BRCA test - Multisite vs Sequencing for Ashkenazi Jews

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suz90
suz90 Member Posts: 7
edited June 2014 in Genetic Testing

I just got my results back from the multisite test and it was negative. genetic wants me to maybe get the sequence test but i have a very tiny chance of having another type of mutation and i do not have a huge family history. i did have BC at 36 and have been fine for 10 yrs. should i get the next test? let me add that it took a lot out of me and i have been a wreck over this entire testing process. just wonder if the multisite is sufficient. i can't seem to figure that out. also some of my research suggests that the sequence can turn up other factors that are ambiguous. any thoughts?

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  • HeleneS
    HeleneS Member Posts: 30
    edited May 2010

    I was diagnosed Nov '09 at 41 with DCIS (later they found IDC) and the genetic counselor recommended running both tests.   If your insurance doesn't cover it then maybe it's not worthwhile to do (it's expensive) because such a high percentage of the Ashkenazi mutations are detected in the first test, but if it's covered why not be thorough?  You mentioned that you had a hard time doing the test, so you would have to weigh this as well -- chances are the second test will be fine, but why not be sure?  If you want more info on BRCA and Ashkenazi Jews I would recommend you get in touch with Sharsheret, a group geared towards the needs of young Jewish women with BC or at high risk.  The website is www.sharsheret.org.

  • delt6018
    delt6018 Member Posts: 1
    edited May 2010

    I have just tested positive to BRCA1 (68_69delAG or185delAG) gene. I understand that this gene is found in people of Askenazi jewish descent.I have 3 first cousins who have tested positive to this gene also as our DNA and gene mutation where crossmatched. The thing is my family's recent known genetic history does not include any Jewish relatives yet this gene and breast/ovarian cancer is very prevalent in my family. My mother and her sister must have both had this gene. My mother had both breast and ovarian cancer and three of her sisters had either breast or ovarian cancers at a young age. I have 4 first cousins who have had breast cancer at a very young age including one cousin who died at 38 after contracting breast cancer at 32. I also have great aunts and second cousins who contracted breast cancer at a young age.My mother used to talk about some Jewish ancestors but even so it is very odd that the gene is still so dominant in the the family's DNA considering all of the intermarriage that has gone on since.DNA and genetics are obviosuly very complicated.

  • Mutd
    Mutd Member Posts: 148
    edited May 2010

    det6018, not all of the "Jewish" mutations are always Jewish. The one in BRCA2 is exclusively Ashkenazi Jewish, but the other two, in BRCA1, are common in many other groups. Just not quite as common as in people of Jewish origin.

     Your mutation (185delAG or 187delAG) has been known to emerge several times in the history of the humankind. One of these events must have been in the Jewish during captivity in Babylon, and from there it spread to many ethnic groups, some of them have no clues that they were Jewish. Like in Spain and Portugal, the Jews were forcibly converted 5 centuries ago, and then expelled to Spanish and Portuguese colinies where their descendants lost the knowledge about the family roots. So now the Babylonian mutation is found all across Latin America, and in India and other South Asian locations. But it wasn't even the only event when the mutation has been born. Some Brits have a completely different origin of their "same" mutation.

  • suz90
    suz90 Member Posts: 7
    edited May 2010

    Thank you for sharing your story. I was thinking about it over the weekend and I thought about how brave you are. Maybe the post below you can shed a little light. It is very complicated!

    Take care, Suzanne

  • MRDRN
    MRDRN Member Posts: 537
    edited June 2010
    What is sequencing? 
  • karen1956
    karen1956 Member Posts: 6,503
    edited June 2010

    I had the multi site 3 testing after I was Dx...it was negative...I asked the genetic counselor the likelihood of the full testing being positive she said that the multi-site 3 was where the mutation generally showed up in Askenazi Jews....as I was having a bilat, chemo, rads and ooph, my Tx would not be different if unfortunately, I had been positive....the difference would be for my daughters.

    Why does the geneticist want you to have the full blown testing...what purpose does it serve?  Congrats on 10 years!

    I agree with Helene...Sharsheret is a wonderful resource. 

  • tibet
    tibet Member Posts: 545
    edited July 2010

    I am Ethical Chinese, and have the BRCA1 mutation without any family history. Can someone tell me where this gene could possible come from?

  • Mutd
    Mutd Member Posts: 148
    edited July 2010

    Newalex, is your mutation the same one, called "187delAG"? It is common in India and Malaysia but probably very rare in mainland China...

  • HeleneS
    HeleneS Member Posts: 30
    edited July 2010

    I want to clarify for everybody that if a woman is negative or positive for a mutation that does not mean that her children do not have the mutation.  It is possible to inherit it from either parent.

