State of the Project: January 2018


The purpose of the McFadden DNA Project is to use Y-DNA testing to learn more about the origins and history of the Gaelic surname Mac Pháidín and the various modern surnames derived from it (McFadden, Macfadyen, McFadzen, etc.). Y-DNA testing can demonstrate whether or not various lineages and spellings are genetically related, and also allow for rough estimates of how far back they connect. Our focus is both genealogical and historical.


The McFadden Y-DNA project now has 53 participants, including men with the surnames Fadden, MacFadden, MacFadyen, McFaddan, McFadden, McFaddin, McFadyen, and McFadzen.

It is believed that some men with names like Paden, Peadon, and Patterson may be descended from Mac Pháidín lineages, but these names have other origins as well and thus far no genetic connection has been discovered between P- and Mc/Mac- names. For this reason, men with these names are not currently included in our analysis. We still welcome men with P- surnames to join our project in hopes of finding a connection.

Among our 53 participants, the breakdown of tests taken is as follows:
– Big Y: 2
– Y111: 7
– Y67 or higher: 32
– Y37 or higher: 47
– Y12 or higher: 53

We recommend new testers choose the Y67 or Y111 tests, but the Y37 can also be of use. Ultimately we would like as many people to take the Big Y as possible. Click here for more information about the Big Y and why we’re asking people to take it.


A Y-DNA haplogroup is a group of men that have a common ancestor along their direct paternal line and share a DNA marker or signature that establishes this connection. A haplogroup can be as small as a pair of close relatives, or as large as all of humanity. A man will be part of a series of haplogroups stretching back in time along their paternal line.

The vast majority of testers in our project (44 of 53) belong to the haplogroup R-M269. R-M269 is the most common haplogroup in Europe and is thought to be more than 5000 years old. Within M269, 38 testers are DF13+. Within DF13, 26 testers (half of the project) are in the haplogroup M222.

M222 is a distinctly Gaelic haplogroup that is common in Ireland and Scotland. The most recent ancestor of M222 lived roughly 2000 years ago and is thought to have been a Gaelic king or chief of some sort. M222 is commonly associated with the semi-mythical ruler Niall of the Nine Hostages, but it is now believed to predate Niall by several centuries. The fact that half of our project is M222+ may be coincidental and we cannot assume that all M222+ McFaddens are of the same McFadden lineage. This is why advanced testing like the Big Y is crucial in helping us sort out ancient lineages.

Haplogroup breakdown:

R-M269: 44
– - DF13: 38
– - – - CTS1751: 3
– - – - DF1: 1
– - – - DF49: 26
– - – - – - M222: 26
– - – - Z251: 2
– - – - Z253: 6
– - U106: 6
R-M512: 4
I-M253: 3
E-M2: 1
N-M231: 1

Established Lineages

A new group is formed in our project every time two or more Mac Pháidín testers match each other. Thus far, we have discovered 10 distinct Mac Pháidín lineage groups, some of which may be related to each other. Click here to view our results page at FTDNA: Project Results. Please note that because of individual privacy settings, most results are only visible to project participants. The number of project participants in each group is shown in parentheses.

R-M269 > P312 > L21 > DF13 > CTS1751 > BY595 (3)

This group is of Scottish origin, with lines going back to the Isle of Islay and the Isle of Mull. Mull is said to be the medieval homeland of the Mac Pháidíns. See our page The MacFadyens of Mull for more information. The BY595 haplogroup is about 1500 years old and contains an interesting mix of Irish and British lineages, the most notable of which is the main cluster of Ó Faoláins (Phelan, Whalen). Advanced testing (Big Y) is necessary to determine where exactly this group fits within BY595.

