Dna type guidance please

[Heather Positive Thinker]

Now, I have someone who has long shown on paper he is my distant cousin - thing is, he has had a dna test now and we have no match!!

So, does this mean someone has dallied outside the gene pool somewhere? Or is there any other reason this could happen?

[Olde Crone Holden]

How distant? As far as I understand it, the shared DNA is lost by about the fourth generation away from the common ancestor. (If you are talking about autosomal DNA). We only inherit APPROXIMATELY half our DNA from each parent - that is just a statistical average. You might inherit more of your father's DNA and less of your mother's for example, so you can see that eventually any common DNA is "lost".

OC

[Heather Positive Thinker]

Hi OC, well it would be 5th cousin. However, may be you are right as on dads side Ive had connections back to 1520!

[Anne in Carlisle]

Entirely depends on the type of test. If it was Y-dna, the he wouldn't match you because you are female!
Anne

[Heather Positive Thinker]

He had autosomal anne, same as I had.

[Olde Crone Holden]

Well, funnily enough Heather, today's Lost Cousin newsletter answers some of your query. Basically what I said upthread but he goes into more detail.

Let me know if you don't have a link to the newsletter and I'll put it on here

OC

[Heather Positive Thinker]

Oh please, OC Im off to bed now, but look forward to reading it tomorrow.

You know, my sister is blond, blue eyed and has the hanson neck problem and I always looked like a cuckoo in the nest. I wonder if I could get her to do a test as she is much more like mums side in nature than I ever was. Mum used to say to me, "You are your father's daughter" because we were/are so alike in nature. Be interesting if I could get sis to take a test to see if it picks up more of mums distant rellies.

[Olde Crone Holden]

Hope this works, Heather. Let me know if it doesn't!

http://lostcousins.com/newsletters2/midjul15news.htm

I have three daughters. Two look very like me, one doesn't look like me at all but does look like my paternal grandmother! She (my daughter) has just been diagnosed with psoriatic arthritis. My mum had this but none of the rest of us have it.

He says in that article in the newsletter that you do have to find the right family member to take the test, so your idea of getting your sister to take the test is a good one!

OC

[PhotoFamily]

Part way down this page, in a table beginning "Average autosomal DNA shared"

http://www.isogg.org/wiki/Autosomal_DNA_statistics

My father does not share "significant" segments with his 3rd cousin - but there's plenty of other matches with other cousins on this ancestral line to be certain that everyone is who they appear to be on paper I'm told that 10% of 3rd cousins do not share significant segments.

My father does share two segments >6cM but < 7cM with his 3C. At least one is validated with matches with other cousins. I don't know where you and your cousin tested, but gedmatch.com will accept results from the Big Three (AncestryDNA, 23andme and familytreeDNA) and allow you to directly compare your two kits.

So, the gist of this is: once you move beyond 2C, there are diminishing chances that you'll share significant segments. But it's worth a try.

It's very difficult to prove a very distant "NPE" using autosomal DNA.

[Heather Positive Thinker]

Many thanks, thats reassuring - knowing the women in my line, I couldnt imagine any outside dalliances as all of the people involved have been very religious and as they were knocking out kids every year, cant imagine they had time anyway

The paperwork for the match with distant cousin is absolutely correct - as you say, I must have got more of dads dna and sis clearly has more of the Hanson bunches with her colouring and manner. Now, big problem is, as a Hanson she will have most definite ideas about everything and if she says no to a test, that will be it

Thanks for that OC, very kind of you x