Is it possible to match someone else's DNA in very nearly the exact same location on BOTH sides of a
So I have a lady that I match DNA on chromosome 13. There are a number of people that we both match on that same sequence. But there are a number of other people that we both match on that same sequence that DON'T match the first group. Could she and I match on both sides of that part of the chromosome?
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Hi Anne,
I think the short answer is it's possible but unlikely. I'm concerned that I don't know what you mean by "both sides" - can you clarify? I wonder if what you're seeing & describing is actually neighboring or somewhat overlapping regions rather than complementary sequences. Hope I can help further with additional understanding.
Best, E
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okay. Chromosomes have two strings. One side comes from my mother. One side comes from my father. Is it possible that someone is a DNA match to my father, and therefore me at the exact same length on Chromosome 13 as that same person matches my mother, and therefore me on the same length on the other side of my Chromosome 13? I figure it would be highly unlikely, but possible. I'm not quite sure what I'm seeing on my Chromosome 13, but there seem to be three groups of people matching on my Chromosome 13 at the same length. If I only have two strings (mother and father) on my chromosome, how do I get three different groups at the same place? I know that trisomy (three strings on a single chromosome) can exist (Down's Syndrome and others) but so far as I know I am normal...😁
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Gotcha, that was helpful. So I think we're both in agreement that it's possible but unlikely. One thought is that I've seen some sites include tools that show a match at a location if it is similar to some high percentage but not always 100% so I guess that's possible also as an explanation of how you get two & three groups that match you in one region. Or perhaps they have partially overlapping sequences in the region (for example group A matches your sequence from base 1 to 150 and group B matches you from base 85 to 165) but it sounds like you're saying the matching regions are identical in location and length so I don't think that would explain having several distinct groups of matches. Have you seen if your mother and father match each other in that region? I guess if it is a highly conserved sequence that is also possible. If there is a way to include a screenshot without disclosing anything private I (or someone else) might be able to give a more definitive answer.
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Right. Actually not on my DNA, on my grandmother's who is the farthest back we can go. So splitting to mother's or father's line is interesting. Yes, i was working on a couple of screen shots to show what I was seeing Let me finish them and see if you can see anything I am missing.
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