DNA Matching and blood typing- Please help me

[HK Cronk]

I will try to make a very sordid and long story as short as I can. I have been seeking the truth to my parentage particularly in reference to my father. After many years my aunt came forward and said she wanted to be tested to see if we were in fact related as she is the only surviving sibling and who I was told was my father has been dead for decades. The reason why I know he isn't my father is due primarily to blood typing. I am AB RH Neg and he was 0positive. According to ALL the blood charts this is an absolute impossibility. I have proof of his blood type via Military medical records. The DNA came back for my aunt and I and we share 1838 centimorgans over 67 strands. In short it blanky states that we are close family- first cousins, aunt or half sibling. First cousins has been ruled out as my "dad" was the only boy. She cant be my aunt as the blood typing negates that possibility. My only conclusion is she is my half sister! I have downloaded my dna from both Ancestory and FDNA on to GED Match and am hoping she allows me to so the same for her DNA to hopefully draw a more substantial case for us being half siblings. I am just needing some direction. Blood typing is pretty cut and dry, But need some input as to what else I could do that would prove my case even more despite having my uncooperative mother finally talk. she has been silent for over 50 years.. in short my whole life. I am so close to the answer I just want to be sure I have the scientific data to prove my case before I proceed with going to my loved ones with the information...

[mattn]

I will try to make a very sordid and long story as short as I can. I have been seeking the truth to my parentage particularly in reference to my father. After many years my aunt came forward and said she wanted to be tested to see if we were in fact related as she is the only surviving sibling and who I was told was my father has been dead for decades. The reason why I know he isn't my father is due primarily to blood typing. I am AB RH Neg and he was 0positive. According to ALL the blood charts this is an absolute impossibility. I have proof of his blood type via Military medical records. The DNA came back for my aunt and I and we share 1838 centimorgans over 67 strands. In short it blanky states that we are close family- first cousins, aunt or half sibling. First cousins has been ruled out as my "dad" was the only boy. She cant be my aunt as the blood typing negates that possibility. My only conclusion is she is my half sister! I have downloaded my dna from both Ancestory and FDNA on to GED Match and am hoping she allows me to so the same for her DNA to hopefully draw a more substantial case for us being half siblings. I am just needing some direction. Blood typing is pretty cut and dry, But need some input as to what else I could do that would prove my case even more despite having my uncooperative mother finally talk. she has been silent for over 50 years.. in short my whole life. I am so close to the answer I just want to be sure I have the scientific data to prove my case before I proceed with going to my loved ones with the information...

Why would you think she is your half sibling? What is your age difference and who do you think the parent you share is? Would you share a mother or father? Seems far fetched to me, I would say she is most likely your aunt. Blood tests can be wrong.

[ech124]

In your familyfinder account, you want to run the "in common with" feature between you and your "aunt".

Hopefully you have already done paper trail research to compile a detailed ancestral history of who you thought were your paternal grandparents.

Using the "in common with" cluster, look for those that have also done detailed trees. If your aunt is a full aunt, then some of those cluster will be DNA from the grandfather and some from the grandmother. If you find a mixture of trees, some pointing to one branch and some pointing to the other, it is extremely probable that this is your full aunt, since you would carry some DNA from both branches. This method is just an additional tool in the mountain of evidence you need to examine.

[HK Cronk]

Blood typing is different than testing. My grandfather was a known philanderer.. it is him that I believe to be my real father. As I said it is a very sordid story. But not far fetched, sadly. I have every reason to believe that this is HIGHLY likely.

[John McCoy]

The blood types won't lie, and if you have autosomal DNA samples, they won't lie either, for relationships within 2-3 generations. They may be ambiguous, but there should be few enough possibilities that you can systematically sketch out each one and use the genetic data to rule out some of them.

I highly recommend the classic little book by Sissela Bok, "Secrets: On the ethics of concealment and revelation". An easy read, and an excellent way to clarify the issues. It is important to understand how family secrets affect those who keep them and those who are kept from knowing. You have every right to know.

[prairielad]

I am assuming you are male, but if not and are female, and grandfather is your father you will share your entire X with your paternal aunt.

If male, X will not help in determining as there is no X transmission from father to son (sons get the Y)

[mattn]

Blood typing is different than testing. My grandfather was a known philanderer.. it is him that I believe to be my real father. As I said it is a very sordid story. But not far fetched, sadly. I have every reason to believe that this is HIGHLY likely.

Then see if your Aunt has a 1st cousin or close relative from her mother's side that will test. If you are related to the mother's side relative than she is proven as your Aunt.