Archiver > GENEALOGY-DNA > 2004-11 > 1101781625

From: Philip Ritter <>
Subject: A 2-step mutation in one generation
Date: Mon, 29 Nov 2004 18:27:10 -0800

We just got word from FTDNA confirming that we have a two step mutation on
DYS385a in a single generation. One of our participants in the Hamman
project had a value of 9 repeats at this marker, while a cousin several
times removed had an value of 11. Another Hamman not previously unknown to
be a co-lineal was also a perfect match on 25 markers with the participant
who had the value of 11. Since 11 is the common value for R1b haplogroup
members (the haplogroup to which these related folks clearly belonged), I
suggested to participant 14722 that his line probably had had a mutation or
two. He recruited his brother (and lined up a couple of others to possibly
take the test). The results for the brother came back with a value of 11
at DYS385a. I just got an email from FTDNA (below) confirming that the
value of 9 is correct for the original participant. So clearly there has
been a two-step mutation for one brother but not the other. The FTDNATiP
calculator estimates that there is only a 6.8% chance that these two
brothers share a common ancestor in the last 100 years, but of course this
is an example of a rare event having occurred. The results can be seen at

>From: Catherine/FTDNA <>
>Subject: Kit 14722
>Per your request the lab pulled the pherograms for kit 14722. The lab
>report shows that the pherograms were called correctly and the scores were
>correct as called.
>Catherine McDonald
>Family Tree DNA
>"History Unearthed Daily"

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