How often is it a false positive?

S

sdelorenzo

Guest
Catherine,
I would call his cf nurse on Monday. Ask her the sweat test score. That should be a good indication. Usually double delta scores are above 60.
Also, ask her to request a blood draw for genetic testing. It would be simple for her to order it for you to go into the lab at the hospital for Tues or Wed of this week. Double delta scores take about 2 weeks to come back. That way you should know for sure if he in fact does carry both genes. What a blessing that would be if in fact he didn't have both genes!
Sharon, mom of Sophia, 8 and Jack, 6 both with cf, Grant, 15 months no cf
 
S

sdelorenzo

Guest
Catherine,
I would call his cf nurse on Monday. Ask her the sweat test score. That should be a good indication. Usually double delta scores are above 60.
Also, ask her to request a blood draw for genetic testing. It would be simple for her to order it for you to go into the lab at the hospital for Tues or Wed of this week. Double delta scores take about 2 weeks to come back. That way you should know for sure if he in fact does carry both genes. What a blessing that would be if in fact he didn't have both genes!
Sharon, mom of Sophia, 8 and Jack, 6 both with cf, Grant, 15 months no cf
 
S

sdelorenzo

Guest
Catherine,
I would call his cf nurse on Monday. Ask her the sweat test score. That should be a good indication. Usually double delta scores are above 60.
Also, ask her to request a blood draw for genetic testing. It would be simple for her to order it for you to go into the lab at the hospital for Tues or Wed of this week. Double delta scores take about 2 weeks to come back. That way you should know for sure if he in fact does carry both genes. What a blessing that would be if in fact he didn't have both genes!
Sharon, mom of Sophia, 8 and Jack, 6 both with cf, Grant, 15 months no cf
 
S

sdelorenzo

Guest
Catherine,
I would call his cf nurse on Monday. Ask her the sweat test score. That should be a good indication. Usually double delta scores are above 60.
Also, ask her to request a blood draw for genetic testing. It would be simple for her to order it for you to go into the lab at the hospital for Tues or Wed of this week. Double delta scores take about 2 weeks to come back. That way you should know for sure if he in fact does carry both genes. What a blessing that would be if in fact he didn't have both genes!
Sharon, mom of Sophia, 8 and Jack, 6 both with cf, Grant, 15 months no cf
 
S

sdelorenzo

Guest
Catherine,
<br />I would call his cf nurse on Monday. Ask her the sweat test score. That should be a good indication. Usually double delta scores are above 60.
<br />Also, ask her to request a blood draw for genetic testing. It would be simple for her to order it for you to go into the lab at the hospital for Tues or Wed of this week. Double delta scores take about 2 weeks to come back. That way you should know for sure if he in fact does carry both genes. What a blessing that would be if in fact he didn't have both genes!
<br />Sharon, mom of Sophia, 8 and Jack, 6 both with cf, Grant, 15 months no cf
 
H

hmw

New member
No, it's not denial... it's wanting to be sure. If he's never had the blood test, he needs it to be sure either way. You are very fortunate in that you know to be looking for df508- it's the simplest genetic test you can do and the one that comes back the fastest.

My thoughts go in a few different directions. First, I agree you should get the results of the sweat test right away. I think that a positive result combined with the elevated IRT makes it very likely that he does in fact have CF, but as a cautionary note if it's under 60, as we've seen many times here: Sweat tests are not always positive in those who have CF. There are kids here who tested well below 60 who have both symptoms and a clear genetic dx. Babies esp do not always sweat much and may test lower than they would later in life.

However, conversely... IRT levels alone cannot diagnose CF. In actuality, most kids that have an elevated IRT do not have CF- it's a screen, not a diagnostic test and in the interest of catching the babies that NEED the dx, it catches others that don't actually have the disease and need to be eliminated (via genetic testing, sweat tests, monitoring symptoms, etc.)

Lastly, I agree with the others that have posted that even if he's a DDF508, it's completely possible (if not likely, given how proactive you've been with his treatments) for him to be completely asymptomatic at this young age. Provided his sweat test wasn't through the roof, there really are measurable odds that he doesn't have cf given he's never had the genetic testing- but I wouldn't base the assumption on the good health you see right now.

In our experience, Emily had far fewer colds and ear infections, etc than one of her brothers did as a baby, and this with constant exposure to bugs due to having 2 & 4yr old siblings. Her main symptom in infancy was reflux, and even without benefit of any tx, she grew well as a baby and young toddler. She didn't start really going downhill until she was about 3, when she started getting sick much more often and stopped growing well.
 
H

hmw

New member
No, it's not denial... it's wanting to be sure. If he's never had the blood test, he needs it to be sure either way. You are very fortunate in that you know to be looking for df508- it's the simplest genetic test you can do and the one that comes back the fastest.

My thoughts go in a few different directions. First, I agree you should get the results of the sweat test right away. I think that a positive result combined with the elevated IRT makes it very likely that he does in fact have CF, but as a cautionary note if it's under 60, as we've seen many times here: Sweat tests are not always positive in those who have CF. There are kids here who tested well below 60 who have both symptoms and a clear genetic dx. Babies esp do not always sweat much and may test lower than they would later in life.

