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Archiver > GENEALOGY-DNA > 2005-06 > 1119714332


From: Thomas Krahn <>
Subject: Re: [DNA] Question about DYS 464
Date: Sat, 25 Jun 2005 17:51:00 +0200
References: <000a01c57984$b5c5f2e0$fd2ffea9@pierce>
In-Reply-To: <000a01c57984$b5c5f2e0$fd2ffea9@pierce>


brad pierce wrote:

> That member is the only one in the group who has marker 464e. (...)

Dear Brad,

Nobody has answered your questions, yet. So I guess it is my turn to
step in:

I don't want to critizize other companies and I am pretty shure, that
they have checked the electropherograms several times, if they send out
a result with 5 DYS464 alleles. Anyway it would always be very
interesting to see the raw electropherogram or to get at least the peak
heights from the lab that has performed the analysis to get an
impression what guided them to that decission.

The haplotypes look pretty similar, so there is no doubt that the two
persons are closely related. Some scientists suggest to count ANY change
at a DYS464 allele as a one step genetic difference. It doesn't matter
how many steps are really involved and how complex the change may be.
This isn't less accurate than making up complicated theories which
allele really has changed in which direction, because funni things
happen at the DYS464 marker. It seems that genetic recombination and
some kind of "loss of heterozygosity" plays a mayor role in the changes
of DYS464 alleles.

However, I have been allways interested in what is really happening at
the DYS464 cluster. That's why I have developed a method to type at
least one of the DYS464 alleles separately. The drawback of this
DYS464-Extended analysis is, that it only works for R1b males. In your
case, both participants are R1b. So you're lucky, that the new DYS464X
test could work with their DNA. I have explained the extended DYS464
analysis in an earlier posting to this list:

http://archiver.rootsweb.com/th/read/GENEALOGY-DNA/2005-05/1117149512

If you have more questions on DYS464X, then feel free to ask.

Some more answers to your questions:

> Does a mutation that allows an extra copy of 464 ever reverse itself? Can one have an ancestor with a 464e copy that has descendants that have four copies?

It is possible, that we really see a somatic mutation in the DYS464
pattern. A somatic mutation isn't changing the germline cells and thus
it isn't passed to the next generation. In this case I would even
suggest a genetic distance of 0.5 for the DYS464 cluster.

> Will we likely find related families to group H (with the 464e marker) that do not have this marker?
I strongly suggest, that he is related to group H. You can even verify
this by testing the remaining markers at H.

Best regards,

Thomas Krahn



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