How often is it a false positive?

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petnurse

New member
Okay, here goes... I know this is going to sound like denial, but it is not. It's just recent confusion and i hope you guys can help. My son is almost 10 months old and has CF. His newborn screen came back high twice. We then had a sweat test done at a CF center. I honestly do not remember the numbers. My husband and I found out during pregnancy that we were both carriers of DF508, so our son should be DDF508. As a newborn, they repeated the sweat test and did the fecal elastase test. At about 2 or 3 months old they said his enzymes were slightly low, and placed him on Ultrase. About a week later, he was having what we thought was stomach pain, so they doubled his enzymes to two. That completely ripped his system up. Ever since, he has been on one enzyme. It turns out it was reflux causing the problems. Recently, we have cut him back to a half an enzyme and we are waiting on his recent test to see if he is pancreatic sufficient. He has always been a big baby. Whenever his brothers have brought home illnesses and colds, he never gets terribly sick and never produces mucus. We do all of the therapies and meds. I am so incredibly grateful that he does not show signs, and I am fully aware that the early proactive treatments are what keeps him healthy. BUT, I have recently started to wonder if anything could have been a false positive. He does not taste salty, he does not cough/get sick, he may not need enzymes, he is a big healthy guy, etc. His doctor even mentioned the fact that he may have a helper cell that is keeping him healthy. All of that is GREAT news and we are blessed. The CF clinic goofed and never tested his DNA, so that is scheduled to take place in a couple of months. That will make it all real, but in the meantime....any input?...be gentle :)
 
P

petnurse

New member
Okay, here goes... I know this is going to sound like denial, but it is not. It's just recent confusion and i hope you guys can help. My son is almost 10 months old and has CF. His newborn screen came back high twice. We then had a sweat test done at a CF center. I honestly do not remember the numbers. My husband and I found out during pregnancy that we were both carriers of DF508, so our son should be DDF508. As a newborn, they repeated the sweat test and did the fecal elastase test. At about 2 or 3 months old they said his enzymes were slightly low, and placed him on Ultrase. About a week later, he was having what we thought was stomach pain, so they doubled his enzymes to two. That completely ripped his system up. Ever since, he has been on one enzyme. It turns out it was reflux causing the problems. Recently, we have cut him back to a half an enzyme and we are waiting on his recent test to see if he is pancreatic sufficient. He has always been a big baby. Whenever his brothers have brought home illnesses and colds, he never gets terribly sick and never produces mucus. We do all of the therapies and meds. I am so incredibly grateful that he does not show signs, and I am fully aware that the early proactive treatments are what keeps him healthy. BUT, I have recently started to wonder if anything could have been a false positive. He does not taste salty, he does not cough/get sick, he may not need enzymes, he is a big healthy guy, etc. His doctor even mentioned the fact that he may have a helper cell that is keeping him healthy. All of that is GREAT news and we are blessed. The CF clinic goofed and never tested his DNA, so that is scheduled to take place in a couple of months. That will make it all real, but in the meantime....any input?...be gentle :)
 
P

petnurse

New member
Okay, here goes... I know this is going to sound like denial, but it is not. It's just recent confusion and i hope you guys can help. My son is almost 10 months old and has CF. His newborn screen came back high twice. We then had a sweat test done at a CF center. I honestly do not remember the numbers. My husband and I found out during pregnancy that we were both carriers of DF508, so our son should be DDF508. As a newborn, they repeated the sweat test and did the fecal elastase test. At about 2 or 3 months old they said his enzymes were slightly low, and placed him on Ultrase. About a week later, he was having what we thought was stomach pain, so they doubled his enzymes to two. That completely ripped his system up. Ever since, he has been on one enzyme. It turns out it was reflux causing the problems. Recently, we have cut him back to a half an enzyme and we are waiting on his recent test to see if he is pancreatic sufficient. He has always been a big baby. Whenever his brothers have brought home illnesses and colds, he never gets terribly sick and never produces mucus. We do all of the therapies and meds. I am so incredibly grateful that he does not show signs, and I am fully aware that the early proactive treatments are what keeps him healthy. BUT, I have recently started to wonder if anything could have been a false positive. He does not taste salty, he does not cough/get sick, he may not need enzymes, he is a big healthy guy, etc. His doctor even mentioned the fact that he may have a helper cell that is keeping him healthy. All of that is GREAT news and we are blessed. The CF clinic goofed and never tested his DNA, so that is scheduled to take place in a couple of months. That will make it all real, but in the meantime....any input?...be gentle :)
 
