F508Del and M470V

blaakq

New member
My daughter was diagnosed at 2mos with CF. Positive sweat of 92 and only mutation they could find was F508Del. She is now 6, and her CF Center did an extensive lab draw to find the second mutation. It came back as M470V. All research I have done says this isn't a CF causing mutation. Creon saved her life as a baby and we have had no hospitalizations in the years following. I am just confused as to what this polymorphism means. Her CF Specialist said those were beyond her understanding. Any info out there would be greatly appreciated.
 

kyeev

New member
My daughter was diagnosed at 2mos with CF. Positive sweat of 92 and only mutation they could find was F508Del. She is now 6, and her CF Center did an extensive lab draw to find the second mutation. It came back as M470V. All research I have done says this isn't a CF causing mutation. Creon saved her life as a baby and we have had no hospitalizations in the years following. I am just confused as to what this polymorphism means. Her CF Specialist said those were beyond her understanding. Any info out there would be greatly appreciated.

Yes, you're right. M470V doesn't cause disease.
You're going to have to get her bloods sent out again for DNA sequencing.
(That's where they sequence the entire gene to find the mutation).
She must have a rare mutation.
(Typical screens look for the top 30 mutations).
 

blaakq

New member
Thank you so much for the reply. I have contacted our CF Center and they are looking into it for me. I just hate to think my poor child has to be poked again!!! It really bothers me they were satisfied with that result if it isn't a true cause. Maybe we will get ti the bottom of it soon!
 

JustDucky

New member
First I would ask if they did the full sequencing before running the test again....they may have already did it. Unfortunately, unknown mutations exist despite testing for 1600+ mutations currently known. It doesn't happen very often, but it does. Every few years or so, you can have the test repeated on her (the full sequencing) to see if the unknown mutation pops up. I know that this has happened to a few people on this forum...years ago, only one mutation is ID'd, but after years, the second is finally found. This could easily be the case with your daughter. Good luck! At this point, her early diagnosis despite knowing only one mutation is a good thing, she is getting the treatment she needs.

Jenn 41 wCF
 

kyeev

New member
First I would ask if they did the full sequencing before running the test again....they may have already did it. Unfortunately, unknown mutations exist despite testing for 1600+ mutations currently known. It doesn't happen very often, but it does. Every few years or so, you can have the test repeated on her (the full sequencing) to see if the unknown mutation pops up. I know that this has happened to a few people on this forum...years ago, only one mutation is ID'd, but after years, the second is finally found. This could easily be the case with your daughter. Good luck! At this point, her early diagnosis despite knowing only one mutation is a good thing, she is getting the treatment she needs.

Jenn 41 wCF

There is a crucial difference between the terms "sequencing" and "screening".
Screening is where you look for specific mutations. e.g. the typical 29 mutations.

Where I have used the term sequencing, this actually means to sequence the entire gene, all 150,000 bases, which will detect ALL mutations.
Hence Blaakq needs to ask for "DNA sequencing".
 
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