Questions about CF in an infant...

[wvliz07]

Hi,

I am hoping someone here can help me understand CF a little bit better, especially as it pertains to babies. Maybe alleviate some worries. I apologize if this is inappropriate to post here... but I didn't know where else to go.

My daughter is 9 months old and has always been small. She was born full term and was 5lbs 12oz. I breastfeed her and started solids around 6 months. Until she was 4 months old, she gained weight and grew normally. Since then, she has gained only ounces and has barely grown in length at all. She is still under 13 pounds and around 26 inches, which has put her below 1% on growth charts. She is NOT thin, emaciated-looking, bony, or anything like that. She has rolls, but they are small rolls. Her cheeks are chubby, her wrists are plump, her belly sticks out and has rolls when she sits. She's just small.

Otherwise, my daughter seems to be the most healthy child you could imagine. She crawls, stands, cruises. She eats a large variety of food, and she eats a lot. She "talks", sleeps pretty well, has normal elimination habits, and has pretty much never been sick. She doesnt cough or sneeze, have runny stools, spit up, or anything. Aside from being overweight, my husband and I are healthy. No one in our families has CF, or any other genetic conditions that we are aware of.

At my daughter's 9 month checkup today, her pediatrician informed me that she is concerned my daughter could have CF. My instinct tells me that she does not, and I am sure her doctor must rule this out to "cover her butt". I am frustrated, though and hoping someone can answer some questions for me.

It is my understanding that all babies are tested for CF at birth with the heel stick blood test that is smeared onto paper and sent away for testing. I do remember my daughter having this done, and I was never made aware of any abnormal test results. Is it possible for that test to have been negative for CF, and for her to have developed it later? Or for it to have been falsely negative?

Is it reasonable to think that she could possibly have CF while showing no signs of illness? Is lack of weight gain and growth, in and of itself, really sufficiently concerning enough to think she may have CF? Has anyone else had a child like this who turned out to have CF? Are some people undiagnosed until later in life? Does one always have the disease from birth? How is a baby tested? I've read about a sweat test - is that it?

I realize that I could google these types of things (and I am), but I really would love to discuss some of these things with real parents dealing with CF.

Thank you so much for reading and I am truly sorry if this wasn't appropriate to post here.

Liz

 

[nmw0615]

I was a false negative in my newborn screening and had no symptoms if the disease, except no weight gain. It is possible.

A person with CF is born with the disease. It's genetic, so it is determined my the same factors that determine eye color, hair color, etc.

 

[wvliz07]

I was a false negative in my newborn screening and had no symptoms if the disease, except no weight gain. It is possible.

A person with CF is born with the disease. It's genetic, so it is determined my the same factors that determine eye color, hair color, etc.

Thanks... =/

 

[2005CFmom]

I am not totally familiar with newborn screening, but this is my understanding. It varies by state in how they screen for CF. Some screen for a certain enzyme in the blood that can be elevated that triggers a DNA screening, and some states go straight to the DNA screening. This means they test for 30 -50 of the most common genes, but there are about 2000 known CF genes! So although what they screen for would catch about 90%, there is a chance it would not be caught.

My daughter was 8 years old when she was diagnosed (our state did not have newborn screening at the time of her birth). She ate like a horse from the start, but was always on the small side (around 25% on the charts). She developed a cough that did not go away and that eventually triggered the CF testing.

Sweat testing was the "gold standard" for testing, but hopefully they are moving more towards DNA gene sequencing. Both should probably done to verify results, as neither is perfect. When the doctor suspected CF for my daughter, the sweat test and a DNA screening were both scheduled. Both came back positive for CF.

 

[wvliz07]

I am not totally familiar with newborn screening, but this is my understanding. It varies by state in how they screen for CF. Some screen for a certain enzyme in the blood that can be elevated that triggers a DNA screening, and some states go straight to the DNA screening. This means they test for 30 -50 of the most common genes, but there are about 2000 known CF genes! So although what they screen for would catch about 90%, there is a chance it would not be caught.

My daughter was 8 years old when she was diagnosed (our state did not have newborn screening at the time of her birth). She ate like a horse from the start, but was always on the small side (around 25% on the charts). She developed a cough that did not go away and that eventually triggered the CF testing.

Sweat testing was the "gold standard" for testing, but hopefully they are moving more towards DNA gene sequencing. Both should probably done to verify results, as neither is perfect. When the doctor suspected CF for my daughter, the sweat test and a DNA screening were both scheduled. Both came back positive for CF.

So, to clarify, a sweat test can also produce a false negative, and I need to also ask for the DNA test to be sure? The doctor wants us to feed her more for a month, and see if she gains weight. I'm just a nervous wreck, and now I don't think I can wait a month... It sounds like maybe we just need to test her now.

 

[2005CFmom]

I'm sorry the doctor even mentioned CF if they were not at the point to actually test for it! Who wants to hear, "your child might have CF, let's wait and see"? I thought the doctor was already pursuing testing.

