R1b-CTS4466 Plus

  • 924 members

About us

Display of Y-DNA Results

The Y-DNA Results page groups the participants according to their positive results for the SNPs associated with the Irish Type II haplotype wherever possible.  This is a fluid arrangement, since more SNPs are being identified regularly, through the extensive SNP tests, particularly the BIG Y and Y-Elite; and the groupings will change as we are confident that newly discovered SNPs appropriately separate into different subclades below CTS4466 and its equivalent SNPs. 

While the spreadsheet is usually up to date with the newest SNPs identified, this page may be a bit behind, so apologies if not all the branches are listed here yet.  We are in the midst of revising the letter/number designations of each branch.  They should be updated soon.  If you see any errors, please let us know.

Explanation of Groupings

The labelling of the groups is based on the chart of SNPs displayed on the Background page.  Participants in these groups have not tested positive for any further related SNPs, except those which are found uniquely in an individual and considered 'private' SNPs.

(Note: A plus denotes a positive result, a minus indicates negative, a single '/' indicates equivalents and a double '//' indicates an SNP downstream of the previously listed SNP - a branch found in some but not all those positive for the SNP preceding it.)

We have updated the letter/number designations of the groupings in the Results spreadsheet and are in the process of doing so below now.  We are also slowly widening our descriptions of the geographic trends and surnames in the various branches.

A1.  A7751+ // FGC43844+
       The current individuals in this branch are Jones or likely have Jones genetic heritage.  The names Jones, Morgan, Roberts are all
       originally of Welsh origins.  Matching Sellers (two in the project) are from Wales as well.  At  this level, we could be looking at
       the earliest beginnings of the Irish Type II haplotype. 

A2.  A7751+ // A17979+
       This is a surname-specific branch for Morgan.  Morgan is a Welsh personal name  The surname is found in Ireland, most
       numerous in Down and Armagh in the 16th century.  The current participants are from Armagh/Monaghan.

B.  S1115+
S1115 had originally been considered an equivalent of CTS4466, until a BIG Y result showed otherwise.

B1.  S1115+ // A12404+
A McCormick is currently alone in this group.  He has Ulster origins.

B1a.  S1115 // A12404+ //A12402+
This is a surname-specific branch for Roberts, with a few Jones and a Sturgill added.  Indicative of Welsh origins. 

B2.  A541+ (S1121-,A195-, A151-, A212-, A663-)
A541 is a branch directly beneath CTS4466 itself.  There are only a few participants who has no positive SNPs beneath A541.
       Others have tested the  BIG Y and have found other branches for themselves.  A541 and its multiple branches currently account
       for approximately 80% of all branches of CTS4466.

B2a.  S1121+

       This is a major SNP downstream of CTS4466 beneath A541, containing over half of those positive for A541.

B2a1.  S1121+ // L270/Z16521/Z16518+
       L270.2 was the first downstream subclade of CTS4466 found through the Geno 2.0 test, even prior to discovery of its upstream
       S1121.  While Sullivans dominate it, there are other surnames as well with no known relationship to Sullivan.  At least some are
       likely to have originally been from that clan before surnames were adopted.  There are a number of other SNPs equivalent to
       L270.2.  Since it is found in more than one location on the haplotree, it has been superceded by Z16521 as a more appropriate
       choice for the panels being offered by the testing companies.

B2a1a.  S1121+ // L270/Z16521+ // A1133+
       This is a branch beneath L270
, with mainly Sullivans and Keiths.

B2a1b.  S1121+ // L270/Z16521+// BY3863+
       This is a surname-specific branch ofTeagues, with one Hart.

B2a1b1.  S1121+ // L270/Z16521+// BY3863+ // Y29013+
     A further branch of Teagues.

B2a1c.  S1121+ // L270/Z16521+ // PR2745+
   A branch of Sullivans.

B2a1c1.  S1121+ // L270/Z16521+ // PR2745+ // BY16025+

  A downstream branch of Sullivans.

B2a1d.  S1121+ // L270/Z16521/Z16518+ // FGC42469+
Another Sullivan branch (the second individual with this terminal SNP was tested anonymously through the PCP
       [Personal GenomeProject]).

B2a1e.  S1121+ // L270/Z16521/Z16518+ // FGC65178+
A McCarthy branch(a match not in the project yet).

B2a2.  S1121+ // Z16252+
      Z16252 defines another major subclade below S1121 with a number of further SNPs downstreamThere are several 
       instances of Welsh surnames present in this high level branch as well, further supporting the possibility that the subclade
       originated in Wales.

B2a2a1.  S1121+ // Z16252+ // FGC29280+
   This is a subclade with various surnames - surely to be subdivided with more NGS testing.

B2a2a1a.  S1121+ // Z16252+ // Z18170+ // FGC29280+ // S1126+
A subclade with a Hughey -  his 'cousins' another step downstream.

B2a2a1a1.  S1121+ // Z16252+ // Z18170+ // FGC29280+ // S1126+ // A542+
       A subclade with a number of surnames, some predicted but not tested yet.  Further NGS testing should identify separating

B2a2a1a2.  S1121+ // Z16252+ // Z18170+ // FGC29280+ // S1126+ // A726+
This terminal branch also contains several different surnames.

B2a2a1b.  S1121+ // Z16252+ // Z18170+ //FGC29280+ // FGC29286/FGC29289+ 
       Another branch with different surnames, both Irish and Scottish.

B2a2a1b1.  S1121+ // Z16252+ // Z18170+ // FGC29280+ // FGC29286/FGC29289+// BY15516+
A further branch for Ferguson and a Thompson.

B2a2a1c.  S1121+ // Z16252+ // Z18170+ // FGC29280+// BY3536/BY3522+
A surname-specific branch for Ballard.

