DNA phasing with data from different companies

Question

If I get tested by, say, 23andme, and my mother is tested by FTDNA, will we be able to do phasing?  It sounds like I can import both results to GEDmatch and do the phasing in there, but I just want to make sure that works out okay with tests from different companies.

Comments

Fantastic question!

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HOW TO  MERGE  2  DNA TEST RESULTS  TO A LADY

GENI.COM  SAYS  IS MY GRANDMOTHER ON

MY FATHERS SIDE....

HOW  IS  THAT DONE???    YES  I DO  HAVE GEDMATCH

BUT  I   STILL  DO NOT  KNOW  HOW TO DO THIS.....

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Nancy, at the top is a tab labeled Post/Ask Question.  Could you ask your question again using that tab please?

Also, it is easier for us to read if you do not use all capital letters.  If your device cannot do that, then OK.

When you ask again in your own question, could you explain what you mean by MERGE 2 DNA TEST RESULTS?  It is not clear what you want to do, or why you want to merge.

Answer 1

There is an issue in doing this as different companies test at different positions. I have not done a direct comparison with 23andMe, but know that ancestry and ftDNA only have about 60-70% of the markers they use in common. An example from my own test data for Chromosome 22:

Ancestry: 10459 markers including 31 null results

ftDNA: 10155 markers including 8 null results

Of these markers only 6326 were at the same locations.

So if you phased between an ancestry parent test kit and an ftDNA child test, then you would lose just over a third of the markers. Phasing like that will certainly not be as good as phasing using the same test companies.

I'd recommend checking the marker match before you go ahead.

Answer 2

Gedmatch can phase results from different companies. One thing you need to be aware of is whether the relevant company’s current chip results can be imported into standard gedmatch. Some require gedmatch genesis which is currently in beta mode.

Comments

23andMe can only go into Genesis. You can put the FTDNA into Genesis as well as into GEDmatch. So you can get all your kits together but the matching pool in Genesis is much smaller until eventually GEDmatch and Genesis merge. You will have to check on Genesis that it provides the sort of tool you want to use.

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I have gotten my mum's test from FTDNA and mine and my sisters' from 23andMe, and we ran phasing in Genesis.

Interestingly when we look at DNA matches for our phased father DNA, she has three times as many matches as I do. Any idea of why?