But yes, sweat testing can produce a false negative. And without significant symptoms, it may be difficult to get an insurance company to pay for genetic sequencing because it is costly.

But if your daughter is not showing symptoms, I would not panic about it. I know everyone is about being proactive, and the sooner you start treatment the better. But my daughter went 8 years without treatments. She is now 16 and her lung function was 101% at her last visit, 5 feet and 112 lbs... so she is doing well.

 

[wvliz07]

Who wants to hear, "your child might have CF, let's wait and see"?

EXACTLY. I should have been more clear about that in my post... I don't love this pediatrician. Nor do I love (most) doctors in general. So I'm reading everything and of course I'm scared to death. I'm wondering what "costly" means. Because I really don't care how much it costs, I need to know if my baby girl is healthy and if she isn't, what I can do to make her as healthy as she can be. And I'm not afraid to fight with the insurance over it. I know that if I don't, every little cough or GI issue is going to send me into a panic.

I'm glad to hear your daughter is doing so well. Calms me some Thank you for your help.

 

[2005CFmom]

My husband had to have the DNA sequencing done several years ago, and I believe the cost would have been about $3000 if insurance had not covered it.

 

[Aboveallislove]

Dear Liz,
First, a very very big mommy hug. You must be a complete wreck. And this forum is perfect for questions. Those who are here know the fear and the worry. I guess what I wonder is your daughters growth/size the only thing that is making the doctor think "CF?" And what an idiot to say "oh, maybe but let's wait and see." I'd call back and say you want him to set up a sweat test now b/c if it is CF you need to start treatment. OR ask for a fecal elasticity test to see if their is an absorption issue. If she has CF that is the problem with no weight gain so the stool would show it. Honestly from what you right nothing strikes me as "CF" but of course you want to have it checked and everyone with CF is different. Also, before you start "feeding her more" I'd strongly strongly recommend you contact Ellyn Satter Associates (if you're on facebook she has a page). Post your the problem on her page and ask for some guidance on the eating because pushing your daughter to eat might backfire. . . especially if you are panicked to get her to eat so you convince yourself it isn't CF. Our CF son was doing fine until I panicked and pushed him to eat and then he dropped from 30ish% to teens and they started talking feeding tubes. A great occupational therapist put me on to her books and now he is at 60%+ for both weight and height. Good luck and I'll pray tonight for strength for you and your husband and that your daughter is CF free. And another virtual big hug.

 

[m.coteklein]

Liz,

As NMW0615 said, CF is a genetic disorder that means it is encoded into the DNA ( an error in the CFTR gene in particular i.e. the sequence is not "stated correctly"). There are tons of CFTR mutations that can cause CF. That being said, both Parents have to be carriers of a form of a CFTR mutation, and at that, both of these gene mutations have to match up in a correct way to produce someone who is CF bearing. So, CF can not formulate in one who is not already genetically affected. However, CF is a progressive disease, and people can develop symptoms of the disease later in life. Think of it as a gradient ranging from mild to severe: One person can be in the mild stage for years (as high as you can imagine;for example we can say 60 years) and show no symptoms until late, others can jump right into the severe stage and show very harsh and serious conditions within a few days of being born. The Sweat Test is usually a very good indicator of potential CF or not. That being said, some people can pass them and still have CF (this can depend on the CFTR mutation one has.) Err on the side of caution-get a genetic test. It is the really only sure fire way to know (which errors can happen too...but very seldom). I'm so sorry you have to go through this;i'm not the parent, but the son. Keep us informed.

 

[wvliz07]

Dear Liz,
First, a very very big mommy hug. You must be a complete wreck. And this forum is perfect for questions. Those who are here know the fear and the worry. I guess what I wonder is your daughters growth/size the only thing that is making the doctor think "CF?" And what an idiot to say "oh, maybe but let's wait and see." I'd call back and say you want him to set up a sweat test now b/c if it is CF you need to start treatment. OR ask for a fecal elasticity test to see if their is an absorption issue. If she has CF that is the problem with no weight gain so the stool would show it. Honestly from what you right nothing strikes me as "CF" but of course you want to have it checked and everyone with CF is different. Also, before you start "feeding her more" I'd strongly strongly recommend you contact Ellyn Satter Associates (if you're on facebook she has a page). Post your the problem on her page and ask for some guidance on the eating because pushing your daughter to eat might backfire. . . especially if you are panicked to get her to eat so you convince yourself it isn't CF. Our CF son was doing fine until I panicked and pushed him to eat and then he dropped from 30ish% to teens and they started talking feeding tubes. A great occupational therapist put me on to her books and now he is at 60%+ for both weight and height. Good luck and I'll pray tonight for strength for you and your husband and that your daughter is CF free. And another virtual big hug.