B2a2a2.  S1121+ //Z16252+ // Z18170 // A150+
     A150 is an SNP subclade identified in early testing with an O'Mahony and Finns.

B2a2a2a.  S1121+ // Z16252+ // Z18170+ // A150+ //BY2877+
Another downstream level under A150.

B2a2a2a1.  S1121+ // Z16252+ // Z18170+ // A150+ // BY2877+ //FGC11145/FGC11150+
       FGC11145 and two equivalents define a subgroup beneath A150, including the surnames O Mahony and O'Reilly.

B2a2a2a2a.  S1121+ // Z16252+ // Z18170+ // A150+ // BY2877+ // A745+
       To date, this group is found mainly in O Mahonys.  Both A745 and FGC11145 are identified by a 22 at DYS447.

B2a2b.  S1121+ // Z16252+ // A159+
       A159 is a second SNP found below Z16252 with a mix of surnames.        

B2a2b1.  S1121+ //Z16252+ // A159+ // BY2881+
      A group of CTS4466 SNP Pack results discovered a number of participants at this level.

B2a2b1a.  S1121+ //Z16252+ // A159+ // BY2881+ // BY149+
       A downstream branch of A159 and BY2881, also with a mix of surnames.

B2a2b1a1.  S1121+ //Z16252+ // A159+ // BY2881+ // BY149+ // Z17982/Z17983+
A new branch with Irish and a Scotsman at the moment.

B2a2b1a1a.  S1121+ //Z16252+ // A159+ // BY2881+ // BY149+ //A664+        
       A branch with a variety of surnames.

B2a2b1a1a1.  S1121+ //Z16252+ // A159+ // BY2881+ // BY149+ // A664+ // A1511+
A surname-specific branch of McCartneys.

B2a2b1a1a2.  S1121+// Z16252+ // A159+ // BY2881+ // BY149+ // Z17982+ // A664+ // A7752+
An Irish branch.

B2a2b1a1a3.  S1121+ // Z16252+ // A159+ // BY2881+// BY149+ // Z17982+ // A664+ // A12015+
Another Irish branch.

B2a2b1a1a4.  S1121+ // Z16252+// A159+ // BY2881+ // BY149+ // Z17982+ // A664+ // BY15517+
A surname-specific branch for Quirk/Kirks.

B2a2b1a1b. S1121+ // Z16252+ // A159+ // BY2881+ // BY149+ // Z17982+ // BY21825+

B2a2b1a2.  S1121+, Z16252+ // A159+ // BY2881+ // BY149+ // A923+
A variety of mainly Irish surnames.

B2a2b1a2a.  S1121+ // Z16252+ // A159+ // BY2881+ //BY149+ // A923+ // BY21613+
A new branch with an SNP not yet named.

B2a2b1a2b.  S1121+ // Z16252+// A159+ // BY2881+ // BY149+ // A923+ // BY21614+
A surname-specific branch for Sheehan.

B2a2b1a3a.  S1121+ // Z16252+// A159+ // BY2881+ // BY149+ // A6507+ // A6508+
       An Irish branch.

B2a2b1a3b.  S1121+ // Z16252+// A159+ // BY2881+ // BY149+ // A6507+ // S27124+
A branch of Cork men.

B2a2b1b.  S1121+ // Z16252+ //A159+ // BY2881+ // A9185+
More Irishmen.

B2a2b2.  S1121+ // Z16252+ // A159+ // Y71840+ 
        A surname-specific branch for Roberson/Robinsons.

B2a2c1.  S1121+ // Z16252+ // A1134+ // BY2880+
A new branch defined by Pack testers. 

B2a2c1a1.  S1121+ //Z16252+ // A1134+ // BY2880+ // A804+ // A802/A803+
      A branch of O'Donoghues.

B2a2c1a1a.  S1121+ // Z16252+ // A1134+ // BY2880+ // A804+ // A802/A803+ //A914+
The branch of The O'Donoghue of the Glens.

B2a2c1a2.  S1121+ // Z16252+ // A1134+ // BY2880+// A804+ // FGC29067/FGC29074+
The branch also has O'Donoghue and a Warren.

B2a2c1a2a.  S1121+ //Z16252+ // A1134+ // BY2880+// A804+ // FGC29067+ //FGC29071+
Parallel to A802, with a Kane and a McCarty.

B2a2c1b.  S1121+ // Z16252+ // A1134+ // BY2880+ // A2221/A2222+
A surname-specific branch for Moriarty.

B2a2c1b1.  S1121+ // Z16252+ // A1134+ // BY2880+ // A2221+ // A6464+
Murray and Carty surnames.

B2a2c2.  S1121+ // Z16252+ //A1134+ // A809+
Courtney/Cournane and Mahoney.

B2a2c2a.  S1121+ // Z16252+ // A1134+ // A806+
       An Eóganacht Loch Lein Carroll surname.and Leahy.

B2a2c2a1.  S1121+ //Z16252 // A1134+ // A806+ // A2331+
       A surname-specific branch for Lee.

B2a2c3.  S1121+ // Z16252+ // A1134+ // A6511+
An English branch.

B2b.  A1135+ and/or A1136+ and/or Z21065
These SNPs aren't always all captured in either the BIG Y or the CTS4466 SNP Pack, but they so far are considered equivalent.

B2b1.  A1135+ // A195+
       This is a second major SNP downstream of CTS4466 under A541 and parallel to S1121.

B2b1a1.  A1135+ //  A195+ // A761+ // A88+
       A variety of Irish surnames, mainly Creameans/Cummings.

B2b1a1a.  A1135+ //A195+ // A761+ // A88+ // Z162589/Z16259+
      Another variety of Irish surnames.