  • Chocolaterocks
    Chocolaterocks Member Posts: 364
    edited December 2010

    Hi I am hoping someone will know this answer- since I won't get the results probably until next year due to the holiday.  As a Ashkenzi Jew with lots of BC in the family and LCIS atleast. I had testing and they just said that the 1st test in negative but waiting for the results of the 2nd. I signed for multi- ite- so does anyone know what I actually waiting for. BRCA 2?

    thanks so much. Happy Holidays!

  • HeleneS
    HeleneS Member Posts: 30
    edited December 2010

    There are about 1,000 different mutations they have located on the BRCA genes.  One of three of them occur in about 90 something percent of Ashkenazi Jews who have a BRCA mutation.  They test for those first because it is most likely that if you have a mutation you'll have one of those.  You're negative for those so the next step is to check for the hundreds of others (which you are much less likely to have).  Good luck!

  • suz90
    suz90 Member Posts: 7
    edited December 2010

    that is good news! I am very curious to see if they detect anything else but your chances are very low at this point of carrying a mutation. I did not have the 2nd test. I regret it now but at the time I was overhwhelmed. this is a big year being it's my 10th year cancer free. still I worry. mainly because I have young children. I suppose I should have just kept testing but at that point in time I froze and felt it was very unlikely. I do not have a huge history in my family but I also do not have a big family of aunts and sisters. please let me know the results. either way you are going to be fine. it's all about monitoring. happy new year!

  • Chocolaterocks
    Chocolaterocks Member Posts: 364
    edited December 2010

    hey thanks, I am really lucky they sent info  that I am negative for 2 mutations for BRCA 1 and 1 mutation for BRCA 2 so hopefully all else will be good.

    thanks so much.  I am fortunate that my insurance with much prodding and me pushing all physicians was able to have the test. I will let you know the final results.

    good holidays to all.

  • lilach
    lilach Member Posts: 1
    edited December 2011

    Hi,

    I'm not used to surf in this fortum, but got link to this message from a friend that asked me to reply.

    A disclosure: I am a genetic researcher that works in a private company in Israel, but I don't want to make advertisement to my company.

    The first question is why you want to find the responsible mutation to BC (if exists). If you want to check your relatives (for examples., yout daughters) to know who is in a risk and should do breast examination often - this is a good reason.

    But if you just want to know if you are have a hereditary risk to develop cancer again, it is not a good reason. I will explain: if the tests will find a mutation known as responsible to cancer, you will know that you are in a risk, and should be examined often. But if all genetic tests are negative, this does not promise that you are not a carrier of a mutatin that have not been checked! There are many mutations that may cause to cance, only part of them have been identified thus far by scientists. So it is simpler for you (if you do not have daughters) to not do the test, and just examine your breast and ovaries soon, every 6 month or even less.

    Regardind sequencing of the BRCA genes in Ashkenazi Jewish women: only a few percentages  (~3.5%) of Ashkenazi women with breast cancer have a BRCA mutation. 90$ of these mutations are the 3 mutations that you most probably checked. So the chance that you have another BRCA mutation that deserves an expensive sequencing of the whole two genes is low, and I would not recommend to do this test. By the way, when you consider which genetic tests to do, it is much better to consult with a genetic advisor/clinician and not with a physician. Today we know that only ~20% of Ahkenazi women that surely have hereditary breast cancer (because 3 or more women in the family had the disease) - have BRCA mutations, and 90% of the are 3 common mutations. This means that the other 80% women with BC have mutations in other genes! There are 44 genes that have been linked with BC thus far, but in the "old" method of sequencing, it is very expensive and not practical to sequence all of them.

    A new generation technology for sequencing have been developed during the  last years, and begins entering to the clinical diagnostic tests. Several companies today develop tests, based on the new technology, that will sequence many genes in parallel, at the same cost as the seqeuncing of BRCA alone today.

    So if it is not urgent for you, I would recommend that you will wait for about 6 months until  new generation sequencing of all the BC genes will be available, and do this test instead of sequencing BRCA1and BRCA2 alone.

    I  hope I helped.

    Have a happy and healthy new year!

  • Mutd
    Mutd Member Posts: 148
    edited December 2011

    Happy Hanukkah and New Year, Lilach!

    Thanks for sharing! So you think that there are BRCA1, BRCA2, BRCA3, and so on to BRCA44? An additional set of 42 genes for breast cancer which runs in families? And you say that every women with a family history of three relatives with cancer must have a mutation in one of the 44 genes? I find it very difficult to believe it, because not every cancer in cancer families is "genetic", and because a mutation is never shared by 100% of the relatives (usually it's 50% or less). Also, do you know how much stronger is the risk of cancer in the women with the "42 extra genes"? There are some already known "breast cancer genes" which increase the risk, but only by a few percentage points (one example is CHEK2). If your 42 genes are all like this, then are they really useful for anything practical?

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