Please help me understand daughters mutations


New member
We found out last year my daughter's mutations. No one, according to them, has her specific mutation. Here is what it said:

869+1 869+4

1521 1523 delCTT (p.Phe508del)
Legacy Delta 508

Sorry I know this is highly confusing. I got it that she has one Delta508. But the other?

Thank you anyone who can help me.


Super Moderator
I looked on these sites (linked below), I did not see your daughters 1st mutation (thus it not being known previously).

I probably won't be much help and this will be more technical than what you were probably looking for, but this is the information I came up with. I am just figuring this information out and am just piecing things together that have have read or heard from other posters. So this is my best guess at what this means...

Start with Delta 508, that is the Legacy name. Not all mutations will have these, only the ones identified and named before they started using the new nomenclature. Then there is also a protein name: (p. Phe508del) and a nucleotide (DNA) name: c. 1521 1523 delCTT. The dna name describes where in the dna strand and what the change is.​

So it looks like your daughters other mutation only has the
nucleotide (DNA) name: c. 869 +1 869 +4 delGTAA ins ACATTATT which I am assuming means that at the spot on the DNA strand (869) there is deletion of information and an insertion of incorrect information.​

I have no idea what class that makes it, but now you have an idea of what all those number mean.

edit to fix spacing, hope it worked


New member
THANK YOU Teri! Only one reply but a very informative one. You have no idea how much I appreciate your time. If you or anyone else ever hears of anything that could make me understand her mutation better please let me know.

Thank you again Teri!


New member
The only thing I can add is that the "del" is short for deletion in the dna. Typically del type mutations behave similarly. So maybe this means that the unknown one behaves similarly to a delta508 and that the combination of the two gene mutations would be similar to a person having two df508 genes.

I would confirm this statement with your doctor just to be sure.

Here is a reference to learn about gene mutations.


New member
My bay ha been diagnosed with Delta508 with C1521_1523 delCTT. Have you been able to find out more about these mutations? Apparently the second one is rare.... Sorry to bother you but really needing help here...


New member
Hi all, My 22yr old daughter has JUST been diagnosed with CF (No family history that we are aware of) - her mutations are
c. 1521 1523 delCTT (p.Phe508del)
c. 743+1G>C

I do not know what these mean. I understand the first one is very rare and the second one is the most common, is this correct?

any assistance would be great


Active member
Delta F508 is the most common mutation. CF is a disease that you are born with, she has had it for 22 years. Nothing, in her life, has changed except she will be getting the proper care for this disease.

Like her, I have Delta F508 and one rare mutation. She must be seen at an approved CF Clinic by a CF Specialist. I am 75 and like me, she will have a long and reasonably healthy life.



Active member

My second mutation is V562I, a mutation that was discovered in Northern Ireland from only 7 families. As it turns out my 3rd Great grand father left Louth sometime between 1800 & 1820. Delta F508 will be the predominate mutation and "likely" DD will have more digestive problems than lung problems.

Feel free to contact me at any time.

Bill Duffy


Active member

It is cases like this that I am willing to put up with a bigot like twisted. Unlike him, I can help.


New member
Bill, thanks for replying. Sorry for the delay in responding but I am new to these kind of forums and could not find where to reply - I'm learning fast :)

She is under the care of St Vincents CF unit in Dublin. While she had numerous chest infections through childhood, negative sweat tests at 4mts, 11mts and again at 21yrs it was only when she was diagnosed with Bronchiectasis last year that put her on the right path. Met consultant who took blood and found 1st mutation almost immediately. Regarding the second mutation he later admitted "I sent it abroad and told them to keep looking until they found it". 6 months later she was diagnosed (April 2015) She is doing well now