17p del - any clues?

Hi all

There are some great questions popping up on the forum recently - hope no-one minds if I chuck another one in!

Does anyone know whether a person's mutated/non-mutated status correlates with having the 17p deletion, i.e. can a person with CLL have mutated status (good prognosis) and also have the 17p deletion (poor prognosis)?

Are mutation status and the various deletions linked at all, or are they entirely independent of each other?

Any info/experiences will be most appreciated - as always! Thanks.

Debs.☺

8 Replies

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  • Hi Debs,

    It's important to keep in mind the following when looking at prognostic factors:

    1) A sample of cells from your blood is taken and analysed - we aren't looking at just CLL cells, but initially lymphocytes and then the B-lymphocytes which in turn are made up of healthy B-lymphocytes and CLL cells. Depending on the patient and how long they've had CLL and what treatments they've had, there can be a population of slightly different CLL cells that have inherited various copying mistakes in their genetic material as well as being selected out* and possibly being corrupted by previous chemotherapy treatments.

    2) The probes used aren't sophisticated enough to tell the full story about the actual damage involved and how that has affected the cell's viability.

    3) Most of our cell DNA is in the 46 (23 x 2) chromosomes inherited from our mother and our father respectively. The 11, 13, 17 numbers you often see in CLL specify the chromosome number. Chromosomes have a short P (petite) arm and a long Q arm (Q comes after P). Hence the p or q after the 11, 13, tells you whether the deletion is in the short or long arm of the chromosome., i.e. 17p deletion means there's a deletion in the short arm of chromosome 17.

    The test results are expressed as a percentage of what's found from all the cells analysed. From the analysis of the CLL genome of CLL patients by many research groups around the world, it has been possible to sometimes identify for a given marker, a cluster of patients who on average have done well and a separate cluster of patients who on average haven't done so well. I use the word cluster loosely, because in reality, you get a scattering of results all over the place with somewhat greater concentrations in two areas. It's then a 'simple' matter of deciding on a percentage which separates the two clusters and calling the group below the cut-off point 'negative' and the group above the cut-off point 'positive'.

    From the above, I hope it is now obvious that it is quite possible to have multiple and largely independent abnormalities in our CLL genome. There are likely to be some strong associations of certain abnormalities due to the way they work together to make the abnormal cells survive and propagate.

    With regard to the mutated/unmutated prognostic factor, each B-lymphocyte (and hence each CLL cell) has a B cell receptor (BCR) and depending on how that particular B-cell has matured, it may or may not have gone through somatic hypermutations in rearranged immunoglobulin heavy-chain (IgVH) genes for the B cell receptor to key it strongly to a specific antigen. (This is how our newly minted B-lymphocytes, working with helper T-lymphoctytes, differentiate to generate immunoglobulins (antibodies) that lock onto different protein structures in the vast array of pathogens out to get us, hence marking them for destruction by our immune system.) IgVH mutated CLL cells have gone through that hypermutation process - they are considered more mature and as we know, that correlates with a better survival time with CLL.

    * Some CLL clones will be more susceptible to the treatment therapy, leaving more of those less susceptible to the treatment to grow back when remission ends. That's why subsequent treatments with the same therapy are less effective, i.e. remissions are shorter and why it is unwise to repeat the same therapy if a remission lasts less than 2 years.

    Neil

  • Wow! A fascinating and much appreciated response.

    As I've said before, even though I have CLL myself, I find it a really interesting subject - there's always lots to learn!😕

    Thanks very much for your detailed reply, Neil. I'm always keen to know more about this condition! 😊

    Debs.

  • Great info from our Aussie friend!

    Always learn new info on here!

  • My husband was diagnosed with CLL with deletions 17p and 11q. This diagnosis was given us by the dr who sent out his blood for testing and this was the results of specific tests they did.

    I would certainly ask my doctor if I was in questions of the kind of CLL I had. Asking questions is always a good thing.

  • hi Aussieneil I have B cell 11q CLL I believe this has a bad prognosiss am I right

  • 11q deletion is associated with bulky nodes and a shorter time to treatment, but you could have ended up with worse. Dr Sharman has written a rather thorough blog about 11q deletion here:

    cll-nhl.com/2013/11/11q-del...

    What actually happens in your case will still be unique to you, so don't let the 11Q label define you.

    Neil

  • thank you Neil info was helpful cant see any thing about -11q or is that just saying I have the 11q deletion, sorry for being a pain this is a bit over my head but really want to understand were I am with this complex disease . thanks

  • -11q is shorthand for 11q deletion (a subtraction from 11q or more sloppily just 11q).

    Neil

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