Thank you so much. I agree, that doctor is an idiot. We're going to find a new one, ASAP. It's good to know about the fecal elasticity. I didn't realize there was a way to check the stool for that. I am against feeding her more and have already decided I'm just going to keep doing what I'm doing. She's 9 months old and should be learning to feed herself and tasting different tastes and textures, not having more and more calories crammed down her for the sake of her gaining weight. That doctor was also annoyed that she wasn't eating 3 meals a day at 6 months, and that probably should have been my clue to go elsewhere. What difference does a few ounces make, it doesnt change whether she has CF or not. I'm so annoyed, and disgusted, the longer I sit here and think about it. I will check out that facebook page, though. Thank you again for your advice and kind words.

 

[wvliz07]

Liz,

As NMW0615 said, CF is a genetic disorder that means it is encoded into the DNA ( an error in the CFTR gene in particular i.e. the sequence is not "stated correctly"). There are tons of CFTR mutations that can cause CF. That being said, both Parents have to be carriers of a form of a CFTR mutation, and at that, both of these gene mutations have to match up in a correct way to produce someone who is CF bearing. So, CF can not formulate in one who is not already genetically affected. However, CF is a progressive disease, and people can develop symptoms of the disease later in life. Think of it as a gradient ranging from mild to severe: One person can be in the mild stage for years (as high as you can imagine;for example we can say 60 years) and show no symptoms until late, others can jump right into the severe stage and show very harsh and serious conditions within a few days of being born. The Sweat Test is usually a very good indicator of potential CF or not. That being said, some people can pass them and still have CF (this can depend on the CFTR mutation one has.) Err on the side of caution-get a genetic test. It is the really only sure fire way to know (which errors can happen too...but very seldom). I'm so sorry you have to go through this;i'm not the parent, but the son. Keep us informed.

Thank you, that makes sense. The only thing I can't wrap my head around is if malabsorption is causing the slow weight gain, why don't her stools seem to be affected... She eats plenty of fat, and it has to be going somewhere.

 

[m.coteklein]

Liz,

Digestion is so weird. here's what I mean, "too much of this and/or too little of that" can throw everything into disorder. Even lung function has been know to correlate with weight (weird I know right?). So I wish I could help you on this one, but I'd be afraid to steer you in the wrong direction because that is one tough question. I think the only way you can really figure out if something is going awry is either a.) through blood work or b.) ultrasound or x-ray. I'm not too familiar with how an infants (by the way congratulations on the child!) defecation composition is different from that of a teenager or an adult. I assume similar things maybe can maybe expressed differently as things are continually forming and changing in newborns whereas in adults things major development events have ceased. So, on this one I would ask a CF parent on what they observed before they're kid was diagnosed at a young age. If you have any other questions though feel free to ask!

 

[2005CFmom]

The only thing I can't wrap my head around is if malabsorption is causing the slow weight gain, why don't her stools seem to be affected... She eats plenty of fat, and it has to be going somewhere.

This made me think of something I had read on these boards before. Dump the contents of her diaper in the toilet. If it floats, it may mean that there is a high fat content... if it sinks, the fat is likely being absorbed. My daughter has to describe to the doctor what her poops have been like since her last visit... do they sink or float? So there is something to this.

 

[Aboveallislove]

Yes I totally forgot to mention the float test. Drop the stool in the toilet and see if it sinks or floats. If it floats then there is likely some malabsorption. If it sinks then likely not an issue. Do over several days. If regularly floats get to knew ped ASAP to discuss. If it sinks every time. Take a deep breathe and relax and follow up with knew ped on everything. And what an idiot doctor...eat three meals a day??? That's crazy. Three meals and two to three snacks. I'd strongly recommend child of mine as a book so you have some support for when doctors push the weight on you. First of corse make sure no medical reason, but really a great resources.

 

[Printer]

Being below 1% on the Growth Charts is an indication of FAILURE TO THRIVE. This is a red flag for CF. Your Pead is serving you well and not just covering her ass. You need to have your child checked at an APPROVED CF CLINIC by a CF SPECIALIST. Do not ignore her instructions as CF in a possibility.

Bill

 

[Printer]

There are more than 1800 known mutations, any 2 will cause CF. Post Natal testing is only for the most common 32 - 50 mutations. You do the math. Everyone who has CF is born with it as it is a genetic disease. If your child has CF it is because both you and yous husband are carriers. Almost 100% of the time, carriers show zero symptoms.

Late Dx is very common.

Bill

 

[Aboveallislove]

Bill I agree that it is a red flag but then she should get in ASAP not wait another month. And if this doctor won't find another to do it.

 

[Printer]

She should contact an APPROVED CF CENTER and make an appt with a CF SPECIALIST but this could take a month to accomplish. The child will not be at risk for a month delay.

Bill

 

[Printer]

The sweat test given by a "local Doctor" is not the same as given at a CF Center by a trained specialist.