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View Full Version : Using 23andMe plus YSEQ to Evaluate Potential NPEs and Paper Trail Errors



Mac von Frankfurt
07-31-2015, 03:01 PM
I am extending my Y-DNA testing to determine the terminal SNP for myself, and assumably, an ancestor that immigrated to North America in 1750. Once my testing is complete I will be able to state that ancestor X, born in European City Y, has a terminal SNP of Z. Of course this statement could be wrong for a variety of reasons including the occurrence of non-paternal events (NPEs) and/or a wrong turn(s) along the paper trail.

The IIOGG estimates the probability of an NPE within 300 years is 8 to 22 percent. I like to think the probability of a wrong turn on the paper trail is small but it is not zero. So a ballpark lower bound on the combined probability of ancestor X not actually being my ancestor is 10 percent. This might be acceptable in a large surname study but I am working with a rare surname as well as a rare haplogroup for the region in Europe. Some confirmation of the result seems in order.

I propose to reach out to other descendants of ancestor X in hopes of identifying a few individuals from diverse parts of ancestor X’s descendant tree who are willing to do some Y-DNA testing. I am proposing to start with 23andMe ($99) and then, if they match my R1b-L21 result, follow-up with the L21 panel at YSEQ ($88). This seems like an economical approach to reducing the uncertainty associated with NPEs and research errors.

All constructive comments on my concerns and approach to address them are welcome.

Edit: On the way into work it occurred to me that a $17.50 single SNP at YSEQ would probably be sufficient.