GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2010-03 > 1269811323


From: Vincent Vizachero <>
Subject: Re: [DNA] 23andme cousin results
Date: Sun, 28 Mar 2010 17:26:46 -0400
References: <CCC182DA-E426-430A-BA37-355BD4D5E8AD@earthlink.net><ea3bd9561003272128k3b567d83y190aeb937b77803b@mail.gmail.com><253CFBB8-15B8-4B84-81E5-A4F86DEEC8D7@earthlink.net><ea3bd9561003280921v52a58139o5e8c730e640c5c7f@mail.gmail.com><00d901cace95$a4b8bda0$5e82af48@Ken1><CB6050F2-F6A2-4324-A8E2-060B8829AD1E@earthlink.net><D7B87A3F-726C-41FA-9C5C-B230DEE984A6@vizachero.com><7A2FB73D-4FDA-48A0-A3A7-E084FC6086BD@earthlink.net>
In-Reply-To: <7A2FB73D-4FDA-48A0-A3A7-E084FC6086BD@earthlink.net>


The percent match between a child and one of its parents will depend
on how closely related the parents are to each other, and also on the
set of SNPs compared. But given the array of SNPs in use today, yes
80-85% would be pretty typical.

And even a full genome sequence would not reveal a match as low as 50%
between parent and child. While it is true that a child INHERITS only
50% of its DNA from each parent, if the the two parents themselves
have any SNPs in common (and they literally have to) the match between
parent and child will be >50%.

VV


On Mar 28, 2010, at 4:42 PM, John Carr wrote:

> I see what you mean, so the anticipated % comparison between a child
> and the parent or two siblings is really ~85%, not the 50% that is
> often quoted. The 50% refers to the entire genome, not the
> anticipated match within the selected SNPs used to make the
> comparison.


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