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Archiver > GENEALOGY-DNA > 2008-06 > 1213556256


From: Robert Stafford <>
Subject: Re: [DNA] How could we tell?
Date: Sun, 15 Jun 2008 11:57:36 -0700 (PDT)
In-Reply-To: <20D4D0C2-20B8-49E9-ACF7-3C6A0ED2B455@verizon.net>


Most of the pedigrees in the database are for people still living, so I don't know what that has to do with the situation. However, we know that occasionally immediate family members don't match. If you think the results are wrong, retest. Don't cast aspersions about an organization before gathering your facts.

It should have been clear from the context that I knew they were not just one-marker mismatches.

Bob Stafford





Bill Howard <> wrote:
Definitely not. The pedigrees are for people now living!
I agree with your second sentence, but it does not apply here.
These are NOT one marker mismatches. They are from completely
different sets.
That lends much credence to my contention that SGMF mixed up either
the samples or the pedigrees.
- Bye from Bill Howard

On Jun 15, 2008, at 2:28 PM, Robert Stafford wrote:

> I would say that two sample switches in one group is much more
> unlikely. Many people have tested at both SMGF and other firms with
> matching results. There have been a few mismatches on one marker
> reported. Usually, it was found to be the other firm. Thus, it is
> much more likely that the pedigree is wrong.
>
> Bob Stafford
>
> Bill Howard wrote:
> Not matching one doesn't prove a mistake, but not matching two out of
> ten seems most suspicious......
> - Bye from Bill Howard
>
> On Jun 15, 2008, at 12:54 PM, Robert Stafford wrote:
>
>> Not matching a pedigree doesn't prove a mistake. Afterall, that is
>> why we are testing. You need to have them retested elsewhere to be
>> sure.
>>
>> Bob Stafford
>>
>>
>> Bill Howard wrote:
>> Just a short note about my experience at SMGF - I sent in 10 samples
>> in August 2005 and the results were not posted for more than a year.
>> Some, but not all could later be identified on their web site.
>> However, they made bad mistakes on two of the samples, due, I think,
>> to sample switches, and I made many phone calls to people named
>> Angela, Anna, and Karen. The pedigree did not match the relationships
>> indicated by the test. My phone calls were taken with courtesy and I
>> was told to wait. I waited and waited and waited. More phone
>> calls...... nothing done although I told them exactly what was wrong
>> and they all promised to look into it. Yes, I could have paid money
>> to
>> get the results, but if the samples had been switched, it would not
>> have done any good.
>> That's a 20% error rate in my book.
>> - Bye from Bill Howard
>>
>>
>> On Jun 14, 2008, at 1:10 PM, Robert Stafford wrote:
>>
>>> It is hard to tell what the lab error rate is, since most errors are
>>> not reported publically. However, I suspect there are a lot more
>>> than people think. I have seen about 20 posts about errors here and
>>> on Genforum. I have also private reports from people about errors.
>>> One big problem seems to be clerical errors. I am not clear where
>>> they occur, unless the firms post results to their web sites
>>> manually.
>>>
>>> There are probably many actual lab errors on single markers that
>>> have not been discovered. They would probably not arouse suspicion
>>> and would be discovered only if the person retested. DYS464 seems to
>>> be a big problem, because the relative peak heights are used. I
>>> think it is a good idea to retest at www.smgf.org, if there is a
>>> mutation from the ancestral haplotype. It is a worthwhile project
>>> anyway.
>>>
>>> One of the biggest problems, according to a person who works at a
>>> lab, is sample switches, often on just one panel. I have seen
>>> several cases posted. For people working within a documented
>>> genealogy, they immediate arouse suspicion. However, a loner might
>>> get bad results and never know.
>>>
>>> Bob Stafford
>>>
>>
>>
>> "History is the consensus of survivors in authority"
>> "Reality is the weighted mean of individual perceptions"
>>
>>
>>
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>
>
>
> "History is the consensus of survivors in authority"
> "Reality is the weighted mean of individual perceptions"
>
>
>
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"History is the consensus of survivors in authority"
"Reality is the weighted mean of individual perceptions"



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