B2b1a1a1a.  A1135+ //A195+ // A761+ // A88+ // Z16259+ // BY2876+ // ZS4589+
     A surname-specific branch for McCarthy.

B2b1a1a1b.  A1135+ //A195+ // A761+ // A88+ // Z16259+ // BY2876+ // A1333+
      A surname-specific branch for Riggin/Ragan.

B2b1a1a2a.  A1135+ // A195+ // A761+ // A88+ // Z16259+ // A2219+
A McCarthy(Broagh).

B2b1a1a2a1.  A1135+ //A195+ // A761+ // A88+ // Z16259+ // A2219+ // A2294/A2295+
      A surname-specific branch of Donovans.

B2b1a1a2a2.  A1135+ // A195+ //A761+ // A88+ // Z16259+ // A2220+ // A2219+ // A12017+
       A further branch of Donovans.

B2b1a1a2b.  A1135+ // A195+ // A761+ // A88+ //Z16259+ // A2220+ // A7755+
      A surname-specific branch of Hayes.

B2b1a1b.  A1135+ // A195+// A761+ // A88+ // BY2878+
       A single Burns participant.

B2b1a1b1.  A1135+ // A195+ // A761+ // A88+ // BY2878+ // A89+
       An Irish branch.

B2b1a1b1a.  A1135+ //A195+ // A761+ // A88+ // BY2878+ // A89+ // A155+
       A variety of surnames, Irish, Scottish and Norman(?)

B2b1a1b1a1.  A1135+ //A195+ // A761+ // A88+ // BY2878+ // A89+ // A155+ // A156+
       A surname-specific branch of McDonald.

B2b1a1b1b.  A1135+ // A195+ // A761+ // A88+ // BY2878+ // A89+ // BY15518+
      A surname-specific branch of Irwin/Erwin.

B2b1a1c.  A1135+ // A195+ //A761+ // A88+ // A7660+
An Irish branch, mainly Crowleys.

B2b1a2a.  A1135+ // A195+ //A761+ // Z16254+ // A154+
       A single Welshman.
B2b1a2a1.  A1135+ //A195+ // A761+ // Z16254+ // A154+ // A153+ 
      A variety of Irish and English surnames.

B2b1a2a1a.  A1135+//  A195+ // A761+ // Z16254+ // A154+ // A153+ // A474+
An Irish branch.

B2b1a2a1b.  A1135+ // A195 // A761+ // Z16254+ //A154+ // A153+ // BY11841+
A surname-specific branch for Glennon.

B2b1a2b.  A1135+ // A195+ // A761+ // Z16254+ //A1338+
Another Irish branch.

B2b1a2b1.  A1135+ // A195+ // A761+ // Z16254+// A1338+ // A1336+
A Murray and a Hunter so far.

B2b1a3.  A1135+ // A195+ // A761+ // A12590+
A Gilliam.

B2b1a3a.  A1135+ // A195+ // A761+ // A12590+ //A12589+

B2b1b.  A1135+ // A195+ // A10641
A McAuliffe.

B2b2.  A1135+ // A956+
       An Irish branch.

B2b2a.  A1135+ //A956+ // A2288+
A single Scotsman.

B2b2a1.  A1135+ //A956+ // A2288+ // A5312/A5313+
      A branch of Cork men.

B2b2a1a.  A1135+ // A956+ //A2288+ // A5312+ // A8748+
A surname-specific branch of Bryan.

B2b2a1a1.  A1135+ // A956+ // A2288+ // A5312+ //A8748+ // A7753+
A further downstream branch of Bryan.

B2b2b.  A1135+ // A956+ // A7754+
  Contains a Lynch and Lindsey.  There are numerous septs of Lynch, with Lindsey suggested as a variant form of the name.
       Sharing a terminal SNP supports this to be accurate. Possibly Dál gCais.

B2b3.  A1135+ // A2427+
       A single Morgan, probable Welsh.

B2b3a.  A1135+ // A2427+ //BY21618+
       English surnames.

B2b4.  A1135+ // A9426+
A branch of Welsh Abers.

B2b5.  A1135+ // A11844+
Basically a surname-specific branch of Hickey.

B2b5a.  A1135+ // A11844+ // A12525+
A further sub-branch of Hickey.

 B2c.  A151+
       A151 is under A541, parallel to S1121 and A1135, with a growing list of surnames.

B2c1a1.  A151+ // FGC29768+// BY139+ // BY141+
A mid level branch with one participant at themoment, unsure origins.

A151+ // BY139+ // BY141+ //BY140/BY142+
This branch contains men of Norwegian descent.  (Surnames are not patrilineal in Norway.)  It is likely that these gentlemen
       descend from the same ancestor, perhaps a sailor/merchant/slave who came to Norway, possibly a millennium or more ago

B2c1a2.  A151+ // BY139+// A9865+
       This is an Irish-born subclade.

B2c1a2a.  A151+ // BY139+// A9865+ // A12087+
       A single kit of Northern Irish ancestry.
B2c1a2a1.  A151+ // BY139+// A9865+ // A12087+ // A12149+
    Also Northern Irish/Scottish ancestry.

B2c1b.  A151+ // FGC29768+ // A743+
A single Morrissey.

B2c1b1.  A151+ // FGC29768+ // A743+ // FGC29773+
A branch of Scottish MacAulays.

B2c1b1a.  A151+ // FGC29768+ // A743+ // FGC29773+// FGC29771+
More MacAulays.

B2c1b1a1.  A151+ // FGC29768+// A743+ // FGC29773+ // BY15520+
Yet more MacAulays.

B2c1b1b.  A151+ // FGC29768+ //A743+ // FGC29773+ // F3189+
        One last MacAulay branch.

