Questions about CF Testing

[momof2girls]

My youngest daughter was born in October 2004, she had Meconium Peritonitis. With this came the possibility of her having CF. Today I got the medical records from the Doctor's office where her CF blood tests came back negative, yet they still want to do a sweat test just to rule it out. She was tested for 33 most common cystic fibrosis mutations. So if these all came back negative, what would a sweat test show?? How many mutations are there, and what would the likelihood of her having CF be?

I'm just nervous, CF is no where in either of our families!

Any response is appreciated.

Amy

 

[miesl]

There are thousands of CF mutations.

Is it likely she has two of them? I don't know. It's not something there are statistics for.

A lack of a family history of CF doesn't rule it out. As I'm sure a lot of people on this site can tell you - they (or their child) was the first in the family with CF.

Does your daughter have any of the classic CF symptoms?

 

[anonymous]

Thank you for responding. I'm really trying to educate myself on CF, her symptom was Meconium Peritonitis at birth (an intestinal rupture that formed a meconium cyst 10cm in diameter). She was on neocate for the first year of her life so her stool was green and mucousy, however since she has been whole milk her stool is fine. She did have failure to thrive but that was attributed to the fact she spent three months in the NICU and wasn't fed until she was 2 months old.

I realize that family history doesn't mean much, I mean.. it has to start somewhere right?

I guess I didn't realize that there were soo many mutations.

Again, thank you for your response.

 

[anonymous]

That stats on CF genes are approximately this:

50% of people with CF have 2 DF508's (the most common mutation)
40% of people with CF have one DF508 and another mutation
10% of people with CF have 2 mutations other than DF508

There are over a thousand CF mutations out there, most tests look for the most common 40-80 mutations. My daughter was diagnosed with a positive sweat test, her blood test would not have been positive bc she falls in the 40% category with 1 DF508 and 1 other mutation, which happens to be very uncommon and not caught by Genzyme which screens for 44 mutations (so the blood test looks like she is just a carrier of the DF508). My husband and I do not have any family history of CF either so we were pretty suprised. The way I look at it now is that a person either has CF or they don't. If they do, it is much better to find out ASAP than not to. The blood test is not too bad bc they don't need a lot of blood for it. I hope this info helps and wish you all the best!!

 

[anonymous]

Oh ya, I am the 4th poster again. You already had the blood test for her but I wanted to tell you that the sweat test is not bad either. Painless and the results come within hours to a day or so....

 

[julie]

I would recommend the sweat test, but that can be inconclusive as well if she doesn't 1. sweat enough or 2. has one of the other "rare" mutations that does not create an increase in the sodium levels of the body. If you do a swet test and it is inconclusive or borderline, I would honesltly recommend an extended panel CF screening. Quest Diagnostics laboratory has a test that analyzes the currently known 1060 (and growing daily/weekly/monthly....) CF mutations.

My husband had no history of CF in the family either. His brother isn't even a carrier. he and his brother ended up on opposite ends of the spectrum.

 

[anonymous]

Julie - your post indicated that Quest Diagnostics tests for 1060+ known mutations. I thought only Ambry tested for all of them. If I'm mistaken, do you happen to have contact info for Quest as I'd love to check into the cost through them (my insurance won't pay for extended test and I only know one of my mutations...the infamous F508).

Thanks,

Amy
36 w/ CF

 

[julie]

Amy, I refreshed the topic on the Adults section, but here is a link to the information I posted here a while ago:

<a target=new class=ftalternatingbarlinklarge href="http://forums.cysticfibrosis.com/messageview.cfm?catid=5&threadid=4194">http://forums.cysticfibrosis.com/messageview.cfm?catid=5&threadid=4194</a>

And here is the link to Quest-<a target=new class=ftalternatingbarlinklarge href="http://www.questdiagnostics.com/hcp/topics/cf/cf.html">http://www.questdiagnostics.com/hcp/topics/cf/cf.html</a>. Let me know if you have any other questions. You might have better luck with Quest as they are a well known very reputable company and have been around for a long while.

 

[anonymous]

Thanks Julie...also saw your refresh on the adult site. Emailed the info to my clinic . Hopefully my insurance will pay for this one! I'll keep you posted.

Amy

 

[julie]

Yes please do let me know. I'm still waiting for quest to get back to me about a "write up" so I can change it from ambry on my site. They have been very helpful and informative to me. I hope you have the same experience!

 

[anonymous]

Julie, I just wanted to let you know that my daughters "unknown" mutation (Genzyme) was just recently identified by Quest. I have been meaning to thank you for your information on them (and for all the other good info you share with us!). I read your post about Quest 2 days before we were to visit the geneticist, so I printed it out and gave it to her. She made the call to Quest, got things approved by insurance (something like $1500 for labs that are a member of Quest and over $3000 for non-members - YIKES!). We have an appointment next Monday to find out that exact result (all we know right now is that they were able to identify it) not that it will give us any answers on her particular case right now but it does help us a lot for other reasons.

Thanks!
Kelli (mom of Sydney 2wcf)

 

[julie]

Good to Hear Kelli. Do you mind if I email this little "story" you posted here to Quest. I hope it will light a fire under their butts to get me a write up about THEIR tests so I can put it on my www.cysticfibrosismaleinfertility.com website. I have had contact with a very helpful woman, but I think it is those above her that are kind of sitting on the write up (which they told me they would *try* to do. Maybe if I put it in perspective of more information of their tests reaching more people they will act faster <img src="i/expressions/face-icon-small-smile.gif" border="0">.

Thanks for posting it, I'd be curious to hear what the unknown mutations were.

 

[anonymous]

Sure Julie, feel free to do that. I will let you know what we find out at our appt. next Monday.

Thanks Again!
Kelli

 

[julie]

ok, thank you?