R1b1c7
haplogroup M222 SNP aka North West Irish Variety, IMH and R1bSTR19Irish
John McEwan
20th
May 2006
Background
M222 is a R1b1c subclade SNP first reported in 1999. Links to references
about the SNP are available at the ISOGG SNP index along
with its position in the R1b portion of the ISOGG tree. The SNP was
tested in very few studies to define its prevalence and geographical spread.
The exception was Cinnoglu et al 2004 who found no
derived individuals in 523 individuals in Turkey. One reason for the lack of
testing was that it had been spuriously associated with reduced fertility from
the paper by Sun et al. 1999, which close reading does not support. In Feb 2006
the probable association of this SNP was made with the North West Irish Variety
STR defined haplotype group, first identified by David
Wilson in 2004, and subsequently separately and formally reported by Moore
et al. 2006 who named it IMH or Irish Modal Haplotype.
This STR based group is the most divergent and distinct STR cluster in
R1b and members of the cluster from the 37 FTDNA marker “phase 3” analysis
using data extracted from Ysearch in August 2005 can be seen here (also named R1bSTR19Irish). Its STR
modal values have been estimated, as has
its diversity and estimated age based on ASD measurements,
and its geographic distribution.
Briefly it makes up around 20% of R1b of Irish origin and is also
prevalent in western Scotland. The data of Moore et al. (2006) who used more
restrictive criteria in defining the cluster suggested it is very prevalent in
North West Ireland, and based on its association with surnames they
demonstrated a significant association with Ui
Neill descendants (these are descendants of Niall of the nine hostages an
extremely famous Irish King of the 5th century AD). The cluster is
about 46% of the age of R1b and is most likely at least 3400 years old based on
extremely conservative assumptions. Much more has been written and speculated
about this SNP on the Genealogy DNA listserver.
SNP testing to date has shown a remarkable correlation between M222+
individuals and the R1bSTR19Irish cluster, with 16 publicly positive
individuals out of 47 tested all of which fall within this cluster. In fact
they display almost identical properties to the R1bSTR19 cluster previously
defined above. Around 40 negative results have been reported and they cover a
major part of the balance of R1b. It is still possible that M222+ individuals
exist outside of this cluster but they are rare.
Unfortunately, the various names for this group are used interchangeably
when more caution should be exercised. The North West Irish Variety and
R1bSTR19Irish are essentially equivalent, M222+ appears to date to also be
largely equivalent as well, but a greater number of individuals need to be
tested. The surname derived IMH of Moore et al (2006) in contrast is more
difficult to compare unless additional testing is undertaken. However, it is
likely to represent a smaller less diverse subgroup.
Data summary
To graphically display the results to date, 37 STR haplotypes of
individuals who have also been SNP tested as either: R1b1c6 (SRY2627+), R1b1c7 (M222+), R1b1c9 (S21+), R1b1c10 (S28+) or
R1b1c(xR1b1c6,R1b1c7,R1b1c9,R1b1c10)
were joined with the phase 3 modal
haplotypes and the 184 individuals who were clustered within R1bSTR19Irish group in that analysis.
These were then clustered using the same criteria as that analysis and the
resulting tree is presented in the attached file.
Results
The most striking things about the results are:
·
All M222+ individuals fall within the R1bSTR19Irish
defined group
·
Only one R1bSTR19Irish member did not cluster in this
group in this analysis suggesting it may be improperly assigned.
·
The M222+ individuals are present in most of the major
sub-branches of the R1bSTR19Irish cluster.
·
In contrast R1b1c6, R1b1c9 and R1b1c10 subclades are
much less well defined by 37 STR markers, although R1b1c9 has several distinct
groups.
References
Moore
LT, McEvoy B, Cape E, Simms K, Bradley DG. 2006. A Y-Chromosome Signature
of Hegemony in Gaelic Ireland. Am. J. Hum. Genet 78:334-8
Sun, C.
, Skaletsky, H., Rozen, S., Gromoll, J., Nieschlag, E., Oates, R. & Page,
D. C. 2000. Deletion of azoospermia factor a (AZFa) region of human Y
chromosome caused by recombination between HERV15 proviruses. Hum. Mol. Biol.
9: 2291-2296.
Sun,
C., Skaletsky, H. Birren, B., Devon K., Tang, Z., Silber, S., Oates R.,
Page, D.C. 1999. An azoospermic man with a de novo point mutation in the Y-chromosomal
gene USP9Y. Nature Genetics 23: 429-432
UNDERHILL,
P. A., PASSARINO, G., LIN, A. A., SHEN, P., MIRAZON LAHR, M., FOLEY, R. A.,
OEFNER P. J., CAVALLI-SFORZA, L. L. 2001. The phylogeography of Y chromosome
binary haplotypes and the origins of modern human populations. Ann. Hum. Genet.
65: 43-62