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Emermouse
09-07-2012, 03:53 AM
I have an idea for a story in which case, a couple, well their relationship was on the fritz, the lady went out, had a little too much to drink and had a one-night-stand. It was a completely meaningless one-night-stand and she practically forgot about it and later when she discovered she was pregnant, she assumed her husband was the father.

Years later, some routine bloodwork (the kid's a high-functioning autistic but suffers from nothing else really) reveals that her husband isn't the kid's biological father, which sets in motion an ugly divorce. My question is what kind of bloodwork could unintentionally reveal the truth about a kid's paternity? I've considered using the blood type trick--I heard somewhere a kid will either have his mother's blood type or his daddy's, none of that recessive/dominant stuff usually seen in genetics--but I'm not one hundred percent sure on that theory. Anybody wanna help me out?

Kitty Pryde
09-07-2012, 04:00 AM
Blood type is inherited, or at least the genes that determine it are. If mom and dad are type O, but kid is a, b, or ab, that would indicate that dad is not the genetic father. Or if mom is A, dad is O, but kid is B or AB, that would also work. I could give a long winded explanation if you really want.

lac582
09-07-2012, 04:00 AM
The Rh factor will be the easiest. That's whether the blood is positive or negative. Positive is dominant, so in your scenario, if the mother and father both have a negative blood type, but the child's is positive, then the father MUST be someone else who also has a positive blood type.

Emermouse
09-07-2012, 04:10 AM
Thank you for confirming I wasn't completely off-base with my blood type idea. Nice to know not everything I learned on Unsolved Mysteries was completely wrong. Just out of curiosity, what kind of routine run-of-the-mill testing would turn up this kind of stuff? Because all through my childhood, the only time I think I recalled getting blood typed was when I donated blood when I was seventeen and I want the paternity to be revealed when the kid is young. Any suggestions as to the routine tests or illnesses that would reveal this kind of thing?

lac582
09-07-2012, 04:13 AM
I don't know about routine, but if the kid needed a blood transfusion they'd check his blood type first.

shaldna
09-07-2012, 10:31 AM
As a note - I used to work for the National Blood Service back in the day, and you'd be shocked at how many people have no idea what their blood type is - and even less interest.

Routine tests wouldn't show anything that would raise paternity questions, and, even if it did, if it's not related to the issue at hand, the doctor probably wouldn't even mention it - bear in mind that he'd have to know the (supposed) father and mothers bloods etc to have a comparison.

As mentioned above, the easiest way, and the most blieveable, would be a Rhesus issue.

MAP
09-07-2012, 11:05 AM
Blood type could work. When someone is going under for surgery, sometimes family members can donate blood. So the kid could need some sort of risky surgery. At that point, everyone would need to know their blood type in order to know if they can be donors or not.

But the doctors told me my kids' blood type when they were born. So they might figure that out earlier than you would want them to. My husband and I are both O positive, so it's a good thing I was faithful or my husband would know immediately that something was up if our kids were anything but O. :)

jaksen
09-07-2012, 03:52 PM
I taught science and biology for many years. Before the fear of AIDS we could routinely type every student's blood in Bio class. I typed myself and I was AB+ so my blood would 'coagulate' in all the serums we used. (That way I knew if everything was working right.)

(Btw my father was B and my mother A.)

Moving on, a colleague who worked with me had a student discover she was type A blood. Turned out her Mom was O and so was her dad. This is not possible, so when she told her parents hey Mum, Dad, I'm type A!

Fireworks. The school got a nasty phone call. We teachers were hauled into administration. Long story short, we'd done the test for years; it was something almost every Bio class did in our district, blah blah. We'd done nothing wrong, (at the time.)

The parents had to tell their daughter that she was the child of a 'former boyfriend,' but that her parents knew this was the case already. They just didn't like the way she learned about it.

Back to me:

I am type AB+. My husband is type 0. None of our children have our blood types. I have two B children and one A.

I gave one of my children an A gene; the other two got the B. My husband contributed his O - which means he carries neither A nor B. (Children can have diff. blood types from either or both parents.)

The girl in my story, though, needed to get the A from someone. Since both parents were O, she had to have gotten it from someone else - her mom's old boyfriend.

In years gone by you could 'rule out' a man as being a father by virtue of his blood type. You could not positively tell who was the father, though.

(A and B types are caused by little proteins on the surface of the red blood cell. If you are A you have type A proteins; if you are B, you have type B. If you are AB, you have both proteins hanging out on the surface of your red blood cells. If you are O (zero), you have neither A nor B.)

Cyia
09-07-2012, 04:18 PM
The Rh factor will be the easiest. That's whether the blood is positive or negative. Positive is dominant, so in your scenario, if the mother and father both have a negative blood type, but the child's is positive, then the father MUST be someone else who also has a positive blood type.

Except that if the Rh factors don't match, mom will likely know before the kid is born. The baby's blood type can react to the mother's.

