Prentatal Diagnosis False Positives?

  • Thread starter lemonstolemonade
  • Start date
L

lemonstolemonade

Guest
We have an infant that was diagnosed prenatally with CF through
Genzyme. In your experience, what is the chance that the amnio test
could have given us a false positive?<br>
<br>
We are getting some pressure from family to have her retested
because she is asymptomatic, but it just seems so redundant to me.
We asked about having her retested at her last clinic appointment,
but were reassured by her CF doctor that the odds of a false
positive on a prenatal screening through amnio were infinitely
smaller than getting a false negative through the same
screening.<br>
<br>
I would have to think that amnio testing is pretty accurate,
especially when they are comparing our gene mutation samples to the
baby's samples from the amnio. I can't find anything on the Genzyme
website about statistics for the test, and I haven't heard back
from them when I emailed my question to them.<br>
<br>
Ultimately, we just need some clarification as to the likelihood
that we got a false positive from the amnio test. I don't want to
do anything more invasive than we have to since our infant is still
so small.<br>
<br>
Any thoughts or ideas would be greatly appreciated...<br>
 
L

lemonstolemonade

Guest
We have an infant that was diagnosed prenatally with CF through
Genzyme. In your experience, what is the chance that the amnio test
could have given us a false positive?<br>
<br>
We are getting some pressure from family to have her retested
because she is asymptomatic, but it just seems so redundant to me.
We asked about having her retested at her last clinic appointment,
but were reassured by her CF doctor that the odds of a false
positive on a prenatal screening through amnio were infinitely
smaller than getting a false negative through the same
screening.<br>
<br>
I would have to think that amnio testing is pretty accurate,
especially when they are comparing our gene mutation samples to the
baby's samples from the amnio. I can't find anything on the Genzyme
website about statistics for the test, and I haven't heard back
from them when I emailed my question to them.<br>
<br>
Ultimately, we just need some clarification as to the likelihood
that we got a false positive from the amnio test. I don't want to
do anything more invasive than we have to since our infant is still
so small.<br>
<br>
Any thoughts or ideas would be greatly appreciated...<br>
 
L

lemonstolemonade

Guest
We have an infant that was diagnosed prenatally with CF through
Genzyme. In your experience, what is the chance that the amnio test
could have given us a false positive?<br>
<br>
We are getting some pressure from family to have her retested
because she is asymptomatic, but it just seems so redundant to me.
We asked about having her retested at her last clinic appointment,
but were reassured by her CF doctor that the odds of a false
positive on a prenatal screening through amnio were infinitely
smaller than getting a false negative through the same
screening.<br>
<br>
I would have to think that amnio testing is pretty accurate,
especially when they are comparing our gene mutation samples to the
baby's samples from the amnio. I can't find anything on the Genzyme
website about statistics for the test, and I haven't heard back
from them when I emailed my question to them.<br>
<br>
Ultimately, we just need some clarification as to the likelihood
that we got a false positive from the amnio test. I don't want to
do anything more invasive than we have to since our infant is still
so small.<br>
<br>
Any thoughts or ideas would be greatly appreciated...<br>
 
D

debs2girls

New member
False Positives?

JMO...but I wouldnt think you would get a false positive with an amnio, but I know of some people that have had a false positive through amnio for downs syndrome.
I hope yours is a false positive.
 
D

debs2girls

New member
False Positives?

JMO...but I wouldnt think you would get a false positive with an amnio, but I know of some people that have had a false positive through amnio for downs syndrome.
I hope yours is a false positive.
 
D

debs2girls

New member
False Positives?

JMO...but I wouldnt think you would get a false positive with an amnio, but I know of some people that have had a false positive through amnio for downs syndrome.
I hope yours is a false positive.
 
L

lemonstolemonade

Guest
False Positives?

That is what we were thinking too. They used our genetic info to
screen hers. I would think that we have what we have, but I've
posted this in the Ambry list to see what they might say (even
though it wasn't an Ambry test).<br>
<br>
Thanks for your thoughts!<br>
 
L

lemonstolemonade

Guest
False Positives?

That is what we were thinking too. They used our genetic info to
screen hers. I would think that we have what we have, but I've
posted this in the Ambry list to see what they might say (even
though it wasn't an Ambry test).<br>
<br>
Thanks for your thoughts!<br>
 
L

lemonstolemonade

Guest
False Positives?

That is what we were thinking too. They used our genetic info to
screen hers. I would think that we have what we have, but I've
posted this in the Ambry list to see what they might say (even
though it wasn't an Ambry test).<br>
<br>
Thanks for your thoughts!<br>
 
B

Buckeye

New member
False Positives?