B2c2.  A151+ // A714+/A715+
        A second subclade beneath A151 with a variety of surnames, Irish/Scottish/English.

B2c2a. A151+ // A714+// FGC23796+
A branch with basically English surnames.
B2c3.  A151+ // B42+
Another branch under A151, one kit, probably a German surname.

B2c3a.  A151+ // B42+ //A7659+
        An Irish O'Connell branch, these individuals found in Waterford/Tipperary.

B2c3a1A151+ // B42+ //A7659+ // A7654+
The main Kerry branch of O'Connells.

B2c4.  A151+ // BY21619+
The newest branchof A151, Richie/Pearson.

B3.  A212+ (A218 and/ordownstream SNPs untested)
The A212 branch is parallel to A541, with an 18 at DYS481 separating it very distinctly from the rest of CTS4466.  The
        participants tend to cluster in Northern Ireland, Scotland and the UK.  Kits in this group are only tested positive for A212 itself.

B3.  A212+ (A218+, downstream SNPs untested)
      Kits in this group have tested positive for both A212 and its assumed equivalent A218 but not tested for downstream SNPs.

B3.  A212+/A218+ // negative downstream
   These two BIG Y testers currently shares no other downstream SNPs with the other A212+ BIG Y results.

A212+ // A206+
The first downstream branch of A212 identified, Scottish.

B3a1.  A212+ // A206+ //A208+
        One individual so far, also Scottish.

B3b.  A212+ // A6518+
      A Walker surname-specific branch, across Ireland/England.  Walker is an old English word for 'fuller', and there
        is a matching Fuller in this branch.

B3c.  A212+ // A7699+
        Scottish and Irish.

B3c1. A212+ // A7699+ // A6525+
        A Kelly, surely Irish.

B3c1a.  A212+ // A7699+ // A6525+ // A7756+
        Scotland/Northern Ireland.

B3c1a1.  A212+ // A7699+ // A6525+ //A7756+ // A9513
        A Thompson surname-specific branch, Ireland/UK.

B3c2.  A212+ // A7699+ // A6526+
        Another Thompson and Hamilton, Ireland/UK.

B3c3.  A212+ // A7699+ // BY3535+
   One individual, Ireland/Waterford.

B3c3a.  A212+ // A7699+ // BY3535+ // BY3862+
        A Murphy surname-specific branch, Northern Ireland.

B3d.  A212+ // A7648+
        Stalker/Stoliker, probably Scottish.

B4.  A663
       A third branch parallel to A541, directly downstream of CTS4466.  It contains two distinctly different haplotypes, suggesting it
       is of some age. They all have 14-30 at DYS389 and most have a 14 at DYS442 and 15 at DYS497.  Recent testing has begun to split it.

B4a.  A663+ // A2289/A2291+
A new branch under A663, A2289 and four equivalents separates one of the haplotypes present in A663, identified mainly by a
        12-15 at DYS385 and 15-15-16-17 at DYS464.  McBee, Drennan and Punkett are the surnames currently positive for this SNP.

B4b.  A663+ // A5595+
      A surname-specific branch for Butler.

Has Tested Positive for CTS4466 and/or one or more of the equivalent SNPs
        This includes anyone who has tested for CTS4466 and/or any of the equivalent SNPs  - CTS11267/S7938, CTS3974/S7936,
        CTS5714/S1137, CTS8358/Z3022, Z16247/FGC11133, S1113, S1115, S1120, S1122, S1128, S7364, Z16248, Z3025/A81,
        Z3028, A149.

A? B?, B1?, C? etc
        These '?' groups are potential positives for the relevant SNPs, based on being a relatively close genetic distance to those who have
        tested positive for the SNPs and often sharing particular marker values.  Nigel's phylogenetic tree is also used for reference.  These
        are only possibilities, and further testing will be the only way to know for sure.                   .

Early Findings
Our database is increasing as new members join and we continue to recruit participants whose haplotypes match the Irish Type II modal.  While we still have a large number of participants who have not yet tested for SNPs, this is slowly dwindling as more SNPs are discovered through the BIG Y test and other extensive tests being offered.

For those participants with less than 67 markers tested, upgrading to the 67 marker level of STR testing (or ideally the full 111 marker level) is a way to help us develop and refine these categories and improve our picture of the CTS4466 haplogroup. There are markers in the 68-111 panels that are particularly useful in identifying clusters of individuals. Upgrading will also benefit individual members in their personal genealogy quest by helping to more accurately identify potential relatives, and it would make it easier for us to suggest specific SNP tests in the future. If any participants are interested in SNP testing now, please contact Elizabeth for recommendations before deciding which test to choose.

Updates on the Extensive Y-DNA SNP Testing in the Project

Geno 2.0

While this early multi-SNP test identified for us that CTS4466 was the defining SNP for the Irish Type II subclade, it have been superseded by the CTS4466 SNP Pack, the BIG Y and other NGS tests now available which offer far more coverage of the areas of the Y chromosome relevant to our subclade.


By now, we have well over 100 BIG Y results, and more keep coming in. There is a huge amount of data to review. While some positive SNPs display on the Y-DNA SNP page, it does not include them all. There is a downloadable VCF file available to each participant with the raw data from their test; and Family Tree is also providing a very extensive .BAM file that contains even more data than available in the VCF folder.  Since Family Tree have reloaded the data for all existing BIG Y testers in 2017, the BAMs aren't available right now.  We are asking that everyone with results share the VCF link with us, since it contains much useful information to clarify what is shown in the participants’ personal pages.  All testers receive instructions on how to send us this folder.

