all of his ingredients are ready to go. I mix it all together in a big jug and then measure it out for each feeding. It’s very scientific, and not how I once pictured feeding my baby. But we do get plenty of cuddles even with the bottle, so it all works out okay.

I am now known in the St. Petersburg WIC office as Cyclinex and Prophree girl. I think the wonderful ladies who work there are used to having to counsel women on what and how to feed their babies, so they got a kick out of me marching in there and telling them exactly what Jacob needs, down to the gram.

When Jacob gets older and starts on solids, it will be a whole new world for me, and I imagine a much more complicated one. But for now, I’ll be the one in the kitchen measuring out various white powders.

A letter to Jacob’s ASS1 genes

Dear Jacob’s ASS1 genes,

You were given one job. That job was to produce arginosuccinate synthetase. But somehow you forgot how to do it. Or perhaps you never knew? In my DNA and in Daddy’s DNA, you had a dominant partner covering for you. But now there is nowhere to hide. You have been found out.

Right now we don’t have a way to fix you. One day that may change, but until then, here is a partial list of things Jacob will not be able to do because you fail at your one job:

  • Sample the entries at his family’s annual chili cookoff
  • Travel to any country whose hospitals lack metabolic doctors
  • Have ice cream on his birthday
  • Enter a hot dog eating competition
  • Take someone out for fondue on a first date

But here’s a secret, Jacob’s ASS1 genes: we are all limited in some way, be it by biology, circumstance, or even choice. I will never play professional  basketball. (Who am I kidding… I will never play basketball at all.) I will never be the president of France. I will never go scuba diving because of problems with my ears. But it would be silly to focus on those things, wouldn’t it? The question is not whether we have limitations, the question is whether we let them define us.

I wish you knew how to make the enzyme that Jacob needs. I fear for my son in a world so full of foods that could do him serious harm. I pray every day for the strength and the vigilance to protect his health, and to teach him to do the same for himself when he is old enough. But I won’t allow your deficiency to define his life. Jacob’s story will be so much more than an error in his DNA.



Ammonia by the Numbers

Be warned, readers, I am about to drop some science on you. Feel free to skip this post if chemistry isn’t your thing. On the other hand, I do refer to the classic television show “I Love Lucy,” so there may in fact be something for everyone.

Disclaimer: No information in this post, or in this entire blog, in fact, should be used to diagnose or treat a urea cycle disorder. I am not an expert, and my explanations are based on my best understanding from my discussions with Jacob’s doctors and my own research.

ammonia molecule

the ammonia molecule

That being said, here goes. When we digest protein, we produce nitrogen as a waste product in the form of ammonia. Our liver removes the ammonia from our blood through a chemical process called the urea cycle. A normal urea cycle converts the ammonia into urea, which harmlessly leaves our body when we pee. There are several enzymes involved in making this happen. Jacob’s condition, citrullinemia, is also known as ASS, or argininosuccinate synthase deficiency, because his body does not effectively produce that particular enzyme. Need a visual? Did you ever see the I Love Lucy episode with the chocolates? Think of Lucy as that enzyme. Some chocolates (ammonia) get wrapped (processed into urea), but mostly they stack up and his body doesn’t know what to do with them. Left untreated, his urea cycle would be unable to keep up with the demands placed on it, and his ammonia levels would become dangerous.

While Jacob was in the hospital, he underwent tests every 8-12 hours to determine his ammonia levels. The test requires a venous blood draw that must be immediately placed on ice and processed within an hour of the blood draw at most, but ideally within 20 minutes. This was the hardest part of his stay in the NICU. Jacob’s blood clots quickly, so it would often take several tries for the nurses to get enough blood from his little veins. Occasionally, the lab would not process the blood fast enough, and he would have to go through the whole thing again. It took several weeks after his discharge for the bruises to fade. Once properly processed, the lab results would tell us how well Jacob was tolerating the amount of protein he was taking in via formula and breast milk. Normal ammonia levels vary by age, and different hospitals often have different acceptable results. According to WebMD, normal results for children range from 40-80 micrograms per deciliter (μg/dL). Jacob’s highest level, at 4 days old, was in the 70s. After he was admitted to the NICU and started on his special diet, his levels hovered in the high 30s to low 40s. Though we can’t be sure, these numbers encourage us that he never sustained any brain damage due to high ammonia levels. Ammonia levels over 200 μg/dL for more than 2 hours would put a child at serious risk for brain damage.

Managing Jacob’s protein intake will be our primary way of preventing high ammonia levels. We will have to be especially vigilant when he gets sick (cold, flu, etc). When we are sick, our bodies actually break down existing lean tissue. Our liver then processes that protein the same way it does when we drink a glass of milk. So, when Jacob is sick, there will be additional demands on his liver from his body’s natural response to illness. Jacob’s “sick day formula” has almost no protein in order to compensate, but he is still likely to end up in the hospital if the illness becomes prolonged.

