Re: DNA testing-Need Help!
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In reply to:
DNA testing-Need Help!
Barbara Bognetti 5/16/08
Barbara, I have considerable experience in this area.I am very, very familiar with FA and with genealogy research.,It has nothing to do with the DNA testing for genealogy. Don't worry about anything anyone tells you about how many FA mutations there are, etc. That's not relevant.When a person is tested for FA, they are tested for every mutations there is a test for.
Forget using the FA genetic testing or DNA testing to trace FA in her family. It is a mistake to focus on the FA...what your friend needs to do is to just research her genealogy just as anyone else would. In doing so, if she tracks all her lines, she will know two of them were the carriers..she just isn't likelyto find out which ones. Unless she happens to come from a closed ethnic group, like the Acadians ("Cajuns"). The incidence of FA is higher in closed populations (i.e. ethnic groups who are somewhat isolated from other populations) where the incidence of intermarriage through multiple generations is higher.
The closest she will come to finding out which two grandparents it came through is to research herwhole pedigree and all their collateral lines, and if she findsyou find that her parents or grandparents are 2nd or 3rd 4th or 5th cousins, then track those lines back to a common ancestor ...that might tell you.Of couse, such an undertaking would take years, because it would be necessary to do your own research and stay away from the temptation to plug her into someone else's pedigree unless she has proved with genealogical standards that she belongs there, and also that the pedigree she's plugging in to can cite bonafide sources to confirm the data in every generations...not stuff lifted out of massive gedcom files a lot of people enjoy collecting--and those files are full of corrupted data. That's not research, anyway.
If your friend has a distance cousin with FA, that's helpful. Unfortunately, another aspect is that in "olden" times, someone with FA did not have the supportive care available today (i.e. corrections for scoliosis, treatment for pneumonia) so if the age of onset was fairly young, that person might not survive to even have children.Also, people died from so many different things at such an earlier age..childbirth, infection, appendicitis, flu...she probablycouldn't identify an FA ancestor anyway. She willalmost certainly find intermarriage, because it was the rule, rather than the exception, prior to 1900s, for cousins to marry...often 2nd cousins and sometimes first cousins. This wastrue for in all socio-economic levels. So unless she can find someone else in the pedigree confirmed to have FA, and trace that person to a common ancestor, it is highly unlikely she will ever know.It is just as likely there is no other incidence of FA in the her ancestry since it takes inheriting the gene from both parents.
Actually, it is estimated that the incidence of FA carriers is likely quite high...as high as cystic fibrosis. So even if there was FA testing for genealogy in a database, a larger certain percentage would test positive for FA without being related at all. The gene has likely come through many lines to the AMericas...it's been found all over the world.
Something else for her to consider is that family members may not be open with her about giving family history if she talks about the FA...there is considerable guilt in carriers, and this is difficult for them to address. It is better to just be interested in your family history,regardless, and approach them that way. There are articles online about how to interview the family. In fact, the National Ataxia Foundation published one I wrote with regard to genealogy reseasch in ataxia families. I have a copy of it on file and would be happy to send it to you if she is interested.
I hope your friend is a member of the National Ataxia Foundation...it is a wonderful resource for support and education. NAF gives a lot of money to support FA research. There is a large component of FA members, in addition to people with othe kinds of inherited ataxias. My family is associated with SCA3, and I've been active in NAF for many years. It holds a wonderful national membership meeting every year, at which leading ataxia researchers come to present info on latest research. It's 2-3 days long, with lots of othe helpful seminars and fun social events. There are usually abt 500 in attendance and the location is in a different part of the country each year, to give everyone a chance to attend at least once in a while, if not annually. It is going to be in Seattle in March or April of 2009; 2010 in Chicago. This year it was in Las Vegas, last year in Memphis, the year before in Boston, the year before,Tampa. She can check out the NAF website at
Hope this info helps. If I canhelp in any way, please just ask. Dianne Blain Williamson, BSN,MSW, RN, volunteer Ambassador for AL-TN, National Ataxia Foundation (Minneapolis).