Debbie Kennett’s blog provides some interesting insights into the test: 

Roberta Estes has also prepared an informative blog post: 

For those of you who have taken the BIG Y test, Family Tree has a tutorial at:  https://www.familytreedna.com/learn/user-guide/other-test-results/big-y-page/ and a webinar at https://www.familytreedna.com/learn/ftdna/webinars/.  The webinar is labeled 'FTDNA Product Launch Webinar:  Getting to Know  BIG Y Results'.  Clicking on it, you will be asked to register and you will immediately be transferred to the link to see it.

Dennis Wright has compiled a Testing and Analysing Big-Y - a Primer which you can find at https://dl.dropboxusercontent.com/u/14028750/Testing%20and%20Analysing%20Big-Y.pdf which explains the details provided on your BIG Y pages and how you can review the data yourself if you wish.

Alex Williamson is one of the gurus of the genetic genealogy community.  He maintains a very comprehensive The Big Tree at http://www.littlescottishcluster.com/RL21/NGS/Tree.html that analyzes all the BIG Y results to which he has access.  Our participants can be seen individually on his link P312>L21>DF13>FGC11134 .

YSEQ offers an informative primer 'I've Received My Y Chromosome Sequencing Results - What Now?' available at https://dl.dropboxusercontent.com/u/5676413/2014-08_I4GG.pdf.

CTS4466 SNP Pack

The CTS4466 SNP Pack was introduced by Family Tree in early 2015.  It tested for all known branches of the CTS4466 tree at that time.  Its results are incorporated into the participants' Haplotree & SNPs link and display the terminal SNP in the Y-DNA Haplogroup box at the top of their home page.  It was updated to include newly identified branches in 2017, and we are waiting for Family Tree to update it again.  It is quite useful to confirm to which branch a participant belongs, though new branches can only be identified through the BIG Y test.

Comprehensive Y-DNA Sequencing

A number of our participants have availed of a Comprehensive Y-DNA Sequencing test.  These meld well with the BIG Y, though additional analysis is needed to correlate both sets of results.  Fortunately, the participant who ordered the first Full Genome test has also taken the BIG Y, so we are able to compare the two to confirm accurate interpretation of the results. The other participants who have received results from such tests are included in the BIG Y & FG Results chart mentioned above in addition to Joe's chart. 

For the adventurous, James Kane maintains a very comprehensive spreadsheet of all SNP results from many sources in addition to Family tree's tests at http://it2kane.org/matrix/R-FGC11134_matrix.html.  It is vast, and can only be downloaded in its present form by copy and paste, which is not ideal; but trying to review it online would be quite difficult.  Not for the faint-hearted but very informative.

First Subclade of CTS4466 - L270.2

The first formal subclade under CTS4466 that was identified is defined by the SNP L270.  Since this SNP was previously discovered in haplogroup J, ISOGG has agreed with our proposal that it be recognised as L270.2.  At the moment, the subclade is dominated by Sullivans, but other surnames also feature, some genealogically related to Sullivans and others with no apparent connection.  Just recently, another SNP downstream of L270.2 has been identified - A1133.  It is now available for individual testing as well as L270.

Nigel has created a phylogenetic tree for the Irish Type II members of the McCarthy Surname Study, including kits of other surnames with similar haplotypes.  The chart includes a branching suggesting the possible structure of this L270 subclade. Those kits which have tested positive for the SNP are highlighted orange, while kits tested negative are highlighted tan. The chart can be found in the Files section of our Forum or at http://mccarthy.dnagen.org, under DNA Phylogenic Trees, Group A, Irish Type II. It will be regularly updated as more test results arrive, both positive and negative.

The L270 genetic signature that differentiates it from the overall Irish Type II modal includes key STR mutations at four markers:  DYS481 (up from 22 to 23 or more) in panel 4b, DYS710 (down from 35 to 34 or less) in panel 5a, DYS533 (down from 13 to 12 or less) in panel 5b and DYS552 (up from 24 to 25) in panel 5d. As we see more results, this may change somewhat, but these values are good indicators of those likely to prove positive for the SNP. To date, the chart has correctly predicted both positive and negative results. It should be noted, however, that this is a "best guess" tree and liable to change as more data becomes available.

S1121 & Other Significant SNPs

S1121 was first found in the Chromo2 test, and the BIG Y test also includes it.  It defines the largest subclade beneath CTS4466.  The BIG Y in particular has provided us with a number of other SNPs that are common 1) to all Irish Type II participants, 2) to certain clusters of participants, even surname-specific branches, and 3) individual to each participant.  By now, we have expanded the tree considerably through the numerous BIG Y tests taken by project members, and more branches beneath these continue to be discovered as more BIG Y test results come in.  In addition to A541 which is upstream of S1121, A195 and A151, as well as A212 and A663 that are parallel to A541, we have two branches upstream of A541 as well - S1115 and A7751.  The hierarchical tree on the Background page lists all the current ones and the subclades further downstream, and we have a chart available on the Forum in the Files section or at https://www.dropbox.com/s/0k65l8gk6n3jk1u/CTS4466%20tree%2020161801.xlsx?dl=0.  As our analysis continues, we update everyone with our ongoing conclusions, posting the data in files available on the Forum or through dropbox links on the website. 

We intend to provide further analysis of the different branches that have been identified in the near future.


The questions in the minds of everyone who is interested in the Irish Type II haplotype are where did it originate and how is it related to the ancient Eóganacht tribes who ruled Munster unopposed for over 500 years, from about 500 to 1000 AD.