Jacob has a gastric tube. And I love it.

Warning: There is an image of a human stomach in this post. In case you’re squeamish.

When Dr. S first told me that my 11-day-old son was going to have to have surgery to have a tube inserted into his stomach, I was appalled. I asked her if she would elect for the surgery if it was her own child. She said she absolutely would. If Jacob were to enter a state of hyperammonemia, the only way we could get him life-saving medicine before arriving at the hospital would be to inject it directly into his stomach. Okay, I said, that makes sense, in case of emergency.

I demanded to talk to the surgical team and learn everything I could about the surgery and the gastric tube itself. Our surgeon, Dr. R, was informative and patient, which inspired confidence. The surgeon goes in through the child’s bellybutton with a camera, finds the stomach, and inserts the tube to the stomach and out through the abdominal wall. Sometimes they stitch the stomach to the lining of the abdominal wall, as they did for Jacob. You can see his stomach in the top right image below. The abdominal wall is above it.

As it turns out, having direct access to your child’s stomach is incredibly convenient. I bet some parents are jealous that I can do the following:

1. Baby swallowed too much air and is fussing but refuses to burp? Grab a syringe and pull the excess air out of his stomach. Voila! Happy baby.

2. Administer medications directly into his stomach. Now, not every baby takes a nasty-tasting (yes, I tried it) medicine every 8 hours. But ever try to give a baby medicine drops like poly-vi-sol? Not fun.

Jacob has a mic-key button, which gives you access to the tube that goes into his stomach. It sits to the right of his belly button. You can see it in the photo of him right after his bath (left). The diagram on the bottom right is a view of the mic-key button from the side. There are two ports. We use the feeding port, which is on the top. The balloon port inflates, you guessed it, the balloon which is located inside his stomach. This keeps the mic-key button from falling out. When we aren’t using it (most of the time), the port cover sits inside the hole to the tube. Jacob doesn’t even seem to know it’s there. He does grab at it like he grabs at anything you put near his hands. One day he’s going to pull it out and Mommy is going to have to put it back in. The surgeon sent me home with detailed instructions that I hope I don’t have to use just yet.

Jacob will have the tube until he is old enough to decide whether he wants to keep it or not. Can someone tell me when children are ready to make educated decisions that they won’t regret? For me, it was somewhere in the vicinity of 27. At least, so I think, but I’m only 29. Ask me again in ten years.

Citrulli-what-ia? (the backstory)


Jacob at about one hour old.

Jacob had been home for 48 hours when we received the call from his pediatrician. “One of Jacob’s newborn screening tests came back positive. Please go to the hospital immediately. Tell admitting that you are there to see Dr. S.”

No parent ever wants to receive a call like that. It was a terrifying forty minute ride to the hospital in a nearby large city – our local hospital apparently did not have the resources to deal with whatever it was Jacob apparently had. I didn’t understand how my apparently perfect, healthy son needed to go to the hospital so urgently.

What ensued was six days in the NICU. J’s Daddy and I learned that we were both carriers of the recessive gene for citrullinemia, a urea cycle disorder, and Jacob had received both recessive copies. His body was unable to make an enzyme necessary to process proteins and remove ammonia from the body, putting him at risk for neurological damage. Thanks to modern medicine and a veritable army of prayer warriors, his ammonia levels were not dangerously high.

Still, it was a terrible week. Jacob was hooked up to monitors for six of the first twelve days of his life. He was put on a special formula combined with a little bit of pumped breastmilk, and he had many blood draws to test his ammonia levels and see how much natural protein he could tolerate. We calculated that he had been stuck about 40 times, and every time we feared that his ammonia would shoot up. It didn’t. We met with our amazing team – a metabolic geneticist and dietician – every day. Bleary-eyed, Daddy and I traded night shifts so that Jacob would never have to be alone. Finally, after recovering from surgery to put in a gastric tube to deliver his medicine, Jacob was released on Valentine’s Day.

Children like Jacob with urea cycle disorders need to follow very strict diets to manage their condition. I have a gram scale in my kitchen to measure his formula. Jacob will always be one mouthful away from a crisis. So, instead of returning to work and putting Jacob in day care, Daddy and I decided that I would stay home for at least the first few years. All of a sudden I went from a promising career in private school administration to being a stay-at-home mom. I was strangely thrilled. What an amazing gift to be able to care for this unique little boy. His condition may occur once in 57,000 births, but he is the only him that will ever live. How lucky am I to get to know him inside and out?

The most important thing I know about citrullinemia is that I don’t know what to expect. The condition is so rare and hospitals only began screening for it in the last ten years or so. There are very few children out there with a successfully managed case. So, I’m thinking of this blog as an anecdotal case study of sorts. But it is also a place to connect with the wider world as I go about the delightful challenge of raising my new little man.