Help Understanding CF Mutation Analysis

[rpauley]

My nephew has been quite sick lately. He has had upper respiratory infections twice this year, so the doctor ordered a cystic fibrosis mutation analysis. I need help understanding the results. Results: Positive for one copy of the L206W mutation, one CF mutation has been identified in this individual. The presence of a second mutation, which would confirm a diagnosis of CF, cannot be ruled out. Please help me understand this. Thank you, RP <img src="i/expressions/face-icon-small-confused.gif" border="0">

 

[anonymous]

At this point this would "mean" that he's just a carrier (i.e. only ONE copy of the CF gene); however, if the test was NOT done at AMBRY which looks for the 1000+ KNOWN mutations of the CF gene, you should throw the test results "out"

 

[thefrogprincess]

Since they cannot rule out another mutation you need to have a more thourough test done. Make sure its done by AMBRY, for the reasons the previous poster mentioned.

 

[rpauley]

I appreciate the information and I will pass this along to my sister. Thanks

 

[anonymous]

why dont they do a sweat test that would let u know if he had cf or not....then that way u would know if there was another gene to fined

 

[anonymous]

RP, did he have a sweat test or just a blood test? If he did have a sweat test, it really needs to be repeated. IF he had only blood, I would recommend a sweat test as well as the blood being done at ambry. Quest Diagnostics also has a similar test avilable and they are more known to insurance companies, but I believe Ambry Pioneered this particular testing.

<a target=new class=ftalternatingbarlinklarge href="http://www.ambrygen.com/">http://www.ambrygen.com/</a> Ambry Genetics

<a target=new class=ftalternatingbarlinklarge href="http://www.questdiagnostics.com/index.html
">http://www.questdiagnostics.com/index.html
</a>
Please let us know how this goes.

Julie (wife to mark 24 w/CF)

 

[anonymous]

I agree with the other posters. Your sister should request a sweat test. Currently, <b>NO</b> genetic test, Ambry included, can find 100% of the mutations that cause cf. There are a few rare mutations that have still not been identified. Likewise, it is possible to have a negative or borderline sweat test. For cases that are not straightforward (ie two mutations found or clearly positive sweat chloride test), a combination of both genetic and sweat testing plus clinical presentation is how they diagnose. Most cases are very straight forward - positive sweat test and two mutations identified. I'd request the sweat test. If your nephew tests negative, I'd assume, at least for now, that he's just a carrier. If, however, his sweat test is high negative or borderline, I'd request a second sweat test and a genetics test from Ambry just to be on the safe side. If, of course, the sweat chloride test is positive, no further testing is necessary. Good luck. I hope your nephew is *just* a carrier!!

 

[rpauley]

I appreciate all of the information that everyone is providing me. Thanks again and I will let everyone know how things are going.