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R-DF41 / R-CTS2501

  • 226 members

About us


For more information on the R-DF41/R-CTS2501 haplotree structure, please see the tree below, or visit:
To join the R-DF41 project, most project members will meet one of these criteria:
  • A positive (derived) result for DF41 or CTS2501 or any of the SNPs located under R-DF41/R-CTS2501
  • A close Y67 or Y111 match with a result that is positive for one or more of the DF41 SNPs
  • A close paternal relative that meets one of the above two criteria
  • Planning to order tests and wants assistance with determining what to order
The DF41 SNP was first made available in early 2012, over time the numbers testing positive for it have progressively grown, given the number of STR signatures that are DF41+ it's apparent that it's a fairly old SNP. It was added to the ISOGG tree during the Summer of 2012 and currently bears the long haplogroup title of R1b1a2a1a2c1i

Through testing we know that the following SNP's are valid subclades of R-DF41. 

  • S775 (R1b1a2a1a2c1i1)
  • L744/L746/L745 as found in Stewart samples (R1b1a2a1a2c1i1a) 
  • BY114 (R1b1a2a1a2c1i2)
  • L563 which appears to have an origin in the Isle of Man (R1b1a2a1a2c1i2a)
The current geographic spread includes men from Ireland, Scotland, Isle of Man, Wales/Western England. 

R-CTS2501 which is on the National Geographic Geno 2.0 chip appears to be DF41 equivalent. All CTS2501+ men so far tested have tested DF41+, likewise men from each of the DF41+ clusters have tested CTS2501+. FamilytreeDNA recently updated their haplogroup tree basing it on the Geno 2.0 product. It's somewhat behind the ISOGG tree. In this new tree DF41 isn't included but CTS2501 is. The "long version" given for our haplogroup is: R1b1a1a1a1a1g

Below is a tree generated by Larry Walker using the current project members results. (URL:

Due to combination of BigY testing from FTDNA and other "Next Generation Testing" such as that form "Full Genomes" (FGC) a number of interesting and new SNP's have been discovered under DF41 which appear to mark the individual clusters. Below is a image taken from the "BigY" tree generated by Alex Williamson. The original tree (which covers all L21+ results) can be found here:

An updated version of the below diagram that is specific to DF41+/CTS2501+ men who have done the BigY test can be found here: 


There are also a number of discussion Fora on the Internet that contain information regarding DF41 and ongoing testing these include:
Anthrogenica -- DF41 (L21>DF13>DF41):
Molgen -- DF41+:
Worldfamilies -- 
R-L21: DF41 another new subclade to watch - it is old!: 
Yahoo Group -- Clan DF41:

Some of the surnames that have tested DF41+ include: 
Akers, Bettcher, Bismire, Black, Braton, Brattin, Braton, Bratton, Braughton, Burns, Cannon, Carroll, Christian, Clancey,Conn, Cooper, Creer, Cutler, Dixon, Dowie, Duffy, Dugger, Dwyer, Edmonds, Edwards, Elder, Ellis, Fisher, Gordon, Hall, Hudock, Loveland, MacKenzie, MacMillan, Major,Majors, Mayson, McBirnie, McBurney, McClellan, McClelland, McConnell, McCowan, McCowen, McCown, McCune, McCrere, Miller, Milligan, Mitchell, Moore, Morrison, Nuckolls, O’Hare, Philips, Pierce, Price, Robinso, Ryley, Salmon, Samuel, Simpson, Selfe, Smith, Stephens, Stevens, Stewart, Stuart, Swanson, Tuite, Thomas, Thompson, Walker, Ward, Webb, Williams, Wilson, Woodall, Wright