P

petnurse

New member
Okay, here goes... I know this is going to sound like denial, but it is not. It's just recent confusion and i hope you guys can help. My son is almost 10 months old and has CF. His newborn screen came back high twice. We then had a sweat test done at a CF center. I honestly do not remember the numbers. My husband and I found out during pregnancy that we were both carriers of DF508, so our son should be DDF508. As a newborn, they repeated the sweat test and did the fecal elastase test. At about 2 or 3 months old they said his enzymes were slightly low, and placed him on Ultrase. About a week later, he was having what we thought was stomach pain, so they doubled his enzymes to two. That completely ripped his system up. Ever since, he has been on one enzyme. It turns out it was reflux causing the problems. Recently, we have cut him back to a half an enzyme and we are waiting on his recent test to see if he is pancreatic sufficient. He has always been a big baby. Whenever his brothers have brought home illnesses and colds, he never gets terribly sick and never produces mucus. We do all of the therapies and meds. I am so incredibly grateful that he does not show signs, and I am fully aware that the early proactive treatments are what keeps him healthy. BUT, I have recently started to wonder if anything could have been a false positive. He does not taste salty, he does not cough/get sick, he may not need enzymes, he is a big healthy guy, etc. His doctor even mentioned the fact that he may have a helper cell that is keeping him healthy. All of that is GREAT news and we are blessed. The CF clinic goofed and never tested his DNA, so that is scheduled to take place in a couple of months. That will make it all real, but in the meantime....any input?...be gentle :)
 
P

petnurse

New member
Okay, here goes... I know this is going to sound like denial, but it is not. It's just recent confusion and i hope you guys can help. My son is almost 10 months old and has CF. His newborn screen came back high twice. We then had a sweat test done at a CF center. I honestly do not remember the numbers. My husband and I found out during pregnancy that we were both carriers of DF508, so our son should be DDF508. As a newborn, they repeated the sweat test and did the fecal elastase test. At about 2 or 3 months old they said his enzymes were slightly low, and placed him on Ultrase. About a week later, he was having what we thought was stomach pain, so they doubled his enzymes to two. That completely ripped his system up. Ever since, he has been on one enzyme. It turns out it was reflux causing the problems. Recently, we have cut him back to a half an enzyme and we are waiting on his recent test to see if he is pancreatic sufficient. He has always been a big baby. Whenever his brothers have brought home illnesses and colds, he never gets terribly sick and never produces mucus. We do all of the therapies and meds. I am so incredibly grateful that he does not show signs, and I am fully aware that the early proactive treatments are what keeps him healthy. BUT, I have recently started to wonder if anything could have been a false positive. He does not taste salty, he does not cough/get sick, he may not need enzymes, he is a big healthy guy, etc. His doctor even mentioned the fact that he may have a helper cell that is keeping him healthy. All of that is GREAT news and we are blessed. The CF clinic goofed and never tested his DNA, so that is scheduled to take place in a couple of months. That will make it all real, but in the meantime....any input?...be gentle :)
 
M

Mommy2Zeke

Guest
You said his newborn screening came back twice with a 'high'. What do you mean by this? The newborn screening is a blood test that is positive or negative... and I believe it tests for the top 23 mutations of CF. So if your son is DDf508-(most common) that should be what came back on the newborn screening- thus there wouldn't be a need for further genetic testing really.

False genetic positives really don't happen unless there was a mix-up in the lab- but the likelihood of that happening twice is rare.

And it is possible for DDf508 patients to be pancreatic sufficient...so your son could be asymptomtic for now. My son (also DDf508) has yet to have lung involvement per se... unless you count H. flu cultured nasally- which non-cfr's can culture too. He's never had full blown pneumonia.
 
M

Mommy2Zeke

Guest
You said his newborn screening came back twice with a 'high'. What do you mean by this? The newborn screening is a blood test that is positive or negative... and I believe it tests for the top 23 mutations of CF. So if your son is DDf508-(most common) that should be what came back on the newborn screening- thus there wouldn't be a need for further genetic testing really.

False genetic positives really don't happen unless there was a mix-up in the lab- but the likelihood of that happening twice is rare.

And it is possible for DDf508 patients to be pancreatic sufficient...so your son could be asymptomtic for now. My son (also DDf508) has yet to have lung involvement per se... unless you count H. flu cultured nasally- which non-cfr's can culture too. He's never had full blown pneumonia.
 
M

Mommy2Zeke

Guest
You said his newborn screening came back twice with a 'high'. What do you mean by this? The newborn screening is a blood test that is positive or negative... and I believe it tests for the top 23 mutations of CF. So if your son is DDf508-(most common) that should be what came back on the newborn screening- thus there wouldn't be a need for further genetic testing really.

False genetic positives really don't happen unless there was a mix-up in the lab- but the likelihood of that happening twice is rare.

And it is possible for DDf508 patients to be pancreatic sufficient...so your son could be asymptomtic for now. My son (also DDf508) has yet to have lung involvement per se... unless you count H. flu cultured nasally- which non-cfr's can culture too. He's never had full blown pneumonia.
 
M

Mommy2Zeke

Guest
You said his newborn screening came back twice with a 'high'. What do you mean by this? The newborn screening is a blood test that is positive or negative... and I believe it tests for the top 23 mutations of CF. So if your son is DDf508-(most common) that should be what came back on the newborn screening- thus there wouldn't be a need for further genetic testing really.

