04 December 2016

Who I am: DNA testing and paternity (part 3)

This is one in a series of posts on the search for my biological family.

My previous Y-DNA test was a 37-marker test, and showed 179 possible matches. I recently paid for the upgrade to the 67-marker test, and just got the results back this morning. According to this test, I have 22 possible matches, but at a genetic distance of 4-7. What this means is that none of the people I match are particularly close. For example, at a genetic distance of 4, the probability that I share a common ancestor with a particular person only reaches beyond 50% at seven generations.

Some of the more common surnames that appeared on the 37-marker test have disappeared. Some are still there, but again, the larger genetic distances does not give me much confidence in the results. Also, there are fewer results because fewer people have done 67-marker (or 111-marker) tests.

Even before getting back these most recent results, I had considered it likely that I would eventually pay for the 111-marker test. But now you can perhaps see, as I do, why this would probably be a waste of time. The test would surely give me fewer results, but they would all be at considerable genetic distances (7+) and unlikely to give me any useful information. What these tests results have demonstrated is that no one who is genetically close to me has taken a DNA test with any of these companies, so no amount of further testing by me is going to uncover anything.

Back to square one...
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