However, conversely... IRT levels alone cannot diagnose CF. In actuality, most kids that have an elevated IRT do not have CF- it's a screen, not a diagnostic test and in the interest of catching the babies that NEED the dx, it catches others that don't actually have the disease and need to be eliminated (via genetic testing, sweat tests, monitoring symptoms, etc.)

Lastly, I agree with the others that have posted that even if he's a DDF508, it's completely possible (if not likely, given how proactive you've been with his treatments) for him to be completely asymptomatic at this young age. Provided his sweat test wasn't through the roof, there really are measurable odds that he doesn't have cf given he's never had the genetic testing- but I wouldn't base the assumption on the good health you see right now.

In our experience, Emily had far fewer colds and ear infections, etc than one of her brothers did as a baby, and this with constant exposure to bugs due to having 2 & 4yr old siblings. Her main symptom in infancy was reflux, and even without benefit of any tx, she grew well as a baby and young toddler. She didn't start really going downhill until she was about 3, when she started getting sick much more often and stopped growing well.
 
H

hmw

New member
No, it's not denial... it's wanting to be sure. If he's never had the blood test, he needs it to be sure either way. You are very fortunate in that you know to be looking for df508- it's the simplest genetic test you can do and the one that comes back the fastest.

My thoughts go in a few different directions. First, I agree you should get the results of the sweat test right away. I think that a positive result combined with the elevated IRT makes it very likely that he does in fact have CF, but as a cautionary note if it's under 60, as we've seen many times here: Sweat tests are not always positive in those who have CF. There are kids here who tested well below 60 who have both symptoms and a clear genetic dx. Babies esp do not always sweat much and may test lower than they would later in life.

However, conversely... IRT levels alone cannot diagnose CF. In actuality, most kids that have an elevated IRT do not have CF- it's a screen, not a diagnostic test and in the interest of catching the babies that NEED the dx, it catches others that don't actually have the disease and need to be eliminated (via genetic testing, sweat tests, monitoring symptoms, etc.)

Lastly, I agree with the others that have posted that even if he's a DDF508, it's completely possible (if not likely, given how proactive you've been with his treatments) for him to be completely asymptomatic at this young age. Provided his sweat test wasn't through the roof, there really are measurable odds that he doesn't have cf given he's never had the genetic testing- but I wouldn't base the assumption on the good health you see right now.

In our experience, Emily had far fewer colds and ear infections, etc than one of her brothers did as a baby, and this with constant exposure to bugs due to having 2 & 4yr old siblings. Her main symptom in infancy was reflux, and even without benefit of any tx, she grew well as a baby and young toddler. She didn't start really going downhill until she was about 3, when she started getting sick much more often and stopped growing well.
 
H

hmw

New member
No, it's not denial... it's wanting to be sure. If he's never had the blood test, he needs it to be sure either way. You are very fortunate in that you know to be looking for df508- it's the simplest genetic test you can do and the one that comes back the fastest.

My thoughts go in a few different directions. First, I agree you should get the results of the sweat test right away. I think that a positive result combined with the elevated IRT makes it very likely that he does in fact have CF, but as a cautionary note if it's under 60, as we've seen many times here: Sweat tests are not always positive in those who have CF. There are kids here who tested well below 60 who have both symptoms and a clear genetic dx. Babies esp do not always sweat much and may test lower than they would later in life.

However, conversely... IRT levels alone cannot diagnose CF. In actuality, most kids that have an elevated IRT do not have CF- it's a screen, not a diagnostic test and in the interest of catching the babies that NEED the dx, it catches others that don't actually have the disease and need to be eliminated (via genetic testing, sweat tests, monitoring symptoms, etc.)

Lastly, I agree with the others that have posted that even if he's a DDF508, it's completely possible (if not likely, given how proactive you've been with his treatments) for him to be completely asymptomatic at this young age. Provided his sweat test wasn't through the roof, there really are measurable odds that he doesn't have cf given he's never had the genetic testing- but I wouldn't base the assumption on the good health you see right now.

In our experience, Emily had far fewer colds and ear infections, etc than one of her brothers did as a baby, and this with constant exposure to bugs due to having 2 & 4yr old siblings. Her main symptom in infancy was reflux, and even without benefit of any tx, she grew well as a baby and young toddler. She didn't start really going downhill until she was about 3, when she started getting sick much more often and stopped growing well.
 
