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Archiver > GENEALOGY-DNA > 2003-03 > 1046533497


From: Charles <>
Subject: Re: [DNA] DYS454 & DYS455: Different Scores from FTDNA & RG
Date: Sat, 01 Mar 2003 10:46:03 -0500
References: <20030301091335.36825.qmail@web41215.mail.yahoo.com>


Dear David,

A member of my Kerchner surname project has had exactly the same problem
occur with the same two markers. Three members of our project have been
tested by FTDNA and RG. The first two were tested a year ago when RG was
not testing marker DYS454 and DYS455 and thus the results for those two
markers are not available to me for the earlier testees. In the past 6
months a 3rd member of my project submitted his sample to RG to gain
more markers for comparison. And to his and our surprise and confusion
RG gave him results for DYS454 and DYS455 which were not in agreement
with FTDNA's results. FTDNA got 11 and RG got 10 for each of those
markers. I suspect that RG has a calibration problem on these
"new-to-them" markers. On all the other common/shared markers by the two
labs the results have agreed. I think RG has a problem with calibration
in their use of these two new markers in their lab.

I believe that FTDNA's lab at University of AZ was the
discoverer/definer of markers DYS454 and DYS455. Since they have the
most experience with the marker I am going to trust FTDNA's results and
assume that RG has a calibration problem. I and my participant have
called RG and discussed this issue with them on behalf of the
participant in my group. They said they would look in to it but offered
no logical explanation other than some vague comments to my participant
about "lab differences and the need for industry standardization". Not a
very scientific answer, in my opinion. Personally I think the problem is
with RG's lab calibration and protocol for testing these new markers in
their offering.

Charlie Kerchner


David Faux 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.
>
>
>
> Dr. David K. Faux, 4028 Larwin Ave., Cypress, CA, 90630, USA
>
>
>
>
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