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Heteropaternal Chimera Paternity Testing

  1. May 7, 2015 #1
    Hello, I'm hoping someone can give me some insight to my fears.
    To start, I cheated on my long term boyfriend #1 (whom I'll reference as #1 going forward) with my ex-boyfriend #2(referenced as boyfriend #2) within a 30 hour period. Boyfriend #1 and I don't practice safe sex. Boyfriend #2 and I did use a condom however it broke unbeknownst to me until afterwards. I few weeks later I learned that I was pregnant and when researching online for my calculated due date I discovered that both instances of intercourse were performed on my ovulation date (FYI: I've previously been pregnant with fraternal twins). Both boyfriend #1 and #2 were made aware of my pregnancy and of each other.
    Boyfriend #1 is a darker skin tone African American with straight black hair. #2 is both middle eastern and darker skin toned Puerto Rican heritage with black curly hair and a single dimple nearer to the corner of the lip.
    Fast forward my child is now 7 months old and has genetic features of both men. Courageous family and friends alike ask me if my current boyfriend #1 is her father in a cautiously questioning tone. He too sometimes doubts because of the lack of similarities. The close friends and family that I have disclosed this concern to agree that my child shares a striking resemblance to #2. The "perceived" (I realize this is based on perception of each individual) characteristics shared between child and #1 are few; his family and friends tend who are unaware of the circumstances all speak of only one likeness and that is the eye region (shape of her eyes and arch & thickness of eyebrows) I'll also note that he has closed earlobes and rounded jawline. #2 and child share several "perceived" characteristics such as the black curly hair, the single dimple in exactly the same odd location of the face however child's dimple is on the opposite side of face, skin tone, nose structure, slightly protruded chin, and open earlobes. Child also has two distinct separate patches of skin discoloration, one lighter and one darker than her overall skin tone.
    My dilemma begins here: we have all had cheek buccal swab DNA testing performed and 20/20 alleles matched with #1 and 10/20 matched with #2. Those who are aware along with myself, #1 and #2 were all visibly shocked and in disbelief by the results. After the shock #1 is elated and #2 is in denial. #2 did some research and has explained to me the probability that child may be Chimera having two separate DNA, one in her tissues and a separate one in her blood. He reasons that I could have released two eggs and he fertilized one and #1 the other however instead of having fraternal twins the eggs fused. He now wants me to take child to a hematologists or have a blood DNA test performed. Is this wishful thinking or a true possibility?
  2. jcsd
  3. May 7, 2015 #2


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    As far as I know that's never been reported, I'm not even sure if it's possible. All accounts of chimerism I've read have been the same father, it strikes me as likely two fathers couldn't make a chimera due to graft vs host disease.
  4. May 7, 2015 #3
  5. May 7, 2015 #4


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    Nothing in that link suggests chimerism with multiple fathers is possible.
  6. Jun 24, 2015 #5

    I've been doing a lot of reading on this subject. The peer reviewed link above indicates a possibility of heteropaternal chimera.
  7. Jun 24, 2015 #6
    So what are you asking?

    If it is possible to have chimerism with two fathers?

    Of are you asking who is the father of the child?

    A DNA test has certain PCR primers that have a certain known probability to produce identical results for two random persons. They should know in the lab how likely the result you got is. Saying 20/20 and 10/20 means nothing. They can both or neither be the father.

    Donno why you talk about dimples and law lines.

    Anyway, does it really matter who the father really is? If so, maybe you should have thought about this beforehand. If not, follow that instinct that made you go down this path in the first place.
  8. Jun 25, 2015 #7


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    Minor point but that isn't a peer-reviewed source. It is an answer from a prominent university though. However I don't see anything in the article that supports heteropeaternal chimerism. It mentions the phenomenon of one twin absorbing another but as far as I know there's not any known cases of the two being half brothers with different fathers.
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