Anyone out there experience a false-negative newborn state screening test for their child? My 3-year old daughter was screened for cf when she was born (part of standard state-mandated testing in Wisconsin) with normal results. Since birth she has had frequent respiratory infections and GI difficulties. Her growth pattern is normal though. My brother died of cf in 1985 at age 7 so I know it's likely I'm a carrier. Any insight anyone has would be greatly appreciated!
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
False Negative Newborn Testing
- Thread starter hhildema
- Start date
Anyone out there experience a false-negative newborn state screening test for their child? My 3-year old daughter was screened for cf when she was born (part of standard state-mandated testing in Wisconsin) with normal results. Since birth she has had frequent respiratory infections and GI difficulties. Her growth pattern is normal though. My brother died of cf in 1985 at age 7 so I know it's likely I'm a carrier. Any insight anyone has would be greatly appreciated!
Anyone out there experience a false-negative newborn state screening test for their child? My 3-year old daughter was screened for cf when she was born (part of standard state-mandated testing in Wisconsin) with normal results. Since birth she has had frequent respiratory infections and GI difficulties. Her growth pattern is normal though. My brother died of cf in 1985 at age 7 so I know it's likely I'm a carrier. Any insight anyone has would be greatly appreciated!
My understanding is that there can be a greater chance of False Negatives rather then False Positives. Many things can cause this from contamination to poor knowledge of test procedures to limited testing. Definitely repeat the test with an extended panel if its not already done &/or have you and your husband tested to be sure. I am sorry to hear about your bro, but this shows how very important it is to be sure! Good Luck & Keep us updated, please!
My understanding is that there can be a greater chance of False Negatives rather then False Positives. Many things can cause this from contamination to poor knowledge of test procedures to limited testing. Definitely repeat the test with an extended panel if its not already done &/or have you and your husband tested to be sure. I am sorry to hear about your bro, but this shows how very important it is to be sure! Good Luck & Keep us updated, please!
My understanding is that there can be a greater chance of False Negatives rather then False Positives. Many things can cause this from contamination to poor knowledge of test procedures to limited testing. Definitely repeat the test with an extended panel if its not already done &/or have you and your husband tested to be sure. I am sorry to hear about your bro, but this shows how very important it is to be sure! Good Luck & Keep us updated, please!
I would definitely insist on more testing -- sweat test and full genetic testing -- do not let things go with only that screening. If she is having respiratory and GI problems coupled with your brother's history I cannot imagine a doctor who would not jump to test again - I think it would be very irresponsible of any doctor to not follow up with full testing.
I would definitely insist on more testing -- sweat test and full genetic testing -- do not let things go with only that screening. If she is having respiratory and GI problems coupled with your brother's history I cannot imagine a doctor who would not jump to test again - I think it would be very irresponsible of any doctor to not follow up with full testing.
I would definitely insist on more testing -- sweat test and full genetic testing -- do not let things go with only that screening. If she is having respiratory and GI problems coupled with your brother's history I cannot imagine a doctor who would not jump to test again - I think it would be very irresponsible of any doctor to not follow up with full testing.
Thanks to both of you for your reply. My daughter will see her pediatrician on 12/01 for her three-year well-check and I will inquire about testing options. Do you think the sweat test is still the "gold standard" for diagnosing or should I inquire about DNA testing? Also, my daughter is very big for her age which I know isn't typical for CF patients so maybe she has something that's mimicing CF? Any info about that? Thanks once again for your replies and for the encouragement to ask about thorough testing!
Thanks to both of you for your reply. My daughter will see her pediatrician on 12/01 for her three-year well-check and I will inquire about testing options. Do you think the sweat test is still the "gold standard" for diagnosing or should I inquire about DNA testing? Also, my daughter is very big for her age which I know isn't typical for CF patients so maybe she has something that's mimicing CF? Any info about that? Thanks once again for your replies and for the encouragement to ask about thorough testing!
Thanks to both of you for your reply. My daughter will see her pediatrician on 12/01 for her three-year well-check and I will inquire about testing options. Do you think the sweat test is still the "gold standard" for diagnosing or should I inquire about DNA testing? Also, my daughter is very big for her age which I know isn't typical for CF patients so maybe she has something that's mimicing CF? Any info about that? Thanks once again for your replies and for the encouragement to ask about thorough testing!