R-M269 > P312 > L21 > DF13 > DF1 > S6365 > L705 (1)

This group is related to and possibly descended from the Barretts of County Mayo. The Barretts were among the “Old English” that came to Ireland as part of the 12th century Norman Invasion and eventually assimilated into Irish culture. As part of their assimilation, the Barrett chief took on the name of Mac Páidín. In addition to matching the Barretts, this group shares a distant ancestor with a number of Welsh lineages, which perfectly fits the Barrett history. For more information, please see our Clan Padden of Mayo page.

R-M269 > P312 > L21 > DF13 > DF49 > M222 Group 1 (4)

This group interestingly contains lines of both protestant Ulster Scots and Catholic Donegal origin. The signature of this group is very close to the M222 signature, which makes it impossible to speculate where it might fall within M222 or whether it might be related to other M222+ McFadden groups. Advanced testing (Big Y) needed.

R-M269 > P312 > L21 > DF13 > DF49 > M222 Group 2 (DF105 > A10526) (12)

This group is currently the largest and oldest in the project. The most recent ancestor appears to have lived in Co. Donegal a minimum of 400 years ago, possibly much earlier. The A10526 haplogroup likely originated in Scotland. Group 2a’s position has been established through two Big Y testers, while Group 2b’s connection to 2a is only assumed. Big Y testing required for confirmation.

R-M269 > P312 > L21 > DF13 > DF49 > M222 Group 3 (4)

This group appears to be of Scottish origin, but thus far only links to Ireland have been found. One line goes back to Co. Antrim and two others are of undetermined Irish origin. The most recent common ancestor lived a minimum of 300 years ago. Advanced testing (Big Y) needed.

R-M269 > P312 > L21 > DF13 > DF49 > M222 Group 4 (2)

This group contains one Irish lineage that traces back to County Tyrone and a Colonial American lineage from Pennsylvania. The most recent common ancestor lived a minimum of 300 years ago. Advanced testing (Big Y) needed.

R-M269 > P312 > L21 > DF13 > Z251 (2)

This group includes an Irish lineage from County Mayo and an American lineage of unknown Irish origin.

R-M269 > P312 > L21 > DF13 > Z253 (6)

The two documented lineages in this group go back to the area of Cootehill, Co. Cavan, Ireland. Both lineages are notably associated with medicine, and the common ancestor likely lived just beyond what is currently documented. This group may be related to a cluster of McClures, but advanced testing (Big Y) is needed to prove or disprove that connection.

R-M269 > U106 (3)

The common thread amongst the lineages of this group is that they trace back to Virginia in the late 1700s/early 1800s. Beyond that, there seems to be some conflicting information about their origins, particularly in the case of John William McFadden of Rockbridge County. This is also a difficult group to work with genetically because its DNA signature at 67 markers is close to that of a major haplogroup, which can result in hundreds of extraneous matches and sabotage attempts to estimate the group’s age. It would be beneficial for members of this group to test to 111 markers and take the Big Y for those reasons.

R-M512 Group 1 (3)

More information needed about this group.

Ungrouped (13)

In addition to the above groupings, there are currently 13 participants that do not appear to match anyone else in the group. This is likely due to the size of the project and we anticipate new groups will be formed as the project continues to grow.

What’s Next

– We continue to ask men with any surname derived from Mac Pháidín (McFadden, MacFadyen, McFadzen, etc.) to join our project. The more people that join, the more we will be able to learn! More info: DNA Testing FAQ

– While men of any background are encouraged to participate, we are particularly hoping more men with direct links to Scotland will get involved. Is your name MacFadyen, McFadzen, or one of the other distinctly Scottish variations? We want you!

– In order to prove or disprove connections within the project, particularly between men and groups that are M222+, we’re hoping more testers will take the Big Y. More info: The Big Y: What is it and why is it important?

- The biggest hurdle for our project is the cost of testing. We’re pleased that over the past year we’ve been able to sponsor tests for three individuals. If you would like to contribute to our efforts, donations can be made through the following link:

– Don’t forget to follow us on Twitter and Facebook!

As always, please feel free to e-mail me with any questions, concerns, or comments. I can be reached at

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