Parent/child FTDNA match

[Annie65115]

My daughter's results are back and thankfully it would appear that she is indeed my daughter! Hurrah! (I do remember giving birth so I wasn't in too much doubt!!)

But there's something I don't understand. Obviously she should have inherited 50% (ish) of her DNA from her dad, but on the chromosome browser it shows a match with me across the length of every single chromosome. How come?

[hurworth]

That is exactly what you would expect to see.

She has 46 chromosomes - 2 copies of each.  One from you and one from her father.

So what you are seeing is that she matches you across every chromosome, because she she received one of each pair of chromosomes from you.

[Annie65115]

ah, I knew the answer would be stupidly simple (and me just stupid!)

thank you

[hurworth]

On FtDNA it just shows where you match.  Not whether you are a half-match (a match on one chromosome) or a full-match (on both chromosomes) at that segment.  Full siblings would have quite a few segments where they match on both chromosomes.  And identical twins would match fully, but on the chromosome browser it would look the same as you and your daughter.

Over on Gedmatch there is a one-to-one tool which can do it.  You shouldn't be a full match anywhere with your daughter unless you and her father are somehow related.

[Annie65115]

I've got us both on gedmatch now (my daughter's file wasn't ready last night but it's all through now!)

I see what you mean about full/half matches on the 1-1 screen. However, there are a few bands of full match (and the occasional tiny sliver of no match!)

I ran the "are your parents related?" tool which confirmed that there was no sign of consanguinuity between me and her dad (that's a relief!!)

So these occasional intermittent bands of full match - I guess that is par for the course and only to be expected by chance??