Adult Cystic Fibrosis: Anyone have CF mutation S895N?

Posted by helen1000 @helen1000, Jan 1 11:48am

I carry a CF variance S895N, very common in Taiwanese, or specifically for Asian. Asian do not carry the most common CF mutation Caucasian carry and the symptoms are quite different ( usually without digestive symptoms or just BE or sinus infection) so CF is very much underdiagnosed in Asia. Though my sweat tests ( twice) is negative, I believe this mutation causes me bronchiectasis. I had frequent newborn pneumonia. My parents told me I had Otitis media twice before school age. I am now diagnosed as mild bronchiectasis/ MAC. I wonder how likely a mutation carrier will develop another CF mutation and become a CF patient. By research, I know currently there is no medication to treat this mutation.

I will see a CF director in NYU to understand this mutation next month. If anyone can recommend a great doctor in CF, that will be appreciated.

Interested in more discussions like this? Go to the Cystic Fibrosis Support Group.

Profile picture for Pug, Volunteer Mentor @ckscoville

@helen1000 I have been on Trikafta continuously since June of 2021. During the past four and a half years, I've had a number of infections, as well as a variety of antibiotic treatments while on Trikafta. The most recent (IV) treatment was with Meropenem. The only side effect of the last treatment was a rash -- thankfully non-itching! -- that looked like measles, but it disappeared after a few days. I'm not familiar with Alyftrek ...maybe someone else on this forum is and can chime in.

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@ckscoville I am so sorrythat it seems not working on you very effectively. I know the effect also depends on what type of mutation it is. My mother's cancer mutation does not respond as well as my friend's mother to the same therapy medication. Are you sure your mutation responds well to Trikafta? Alyftrek is a new medication, and can take once a day. Did you ever discuss with your health provider to switch to the new one? It looks like more effective than Trikafta based on my research ( just started this year) may not be sufficient enough though. But it is recognized as a better one definitely!

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Hello,
I have been thinking about your post for some time. When you mentioned your family history of TB it reminded me of an article I read on CF many years ago which described how CF had possibly evolved from Typhoid and that carrying defective CFTR provided protection from Typhoid. So when I read your post, I did a quick google search and came up with this from AI https://share.google/aimode/G9E6Xta3B5e2k497p.
Scroll down to other potential factors and there you will see they discuss TB and CF with a link to an article.
I hope your journey with Alyftrec provides you much relief. Trikafta has certainly made a big difference for me and my CF journey. I’ve been on it for 6 years now and it is still highly effective.

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Profile picture for Pug, Volunteer Mentor @ckscoville

@helen1000 I have been on Trikafta continuously since June of 2021. During the past four and a half years, I've had a number of infections, as well as a variety of antibiotic treatments while on Trikafta. The most recent (IV) treatment was with Meropenem. The only side effect of the last treatment was a rash -- thankfully non-itching! -- that looked like measles, but it disappeared after a few days. I'm not familiar with Alyftrek ...maybe someone else on this forum is and can chime in.

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@ckscoville @helen1000 Alyftrek is apparently easier on the liver than Trikafta. I don't know that our local CF clinic has seen any significant difference in FEV1 with the use of Alyftrek, but side effects do appear to be lessened. However, Alyftrek has only been on the open market for a year.
Vertex is testing an add-on (just finished phase 2a, I think) that totally normalizes CFTR (the protein that doesn't function properly in CF) in vitro, which may provide even better results. But damaged lungs cannot be made new again, regardless. Sigh.

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Profile picture for tw508 @tw508

@ckscoville @helen1000 Alyftrek is apparently easier on the liver than Trikafta. I don't know that our local CF clinic has seen any significant difference in FEV1 with the use of Alyftrek, but side effects do appear to be lessened. However, Alyftrek has only been on the open market for a year.
Vertex is testing an add-on (just finished phase 2a, I think) that totally normalizes CFTR (the protein that doesn't function properly in CF) in vitro, which may provide even better results. But damaged lungs cannot be made new again, regardless. Sigh.

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@tw508 Thank you so much for the sharing. From my research, Alyftrek has more side effects than Trikafta. But it may be from patients who has side effects. 🙂 So I will take your words for credits! I am still waiting for insurance to approve Trikafta as they can't Alyftrek if I dont take Trikafta first.

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You may need to get liver function tests monthly for the first 6 months with Trikafta, but this isn't true for Alyftrek. This has happened at our CF clinic, don't know about nonCF BE patients.

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Profile picture for tw508 @tw508

You may need to get liver function tests monthly for the first 6 months with Trikafta, but this isn't true for Alyftrek. This has happened at our CF clinic, don't know about nonCF BE patients.

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@tw508 Well noted and thanks!

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Profile picture for tw508 @tw508

Some therapies (antibiotics, eg) select for resistant bacterial or tumor populations. That is not true of the CFTR modulators Trikafta or Alyftrek, which work by helping the mutant chloride channel protein fold, getting it to the surface of the cell, and increasing the amount of time the channel stays open. There's no apparent theoretical advantage to the host cell to keep the modulator from entering the cell where it is needed.
That's not to say the modulators prevent all pulmonary exacerbations (PE) long term - they don't. But PE are greatly reduced. It is quite likely that the bacteria colonizing the lung adapt to the changing conditions resulting from a vastly different extracellular environment post-modulator treatment and can flare up, often in response to viral insults. However, data do show that the bacterial burden in the CF lung (the only population studied to date) remains orders of magnitude lower even after several years of effective modulator treatment.
I hope that helps.

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@tw508 Your ability to explain a complex process very clearly is impressive. I would guess that you have a scientific background or occupation, right?

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Profile picture for Pug, Volunteer Mentor @ckscoville

@tw508 Your ability to explain a complex process very clearly is impressive. I would guess that you have a scientific background or occupation, right?

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@ckscoville Well, yes. If there are half a million people in the US with BE, some of us are bound to be scientists, right?
I have a PhD in microbiology, and specialized in cystic fibrosis for several decades (yes, I'm ooooold). I also was a member of an institutional review board that reviews clinical trials, until I retired.
But I'm always learning, and enjoying being a member of this group!

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Profile picture for tw508 @tw508

@ckscoville Well, yes. If there are half a million people in the US with BE, some of us are bound to be scientists, right?
I have a PhD in microbiology, and specialized in cystic fibrosis for several decades (yes, I'm ooooold). I also was a member of an institutional review board that reviews clinical trials, until I retired.
But I'm always learning, and enjoying being a member of this group!

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@tw508 And we are very glad to have you here! That's quite a resume.

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My CF director told me that my S895N can be classified as another CF mutation, and this mutation is responsive to Trikafta. Finally I know why I got BE/CFRD. What a relief!

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