Most docs start with a sweat test. As far as I know, it can come up with false negatives, but not false positives. Genetic testing is probably a better choice, but most docs/insurance companies start with the sweat test. Sometimes even genetic testing doesn't pick up 2 mutations though. With my son the first test from Ambry genetics didn't pick up both mutations, so they did a full sequence test and that picked up the other mutation.
Also, about your daughter being big for her age, not all people with CF are pancreatic insufficient. That is what makes them not properly absorb food and therefore they have trouble with weight gain. Some people with CF that aren't pancreatic insufficient have no trouble gaining weight or keeping it on.
Especially because of the family history of CF and the symptoms you described, keep pushing those docs till you get an answer! Even if the sweat test comes back negative, push for the genetic testing. And if that comes back negative push for an extended panel or full sequence gene test. I hope your daughter is doing well and that you get an answer one way or another. Keep us posted!
Also, about your daughter being big for her age, not all people with CF are pancreatic insufficient. That is what makes them not properly absorb food and therefore they have trouble with weight gain. Some people with CF that aren't pancreatic insufficient have no trouble gaining weight or keeping it on.
Especially because of the family history of CF and the symptoms you described, keep pushing those docs till you get an answer! Even if the sweat test comes back negative, push for the genetic testing. And if that comes back negative push for an extended panel or full sequence gene test. I hope your daughter is doing well and that you get an answer one way or another. Keep us posted!
Most docs start with a sweat test. As far as I know, it can come up with false negatives, but not false positives. Genetic testing is probably a better choice, but most docs/insurance companies start with the sweat test. Sometimes even genetic testing doesn't pick up 2 mutations though. With my son the first test from Ambry genetics didn't pick up both mutations, so they did a full sequence test and that picked up the other mutation.
Also, about your daughter being big for her age, not all people with CF are pancreatic insufficient. That is what makes them not properly absorb food and therefore they have trouble with weight gain. Some people with CF that aren't pancreatic insufficient have no trouble gaining weight or keeping it on.
Especially because of the family history of CF and the symptoms you described, keep pushing those docs till you get an answer! Even if the sweat test comes back negative, push for the genetic testing. And if that comes back negative push for an extended panel or full sequence gene test. I hope your daughter is doing well and that you get an answer one way or another. Keep us posted!
Also, about your daughter being big for her age, not all people with CF are pancreatic insufficient. That is what makes them not properly absorb food and therefore they have trouble with weight gain. Some people with CF that aren't pancreatic insufficient have no trouble gaining weight or keeping it on.
Especially because of the family history of CF and the symptoms you described, keep pushing those docs till you get an answer! Even if the sweat test comes back negative, push for the genetic testing. And if that comes back negative push for an extended panel or full sequence gene test. I hope your daughter is doing well and that you get an answer one way or another. Keep us posted!
Most docs start with a sweat test. As far as I know, it can come up with false negatives, but not false positives. Genetic testing is probably a better choice, but most docs/insurance companies start with the sweat test. Sometimes even genetic testing doesn't pick up 2 mutations though. With my son the first test from Ambry genetics didn't pick up both mutations, so they did a full sequence test and that picked up the other mutation.
Also, about your daughter being big for her age, not all people with CF are pancreatic insufficient. That is what makes them not properly absorb food and therefore they have trouble with weight gain. Some people with CF that aren't pancreatic insufficient have no trouble gaining weight or keeping it on.
Especially because of the family history of CF and the symptoms you described, keep pushing those docs till you get an answer! Even if the sweat test comes back negative, push for the genetic testing. And if that comes back negative push for an extended panel or full sequence gene test. I hope your daughter is doing well and that you get an answer one way or another. Keep us posted!
Also, about your daughter being big for her age, not all people with CF are pancreatic insufficient. That is what makes them not properly absorb food and therefore they have trouble with weight gain. Some people with CF that aren't pancreatic insufficient have no trouble gaining weight or keeping it on.
Especially because of the family history of CF and the symptoms you described, keep pushing those docs till you get an answer! Even if the sweat test comes back negative, push for the genetic testing. And if that comes back negative push for an extended panel or full sequence gene test. I hope your daughter is doing well and that you get an answer one way or another. Keep us posted!