False genetic positives really don't happen unless there was a mix-up in the lab- but the likelihood of that happening twice is rare.

And it is possible for DDf508 patients to be pancreatic sufficient...so your son could be asymptomtic for now. My son (also DDf508) has yet to have lung involvement per se... unless you count H. flu cultured nasally- which non-cfr's can culture too. He's never had full blown pneumonia.
 
M

Mommy2Zeke

Guest
You said his newborn screening came back twice with a 'high'. What do you mean by this? The newborn screening is a blood test that is positive or negative... and I believe it tests for the top 23 mutations of CF. So if your son is DDf508-(most common) that should be what came back on the newborn screening- thus there wouldn't be a need for further genetic testing really.
<br />
<br />False genetic positives really don't happen unless there was a mix-up in the lab- but the likelihood of that happening twice is rare.
<br />
<br />And it is possible for DDf508 patients to be pancreatic sufficient...so your son could be asymptomtic for now. My son (also DDf508) has yet to have lung involvement per se... unless you count H. flu cultured nasally- which non-cfr's can culture too. He's never had full blown pneumonia.
 
P

petnurse

New member
Jen, The newborn screen does not test for a mutation. It tests their IRT levels, which can be affected by jaundice, pitocin, traumatic delivery. It may be differnet in different states, but the newborn screen is not a genetic screen here.
 
P

petnurse

New member
Jen, The newborn screen does not test for a mutation. It tests their IRT levels, which can be affected by jaundice, pitocin, traumatic delivery. It may be differnet in different states, but the newborn screen is not a genetic screen here.
 
P

petnurse

New member
Jen, The newborn screen does not test for a mutation. It tests their IRT levels, which can be affected by jaundice, pitocin, traumatic delivery. It may be differnet in different states, but the newborn screen is not a genetic screen here.
 
P

petnurse

New member
Jen, The newborn screen does not test for a mutation. It tests their IRT levels, which can be affected by jaundice, pitocin, traumatic delivery. It may be differnet in different states, but the newborn screen is not a genetic screen here.
 
P

petnurse

New member
Jen, The newborn screen does not test for a mutation. It tests their IRT levels, which can be affected by jaundice, pitocin, traumatic delivery. It may be differnet in different states, but the newborn screen is not a genetic screen here.
 
M

Mommafirst

Guest
You are right, Catherine, its a test of IRT levels. And those CAN be false positives -- including being a carrier, which is very likely since you and your hubby both are. The truth is, its totally possible for a child with CF to not have any symptoms at 10 months of age. Alyssa was/is pancreatic sufficient at that age, very resisitant to colds (CF is not a weakened immune system) and overall very healthy at age 10 months.

Ultimately you won't know for sure until you have the genetic testing done. You are lucky in that you know its ddf508, that testing should be quick.
 
M

Mommafirst

Guest
You are right, Catherine, its a test of IRT levels. And those CAN be false positives -- including being a carrier, which is very likely since you and your hubby both are. The truth is, its totally possible for a child with CF to not have any symptoms at 10 months of age. Alyssa was/is pancreatic sufficient at that age, very resisitant to colds (CF is not a weakened immune system) and overall very healthy at age 10 months.

Ultimately you won't know for sure until you have the genetic testing done. You are lucky in that you know its ddf508, that testing should be quick.
 
M

Mommafirst

Guest
You are right, Catherine, its a test of IRT levels. And those CAN be false positives -- including being a carrier, which is very likely since you and your hubby both are. The truth is, its totally possible for a child with CF to not have any symptoms at 10 months of age. Alyssa was/is pancreatic sufficient at that age, very resisitant to colds (CF is not a weakened immune system) and overall very healthy at age 10 months.

Ultimately you won't know for sure until you have the genetic testing done. You are lucky in that you know its ddf508, that testing should be quick.
 
M

Mommafirst

Guest
You are right, Catherine, its a test of IRT levels. And those CAN be false positives -- including being a carrier, which is very likely since you and your hubby both are. The truth is, its totally possible for a child with CF to not have any symptoms at 10 months of age. Alyssa was/is pancreatic sufficient at that age, very resisitant to colds (CF is not a weakened immune system) and overall very healthy at age 10 months.

Ultimately you won't know for sure until you have the genetic testing done. You are lucky in that you know its ddf508, that testing should be quick.
 
M

Mommafirst

Guest
You are right, Catherine, its a test of IRT levels. And those CAN be false positives -- including being a carrier, which is very likely since you and your hubby both are. The truth is, its totally possible for a child with CF to not have any symptoms at 10 months of age. Alyssa was/is pancreatic sufficient at that age, very resisitant to colds (CF is not a weakened immune system) and overall very healthy at age 10 months.
<br />
<br />Ultimately you won't know for sure until you have the genetic testing done. You are lucky in that you know its ddf508, that testing should be quick.
 
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