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Wearin' o' the genes

It's been more than five years since I took a DNA test to look for my Irish cousins, and the bad news that I'm still looking. But the good news is that my genetic quest has linked up people around the world who didn't know they were related.

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The secrets of your family heritage
lie in the molecules of your DNA.

The genetic gambit represents my effort to break through what genealogists call "the brick wall" - the dead end you reach after you've digested all the records you can get your hands on.

Using the Internet as well as written records, I managed to track down all the branches of my Boyle family tree leading back to my great-grandfather, Michael Boyle, who came to Iowa from County Clare during the depths of the Irish potato famine. I even found a rare set of records proving the connection between Michael Boyle's wife, Ellen Howe, and the present-day Howe homestead in County Clare - which I first visited back in 1999.

I got to know so much about the Boyles in that area that I was certain genetic testing would confirm a family relationship - but when the results came back, I was surprised to find that the most likely candidates weren't at all closely related to me.

That was only the beginning of my sleuthing. Since then, I've taken an even more involved DNA test, offered through the Sorenson Molecular Genealogy Foundation. I've entered my profile into a variety of databases, such as the Genographic Project, Ybase, ySearch and Relative Genetics. I've even taken charge of my own Boyle surname project at Family Tree DNA, with 14 people tested so far. In honor of St. Patrick's Day, I'll be updating my own genetic genealogy database over the weekend.

One of the possible "cousins" I met during the first visit to Ireland, John Joe O'Boyle, passed away a couple of years afterward. But when I returned to Clare in 2003, I met his son, Kieran O'Boyle, and brought a DNA sample swabbed from his cheek home with me for testing. For good measure, I arranged yet another test for another Boyle who traced his family back to Clare - Noel Boyle, an Australian who became an occasional e-mail correspondent of mine.

Now I had two more chances to find a connection to my own family tree. I was also prepared to learn that there was no relationship at all.

There was yet another surprise in store, however: Neither Kieran nor Noel were related to me. But they were related to each other. Their genetic profiles were identical!

Although there's a teeny-tiny chance that two unrelated people with the same surname could have the same DNA markers, Noel himself confirmed the connection in a follow-up e-mail: "I did not know at the time that I had a connection, but when I checked further I found out his name. Kieran O'Boyle."

On the other side of the sea, Kieran had no idea that Noel existed until I called him in Ireland today - and he's looking forward to the contact information I'll be passing along this weekend.

But wait ... there's more: Both Noel and Kieran appear to be related to yet another mystery cousin in Michigan. James Boyle's genetic profile is identical to that of the other two, even though James was always under the impression that his Irish ancestors came from County Donegal, not County Clare.

James told me today that he's been working on his family tree off and on for years, tucking all the records away in a box. "That's my treasure box," he said. "Nobody's allowed to touch that box except for me." But nothing in the box was able to show a link to particular people living on the Emerald Isle. It took a DNA test to do that.

So far, that triple play is the only match I've turned up through the Boyle surname project, but it's a doozy. And as time goes on, more people are likely to get tested and add their results to the database. (There's yet another Boyle project under way at Relative Genetics, coordinated by Bonnie Boyle Harvey.)

Someday, I'm sure there'll be a perfect match for my genetic profile - and that could solve at least some of the riddles surrounding my family tree. Just as Internet databases helped me map all the connections leading to Michael Boyle in the mid-1800s, DNA databases will likely help me (or my descendants) write the earlier chapters in the family saga.

Obviously, you don't need to be Irish to benefit from genetic genealogy (though you could argue that everyone's Irish on St. Patrick's Day). Just this week, NBC's TODAY show highlighted the case of a black woman who expected to trace her lineage back to Africa, but discovered through DNA that she was also related to a white Missouri cowboy.

Genealogy is said to be the country's second most popular hobby, right behind gardening, and you can see that popularity in the numbers and varieties of Web sites out there: RootsWeb is a fantastic resource that pulls together many links and databases, and Cyndi's List offers a comprehensive directory of Web sites related to genetic testing and family history.

You can learn more about the science and history behind family trees by clicking into our "Genetic Genealogy" section here on MSNBC.com. If you're interested in the more traditional techniques for genealogical research, this archived article is a good place to start.

Do you have a family saga with a genetic twist? Feel free to tell your tale in the comments section below.