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Mtdna mutation rates

PostPosted: Mon Jul 07, 2014 7:32 pm
by giorgos
Does anyone how close or far a full mtdna sequence match at 1 step distance can be?

Re: Mtdna mutation rates

PostPosted: Sat Jul 12, 2014 6:11 pm
by GailT
giorgos wrote:Does anyone how close or far a full mtdna sequence match at 1 step distance can be?


It is difficult to predict without more information about your subclade and extra mutations, but It could be between 1 to 500 generations. If there have not been any recent mutations in your maternal line, it would be more likely to be the upper end of that range. If you have many recent mutations, it would be more likely to be at the lower end of that range. Soares et al. estimated a mutation rate of about 1 in 3600 years, but the accumulation of mutations is highly variable, so some people have recent mutations that can make the results more useful for genealogy.

I'm looking at a case now in which a mother and two daughters have all tested the FMS. The mother is a 1 step and 3 step match to her two daughters, and the two sisters are more distant than 3 steps. So there are cases of fast mutation sites that are counted as steps but that should really be ignored.

Re: Mtdna mutation rates

PostPosted: Sat Jul 12, 2014 11:05 pm
by stoeni
GailT wrote:
giorgos wrote:Does anyone how close or far a full mtdna sequence match at 1 step distance can be?


It is difficult to predict without more information about your subclade and extra mutations, but It could be between 1 to 500 generations. If there have not been any recent mutations in your maternal line, it would be more likely to be the upper end of that range. If you have many recent mutations, it would be more likely to be at the lower end of that range. Soares et al. estimated a mutation rate of about 1 in 3600 years, but the accumulation of mutations is highly variable, so some people have recent mutations that can make the results more useful for genealogy.

I'm looking at a case now in which a mother and two daughters have all tested the FMS. The mother is a 1 step and 3 step match to her two daughters, and the two sisters are more distant than 3 steps. So there are cases of fast mutation sites that are counted as steps but that should really be ignored.



do all companies compute genetic distance the same ?

I have a supposedly close match in regards to STR's with someone with a genetic distance of 15 !?

Re: Mtdna mutation rates

PostPosted: Sun Jul 13, 2014 2:24 am
by Gioiello
stoeni wrote:do all companies compute genetic distance the same ?

I have a supposedly close match in regards to STR's with someone with a genetic distance of 15 !?


But mutations in mt and Y are very different, first of all for mutation rate, very slow in mt and much faster in Y STRs. You should compare the mt mutation rate to the SNPs in Y and not to the STRs. STRs mutate forwards and backwards and this makes them unreliable beyond a few hundreds of years. Also this was one of my points (against all I should say), and now it is clear to all. Beyond this, the mt is only 16569 bps and the Y tens of millions.