TIP - How MCADD Parents Can Better Work With Their Primary Care Physician

I read this interview with Dr. Beaudet from Baylor College of Medicine and was thrilled to see his comment about how well-educated the parents of children with rare disorders can be about their children's condition.  He also gives some good advice on how you can use that knowledge to work WITH your primary care physician.

It's definitely important to note that the physicians who study rare conditions like MCADD are fairly rare themselves.  Therefore, when a primary care physician caring for a child with a rare condition calls that specialist to ask a question, they are usually more than happy to have a conversation.  We should all use this advice to our advantage.

Metabolic Appointment

We just had our one-year appointment with the metabolic clinic and in many ways, it felt like a victory celebration.  I remember at our very first appointment, they told us that the first year would be the most difficult, but that LB would be more and more like a "normal" kid once he reached that milestone.  He would be able to go longer between meals as his body grew and matured.  He would be able to sleep through the night.  He would be able to eat on a more normal schedule (instead of every few hours around the clock). All of this is true now.  When he is ill, we still might need to wake and feed him, but when he is well, we were given the green light to let him sleep for 10-12 hours at night (provided he eats well during the day and has a hearty bedtime snack).

His metabolic specialists are not recommending any special diet for LB.  They did give us a great list of healthy bedtime snacks that I will post later, but other than that, we were told to feed him a normal, age-appropriate diet.  Apparently, they used to recommend a low fat diet for children with MCADD and refer them to a dietician, but they don't see a need to anymore. They said he could transition from formula to milk and didn't need to move into a toddler formula for any period of time beforehand. 

I have read a lot about children with MCADD being given cornstarch in milk as a way to maintain blood sugar, but when I asked about it, they also said it was unnecessary for LB.  They mentioned that cornstarch is often recommended for something called "brittle MCADD" where children with MCADD also have an on-going issue with low blood sugar.  LB doesn't seem to have any issues with blood sugar, so as long as he's eating normally, there wouldn't be a need to dose him up with cornstarch for a blood sugar boost.  We also, of course, still have the polycose in the cupboard which we can use to introduce additional sugar to his diet during times of illness.

They are doing some bloodwork to check his carnitine levels (which they do at every appointment) and they will let us know the results.  If it is low, we may need to supplement him with oral carnitine, which we already have on hand to use during times of illness.  We should know that within the next week.

Speaking of bloodwork, we finally got around to talking about my acylcarnitine profile results, too. Everyone in the family had a acylcarnitine profile performed shortly after LB's birth to confirm that no one else in the family has MCADD. My husband's bloodwork and our older son's bloodwork came back stone-cold normal. Mine came back with two abnormal results - an elevated C4 and C8. They told us that it wasn't MCADD, but I kept forgetting to ask at our other appointments and I was still curious what it might be (it just seems strange that such an unusual bloodwork panel would come back abnormal for someone who is seemingly healthy, but who has a child with MCADD). They surmised that it may be indicative of my carrier status, but that it wasn't anything to be concerned about. It definitely wasn't MCADD.

We spent quite a bit of time talking about genetics at this appointment, too.  The doctors inquired whether we were planning to have more children and at this point, we're just not sure.  We think we may be done, but there is what we keep referring to as "that nagging 1%" chance that we might try for #3.  They told us that there were a few options for pre-natal testing to diagnose MCADD.  We could opt to do in-vitro fertilization and select only the embryos that are not carriers of MCADD for implantation or we could conceive naturally and take our 1 in 4 chance that our next child would be affected by MCADD (and 2 in 4 chance they would be a carrier or 1 in 4 chance that they would be neither affected nor a carrier).  If we conceived naturally, we would be able to test for MCADD using an amniocentesis or we could wait until after birth to conduct a blood screening.  If we waited until after the baby was born, they would recommend that we feed formula and do the blood test immediately to make sure that the baby would be safe until we knew his/her MCADD status for sure.  We would not have to wait for the traditional newborn screening test results to find out, although the screening would still be conducted.

We also got the results of LB's DNA analysis.  They screened for only the common mutations and found that LB has one common mutation and one uncommon mutation that they were unable to locate within the bounds of the DNA mapping that they performed.  We would need to talk to our insurance company to discuss the cost of a full DNA analysis to find LB's other gene mutation and it could be pretty expensive.  Apparently, insurance companies tend to balk at paying for this level of testing since it doesn't change the course of treatment, so it would likely be a hefty out-of-pocket expense for us.  We agreed that we would not pursue the full DNA analysis at this time, but that maybe in 20 years when our kids might start thinking about kids of their own, they may choose to pursue that more extensive testing to determine 1) whether our oldest son is a carrier and if so, of which mutation and 2) what the uncommon mutation is for LB.  At that point, DNA mapping will probably be a whole lot less expensive, too.

