Are you ready for a brief, but applicable, biology lesson? Great!
Lydia has a metabolic disorder called MCADD. It stands for Medium Chain acyl-CoA Dehydrogenase Deficiency, so everyone just calls it MCADD. Hold on to your seats and put on your 10th grade Bio caps while I explain what this means.
The biology part:
When you eat food, your body breaks it down into different parts for use. For energy use, one of the things your body breaks food down into is fatty-acid chains (f-a chains for our convenience). There are very long f-a chains, long f-a chains, medium f-a chains and short f-a chains. Then your body begins to break down these f-a chains, two f-a at a time in the mitochondria of each cell. This process of breaking it down two at a time is called beta oxidization. As your body progresses from very long to long to medium to short, different enzymes come into play. It's a very specialized process and each length has a different enzyme which is used to break the chains down. Each fatty acid chain will be broken down completely and used for energy, from complex carbs to proteins to simple sugars.
There is another compound (made of two amino acids) called carnitine that helps in this process. If the fatty acid chains are the semi-trailer, the carnitine is the semi-truck. The carnitine shuttles the f-a chains to the mitochondria and the appropriate enzymes. Carnitine is found in many natural foods we eat; your body also makes carnitine.
In Lydia's body, the enzyme which is able to break down medium length fatty acid chains is missing. It is a genetic mutation (I'll spare you that lesson) and every single cell is missing this. This means that after the body has broken down the very long and long fatty acid chains, the carnitine brings the now-medium length (8 to 12 fatty acids) to the mitochondria and there is no enzyme. The cell cannot break down these medium length. Her body can still break down short chains (or simple sugars) but cannot get short chains from medium chains. The carnitine cannot drop the medium chains until they have been oxidized and so as the medium chains aren't oxidized, the carnitine is still attached and can't transport simple sugars to and from cells.
Also remember one important thing that will later come into play: the liver is where simple sugars are stored.
What does this mean for Lydia?
It's fairly simple. Since Lydia cannot break down medium chain fatty acids, she has limited sources of energy. First and foremost, because she
can process long and very long chains, she has a slow-release source of energy. For example, she will be able to eat pasta and get energy from it, 8-10 hours later. She can also process short chains, so she will be able to eat a popsicle and get energy from it 30 minutes later. She can eat medium-chain food, but because she's missing that enzyme, she won't be getting energy from it 5-6 hours later. And for her, after her body processes the long chains, all she has to use for energy are short chains or whatever simple sugars here liver has stored. As an infant, her liver is small and can only store very small amounts of sugar.
Here's the applicable part:
As an infant this means that we have to feed no more than every 4 hours. Even if she starts sleeping through the night at 2 months, we still have to wake her up to eat. As she gets older and her liver matures (and can store more simple sugars in it) she will be able to go longer.
As she grows she will be able to tolerate longer times without food, with the max being about 12-15 hours for an adult. So no 24-hour fasting, crash diets, or protein-only diets. She doesn't have a restricted diet, but she shouldn't eat a lot of fatty or deep-fried foods since her body, quite literally, can't process it.
Another important part of this disorder:
Anytime Lydia's body gets stressed (such as an illness), she needs more energy. If she doesn't get that energy from long or very long chains, her body relies on the short chains. If she doesn't get the food energy she needs, her body will use up all of its simple sugar stores and then essentially go into a diabetic coma. Untreated cases lead to death. If she gets an illness, even something small like a fever or ear infection, we have to
force her to eat-- even just things like popsicles. If she cannot maintain an adequate calorie intake for whatever reason, she has to go to the hospital and get IV glucose until she can maintain an adequate calorie intake. The IV glucose will provide her with enough short chains to get through the extra high needs of something like an illness.
Obviously as an infant, she is more sensitive to this and as an adult, she will be able to have a 12-hour bug without a problem. Mature livers can store a lot of sugar, but her liver is small and immature.
As a parent and as a family:
Right now our girls don't know anything is wrong with Lydia except that we've had to go to the hospital a few times for "shots" (blood draws to confirm the disorder) and that we had to go to Nationwide in Columbus and meet with a "special doctor" (geneticist) about Lydia. As they (and Lydia) get older, we will be talking with them about why she needs snacks before bed, why we're so worried when she gets sick and why we have a special letter for the hospital for her (emergency protocol letter). We'll also explain what they need to watch for and how important it is to tell us if Lydia exhibits certain symptoms.
As a parent, I'm grateful and scared. Scared of course, because of illnesses and not catching the symptoms in time. For example, last night Lydia has some diarrhea and threw up (definitely NOT spitting up, it was downright vomiting) once. Matt and I watched her and over the next hour she became more lethargic, hard to wake, uninterested in nursing. We didn't have any glucogel packets on hand (little packets of glucose gel you can buy at any pharmacy, usually diabetics use them), so Matt mixed up a highly concentrated sugar syrup and we fed it to her through a dropper until she started perking up and then I nursed her a little. Since she didn't throw up or have diarrhea again, we didn't take her to the ER. But I woke up every 2 hours to feed her and give her "sugar shots" as we call them and since she's still under the weather today, we are continuing that procedure until she returns back to normal eating patterns. I'm also nervous because we're moving and that means finding another pediatrician, getting referrals to another geneticist. And one of my biggest worries for her is that we will protect her while she is growing up, but that she will choose to not take care of herself when she's on her own someday.
Grateful, because newborn screening has dramatically cut down on MCADD crises and MCADD deaths. I'm grateful that our geneticist at Nationwide was on top of it and got us an appointment the next day after receiving her newborn screening results. I'm grateful that Matt's a nurse and that I understand science easily so that we both can fully understand what is going on with her. Our pediatrician, who was amazing before, has been extra amazing during this. I'm also grateful that there are children's hospitals within hours both of where we live now and where we are going to live in Georgia, and that the children's hospital in Atlanta actually has a Metabolic Clinic so we have that as a resource too.
I'm also especially grateful that this disorder is so easy to manage-- simply feed her regularly and watch her when she's sick. Of all the genetic disorders she could have gotten, this one really isn't bad. And I'm grateful for blessings because I know the Lord will help Matt and I as we navigate this. If there's anything that's been impressed to me since Charlotte's accident, it's that the Lord is in control and He is protecting our family.