At the beginning of 2012, the Munster Irish Project - https://www.familytreedna.com/public/MunsterIrish - was initiated to study the genetic heritage of the province.  This was prior to the discovery of the CTS4466 SNP that has come to be associated with the Irish Type II haplotype.  Its Y-DNA Results table is grouped by the tribes to which the surnames belong (according to the ancient genealogical tracts) regardless of their haplotype.  It was apparent from the beginning that the Irish Type II haplotype is found throughout Munster; and while almost all of the names associated with the Eóganacht do have a significant amount of Irish Type II in their lineages, it is not limited to those surnames.  The Deisi Mumhan and the Eli, whose territories are both at the edge of the ancient Munster territories, are the only tribes whose associated surnames don't show any Irish Type II (though the Deisi may).

The degree of presence of Irish Type II in historically older tribes, most notably the Corca Laidhe and the Corca Dhuibhne, cannot be reasonably attributed merely to NPEs, adoptions, war (and the accompanying rape/pillage), etc.  It suggests that the progenitor from whom all “Irish Type II” peoples flourished significantly predated the emergence of the Eóganacht as a ruling force in Munster.  What also needs to be considered is the fact that a number of subclades/clusters of CTS4466 contain individuals whose family origins are found in different geographical areas - in the north of Ireland, Scotland, parts of England and the Scandinavian countries, and even a few other continentals.  Travel by sea and the ease of trade that the coastal routes afforded between all these areas, not to mention the active slave trade (Dublin was a noted Viking slave market that existed from the 9th into the 12th centuries) no doubt played a part in the distribution of the Irish Type II as well as all other Irish haplotypes.

The mythical ancestor of the Eóganacht, Eógan Mór, is supposed to have descended from the Milesians, whose arrival in Ireland forms the closing chapter to the ancient Book of Invasions (Leabhar Gabalah Éireann) an 11th century compilation of earlier texts which identifies this event as the final invasion where the Milesians land in Kenmare Bay and bring the Gaelic culture to Ireland.  The sons of Mil, or Miles Espania (the Spanish soldier) were supposed to have invaded Ireland from Spain.  Some of the early scholars suggested dates as early as 1700 BC based on the Book of Invasions.  This genesis myth was taken quite seriously during the period of the Celtic Revival, but there are few who give it much credence now.

While the degree of DNA testing done in men of recent Iberian origin is currently not as extensive as could be wished, there is no evidence of the Irish Type II haplotype in this region, so that it would currently be difficult to support an Iberian origin for the Eóganacht.  If there was a Milesian invasion with male progeny surviving to this day, it's quite doubtful they were Irish Type II.

In any case, to consider the relevance of the Irish Type II haplotype to the genealogy of the Eóganacht, a typical pedigree tree of the various Eóganacht septs has been created based on ancient genealogies and overlaid with the CTS4466 tree with an indication where appropriate of some participants with Eóganacht surnames who have tested to their current terminal SNP.  It has produced some interesting results.  The chart can be downloaded from https://www.dropbox.com/s/wbws2wk4vkluo45/1st%20Millenium%20Origins%20%282015-06-20%29.pdf?dl=0 or found in the Files section of the Forum.  There are explanatory notes included in the chart, but we will add a few remarks here as well.

The following key considerations form the basis of this tree:

  1. Extensive review of pertinent literature by members of The O'Donoghue Society has led to the conclusion that the ancestry of O'Donoghue of the Glens lies in the Co. Tipperary/Cashel O'Donoghues (who are sometimes ignored in genealogical tracts) and not the Eóganacht Raithlind, as suggested in some ancient annals.

  2. Similar research indicates that the O’Donoghue Mór lineage is not Irish Type II.  (See https://www.odonoghue.co.uk/projects/project-1/interpretations).  Y-DNA evidence also suggests that the McCarthy Mٕór lineage is not Irish Type II either. (See “Summary of Findings” at https://www.familytreedna.com/groups/mccarthy-surname-study/about/results.)  The phylogenealogy of both is indicated on the far left of the chart).

There are a number of notes on the chart itself to clarify the arrangement of the SNPs and the Eóganacht surnames included.  The order of the SNP hierarchy (each highlighted in yellow) does not always coincide with the structure of the Eóganacht genealogy, requiring a number of lines and arrows pointing to the reality of the SNP tree with the purported interrelatedness of the various septs of the Eóganacht.

All the Eóganacht surnames are found downstream of A541.  On the left, there is the obvious branch of L270.2, dominated by the O'Sullivans and including McGill(icuddy), consistent with ancient genealogies, but the other main Eóganacht Cashel surnames of McCarthy and O'Donoghue do not share that SNP except for 2% of Irish Type II McCarthys, which is not considered significant enough a proportion to validate such a genealogy.  Instead we show four different surviving lineages attributable to the Eóganacht Cashel.

While we are able to present O’Keefe’s position in a manner consistent with the ancient genealogies, more testing of O’Keeffes is required to confirm this. Note also that many other (mostly Munster) surnames are associated with the O’Keeffe SNP A159.

Almost all other Eóganacht surnames are found under Z16251 and A1135.  Alongside these are pockets of surnames that have no hint of Munster or even Irish origin, often with more diversified haplotypes and/or on earlier branches of the tree.  In some instances, these can be explained by permanent migration out of Munster and/or across the Irish Sea.  However, there is not always an apparent rationalization for non-Eóganacht surnames carrying the same SNPs as Eóganacht surnames.

Rev O’Keeffe’s Book of Munster, a 1703 summary of earlier sources of greater or lesser renown, does list a large number of Munster surnames as derived from the tribal progeny of the Eóganacht Raithlind; it remains to be seen whether such claims can be validated. A number of these, such as O’Callaghan, O’Connelly, O’Donoghue and O’Leary have other independent origins in Munster and often in the rest of Ireland.

