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Archiver > AUTOSOMAL-DNA > 2014-04 > 1397416947


From: "Tim Janzen" <>
Subject: Re: [AUTOSOMAL-DNA] What do these Larg cM & SNP numbers mean?
Date: Sun, 13 Apr 2014 12:22:29 -0700
References: <mailman.1442.1397179830.3798.autosomal-dna@rootsweb.com> <ohRd1n00g3PP5pu01hReQo><78D40E425E5344DC8C1F43AE001084C2@ownerPC><62BDC997-7CEC-4443-BDCA-7A6C5C98DF91@verizon.net>
In-Reply-To: <62BDC997-7CEC-4443-BDCA-7A6C5C98DF91@verizon.net>


Dear Jim,
When using 23andMe data since June 2013 when 23andMe converted to
Build 37 I divide the total cMs by 74 to get the percentage of the genome
that two people share. There are 7438.6 cMs when combining the autosomal
DNA and the X chromosome per Family Inheritance: Advanced. There are 7074.6
autosomal cMs per 23andMe. When using FTDNA's Family Finder I divide the
total number of autosomal cMs by 68 to get the percentage of the autosomal
genome that two people share. There are 6766.2 autosomal cMs per FTDNA. If
you want to include the X chromosome in the calculations, then there are
7158.06 cMs in the entire genome. Therefore divide the total number of cMs
by 71.6 to get the percentage of the entire genome that two people share.
The above numbers are applicable to females, who have two X chromosomes.
The number of cMs (atDNA and X combined) will be lower for men. Men in
23andMe have 7256.8 cMs when combining the atDNA with the X chromosome. Men
in Family Finder have about 6962.13 cMs when combining the atDNA with the X
chromosome.
Sincerely,
Tim Janzen

-----Original Message-----
From:
[mailto:] On Behalf Of Jim Bartlett
Sent: Friday, April 11, 2014 3:31 PM
To:
Subject: Re: [AUTOSOMAL-DNA] What do these Larg cM & SNP numbers mean?

The fudge factor at 23andMe is 72 (as I recall). So 72x2.88 ~ 207cM - pretty
close to a 2C. Their sum is of segments 5cM and more.

Because the don't include Chr X at FTDNA, the factor there is 67 (from
memory). Their sum includes segments 1cM and more.


Jim -


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