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Archiver > GENEALOGY-DNA > 2005-10 > 1129386611


From: Thomas Krahn <>
Subject: Re: [DNA] Autosomal & XSTR Testing
Date: Sat, 15 Oct 2005 16:37:13 +0200
References: <20f.b5ca2c1.307d2b71@aol.com>
In-Reply-To: <20f.b5ca2c1.307d2b71@aol.com>


(I have written this reply on 10/11/2005, but for some reason it didn't
get onto the list. Sorry for the delay!)

Dear Robert,

Autosomals and XSTR are still only useful in specialized cases. We
mainly offer autosomal STRs because we test them anyway in our paternity
testing business. For genealogical purpose autosomal STRs are at the
moment only useful for experiments. E. g. to observe the geographical
distribution of your own fingerprint in comparison to the multitude of
forensic population data. I personally don't see much evidence that with
autosomal markers very much can be said, because most people don't have
ancestors just from a single region, but from different places in the
world. So if you try to calculate a "vector" that should point to your
geographical origin from your autosomal alleles, this vector will point
somewhere between the two or more regions of your origin. This region
might have nothing to do with the two or more real parts of the world
where your ancestors are really comming from. Anyway, experimenting with
one's own autosomal profile might be interesting for some people to
learn more about the capabilities and limitations of biogeographical
prognoses from autosomal DNA markers. Some people (including me) have
published their autosomal STR profiles on our website, so if you want,
you can try to run some virtual experiments with real autosomal STR data
before you decide to order your own autosomal profile. I have extended
the OmniPop spreadsheet from the NIST homepage to show the 166
population as dynamically shaded dots on a world map. If you're
interested, I can send you the Excel file for free. There is a tiny
description also on my website:
http://www.dna-fingerprint.com/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=10

There is probably a very high potential for future biogeographical use
of XSTR markers, because the dilution process happens only in every
second generation in a male-female-male-female etc. line. The XSTR
markers that I have developed (Penta X12, Penta X13, Penta X15, Penta
X16) are the most polymorphic pentarepeat STRs that I've ever seen on
any chromosome. Some of the markers are located in lose proximity on the
X chromosome and behave like linked micro-haplotypes that are stable
over a few generations. This could help finding out more about the mixed
female line in conventional genealogy. You can never be sure to hit the
right line for your haplotype, but if it matches, this can be a very
strong proof of evidence.
The problem with XSTR however, is that there don't exist any good
databases on the web to search for hits, yet. There is just a small
group of scientists working on XSTR. E.g.
http://www.med.uni-magdeburg.de/chrx/forensic_chrx.htm

Feel free to ask me directly,

Thomas

--
DNA-Fingerprint Tel.: +49-3329/697464
Fasanenstrasse 25a http://www.dna-fingerprint.com
14532 Stahnsdorf / Germany mailto:



wrote:

>What do you folks think about the usefulness, efficacy, relevance,
>benefits/detriments, etc. of:
>
>1) Autosomal testing
>
>2) XSTR testing
>
>If it matters, I am thinking of doing DNA-Fingerprint's Autosomal panel and
>their two XSTR panels. Not exactly sure, however, what it does for me.
>(DNA-FP's web site is not informative on this matter.)
>
>Regards,
>Robert Birnbach
>
>
>
>
>==============================
>View and search Historical Newspapers. Read about your ancestors, find
>marriage announcements and more. Learn more:
>http://www.ancestry.com/s13969/rd.ashx
>
>
>



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