To set your mind at ease you could get the genetic test done again
now that's she out of the womb.  It's just a blood test so
shouldn't be invasive for your baby.   Somewhere on here
I saw what the cost of it is but I can't find it now.  I think
it's roughly $300???  I would think that your insurance
company might not want to pay for it again, but if you're having
problems with the extended family, etc about her diagnosis it might
be worth paying for it yourself.  Just make sure that this
preliminary genetic test (that tests for 97 or so mutations) covers
both the mutations you have been told she has.   <br>
<br>
Pam
 
B

Buckeye

New member
False Positives?

To set your mind at ease you could get the genetic test done again
now that's she out of the womb.  It's just a blood test so
shouldn't be invasive for your baby.   Somewhere on here
I saw what the cost of it is but I can't find it now.  I think
it's roughly $300???  I would think that your insurance
company might not want to pay for it again, but if you're having
problems with the extended family, etc about her diagnosis it might
be worth paying for it yourself.  Just make sure that this
preliminary genetic test (that tests for 97 or so mutations) covers
both the mutations you have been told she has.   <br>
<br>
Pam
 
B

Buckeye

New member
False Positives?

To set your mind at ease you could get the genetic test done again
now that's she out of the womb.  It's just a blood test so
shouldn't be invasive for your baby.   Somewhere on here
I saw what the cost of it is but I can't find it now.  I think
it's roughly $300???  I would think that your insurance
company might not want to pay for it again, but if you're having
problems with the extended family, etc about her diagnosis it might
be worth paying for it yourself.  Just make sure that this
preliminary genetic test (that tests for 97 or so mutations) covers
both the mutations you have been told she has.   <br>
<br>
Pam
 
M

Mommafirst

Guest
I'm not really sure what the probability of false positive might
be, though it sounds like it would be very small to me.
 I just wonder what a new test is going to get you.
 Another positive result isn't going to make symptoms appear,
and she could stay asymptomatic for years (hopefully longer).
 Whatever the cost, its not going to be cheap and it seems
like a lot just to prove to some family that the original test was
right.  Having an asymptomatic infant of my own, I know the
maddening feeling of being neither here nor there...pretty much
feeling in wait of the other shoe dropping.  <br>
<br>
I imagine there must be a very small possibility of human error,
but from what I've read this genetic sequencing is quite intensive.
 I find it hard to believe that a diagnosis would be made
without some sort of double checking process.  In my humble
opinion, I don't think its worth the money or emotional upheaval to
wind up right where you already are.  <br>
<br>
That being said, if Ambry or Genzyme feel that an error could have
been made, then heck, grab on to your potential ticket out of the
CF world.  I am very curious to hear how this goes, please
keep us posted!!!<br>
 
M

Mommafirst

Guest
I'm not really sure what the probability of false positive might
be, though it sounds like it would be very small to me.
 I just wonder what a new test is going to get you.
 Another positive result isn't going to make symptoms appear,
and she could stay asymptomatic for years (hopefully longer).
 Whatever the cost, its not going to be cheap and it seems
like a lot just to prove to some family that the original test was
right.  Having an asymptomatic infant of my own, I know the
maddening feeling of being neither here nor there...pretty much
feeling in wait of the other shoe dropping.  <br>
<br>
I imagine there must be a very small possibility of human error,
but from what I've read this genetic sequencing is quite intensive.
 I find it hard to believe that a diagnosis would be made
without some sort of double checking process.  In my humble
opinion, I don't think its worth the money or emotional upheaval to
wind up right where you already are.  <br>
<br>
That being said, if Ambry or Genzyme feel that an error could have
been made, then heck, grab on to your potential ticket out of the
CF world.  I am very curious to hear how this goes, please
keep us posted!!!<br>
 
M

Mommafirst

Guest
I'm not really sure what the probability of false positive might
be, though it sounds like it would be very small to me.
 I just wonder what a new test is going to get you.
 Another positive result isn't going to make symptoms appear,
and she could stay asymptomatic for years (hopefully longer).
 Whatever the cost, its not going to be cheap and it seems
like a lot just to prove to some family that the original test was
right.  Having an asymptomatic infant of my own, I know the
maddening feeling of being neither here nor there...pretty much
feeling in wait of the other shoe dropping.  <br>
<br>
I imagine there must be a very small possibility of human error,
but from what I've read this genetic sequencing is quite intensive.
 I find it hard to believe that a diagnosis would be made
without some sort of double checking process.  In my humble
opinion, I don't think its worth the money or emotional upheaval to
wind up right where you already are.  <br>
<br>
That being said, if Ambry or Genzyme feel that an error could have
been made, then heck, grab on to your potential ticket out of the
CF world.  I am very curious to hear how this goes, please
keep us posted!!!<br>
 
M

miesl

New member
First things first - I would ask for a detailed copy of the amnio results. What they tested for should give you an indication of how foolproof it was.
 
M

miesl

New member
First things first - I would ask for a detailed copy of the amnio results. What they tested for should give you an indication of how foolproof it was.
 
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