GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2010-03 > 1269953773


From: William Hurst <>
Subject: Re: [DNA] Need Help In Understanding and Using the Term "SNP"
Date: Tue, 30 Mar 2010 09:02:05 -0400
References: <260c.4d6239cb.38e345af@aol.com>
In-Reply-To: <260c.4d6239cb.38e345af@aol.com>


Hi Ann and all,

Ann wrote:

>.... A SNP is a spot in the genome which is known to vary in the population.

It seems to me that the SNP concept is more useful in Y-DNA than mtDNA. Finding a new Y SNP may be a cause for celebration. FTDNA starts selling it; trees have to radically revised. But in mtDNA hardly a week goes by that I don't see some coding-region mutation which I've never seen, at least in K. Sometimes I look them up on the mtDB database and they are not listed. (Unfortunately, that database is not being updated and is getting less and less useful.) Yesterday, one of my Project members got his FGS results back. He had one extra coding-region mutation that I hadn't seen. It's not listed on mtDB. My Project member had one FGS match. I invited that person to join the Project; he did. Now there are at least two people in the world with that mutation. Is that a SNP? Technically probably not. I don't care. I don't treat it differently than the next mutation which may be shared with seven Japanese sequences on GenBank.

When I started in this business or hobby or whatever, Y SNPs were considered to be Unique Event Polymorphisms (UEPs). Now some of those mutations are starting to be found in other places. That's very common in mtDNA, of course. I've tried to find mtDNA mutations which are UEPs or near-UEPs. Some of those are in the HVR; 497T, for example, which defines K1a which is about 60% of K. That HVR2 mutation is much more stable than 11914A, the coding-region mutation which defines K1a1, but which shows up elsewhere on the K tree and in many other haplogroups.

OK, now you can go back to STRs and Family Finder. Mutations are at least as interesting as cousins. They don't borrow money and you don't have to send them Birthday cards.

Bill Hurst





This thread: