question on mutatuon


New member
my daughter is in the process of multiple sweat test for a diagnosis and just had her blood work done today. I have a thread in newly diagnosed on everything that is going on with her. I guess Im mainly here to ask about gene mutation. from what I have read online about cystic fibrosis is the gene has to come from each parent.
first question: if the parent has the gene but no signs/diagnosis of CF is their gene mutated also?
second question: with CF if my daughter comes back with a mutated gene, that means she got the gene from us her parents so does that mean we got the gene from our parents??

my daughters uncle is going threw testing and all that too and his all came back negative. my daughters grandfather had blood work done and they told him he didn't have the gene. so if my husbands father doesn't have the gene does that mean that there is no way my husband has the gene to pass to our daughter?? I hope that these questions are not confusing. I am just really in the dark with everything. Her doctors don't want to answer anything until all test results are in. if anyone has any answers I would greatly appreciate a reply :) thank you
ok - the cftr gene (as all :) ) is actually two little parts - each from one parent. You do not know which one is from who unless you do test . the same goes on fron your parents and so on...but the other half of the cftr gene is normal - that means you have no symptoms therefor you have no cf. it's a recesive gene. So if you have a stronger healthy on in pair - they work.
Very rarely - but still possible - a child may inherit the same mutation twice from the mother - but it's extremely rare.
What do you mean a child may inherit the same mutation twice from the mother? I thought one came from the dad and one from the mother. This is the first time I heard this. Does that mean even if it is rare that I could have been the only one to give my son cf? He has DDF508. We don't know where it came from in either side but my dad had a brother that died when he was 4 and they do not know what he died of.


What AleksandraKaczynska is saying is that there's a rare chance that one parent has two mutations on their same gene and the other parents has two perfect genes. So the child will have one gene with two mutations and the other gene will have 0 mutations.

What this means is that the baby will pop positive on the NBS becasuse there's two mutations. The only way to discern if the mutations are on the same gene or not, is to have the parents tested.

However...if your child has DDF508 I do not believe it is possible for both mutations to be on the same gene. Since its the same can't happen twice on the same gene. But i'm not 100% sure about that.

Hope that helps clear it up for you! Good luck!
Okay thank you lauryn.tubes. I have never been tested period and neither has my husband or my other son. I have asked if my other son who does not have cf could be tested to see if he is a carrier but never got a reply. My younger son doesn't follow the "rules" like my older son and his girlfriend is pregnant. My son told her doctor about CF but they just tested his girlfriend to see if she was a carrier and the test came back that she is not. I did not know that one person could carry two mutations. I hope that I could not have been the only one to give my son cf. I hate that he has to face cf. I am so very thankful and blessed to have both of my sons but I never would have done that to any child. We found out my older son had cf when my younger son was one year old - a week after my younger son turned one.


New member
Soooooo..... I'm guessing that what you referr to is two DIFFERENT CF gene mutations on the same chromosone - which would be possible to inherit from one parent ... I think. Seems I've read about this before - need to research.

To answer Jaybug's questions: The severe form of CF to which most physicians and lay-people refer is inherited from both parents - one of the same mutation of a CF gene inherited from both parents. And some C F gene mutations cause more severe illnesses than others. The chemistry of it is quit complicated. This form of CF will usually test positive on the "Sweat"test.
However, it has recently become known that a person can inherit ONE of several different gene mutations from only one parent. This can, maybe or maybe not, cause the person to have milder symptoms of CF. These people may have problems with illnesses related to CF, but usually have fairly healthy lives of a normal lifespan. These peope frequently do NOT test posture for CF on the Sweat test, but will with the genetic test.
It is also possible to inherit different mutations of the CF gene from both parents. Their illness can be mild, moderate, or severe - highly variable from person to person, and depending upon the combination of gene mutations. Those peeple may, or may not test positive for CF on the Sweat test.
It is also important to remember that the "blood" test which includes the genetic test (usually, although it also tests for other things) frequently tests ONLY for the most common CF gene mutations, so it is possible that even this test will miss diagnosing the root cause (CF) of the problem.
I guess the doctor who tested my younger son's girlfriend would have tested for CF completely, right? I remember it was like 1 in 20 people carry the CF gene so I know it is highly unlikely but it would be devastating if the baby had CF as my older son and the baby could not be around each other which would be an additional hardship for my older son. I know I worry too much but is there anything they should look out for during the pregnancy on the ultrasounds? We don't even know if my younger son is a carrier. I guess they were not worried as he is always pretty healthy.
Omg! That just chills me to the bone JazzZyx. I don't want to be the only one who gave him cf. We can't link it to anyone on my husband's side. I don't know why they never tested us. I don't know if our insurance doesn't cover it? I guess they don't think it is important when we are so old and my son is 25. I can't bear the thought of this. I wonder where I could find out.
I am not going to worry about this as I can not change it. I looked up online and everything I read says it has to come from 2 parents. I can let everything worry me but I can not change some things. This would be one of those. I am just going to go forward.


New member
Believing in Jesus.
Thank God, most states and hospitals now test for CF of a baby before s/he is born, based upon samples taken from the amniotic fluid. Based upon these screening tests, further tests will be performed to determine the gene pairing, which is fairly accurate at determining guest how severe the CF wilt be. Up with a few years ago, it has been a genetic craps-shoot whether or not a CF carrier would conceive a child with another CF carrier. My brothers and sisters, and all of our children have been extremely fortunate in the game of chance, and none of us has married and conceived chlihm with mates who also Carry a CF gene mutation.
I encourage you to read the book "Survival of the Sickest," It explores the question of WHY these types of gene mutations developed and persisted in the gene pool in the fist place, considering how devastating they can be, The answer, the theory, seems to be that, when only partly expressed, as when a person is a carrier of CF but does not have the full-blown disease, the gene mutation is actually BENEFICIAL! (This theory has been proven in the case of Sickle Cell anemia.) It seems that a CF gene carrier has resistance to certain diseases that kill, in large numbers, other people who do not have the CF gene mutation. One disease being Cholera, another being Tuberculosis. I could explain why, but it gets deep into the chemistry of the mucosal secretions.
I have personally benefited from this benefit of being a CF gene carrier. I was infected with Tuberculosis while living in Indonesia, but I never developed a severe case of this killer disease. It was not until I returned to the U.S. that it was diagnosed and treated, Also, I never caught any of the several senious diarrheal diseases that are endemic there. Nor did my CF- carrier daughter. My non-CF carrier son and wife did, however.
So, Believing In Jesus, don't be so hard on yourself.
Thank you JazzZyx, for explaining the positive side. I wish the CF gene didn't exist at all. I do not want one of my sons to have to deal with CF. I younger son is basically pretty healthy. Like Forest Gump said - Life is like a box of chocolates. You never know what you will get. Sucks.


Super Moderator
Believing: your oldest son has two ddf508 mutations so he couldn't get two copies on the same chromosome from you since the mutations I. The same Latino. Your son's girlfriend was likely only tested for a small number of common mutations. If you so. Is a carrier most would run a full sequence nnthe mother to see if she carries a rarer one. S ce your other son has two df508 it is simple and cheep to see if he has one copy. If he doesn't the no reason to further test her since the mutations in your family are known...he wouldn't have a rarer one. For peace of mind, it might make sense for him together the simple blood test. If he is positive she can then ask for more testing and to be monitored on ultrasound for M.I. And be ready with good doctors to take care of the baby.
Thank you Aboveallislove. Would my younger son have to be tested at the CF clinic? My sons girlfriend asked my son if he ever has been tested but he hasn't so they ran a test on his girlfriend and it came back within a week that she was not a carrier. I remembered reading that there could be other mutations that are not tested when they run it the first time. I worry about everything and I didn't know if we should request any further testing. They are supposed to find out if it is a boy or girl tomorrow actually. Wouldn't a bowel obstruction or something show up on the ultrasound? I read that on here before. Thank you for helping me see it had to come from my husband too. It sounded like there was the possibility it could come from only me and that gets me down. Since I don't know and I can not change anything I am choosing to let it go.

I mean on a sonogram. It's been 21 years since I had a child.:confused:


Super Moderator
No he does t need to go to cf clinic. Df508 will show na basic five or six panel screen. Have him call his general practioner say he wants to know if he's a cf carrier for df508 and can they send him a script. He can go to local blood draw lab and they'll have results within five days. Worry beed gone!
Wow! Okay I will call and find out. I wonder if our insurance will cover it or if it even costs a lot? Should I worry about his girlfriend as I read about 80% of mutations are shown on that first test but not the other 20%. Would something show up while the baby is still in the womb?


Super Moderator
If cf something could show up While in womb...but we had pretty extensive ultrasounds for ds because I'm old and wanted to be ready with medical care for our baby if God decided to bless us with a special baby....the ultrasound didn't show anything either cf related or heart related (he has a tiny hole in his heart discovered a couple weeks after cf diagnosis). But at this point, I'd just have your son get the test.., it isn't expensive and should be covered by I durance since he has family history and is of childbearing age and this is the basic test. If no df508 take off radar...if he's a carrier she should have full sequence run and they show look at ultrasounds.
Okay- I guess she wouldn't have had full sequence done, right? It took one week and then she told my don they told her she wasn't a carrier. I called my younger sons regular doctor but the lady didn't know what I was talking about and said she has to ask the doctor and get back with me. She asked - CS? I said no cf or cystic fibrosis. ???


Super Moderator
Right...they wouldn't have done a full screening, but if your son has df508 as a carrier they would/should. This is pretty standard test so doctor should know what it is.
Okay. I'm still waiting to hear back from the doctors office. The lady I talked to didn't know anything about it but I know the doctor will as he saw my other son (with cf) for minor things when he turned 21 and was still living close and was no longer seen by his pediatrician. My younger son is going to the appt. tomorrow to see what the baby is so maybe he could get the test done tomorrow too if they get back with me. Thank you!!!


Super Moderator
Also, it doesn't see likely that they Reboth carriers, but you are obviously worried so maybe present it that way that you would feel better knowing that he is isnt a carrier e en though her screening came back ok.