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Archiver > GENEALOGY-DNA > 2007-12 > 1199123492


From: Thomas Krahn <>
Subject: Re: [DNA] STRs in WOY regions > MSI
Date: Mon, 31 Dec 2007 11:51:32 -0600
References: <11985d4c0712291203s44d3bd95l7abbffd6e7dafa01@mail.gmail.com><IGEOKAGLHNEKPCKPADIGEENIABAB.bbailey.lowedna@baileyconnection.com> <11985d4c0712291324ubd15c05sef7d91bc8b7994e@mail.gmail.com><00e501c84a62$8d998c80$6400a8c0@Ken1> <4778087C.1090103@comcast.net><008501c84b2c$d0896a90$6400a8c0@Ken1> <47784C4E.2040008@comcast.net><000001c84b75$3d06ece0$0100a8c0@john> <4778A47A.40604@familytreedna.com><001301c84b93$7d993f10$0100a8c0@john>
In-Reply-To: <001301c84b93$7d993f10$0100a8c0@john>


Dear John,

I said "POSSIBLY the age of the person" because there was a discussion
in the scientific community if this was related to the person's age.

Microsatellite instability (MSI) is known to be related to some types of
cancer, but only in a very late stage.
See: http://en.wikipedia.org/wiki/Microsatellite_instability
However, some people show a certain degree of MSI even though they're
perfectly healthy.

I couldn't confirm a high stutter ratio when testing persons above 90
years of age, but possibly the chance of observing MSI in older
individuals is slightly higher than in children.
However this difference will mainly depend on the concrete individual.
So I wouldn't really consider age as an important factor for selecting a
participant for the WOY project.

Thomas


Alister John Marsh wrote:
> 1) IS AGE OF DNA DONOR IMPORTANT FOR WOY:
>
> One thing which stood right out was your comment...
>
> " Sequencing quality may go down so that one can't even count
> the repeats in those cases. But in some other cases we have had
> perfectly clean reads through the whole STR. It also depends on the
> individual (possibly the age of the person)."
>
> I was considering testing a particular family on WOY. The DNA in store at
> FTDNA, is for an older person. Generally, I recommend to participants that
> they test the oldest member of a family, and some have been pushing 90.
> Given the type of test for WOY, and given that cost might limit the number
> tested, should we be selecting as a preference those of a particular age
> group? Say under 10 years, 10 years to 20 years, 20 years to 30 years, or
> under 50 years?
>
> Also DNA in store for the family I would like to WOY test was submitted a
> number of years ago. I understand that some modern test kits give better
> quality DNA for extensive testing such as WOY. For WOY, do you envisage
> getting a new higher quality DNA sample from the participants, given the
> complexities of the WOY type of test? If so, there might be an opportunity
> to focus on a family member in the optimum age group to give best results.
>
>

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