# Haplogroup R-DF27

In human genetics, Haplogroup R-DF27 (R1b1a2a1a2a) is a Y-chromosome haplogroup which is a subdivision of haplogroup R-M269 (more specifically, its subclade R-) defined by the presence of the marker DF27 (also known as S250). Along with R-U152 and R-L21, the lineage is to a significant extent associated with Proto-Celtic, Celtic and later Celtiberian movements.
It arose comparatively recently, after the beginning of the European Bronze Age, and is mostly prevalent in the population of the Pyrenees region. The regions where it has been mostly found are Basque Country, Navarre, Asturias, Galicia, Portugal, Aragon, Catalonia, Pyrénées-Atlantiques as well as some presence in Great Britain and Ireland, though it has been found in smaller quantities as far away as Germany and Poland.
Specific subclades of DF27 have been associated with specific groups of people, for example R-M167 is associated with the Catalans and R-M153 is associated with the Basques.

## Genetic testing

The technology to test for DF27 was developed by Thomas Krahn, then of Family Tree DNA. This marker was discovered to exist among people who had taken part in the Human Genome Diversity Project. Richard A. Rocca made a pioneering study of DF27, which was published in 2012 in the article Discovery of Western European R1b1a2 Y Chromosome Variants in 1000 Genomes Project Data, in the peer-reviewed journal PLOS Biology. He based his study on 208 people who had tested as R-M269 and were from Great Britain, Tuscany (Italy), Spain, Finland, Utah (United States) and Latin American (Colombia, Puerto Rico, etc).

## Distribution

According to a 2017 article published in Springer Nature entitled, Analysis of the R1b-DF27 haplogroup shows that a large fraction of Iberian Y-chromosome lineages originated recently in situ, DF27 was found in frequences of 40% in the general population of the Iberian Peninsula and in particular spikes at 70% among the Basques. Overall in France it accounts for between 6–20% of the population but has a high level in the Pyrenees area. It is estimated to have developed around 4,200 years ago in north-eastern Prehistoric Iberia as the Neolithic made way for the Atlantic Bronze Age. The DF27 subgroups correspond closely to the various pre-Roman kingdoms formed by the Celtiberians.

## Subclades
### Y-DNA R-DF27 subclades

* DF27*
* R1b1a1a2a1a2a1-Z195
* ZZ12_1
* SK1907

### Y-DNA backbone tree

vtePhylogenetic tree of human Y-chromosome DNA haplogroups :
This article needs to be updated. Please help update this article to reflect recent events or newly available information. (February 2021) :
"Y-chromosomal Adam"
A00
A0-T
A0
A1
A1a
A1b
A1b1
BT
B
CT
DE
CF
D
E
C
F
F1
 F-Y27277
 F3
 GHIJK
G
HIJK
IJK
H
IJ
K
I  
J 
   LT
      K2
I1  
I2 
J1  
J2 
L  
  T 
K2e
K2d
K2c
K2b 
K2a
K2b1
  P
K-M2313
S
 M   
P1  
NO1
P1c
P1b
P1a
N
O
R
Q :
Y-DNA by population
Y-DNA haplogroups of historic people
Footnotes
↑ Van Oven M, Van Geystelen A, Kayser M, Decorte R, Larmuseau HD (2014). "Seeing the wood for the trees: a minimal reference phylogeny for the human Y chromosome". Human Mutation. 35 (2): 187–91. doi:10.1002/humu.22468. PMID 24166809. S2CID 23291764.
↑ International Society of Genetic Genealogy (ISOGG; 2015), Y-DNA Haplogroup Tree 2015. (Access date: 1 February 2015.)
↑ Haplogroup A0-T is also known as A-L1085 (and previously as A0'1'2'3'4).
↑ Haplogroup A1 is also known as A1'2'3'4.
↑ F-Y27277, sometimes known as F2'4, is both the parent clade of F2 and F4 and a child of F-M89.
↑ Haplogroup LT (L298/P326) is also known as Haplogroup K1.
↑ Between 2002 and 2008, Haplogroup T-M184 was known as "Haplogroup K2". That name has since been re-assigned to K-M526, the sibling of Haplogroup LT.
↑ Haplogroup K2b (M1221/P331/PF5911) is also known as Haplogroup MPS.
↑ Haplogroup K2b1 (P397/P399) is also known as Haplogroup MS, but has a broader and more complex internal structure.
↑ Haplogroup P (P295) is also klnown as K2b2.
↑ K-M2313*, which as yet has no phylogenetic name, has been documented in two living individuals, who have ethnic ties to India and South East Asia. In addition, K-Y28299, which appears to be a primary branch of K-M2313, has been found in three living individuals from India. See: Poznik op. cit.; YFull YTree v5.08, 2017, "K-M2335", and; PhyloTree, 2017, "Details of the Y-SNP markers included in the minimal Y tree" (Access date of these pages: 9 December 2017)
↑ Haplogroup S, as of 2017, is also known as K2b1a. (Previously the name Haplogroup S was assigned to K2b1a4.)
↑ Haplogroup M, as of 2017, is also known as K2b1b. (Previously the name Haplogroup M was assigned to K2b1d.) :