There was a case here a few years ago where a man was getting some bloodwork done and discovered that he didn't carry the gene for cystic fibrosis - which was news to him, as his son had been diagnosed with the disease at a very young age. His first response was to question the diagnosis, hoping that the doctors had been wrong and that his son suffered from something less critical and more easily treated. Paternity didn't occur to him until after the CF test came back positive again. Since both parents had to be carriers to pass the condition along, he couldn't be the boy's biological father.

There are any number of genetic conditions for which both parents have to be carriers if it's going to express in their offspring. Find one and have your kid join a case study or treatment study or some such. When they draw mom and dad's blood for the study, they'll see that dad doesn't carry the necessary gene.

Mrs. de Winter
09-07-2012, 05:49 PM
Except that if the Rh factors don't match, mom will likely know before the kid is born. The baby's blood type can react to the mother's.

There was a case here a few years ago where a man was getting some bloodwork done and discovered that he didn't carry the gene for cystic fibrosis - which was news to him, as his son had been diagnosed with the disease at a very young age. His first response was to question the diagnosis, hoping that the doctors had been wrong and that his son suffered from something less critical and more easily treated. Paternity didn't occur to him until after the CF test came back positive again. Since both parents had to be carriers to pass the condition along, he couldn't be the boy's biological father.

There are any number of genetic conditions for which both parents have to be carriers if it's going to express in their offspring. Find one and have your kid join a case study or treatment study or some such. When they draw mom and dad's blood for the study, they'll see that dad doesn't carry the necessary gene.

Yes, but only if the mother is Rh- and the baby is Rh+. And even then, I believe they usually don't type the baby's blood before it is born--I think the mother is just treated as if the baby could be Rh+. I am not sure if they would type the baby's blood after delivery. If the mother is Rh+ and her baby is Rh-, there is no compatibility problem and no reason to worry about the baby's blood type.

OP, blood type is still determined by recessive, dominant or co-dominant genes, so it is not entirely correct that a baby will have either the mother's type or the father's type. Using the Rh example again, Rh+ is dominant over Rh-. So if my husband and I both have Rh+ blood, we could still have children who are Rh- because we could be carriers for the recessive Rh- gene. But if my husband and I are both Rh-, we can't have a child with Rh+ blood--unless my husband was not the father. The same can be true with O, A, B or AB blood type. Here is a good link showing co-dominance with ABO blood type and how two parents can have four children, each with a different blood type:
http://ghr.nlm.nih.gov/handbook/illustrations/codominant

This is a good link showing how Rh factor is inherited:
http://www.yalemedicalgroup.org/stw/Page.asp?PageID=STW026858


If the child needed something like a blood transfusion or a transplant of some type (bone marrow or organ transplant), that would be a plausible scenario in which the child and the parents would get their blood typed.

The genetic disorder idea from Cyia is an interesting one too.

LJD
09-07-2012, 06:11 PM
IIRC, both in Midnight's Children (Salman Rushdie) and The Geometry of Sisters (Luanne Rice) such a device was used (the blood type of the child wasn't possible if both of his parents were actually his (biological) parents).

If the doctor realizes that the kid can't possibly be the father's due to unrelated testing, s/he's not necessarily going to reveal that to the father. (http://www.menshealth.com/best-life/fathers-and-kids-parenting-fraud?fullpage=true) Though he might figure it out himself if he knows the results for both him and his child...

Emermouse
09-08-2012, 04:22 AM
Thank you everyone for the advice. My head is spinning with all the info I've learned about blood types. I think I'll make the parents both type O while the kid's type A, but I'm still trying to figure out under what circumstances this is all revealed. As many have pointed out, it's unlikely the doctor will reveal this fact himself. I've been thinking of making husband a phlebotomist, figuring that given the nature of the field, he'd know something about blood types (if I'm wrong please pipe up and tell me) but I'm still working on some of the steps in between. Again, I'm trying to think of what kind of routine testing would reveal all this and all that. In my story, the kid's fairly healthy, so it can't be cystic fibrosis like someone suggested.

Man, this is more complicated than I thought. Is there a way I can have Husband find out about the kid being the product of a one-night-stand without the cheap "Other guy was black" trope?

LJD
09-08-2012, 04:57 AM
A lot of people do have basic knowledge of how blood types work. As Jaksen says, it is taught in high school bio (maybe not everywhere...but I remember doing it, too).
Even if it wasn't, if the father was in any way suspicious, it could be looked up fairly quickly.
I don't think you need to go as far as making the guy a phlebotomist.

I think It's simply a matter of getting a way for all of them to know their blood type, and I can't say I know much about that.
My bf knows his blood type from donating blood, I think. I'm pretty sure what mine is--my parents told me ages ago. But it might just be based on the fact that both my parents were O, so I had to be O.

