cf blood test

[anonymous]

I am a little confused. My sons doctor wants him to get a sweat test done at childrens hospital. Because he is not gaining weight. He is almost 13 months and weighs 17 lbs.
so I called my OB to see if he had done any testing on me during my preg. he said no-and sent me and my husband to the lab to have blood work done to test for cf.
My question is, is the blood test inconclusive or does it verify anything? I guess I am really confused. My ob doctor said that we both have to test positive for cf gene in order to pass is on to our son. Is that correct?

 

[Emily65Roses]

Yes, both parents need to carry the CF gene in order for the child to have CF. As a CFer, we get one CF gene from mom and one CF gene from dad. If both parents are carriers, the chances are this:
50% your child will carry the gene
25% your child will have CF
25% your child will neither have CF nor carry the gene
In the case of my family, we got the two 25% chances. I have CF and my sister doesn't even carry the gene.

However, the CF gene test isn't always too reliable. To my knowledge they test for a certain number of the more common CF genes, but there are hundreds of different mutations. So even the test sometimes can miss if you or your husband carries a very odd mutated gene. (Again, for instance, my mother gave me the most common CF gene, and my father gave me such a rare mutation that when we had our blood tested at my age 5, there wasn't even a name for it). Your best bet if you're unsure about your son is get him tested (both the common CF test called a sweat test, or a blood test like that you and your husband are getting done) at a CF center. This part is very important. Almost any place that is not an accredited CF center that does the sweat test, will either perform the test wrong, or read the results inaccurately. Most doctors, no matter how educated they may be, don't know what they're doing when it comes to CF. So if after testing you and your husband, you're still not sure, my best advice would be to go to a CF center. <img src="i/expressions/rose.gif" border="0">

 

[anonymous]

Thank you for the fast reply.

So how do I know if the place my child is being sent to for the sweat test is a cf clinic or not? My sons doc said she wanted the sweat test done at Phoenix childrens hospital.
Any thoughts about that place?

 

[Emily65Roses]

For a list of cff.org (Cystic Fibrosis Foundation, the national CF organization) accredited centers, paste this into your browser:
http://www.cff.org/chapters_and_care_centers/
Then just click on your state and look at the list of centers that are there. It appears that your hospital is a CF center. On the AZ page, two of the listed CF centers are: Phoenix Childen's Center, and Phoenix Children's Hospital -- Adult Program. If that's your hospital, then you are indeed scheduled to go to a CF center, and will be likely to get the most accurate results possible. <img src="i/expressions/rose.gif" border="0">