How to Determine Paternity with Autosomal Markers

[Padgett]

I have received the results of both mine and my father's Autosomal Panel 1 markers today.....I did this test now that he is deceased to confirm once and for all that he is in fact my biological father. Some members of his family are not convinced and I never actually met him (I was raised by my step-father).

I'm not sure how to read the results.

We each have two numbers by each marker and in some cases none of those numbers match one another.

For example: his D13S317 is 11, 14 and mine is 12, 13

[Jim Honeychuck]

If you don't get an answer, search the archives. I don't recall this ever being discussed here. If I'm not mistaken, paternity testing uses different markers from the autosomal markers used in population studies.

Good luck in your research.

Jim

[tomcat]

I think a comparison of your Y results would be the most definitive test of paternity. But you should match on one allele at each autosomal locus. You might email Dr. Thomas Krahn and ask him for his opinion on this matter.

[Padgett]

I am female, so testing on Y is not an option.

The autosomal test description when I ordered indicated that it was used for paternity.

[haplogroupc]

Do you share any matches with your father? How many markers?

[Padgett]

We share at least one allele on 10 out of 14 markers. I'm still waiting on his Penta E result.

The markers we do not share an allele are:

D13S317
D18S51
D8S1179
FGA

We share both alleles on the following markers:
CSF1PO
D7S820
vWA

[haplogroupc]

We share at least one allele on 10 out of 14 markers. I'm still waiting on his Penta E result.

The markers we do not share an allele are:

D13S317
D18S51
D8S1179
FGA

We share both alleles on the following markers:
CSF1PO
D7S820
vWA

I have a similar situation with my mom. We don't share 2 markers in common but we have the same exact mtDNA. And we look exactly alike so we're definitely related.

[tomcat]

...
For example: his D13S317 is 11, 14 and mine is 12, 13

In this example you could be off by a single repeat. Are all the non-matching results this close numerically?

[Johnserrat]

I have a similar situation with my mom. We don't share 2 markers in common but we have the same exact mtDNA. And we look exactly alike so we're definitely related.

I wonder if the autosomal tests are giving flawed results. There should really not be this amount of variation in the result. At first glance a person could conclude that they are not related under these circumstances as you would expect to share one allele on each marker.

It is good that you have a mtDNA match! FTDNA should definitely address this issue before a lot of people start believing that their parents are not really their parents.

John

[Padgett]

Yes, all of the non-matches are one away numerically.

For example:

my FGA = 21, 21
his FGA = 19, 22

my D13S317 = 12, 13
his D13S317 = 11, 14

[tomcat]

Yes, all of the non-matches are one away numerically.
...

Well, then there IS the possibility that some alleles added or dropped repeats. I tested most of my siblings autosomally and did not see this occur but have seen 3 possible instances in sibling X chromosome STR results. It happens.

Again, expert opinion is just an email away - Dr. Krahn at FTDNA.

[Padgett]

I'm still waiting on one additional marker and the folks at FTDNA will perform the analysis for me and provide a report indicating what percentage of liklihood that my father is in fact my father versus another random male in the population.

My own research over the weekend has me doubting things. According to what I've read, if you mismatch on 3 or more markers, the alleged father is excluded from paternity. I have a mismatch at 4 markers. There is the possibility of mutations, but unlikely to have occurred several times. I also read that a mutation will usually only be one off and usually moves upward. I have a case where my father is 13, 13 and my alleles are 11, 12. While the 12 is one off, it's lower than his 13.

The wait for that additional marker is driving me crazy. While I never met my father, it is alarming to think that he wasn't in fact my biological father. My mom and I will need to have an interesting talk......

[tomcat]

Knowing is better than not knowing.

And a statistical probability may be the only available fact.

[Padgett]

They were able to complete the analysis without the last marker. Since we are mismatched at 4 markers, the result of the final marker will not change the results.

My presumed biological father is 100% excluded from being my father.

I guess I have a whole entire new set of DNA to find and test. Hopefully, he will want to be found.

[Kathleen Carrow]

Padgett,
I wish you the best with this information..it is brave of you to seek it and was important enough for you to try to find out.
My Dad did not know who his father was( he had a stepfather also)..so as a consequence I do not know my Grandfather's ethnicity or identity.

My grandmother most likely had my father with a similar man to the Merchant Marine Norwegian sailor she later married.My autosomal DNA looks highly Polish..grandmom's romances in the early 1920s when Dad was born were said to be young foreign sailors she met in the Inner Harbor in Baltimore. Dad's birth certificate which I was able to get and supposedly he never did, gave a name of Louis Saybold..which seems to be Polish, Estonian or something very similar.

When Grandmom died My "Grandpop" Dad's stepfather referenced himself as Dad's father.My Dad ( a gentle man) said "But you're not my father..I don't know who my father is..."
So I think there is a likelihood of someone like him being my real GF..which is cool..

I feel like Dad must have asked his Mom also..but he did not know..

I hope that you figure it out..
as Tom said "Knowing is better than not knowing.
And a statistical probability may be the only available fact"

I commend you for your courage..
Kathleen