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Sinclair DNA Study

  • 367 members

About us

Fall, 2016 - Our focus is now on FTDNA's Big Y testing with TMRCA calculation by This is yielding the most incredible information we've ever gotten from DNA testing. I strongly encourage each and every member to order the Big Y test and contact me on the steps to get all that data figured out. Reports will soon be posted to the website outlining exactly what we've found so far.

Fall, 2013 - Please listen in to our Blog Talk Radio show regarding the Herdmanston St. Clair / Sinclair DNA P310 L11 SNP at this link. My guests were Donald Sinclair and Gregg Wilson, both of whom are members of our newly discovered Herdmanston Lineage. In this show, I stress the importance of having SNP matches that fit the narrative of your supposed history. If the SNPs fit with a genealogy or, more critically, with existing medieval land transfer records, then you have a compelling case. Our Herdmanston Lineage has the SNP matches (Mandeville and Wishart, to name but two) AND we've found the medieval documents (the baronies of Eaton Socon and Walkern, to name but two). Read the case at this link.

Summer, 2013 - We've recently discovered the identity of our Mystery Lineage. This is a group in our DNA study who share the SNP P310. The discovery was made possible by testing a living descendant of the Herdmanston St. Clair family. Herdmanston is a farm about 16 miles east of Edinburgh. The same St. Clair family has owned this land since 1162 when they received it from Richard de Morville. Richard was a descendant of the powerful Hugh de Morville, who served as Constable of Scotland under King David I. The de Morvilles were from the department of Manche in Normandy. Based on the fact that our Herdmanston Lineage has an SNP match with the surname Mandeville, and with their Morville (and thus, Redvers) associations, it's very safe to assume they are the living descendants of Saint-Clair-sur-Elle, dep. Manche. More on that at this link.

Fall, 2012 - John Thurso took a test at the request of Shawn Sinclair and turned out to show the SNP Z346*, proving he matches our large Caithness Lineage. John is a descendant of the Ulbster branch of the Sinclair family who descend from George Sinclair, 4th Earl of Caithness. The Sinclair DNA study is currently watching for SNP matches with families who fit the documented history of the Sinclairs of Rosslyn. The Sinclairs received Rosslyn from King Alexander III in 1279. The witnesses to such a gift are a critical clue in claiming descent. The witnesses to the grant of Rosslyn were:
  • Wishart
  • Fraser
  • Umfraville
  • Comyn
  • Fraser
  • Mowat
  • Bisset
  • Graham
The Z346* Sinclair DNA Study members show SNP matches with the name Cumming. This is possibly the same family as the Comyn who witnessed the gift above, but 2 members of the Z346* group have decided it's not. The Wishart connection is curious because our St Clairs of Herdmanston show this name in their SNPs and these two lineages don't share a male ancestor for over 4,000 years. The Bisset name is also curious because it's showing as a match to our Sinclair DNA Lineage of Exeter, New Hampshire. More on the Sinclair DNA Caithness Z346* Lineage at this link.

We currently maintain several websites for the Sinclair family DNA study, serving every variant spelling of our surname. The best way to keep up with these is to follow our website and our blogs - all of which are at 

The news on the Sinclair DNA study is mostly concentrated on SNP studies now. But other news is the continued signup of members around the world. We're averaging one new member per week now.