H

hmw

New member
No, it's not denial... it's wanting to be sure. If he's never had the blood test, he needs it to be sure either way. You are very fortunate in that you know to be looking for df508- it's the simplest genetic test you can do and the one that comes back the fastest.
<br />
<br />My thoughts go in a few different directions. First, I agree you should get the results of the sweat test right away. I think that a positive result combined with the elevated IRT makes it very likely that he does in fact have CF, but as a cautionary note if it's under 60, as we've seen many times here: Sweat tests are not always positive in those who have CF. There are kids here who tested well below 60 who have both symptoms and a clear genetic dx. Babies esp do not always sweat much and may test lower than they would later in life.
<br />
<br />However, conversely... IRT levels alone cannot diagnose CF. In actuality, most kids that have an elevated IRT do not have CF- it's a screen, not a diagnostic test and in the interest of catching the babies that NEED the dx, it catches others that don't actually have the disease and need to be eliminated (via genetic testing, sweat tests, monitoring symptoms, etc.)
<br />
<br />Lastly, I agree with the others that have posted that even if he's a DDF508, it's completely possible (if not likely, given how proactive you've been with his treatments) for him to be completely asymptomatic at this young age. Provided his sweat test wasn't through the roof, there really are measurable odds that he doesn't have cf given he's never had the genetic testing- but I wouldn't base the assumption on the good health you see right now.
<br />
<br />In our experience, Emily had far fewer colds and ear infections, etc than one of her brothers did as a baby, and this with constant exposure to bugs due to having 2 & 4yr old siblings. Her main symptom in infancy was reflux, and even without benefit of any tx, she grew well as a baby and young toddler. She didn't start really going downhill until she was about 3, when she started getting sick much more often and stopped growing well.
 
K

kitomd21

New member
My understanding regarding elevated IRT levels in California is this: initial readings can be "high" in children without CF, HOWEVER, testing on these blood samples doesn't just stop at a "high" reading. The same blood sample is sent for further testing and identification of common CF mutations. This was our experience with our daughter as we viewed the actual mutation report after further testing following an elevated IRT level. Sweat tests on infants are unreliable until they reach a certain thigh circumference...we actually didn't have one performed on Ellie because we had the DNA results via newborn screening. She was also too small for a sweat test at diagnosis.

You noted that there is a different protocol in your state and in your son's case a genetic screen truly is the only answer!! I'll be sending good thoughts and prayers your way!! <img src="i/expressions/face-icon-small-smile.gif" border="0">
 
K

kitomd21

New member
My understanding regarding elevated IRT levels in California is this: initial readings can be "high" in children without CF, HOWEVER, testing on these blood samples doesn't just stop at a "high" reading. The same blood sample is sent for further testing and identification of common CF mutations. This was our experience with our daughter as we viewed the actual mutation report after further testing following an elevated IRT level. Sweat tests on infants are unreliable until they reach a certain thigh circumference...we actually didn't have one performed on Ellie because we had the DNA results via newborn screening. She was also too small for a sweat test at diagnosis.

You noted that there is a different protocol in your state and in your son's case a genetic screen truly is the only answer!! I'll be sending good thoughts and prayers your way!! <img src="i/expressions/face-icon-small-smile.gif" border="0">
 
K

kitomd21

New member
My understanding regarding elevated IRT levels in California is this: initial readings can be "high" in children without CF, HOWEVER, testing on these blood samples doesn't just stop at a "high" reading. The same blood sample is sent for further testing and identification of common CF mutations. This was our experience with our daughter as we viewed the actual mutation report after further testing following an elevated IRT level. Sweat tests on infants are unreliable until they reach a certain thigh circumference...we actually didn't have one performed on Ellie because we had the DNA results via newborn screening. She was also too small for a sweat test at diagnosis.

You noted that there is a different protocol in your state and in your son's case a genetic screen truly is the only answer!! I'll be sending good thoughts and prayers your way!! <img src="i/expressions/face-icon-small-smile.gif" border="0">
 
K

kitomd21

New member
My understanding regarding elevated IRT levels in California is this: initial readings can be "high" in children without CF, HOWEVER, testing on these blood samples doesn't just stop at a "high" reading. The same blood sample is sent for further testing and identification of common CF mutations. This was our experience with our daughter as we viewed the actual mutation report after further testing following an elevated IRT level. Sweat tests on infants are unreliable until they reach a certain thigh circumference...we actually didn't have one performed on Ellie because we had the DNA results via newborn screening. She was also too small for a sweat test at diagnosis.

You noted that there is a different protocol in your state and in your son's case a genetic screen truly is the only answer!! I'll be sending good thoughts and prayers your way!! <img src="i/expressions/face-icon-small-smile.gif" border="0">
 
K

kitomd21

New member
My understanding regarding elevated IRT levels in California is this: initial readings can be "high" in children without CF, HOWEVER, testing on these blood samples doesn't just stop at a "high" reading. The same blood sample is sent for further testing and identification of common CF mutations. This was our experience with our daughter as we viewed the actual mutation report after further testing following an elevated IRT level. Sweat tests on infants are unreliable until they reach a certain thigh circumference...we actually didn't have one performed on Ellie because we had the DNA results via newborn screening. She was also too small for a sweat test at diagnosis.
<br />
<br />You noted that there is a different protocol in your state and in your son's case a genetic screen truly is the only answer!! I'll be sending good thoughts and prayers your way!! <img src="i/expressions/face-icon-small-smile.gif" border="0">
 
You must log in or register to reply here.
Top