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Archiver > GENEALOGY-DNA > 2003-03 > 1046550729


From: Max Blankfeld <>
Subject: Re: [DNA] DYS454 & DYS455: Different Scores from FTDNA & RG
Date: Sat, 01 Mar 2003 14:32:12 -0600
In-Reply-To: <20030301091335.36825.qmail@web41215.mail.yahoo.com>


Dear David and Charles,

Here is our answer and observations to your question and comments:

Charles is right when he says that the lab at the U of Arizona was the
discoverer of these markers.

Dr. Alan Redd, U of Arizona, to be more specific, is the discoverer of
these markers (as well as a few more that Family Tree DNA has been using
and are now being included in our competitors' panel of markers).
It is gratifying that other labs in this industry has decided that novel
markers discovered at the U of A are of such value that they should be
added to their systems...We are pleased by that fact as, perhaps, a test
standard will develop one of these years. The nomenclature is the right and
responsibility of the discoverer to create, and all other labs are expected
to follow that literature, which, therefore, creates the standard.

Since the paper on this marker was written at the U of A, by the U of A,
and published in Forensic Science International, and lists Mr. John Butler,
National Institute of Standard, as a co-author, we at Family Tree DNA
seriously question any results that don't mimic, exactly, the results
produced in the lab that these markers were discovered and are being tested
today, daily.

The problem for accuracy in Ybase is of some concern. With the users not
being sure that they are placing in Ybase the correct values, this tends to
devalue the effort, an issue that we have discussed in house many times.
This is the reason that when FTDNA sells a 'conversion kit' we re-run the
entire string and place in our database the results we obtain from the
Hammer lab, regardless of the other labs original findings. We ask the
person joining our system to provide us the other labs' results so we have
a constant reality check on the accuracy of results being produced by
others in this industry.

Finally, in answering to the issue of "ambiguity" that was raised in
another e-mail, our suggestion would be as follows: if a lab other the lab
that discovered the markers feels that their reading of the data is
ambiguous, then, before giving the results to their customer, they should
contact the discoverer of the markers, the author of the paper about the
markers, and clarify the question of ambiguity.

I hope this answers you question.

Thank you
Max Blankfeld
Director of Marketing
http://www.FamilyTreeDNA.com

"History Unearthed Daily"




At 01:13 AM 3/1/2003 -0800, you wrote:

>We all depend on the accuracy of the tests performed by the labs that we
>chose to analyze our DNA. Even one error in a set of 25 or 26 scores
>could have serious consequences when we are searching for "matches"; or
>could undermine the efforts of those doing surname
>studies. Unfortunately, it appears that there is inconsistency in the
>scores being reported by two labs.
>
>I have had the full Y-Chromosome STR testing done by two prominent labs -
>25 and 26 markers respectively. Some of the loci measured are the same,
>some are different. It goes without saying that the values for the loci
>that are same should be identical.
>
>In comparing the overlapping loci I find that for DYS454 FTDNA reports a
>score of 11; RG a value of 10. Similarly for DYS455 - FTDNA = 11; RG = 10.
>
>Both cannot be correct. There must be a calibration problem or some other
>type of factor which is distorting the results provided by one (or both?)
>labs.
>
>Perhaps it doesn't make much difference for those who are using only one
>lab for their surname study - assuming that if the value is wrong, it is
>consistently wrong. However, many of us wish to compare our true scores
>to world - wide data bases. Which numbers should I put on the Ybase site?
>
>I am requesting that a representative from each of these companies comment
>on this perceived problem. Thank you.
>
>David K. Faux.

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