Some historians consider the Eóganacht Loch Lein to be the original Eóganacht, from which all other septs evolved, migrating eastwards into greater Munster.  There is so far no evidence to support an early independent Eóganacht Loch Lein lineage. The two Moriartys and one Carroll representing this sept and who have deep clade tested all show a relatively late first millennium ancestry shared with O’Donoghue of the Glens, which is unexpected and puzzling.  However, others of these surnames may be found in different areas of the tree, so more testing is required to draw reliable conclusions on the origins of this foundation sept.

The Uí Liathan and Uí Fidgeinti are also tribes with lineages attributed to Eóganacht origins.  As with Eóganacht Raithlind, further surnames purporting to be associated with these, such as Gleason and O’Corráin, not represented in our project at the time of the tree construction, are omitted for clarity for the time being.  Most Donovans and Collinses, the modern day flag bearers of Uí Fidgeinti origins who are Irish Type II, are found beneath Z16259 alongside others with compatible Thomond origins such as O’Hourihane, O’Brien and O’Regan. (O’Briens in Thomond and McCarthys in Desmond were the most powerful families in mediaeval Munster so it is not unexpected that many will have taken these names through “clan affiliation” rather than a paternal genetic descent.)  However, the surnames Donovan and Collins may also be argued as having Corca Laidhe origins, and the identification of some Z16259 O’Driscolls hint at this as an alternative origin. The situation is further confused by the historical record of a migration of Uí Fidgeinti southwards from their Co. Limerick homelands into territories occupied by Corca Laidhe in 1178 and beyond.  (It could, however, be argued that the O’Driscoll name might then have also been assumed by some through affiliation to the dominant “clan” of the area, since I-P37 is the most prominent haplogroup of the O'Driscolls.)

Clearly, from the range of surnames and phylogenetic tree structure under A1135, either Fiachu Fidgenid, the founder, had a far greater progeny than has previously been recognised or the Uí Fidgeinti were just one branch of a major sublineage.  The tree currently suggests the latter. There are many names in the tree structure between A1135 and Z16259 suggestive of locations beyond Munster, although a few, such as Griffin, O’Hearn, Irwin and Allen, further support a Thomond association.  Since Aine is very close to Emly, a 10th / 11th century focal point of the later McCarthy dynasty, we are also investigating possible Eóganacht Aine connections with surnames other than Kerwick/Kirby, represented to date by just one participant who shares ancestry with one of the two significant Daly groups.

The A151 branches are listed at top right.  Subject to further testing now underway, at present it comprises 1) two distinct single surname branches: O'Connell (of Dingle Bay) and MacAulay (of the Outer Hebrides), 2) branches with a strong Scandinavian presence and 3) a subclade of predominantly English, Welsh and Scottish names but including the only other Irish name, one of two Irish Type II Brazils. (The other is in the Z16254 subclade under A1135, but neither corresponds with a possible O'Breassail sept as indicated in the historical Eóganacht genealogies).  There have been several interesting discussions on the Forum about these families. You need to join the Forum (https://groups.yahoo.com/neo/groups/R1b-CTS4466-Plus/info) to view them, and we hope more of you will join to see these discussions as well as the other data available there.

The A212 and A663 branches are parallel with A541 and may pre-date the tree provided. They do not feature Eóganacht surnames and are geographically associated with Northern Ireland, Scotland and England.  This does not preclude a Munster origin as they may have developed in the progeny of migrants who had travelled northwards/eastwards across the Irish Sea.  It's always possible that they could be indicative of the location of the common ancestry of all on the subject tree, though a migration south does not fit well with the early historical information available to us. 

There is the promising potential of Wales as a source from whence the early Irish Type II ancestors migrated to Munster.  The A1 and B1 groups in the Results spreadsheet contain kits dominated by Welsh surnames.  They are all in branches at the 'top of the tree', being the early mutations after CTS4466 and its equivalents.  Even branches of FGC11134, the SNP upstream of CTS4466 on the L21 haplotree, contain Welsh surnames, giving further credence to the possibility of a Welsh origin.  The A212 and A663 branches may have originated from a Welsh source traveling north and then across to Ireland from there.  There have been lively discussions of origins on our Forum.

It is apparent that the validated Y-DNA hierarchy of the Irish Type II tree does not coincide with the Eóganacht genealogies in a straightforward manner.  The DNA is real.  The ancient tracts, not only about the Eóganacht but all the other tribes present in ancient Ireland, are notorious for being conflated, inflated, if not fabricated.  However, that does not mean that they are entirely invented, and the old adage, 'where there is smoke there is fire' could apply here.  Our attempts at correlating the Y-DNA and the ancient annals/genealogies do not reconcile the apparent differences and conflicts, and it's possible they never will, but there is a degree of structure to what we have presented in the chart

The phylogenetic tree from A541 downward supports a concept of one, perhaps early first millennium common ancestor whose progeny is represented in many Eóganacht tribes.  Within Irish Type II, surnames purporting derivation from these tribes are predominantly found in the S1121 subclade of A541, suggesting that if there is a figurehead to this family, S1121 would have been his terminal SNP.  However, in view of the considerable other surnames present in those A541 branches, even taking  into account migrations into and out of Munster, NPEs and surnames gained by clan affiliation, it is problematic to suggest that the common ancestor can be claimed by the descendants of those Eóganacht tribes alone.  Some inter-relationships within the historical genealogies may be viable, but others would need adjustment to be compatible with the genetic data.

The progenitor of the Irish Type II could have been a recent ancestor of the semi-mythical Eoghan Mór, with the S1121 and A1135 subclades of A541 appearing in his progeny, but then again that progenitor might be someone even more ancient. With the relative prevalence of Irish Type II in the Corca Laidhe tribes and their territorial predominance throughout much of Munster prior to their overthrow by the Eóganacht, who disposed them of most of their territory, it's not impossible that the Irish Type II originated within these earlier tribes.  We need to be open minded about the possibilities.  At the moment, Wales seems to be in the mix in a significant way.