In all, it was a great appointment.  It's always great to hear that your child is doing well and developing completely on schedule.  Considering how worried we were the first time we set foot in the metabolic clinic one year ago, this appointment was a breeze.  We'll only need to be seen every six months going forward (another benefit of LB getting bigger and out of the critical and worrisome first year).

Interesting Facts About Newborn Screening

We had another Consumer Task Force Call this week.  I love learning about the newborn screening system that saved my baby's life.  Here are some interesting facts that I wanted to pass on...

• Over 4.2 million infants are screened each year, making newborn screening the most commonly performed genetic testing in the United States.
• The Recommended Uniform Screening Panel (RUSP) included 29 core conditions when it was first recommended by a group of experts in December 2002.  All of these conditions have the potential to result in serious medical complications and/or death if not recognized early and all children benefit from treatment once the conditions are detected.
• By February 2005, the RUSP became national policy and by December 2008, nearly all states were screening for many of these core conditions.  To see which conditions are screened for in your state, visit Baby's First Test!

MCADD - It's Genetic!

So I mentioned yesterday that LB has MCADD because his MCAD enzyme isn't working. What exactly causes that to happen? The answer is genetics. Your body has genes that tell it to make enzymes and his genes that make the MCAD enzyme are what isn't working.

Having errors in your genes isn't all that unusual. Our genetic counselor told us that everyone has errors in their genome, typically around 20. Genetic errors aren't usually problematic because you have two copies of each gene and most of the time, at least one of those copies is fine. The body uses the "good" copy to do what it needs to do. Unfortunately, BOTH of LB's genes that tell his body how to make MCAD either aren't there or are broken, so his body honestly doesn't know how to make the MCAD enzyme. It's kind of like his body's recipe book has that page ripped out or somebody spilled something all over it and it's illegible. As much as he may want to make that enzyme, he just doesn't know how.

How did he end up with two bad copies of the same gene? It's his parents' fault!!  Husband and I just happen to have the same errors in our genetic code and we both passed the "bad" copy of the MCAD gene onto LB. It's likely that Husband and I are both just carriers of the condition. We have one good copy of the MCAD gene and one bad copy, but our bodies can use the good copy to make the enzyme and we are fine. Unfortunately, between the two of us, we didn't give LB a single good copy to work with. With both of us being carriers, the chances of us having a baby with MCADD are 1 in 4. The process looks something like this...

We know through newborn screening that LB has MCADD. That is, he has two bad copies of the gene. We now know that both Husband and I are at least carriers of the condition (Rr) since we produced offspring with one bad copy from each of us (rr). If we are both carriers, then there is a chance that our older son, LM, may also have inherited a copy of our bad gene. He could also be a carrier (Rr) and there is a 50% chance of that. The best case scenario would be that he inherited only our good gene (RR) and there is a 25% chance of that. Since the state was screening for MCADD two years ago when he was born, it is unlikely that the LM has MCADD, but they suggested we re-test him just to be sure -- his sample card may have been mishandled or the wrong test done on the wrong blood spot. Again, it is unlikely that he has it, but we're going to go for "better safe than sorry."

Our genetic counselor told us that in some situations, infant screening has identified the condition in a parent (since testing for it has been only relatively recent). With MCADD, the parent happens to be lucky enough to not have ever been very ill to where their life was in danger due to fasting, but knowing they have the condition going forward can be very helpful for future illnesses, surgeries, etc. Knowing that there is also a possibility that one or both of us could have MCADD (although unlikely), we are both going to be tested to be sure. If one of us ends up testing positive for MCADD, our genetic situation changes slightly...

If one of us were affected with MCADD, that person could only pass a bad copy of the gene onto our child. The unaffected parent could pass on either a good copy or a bad copy. Thus, this would give us a 50-50 chance of having a child with MCADD and all of our children would at least be carriers of the condition.

I doubt either of us has MCADD, but it's also so statistically rare that two people with the same genetic errors have children together, so I guess anything is possible. I'm still really thankful for newborn screening, though. Without it, we would never have known LB had this condition and we certainly wouldn't have know that we were carriers of it either.