NikkiSloan
09-08-2012, 05:15 AM
While you're all talking on the topic - how long does it typically take to get the results from a paternity test?

shaldna
09-08-2012, 01:16 PM
Except that if the Rh factors don't match, mom will likely know before the kid is born. The baby's blood type can react to the mother's.

Not necessarily. In many cases the first baby is fine with no complications, but if the woman gets pregnant again then this is the point where her body treats the baby as an invader - often this is the point where women learn about Rhesus. It's not such a big deal now as they can give you a vaccination to deal with it and that's that. However, one of my mum's friends has a whole different blood group now to when he was born - he was a second Rhesus baby (about 50 years ago) and he got a full blood transfusion - which was pretty extreme, but effective.


There was a case here a few years ago where a man was getting some bloodwork done and discovered that he didn't carry the gene for cystic fibrosis - which was news to him, as his son had been diagnosed with the disease at a very young age. His first response was to question the diagnosis, hoping that the doctors had been wrong and that his son suffered from something less critical and more easily treated. Paternity didn't occur to him until after the CF test came back positive again. Since both parents had to be carriers to pass the condition along, he couldn't be the boy's biological father.

What a way to find out. :(



While you're all talking on the topic - how long does it typically take to get the results from a paternity test?

Here, if you send off routine paternity tests you'll get the results in a couple of weeks.

Edited to add - the majority of paternity tests are done by private companies and not hospitals etc - they start at about 130 and can be done several ways - most usually it's a swab from inside your cheek rather than blood, although it can be done with hair. There are home kits that you can do and send off to the lab.

jaksen
09-08-2012, 04:20 PM
Thank you everyone for the advice. My head is spinning with all the info I've learned about blood types. I think I'll make the parents both type O while the kid's type A, but I'm still trying to figure out under what circumstances this is all revealed. As many have pointed out, it's unlikely the doctor will reveal this fact himself. I've been thinking of making husband a phlebotomist, figuring that given the nature of the field, he'd know something about blood types (if I'm wrong please pipe up and tell me) but I'm still working on some of the steps in between. Again, I'm trying to think of what kind of routine testing would reveal all this and all that. In my story, the kid's fairly healthy, so it can't be cystic fibrosis like someone suggested.



Man, this is more complicated than I thought. Is there a way I can have Husband find out about the kid being the product of a one-night-stand without the cheap "Other guy was black" trope?

If the parents have given blood for a blood drive, they can learn your blood type at that time. The Red Cross used to give donors a little card with your name and blood type on it. Your blood type should also be in your medical records. I simply asked my children's doctors what their blood type was. (My last child I asked after he was born.)

I carry around a Red Cross card that says I am AB+. My sister, who worked at a hospital, is also AB+ and for a while she was 'in demand' at blood banks, even though our blood type can only be given to others with AB+ blood. (We are known as universal receivers; type O are universal donors.)

You could write in a subplot where the father is asked to give blood for a friend who's been in an accident or who needs a bone marrow transplant. Maybe it's just a colleague - I've been in drives where I barely know the people who need the transplant. (Years ago I was in one for the daughter of a friend's friend.) In that way, he learns his blood type. If his wife is standing beside him, at the same drive, she is handed a card, too and he casually says, hey I'm O and she says she's O.

Stuff like this sometimes generate a brief curiosity, which makes him wonder what his child is, too. It's the same thing which happens when a hurricane is bearing down on us - suddenly we are curious about hurricanes and are watching the weather channel. Or if a friend's child has CF or is born with a health issue, we are curious and look it up. Or if a parent has dementia, suddenly we're talking to nurses, friends, etc., about others dealing with the same situation. If you've just been blood-typed, you might wonder what your child's type is, too.

So you ask the pediatrician.

Goldbirch
09-10-2012, 06:03 AM
I was thinking blood-drive, too. I learned that I'm O when I donated as a young adult. (O was a surprise. When I was a child, my mother had told me that I was A, like her. Turned out her understanding of blood type genetics was flawed.)

Depending on how much you want to work up the blood-drive angle, it could be a very simple scenario. Dad could be mildly intrigued by blood types, and already know that he's type O. He could have remembered that kid is A (or B) from when the kid was born, and assumed that meant that Mom was A (or B).

But then one fine day, exactly when your plot requires it, Dad is rummaging through her purse to borrow something, or maybe Mom leaves her Red Cross donor card lying around. (She had it in her pocket after getting home from a drive, she's in the middle of cleaning - plenty of reasons.) In any case, Dad's eye is caught by the O on the card.

Or Mom could have donated blood for the first time, and been surprised (like I was) to find that she was O. So she mentions it over the dinner table. If she had thought she was A 'cause her parents were "and A's dominant", she could have even told him that she was A if he had ever casually asked about it.

NikkiSloan
09-10-2012, 09:17 PM
Thanks, Shaldna! for the insights on paternity tests.