The chart is not meant to be all inclusive at this point and it will be an ongoing project.  We anticipate expanding it to include additional data regularly.  Along with that, our challenge is to try and determine the relative validity of the various ancient Irish tracts and other historical documents that chart the history of all those who are CTS4466/Irish Type II, both in Ireland and wherever their wanderings took them, and discover how they are all related.  No easy task, but we look forward to updating this study as more NGS and CTS4466 Panel data becomes available and we broaden our knowledge.


There is an understandable interest in how old CTS4466 is.  We must first recognize that the TMRCA is only the time to the most recent common ancestor - not necessarily the original one.  The man with the initial SNP that defines the subclade represented by CTS4466 and its equivalents almost surely lived much earlier, perhaps by even 1500 years or more, due to a bottleneck evidenced by a significant number of equivalent SNPs to CTS4466 itself, implying a long period in which the lineage survived by a thread, before S1115 and A7751 occurred.  There were probably more branches in the lineage at one time, but any offshoots from the numerous equivalent SNPs or indeed other branches of CTS4466 itself, based on our current data, have died out.  Hence, the common ancestor to whom we try to estimate a TMRCA period is an embodiment of a complex lineage going back that we will almost certainly never be able to completely decipher.  What we can hope for is continued discoveries of further branches as we receive more BIG Y results for not only the CTS4466+ participants in our project, but also the directly upstream SNPs of FGC11134+ but CTS4466- participants.  These upstream SNPs may also provide clues of their own to the origins of CTS4466.


There are various methods of calculating TMRCA - based on the number of SNPs separating different subclades, the number of mutations present in the dataset chosen, STR diversity, etc.; and different dates have been calculated, depending on mutation rates used, counting of mutations and/or number of SNPs between branches, percent of probability considered, and factors for bottlenecks, back mutations, etc. taken into account, which are variables that can never be known for sure.  While the results are sometimes similar between different citizen scientists and more commercial statisticians studying DNA, even professional statisticians have to admit that there can be no certainty in the level of accuracy any of these methods provide, and it's possible there could be significant underestimations.

It had been suggested that the ancestor of the Irish Type II may have lived sometime in the first half of the first millennium A.D, but increased data has pushed that possibility back a bit.  You can find current estimated TMRCAs for most of the branches of CTS4466 at Alex Williamson’s Big Tree at https://www.ytree.net/DisplayTree.php?blockID=21.  Click on the particular SNP you are interested in and you’ll get a second page, which many include an Age Analysis at the bottom of the page.  For CTS4466, Alex (using Iain McDonald's calculation method) suggests 'the median age of this block is 2316.5 YBP (367 BC). The 95%confidence interval is 854 BC to 17 AD'.

Nigel McCarthy completed a paper in 2016, AN IRISH TYPE II TIMELINE EXPLORED THROUGH UÍ CHAIRPRI AEBDA, which he describes as 'a new approach to determination of mutation rates suitable for constructing a timeline with defined boundary conditions, applied to the subclade of Z16259. Article includes discussion of Uí Fhidgeinti origins.  It can be found in the Files section of the R1b-CTS4466 Plus Project Forum under the title 'Mutation rates for  Z16259 timeline'.  It can also be downloaded from https://www.dropbox.com/s/5roa5ik4l7mvsbl/Irish%20Type%20II%20explored%20through%20U%C3%AD%20Chairpri%20Aebda%20%28Rev%200%29.pdf?dl=0

Ancient Irish DNA

In addition to the citizen scientists who are studying the modern DNA of all those who have tested, the professional scientists and academics have for some years now been gathering data from ancient bones.  There is a growing database of the DNA of ancient specimens all around the world; and there is a paper just published - Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome - by a collaboration between Smurfit Institute of Genetics, Trinity College, and School of Geography, Archaeology and Palaeoecology, Queen’s University Belfast, headed by Professor Dan Bradley, in which the DNA of four prehistoric individuals has been tested for the first time.  It includes a Neolithic woman from a megalithic burial at Ballynahatty, Co. Down, estimated to be 3343–3020 BC based on associated artefacts and three Bronze Age males from Rathlin Island off the coast of Co. Antrim estimated to be of an age of 2026–1534 BC.  The paper can be downloaded for free at http://m.pnas.org/content/suppl/2015/12/23/1518445113.DCSupplemental/pnas.1518445113.sapp.pdf.

The female was determined to be of predominantly Near Eastern origin, indicating there was an influx of early farmers to the island during the Neolithic era.  Her haplogroup was HV0.  The males had a substantial heritage of Bronze Age herders going back to the Pontic Steppes.  One of the males was tested to DF21>Z30233. 

This is not the forum to go into more detail of the paper and its results, but anyone interested can access the paper and its accompanying appendix SI Appendix, Section S1 - listed on page 1 of the document.

Maybe someday Y-DNA testing of other skeletal remains which can be reliably dated by other means will give us an indication of the earliest occurrence of CTS4466 in Munster or elsewhere, if the trail leads us to a different origin.  At the moment, Wales is a possible candidate.

Other Relevant Papers

The Beaker phenomenon and the genomic transformation of northwest Europe - https://www.nature.com/articles/nature25738  (Published February 2018 - full paper by subscription)

Insular Celtic population structure and genomic footprints of migration - http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007152  (Published January 2018)

The Irish DNA Atlas: Revealing Fine-Scale Population Structure and History within Ireland - https://www.researchgate.net/publication/321781959_The_Irish_DNA_Atlas_Revealing_Fine-Scale_Population_Structure_and_History_within_Ireland  (Published December 2017)

Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome - http://www.pnas.org/content/113/2/368  (Published January 2016)

Last updated 9th February 2019