Amber said things almost word for word like I would have - so I'll paraphrase some of this
*yes doctors & ins companies like to start with the sweat test
*yes sweat tests can give a false negative (see my blog)
*yes it's perfectly normal to have good nutrition if pancreatic sufficient (my kids are both sufficient)
*yes even genetic tests sometimes fail to pick up 2 known genes (remember they started with only identifying 400 genes and they are now up over 1400) so it is possible if a gene (or even both) are not showing up it's because they haven't identified it yet. But it is still a whole lot better than a sweat test only.
*let your doctor start with the sweat test but let them know right away you would like to follow up with a genetic test regardless of the outcome of the sweat test. Given the family history I think that is a very reasonable request. Some doctors will order both tests at the same time.
*yes doctors & ins companies like to start with the sweat test
*yes sweat tests can give a false negative (see my blog)
*yes it's perfectly normal to have good nutrition if pancreatic sufficient (my kids are both sufficient)
*yes even genetic tests sometimes fail to pick up 2 known genes (remember they started with only identifying 400 genes and they are now up over 1400) so it is possible if a gene (or even both) are not showing up it's because they haven't identified it yet. But it is still a whole lot better than a sweat test only.
*let your doctor start with the sweat test but let them know right away you would like to follow up with a genetic test regardless of the outcome of the sweat test. Given the family history I think that is a very reasonable request. Some doctors will order both tests at the same time.
Amber said things almost word for word like I would have - so I'll paraphrase some of this
*yes doctors & ins companies like to start with the sweat test
*yes sweat tests can give a false negative (see my blog)
*yes it's perfectly normal to have good nutrition if pancreatic sufficient (my kids are both sufficient)
*yes even genetic tests sometimes fail to pick up 2 known genes (remember they started with only identifying 400 genes and they are now up over 1400) so it is possible if a gene (or even both) are not showing up it's because they haven't identified it yet. But it is still a whole lot better than a sweat test only.
*let your doctor start with the sweat test but let them know right away you would like to follow up with a genetic test regardless of the outcome of the sweat test. Given the family history I think that is a very reasonable request. Some doctors will order both tests at the same time.
*yes doctors & ins companies like to start with the sweat test
*yes sweat tests can give a false negative (see my blog)
*yes it's perfectly normal to have good nutrition if pancreatic sufficient (my kids are both sufficient)
*yes even genetic tests sometimes fail to pick up 2 known genes (remember they started with only identifying 400 genes and they are now up over 1400) so it is possible if a gene (or even both) are not showing up it's because they haven't identified it yet. But it is still a whole lot better than a sweat test only.
*let your doctor start with the sweat test but let them know right away you would like to follow up with a genetic test regardless of the outcome of the sweat test. Given the family history I think that is a very reasonable request. Some doctors will order both tests at the same time.
Amber said things almost word for word like I would have - so I'll paraphrase some of this
*yes doctors & ins companies like to start with the sweat test
*yes sweat tests can give a false negative (see my blog)
*yes it's perfectly normal to have good nutrition if pancreatic sufficient (my kids are both sufficient)
*yes even genetic tests sometimes fail to pick up 2 known genes (remember they started with only identifying 400 genes and they are now up over 1400) so it is possible if a gene (or even both) are not showing up it's because they haven't identified it yet. But it is still a whole lot better than a sweat test only.
*let your doctor start with the sweat test but let them know right away you would like to follow up with a genetic test regardless of the outcome of the sweat test. Given the family history I think that is a very reasonable request. Some doctors will order both tests at the same time.
*yes doctors & ins companies like to start with the sweat test
*yes sweat tests can give a false negative (see my blog)
*yes it's perfectly normal to have good nutrition if pancreatic sufficient (my kids are both sufficient)
*yes even genetic tests sometimes fail to pick up 2 known genes (remember they started with only identifying 400 genes and they are now up over 1400) so it is possible if a gene (or even both) are not showing up it's because they haven't identified it yet. But it is still a whole lot better than a sweat test only.
*let your doctor start with the sweat test but let them know right away you would like to follow up with a genetic test regardless of the outcome of the sweat test. Given the family history I think that is a very reasonable request. Some doctors will order both tests at the same time.
damiensmom
New member
Damien was 2 weeks old and we were sent to a childrens hospital for suspected cf. 1 month we did tests all false negatives. We were sent home only to be called 2 weeks later saying blood panel came back he does have cf.
damiensmom
New member
Damien was 2 weeks old and we were sent to a childrens hospital for suspected cf. 1 month we did tests all false negatives. We were sent home only to be called 2 weeks later saying blood panel came back he does have cf.