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Archiver > GENEALOGY-DNA > 2006-09 > 1159615696


From: valery <>
Subject: Re: [DNA] mtDNA difference between sibling
Date: Sat, 30 Sep 2006 11:28:16 +0000
References: <mailman.750.1159557351.20866.genealogy-dna@rootsweb.com><06CA4F49-8BA1-4030-99A7-CFC61D0D3847@earthlink.net>


Dear Linda,


there is absolutely no need to worry about it. The difference between 2
lineages is not so huge as it once seems.

First, 309th site belongs to one of the C-tracts where even close
relatives may differ. That's considered to be regular or at least
possible. For the examples, read Santos' 2005 paper, where you'll find
one of the most recent statistics on the subject. In more than half of
all transmissions they described, mother and child appeared to be
different at the "lighweight" sites such as C-tracts, at least in some
portion of their mt genomes. Moreover, in several families the authors
detected more stable differences between members, differences that
involve all genomes (so called homoplasmic differences) and the
"heavyweight" differences (sometimes even in all mt molecules). Your
case falls into the intermediate category: different С-tracts in
homoplasmic state. It seems hard to determine what is the exact
percentage of such events in the whole population, since the pedigree
studies are still expensive, and the clone sequencing technique (to
detect heteroplasmy) is even more expensive. To conclude, I'd say,
309th site alone is not a reason for resequencing: you may choose to do
that or leave all unchanged.

The second point is 16428 state. In 2003 Moilanen published 2 complete
Finnish sequences, AY339528 and AY339529. They differ only in one site,
it's 16428. The "longer" sequence (AY339529) limited to HVS area, is
the same as yours, so the "shorter" one (AY339528) has HVS identical to
your sister's HVS. More surprising, these 2 sequences are the only ones
completely sequenced U5s with the transitions at 249/16428. Then I
queried the database of HVSs though there is very little certainty to
find anything interesting because most authors limit the HVS1 area to
16400 site and do not use HVS2 at all. Here the results - all published
to date U5a variants with 16428 or 249:


Shetland, Goodacre 2005, 192-256-270-362-399-428, no HVS2
Britain, Tonks 2006, 153-256-270-362-399-428, no HVS2
Iceland, Helgason 2003, 192-256-270-362-399-428, 73-263-315.1C
Argyll, Sykes 2006, 256-270-362-399-428, no HVS2
Central England, Sykes 2006, 192-256-270-362-399-428, no HVS2
Highland, Sykes 2006, 192-256-270-362-399-428, no HVS2
Caucasian American, SWGDAM, 192-256-270-362 (sequenced between 16024
and 16365), 73-249-263-315.1C

Nothing indicative, except for clear Northern trend in the
distribution. Helgason's variant lacks 249 which contradicts with
Moilanen's findings: none of these mutations (249 and 16428) can be
considered as a further branch on the U5a tree because there is 249
without 16429 and 16428 without 249. On the other hand, the difference
between the 2 complete sequences in only one site seems suspicious,
taking into account that it is a rare site. So, in my view, the most
"parsimonious" answers are the following: 1) either Moilanen overlooked
16428 in one of the samples (so Helgason did 249) or 2) 16428 is very
unstable position in U5a background. I'm more inclined to advocate the
first possibility, until there will be a study with reliable sample
size where the strange behaviour of 16428 becomes proved.


Linda, as it was already pointed here, the best way is to resequence
the "deviant" sample, or at least to check the traces again: more
likely, they overlooked 428 in the lab. Anyway, it is much more
possible than to adopt a child with near exactly the same mt molecule.


Valery













On 29/09/06 23:57:52, Linda R Romero wrote:
> The Excel spreadsheet didn't come through the web properly. Below is
>
> another attempt to clarify what is what. Sorry about that.
>
> LINDA:HVR1 16192T, 16256T, 16270T, 16362C, 16399G,
> 16428A
> HVR2 73G, 249G, 263G, 315.1C
>
> RITA:HVR1 C16192T, 16256T, 16270T, 16362C, 16399G
> HVR2 73G, 249G, 263G, 309.1C, 315.1C
>
> RICK:HVR1 16192T, 16256T, 16270T, 16362C, 16399G,
> 16428A
> HVR2 73G, 249G, 263G, 315.1C
>
> HEIDI:HVR1 16192T, 16256T, 16270T, 16362C, 16399G,
> 16428A
> HVR2 73G, 249G, 263G, 315.1C
>
> I hope this is easier to read.
>
> Linda
>
>
> On Sep 29, 2006, at 2:15 PM, wrote:
>
> > Message: 8
> > Date: Fri, 29 Sep 2006 13:05:31 -0500
> > From: Linda R Romero <>
> > Subject: [DNA] mtDNA difference between siblings
> > To:
> > Message-ID: <>
> > Content-Type: text/plain;charset=US-ASCII;delsp=yes;
> format=flowed
> >
> > I sent the following letter to my sister and my cousin. Would
> > someone please look our results over and comment on the differences?
> > Linda, Rita, and Rick are siblings listed in birth order. Heidi is
> > our mother's first cousin.
> >
> > Thank you
> > Linda
> >
> >
> > Dear Rita and Heidi,
> >
> > Our mtDNA should all be the same. When Rick's and mine differed, I
> > had the test I took in 2002 redone. This time, they came up with
> the
> > same results as Rick's test did. While waiting for my new test
> > results, a big sale from Argus came online and I asked you two to be
> > tested, also. Below are the results of those tests and Rick's and
> > mine. We are all descended from the same woman, our most recent
> > common ancestor (MRCA). Our MRCA is Heidi's grandmother who is also
> > Linda, Rita, and Rick's great-grandmother.
> >
> > I am checking further as to why Rita's mtDNA is different. MtDNA
> > changes very slowly, over thousands of years. Accordingly, we
> should
> > all be the same.
> >
> > My test was originally run and then retested by Relative Genetics.
> > Rick's was done by FamilyTreeDNA, and both of yours were done by
> > Argus Bioscience. That really shouldn't make any difference.
> >
> > When the most recent tests were done for Linda, Rita, and Heidi, I
> > requested that the testing facilities watch for heteroplasmy. None
> > was found. I also requested that FTDNA check Rick's findings for
> > heteroplasmy. However, FamilyTreeDNA has not gotten back to me yet
> > on rechecking Rick's test.
> >
> >
> > LINDA
> > RITA
> > RICK
> > HEIDI
> > HVR2
> > 73G
> > A73G
> > 73G
> > A73G
> >
> > 249G
> > A249G
> > 249G
> > A249G
> >
> > 263G
> > A263G
> > 263G
> > A263G
> >
> >
> > 309.1C
> >
> >
> >
> > 315.1C
> > 315.1C
> > 315.1C
> > 315.1C
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > HVR1
> > 16192T
> > C16192T
> > 16192T
> > C16192T
> >
> > 16256T
> > C16256T
> > 16256T
> > C16256T
> >
> > 16270T
> > C16270T
> > 16270T
> > C16270T
> >
> > 16362C
> > C16362C
> > 16362C
> > C16362C
> >
> > 16399G
> > A16399G
> > 16399G
> > A16399G
> >
> > 16428A
> >
> > 16428A
> > G16428A
> >
> >
> >
>
>
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