Can a non-match actually be related? ie false negative.

[capeflier]

Hi I am hoping someone can shed some light on what I think are unusual results. I have a predicted 4 cousin once removed I am 7 generations to our common ancestor and the other tester is 6 generations.
Our 67 marker y dna test results show 54/67 a non match. This seems way too high to be a random non match result,

Our FTDNA family finder results analyzed at GEDmatch because they dont show up as a match at FTDNA 127.04CM Total shared over 1CM with largest single of only 4.9cm

We have a total of 48 shared regions of over 500snps greater then 1 cm covering almost all the chromosomes
> 1 cm 48 shared segments total127.04
>2 CM 35 shared segments total 106.32
>3 CM 16 shared segments total 55.95
>4cm 5 shared segments total 22.95
>5 cm 0
largest single is 4.9 which is below the match threshold but the total shared segments are higher then ANY of my actual other matches.

I am reasonably certain this person really is my 4th cousin but can not explain how two different technologies have such close to a match but yet are non match results.

Anyone have any thoughts on how I should interpret these results.

Thanks mark

[k.o.gran]

Hi I am hoping someone can shed some light on what I think are unusual results. I have a predicted 4 cousin once removed I am 7 generations to our common ancestor and the other tester is 6 generations.
Our 67 marker y dna test results show 54/67 a non match. This seems way too high to be a random non match result

Hi Mark,

Just to be 100% sure... You both have direct paternal lines to your common ancestor?

[capeflier]

Hi Mark,

Just to be 100% sure... You both have direct paternal lines to your common ancestor?

The common ancestor is by direct paternal unbroken father to son by both of us. This is part of an effort to solve an adoption puzzle but we have ample other non dna related evidence that I have the families right including my mothers direct statements. My father was in my area only one week of his life the week I was conceived .
Thanks, Mark

[nathanm]

Hi I am hoping someone can shed some light on what I think are unusual results. I have a predicted 4 cousin once removed I am 7 generations to our common ancestor and the other tester is 6 generations.
Our 67 marker y dna test results show 54/67 a non match. This seems way too high to be a random non match result,

Our FTDNA family finder results analyzed at GEDmatch because they dont show up as a match at FTDNA 127.04CM Total shared over 1CM with largest single of only 4.9cm

We have a total of 48 shared regions of over 500snps greater then 1 cm covering almost all the chromosomes
> 1 cm 48 shared segments total127.04
>2 CM 35 shared segments total 106.32
>3 CM 16 shared segments total 55.95
>4cm 5 shared segments total 22.95
>5 cm 0
largest single is 4.9 which is below the match threshold but the total shared segments are higher then ANY of my actual other matches.

I am reasonably certain this person really is my 4th cousin but can not explain how two different technologies have such close to a match but yet are non match results.

Anyone have any thoughts on how I should interpret these results.

Thanks mark

You might be related, but probably not via paternal lines. A genetic distance (GD) of 13 is too high for that relationship. According to the FAQ, 54/67 means "Not Related" (within 15 generations).