What medical treatment might unintentionally disprove paternity?
February 22, 2016 9:55 AM Subscribe
Fictional scenario: Jim has a life threatening illness. There is a possible (perhaps experimental) treatment - or a diagnostic tool or whatever - which would involve his adult children (donating tissue or an organ?). Jim refuses it, because he is worried that his children would as a result find out that he is not their biological father. What could the medical McGuffin in this story be?
Hivemind, help me make this story convincing! What is this life-threatening illness, what is the thing Jim would prefer to refuse, and why might it reveal his secret?
Hivemind, help me make this story convincing! What is this life-threatening illness, what is the thing Jim would prefer to refuse, and why might it reveal his secret?
I suspect almost anything involving blood type would work here (kidney donation, partial liver transplant, etc.) If both (putative) parents have blood type O, then their children should as well. If a child has blood type A or B or AB instead, they won't be able to donate to the type-O parent--and if they realize that's the problem, and know their mother's blood type, that could certainly lead them to question paternity.
posted by cogitron at 10:01 AM on February 22, 2016 [1 favorite]
posted by cogitron at 10:01 AM on February 22, 2016 [1 favorite]
Illness: Leukemia.
Thing to refuse: Bone marrow transplant.
Why would it reveal secret? To minimize potential side effects, doctors most often use transplanted stem cells that match the patient’s own stem cells as closely as possible.
posted by googly at 10:02 AM on February 22, 2016
Thing to refuse: Bone marrow transplant.
Why would it reveal secret? To minimize potential side effects, doctors most often use transplanted stem cells that match the patient’s own stem cells as closely as possible.
posted by googly at 10:02 AM on February 22, 2016
People often don't have a bone marrow match in their immediate family, though, so not having one wouldn't be so strange as to cause alarm.
posted by ThePinkSuperhero at 10:09 AM on February 22, 2016
posted by ThePinkSuperhero at 10:09 AM on February 22, 2016
Best answer: Yeah; blood type is the most obvious and straightforward one. If the father were AB and the child were O (or vice versa), that would be a tipoff that the father wasn't the biological father.
See chart near the bottom of this page.
posted by Betelgeuse at 10:31 AM on February 22, 2016 [1 favorite]
See chart near the bottom of this page.
posted by Betelgeuse at 10:31 AM on February 22, 2016 [1 favorite]
Your scenario is difficult. The children are offering tissue donations for a specific procedure that would or might be helpful. Previous posters have suggested several such procedures. The problem for you will be to come up with dialogue where the patient explains why he is refusing the procedure.
It might be simpler if your patient enlists the doctor's aid. The doctor will not give away the patient's paternity secret. The doctor can simply explain to the children that they are not a match, and unless they have deep medical knowledge or go for a second opinion, they will accept this without requiring a complicated explanation of why the patient is refusing the treatment. He won't need to refuse the treatment if the doctor simply explains that he will need to look for different donors.
posted by JimN2TAW at 10:33 AM on February 22, 2016
It might be simpler if your patient enlists the doctor's aid. The doctor will not give away the patient's paternity secret. The doctor can simply explain to the children that they are not a match, and unless they have deep medical knowledge or go for a second opinion, they will accept this without requiring a complicated explanation of why the patient is refusing the treatment. He won't need to refuse the treatment if the doctor simply explains that he will need to look for different donors.
posted by JimN2TAW at 10:33 AM on February 22, 2016
Best answer: Actually, the right way to make this a "problem" is to have the father be O and the child be AB. Then the child can not donate blood to the father and it would simultaneously point to an impossible blood type for the child if the father is the biological father.
posted by Betelgeuse at 10:34 AM on February 22, 2016 [4 favorites]
posted by Betelgeuse at 10:34 AM on February 22, 2016 [4 favorites]
Best answer: Actually, the right way to make this a "problem" is to have the father be O and the child be AB. Then the child can not donate blood to the father and it would simultaneously point to an impossible blood type for the child if the father is the biological father.
If the father were O, their actual children couldn't be AB, but they could be A or B, which would still make them unable to donate blood. So the mere fact that they couldn't donate wouldn't give anything away on its own - to connect the dots, folks would have to be paying attention to the details and have a basic understanding of blood how types work genetically.
posted by aubilenon at 11:00 AM on February 22, 2016 [1 favorite]
If the father were O, their actual children couldn't be AB, but they could be A or B, which would still make them unable to donate blood. So the mere fact that they couldn't donate wouldn't give anything away on its own - to connect the dots, folks would have to be paying attention to the details and have a basic understanding of blood how types work genetically.
posted by aubilenon at 11:00 AM on February 22, 2016 [1 favorite]
I think organ donation is a better bet than blood donation, mostly because I think it's pretty unusual for people to donate blood SPECIFICALLY for a relative. I have myself gone and donated blood to the Red Cross because a family member had received a blood transfusion and I wanted to 'pay it forward', and I'm sure others do that as well, but I was under no illusions that my specific blood was going toward my relative. So I don't think anyone would 'refuse treatment' just to avoid their secret being found out -- they would just say 'Oh, it's not necessary for you to donate to me, I'll just use the blood bank!'
With organ donation or bone marrow, of course you're not guaranteed that your relative will match, but they will specifically test relatives to see if there is one since those matches are more difficult to make. While the doctor maybe would be willing to keep the secret of why there was no match, I think it's more plausible someone would refuse it because they wouldn't trust that once they results were out there, or because they just didn't understand the fact that their kids might not match for other reasons. Another way to spin this (assuming this is fiction and so you can make whatever up) would be an ill adult child asking their parent to be tested, and the parent refusing -- since they're not the patient, they would probably be more worried about the secret leaking out.
posted by rainbowbrite at 11:34 AM on February 22, 2016 [4 favorites]
With organ donation or bone marrow, of course you're not guaranteed that your relative will match, but they will specifically test relatives to see if there is one since those matches are more difficult to make. While the doctor maybe would be willing to keep the secret of why there was no match, I think it's more plausible someone would refuse it because they wouldn't trust that once they results were out there, or because they just didn't understand the fact that their kids might not match for other reasons. Another way to spin this (assuming this is fiction and so you can make whatever up) would be an ill adult child asking their parent to be tested, and the parent refusing -- since they're not the patient, they would probably be more worried about the secret leaking out.
posted by rainbowbrite at 11:34 AM on February 22, 2016 [4 favorites]
Huntington's disease or another genetic disease that shows up late in life would be another angle possibly.
posted by typecloud at 11:57 AM on February 22, 2016
posted by typecloud at 11:57 AM on February 22, 2016
Best answer: HLA typing is similar to blood typing but it has more factors, so it is more exclusionary. HLA typing is done during candidate-matching for organ donation, and it was also used for paternity testing prior to fast and cheap DNA testing.
My understanding is that a father and child should be a 50% HLA match.
posted by muddgirl at 12:00 PM on February 22, 2016
My understanding is that a father and child should be a 50% HLA match.
posted by muddgirl at 12:00 PM on February 22, 2016
Also, with living organ donation, a father worried about paternity could hide his concern by claiming that they would never compromise or risk their child's health for their own.
posted by muddgirl at 12:01 PM on February 22, 2016 [1 favorite]
posted by muddgirl at 12:01 PM on February 22, 2016 [1 favorite]
Response by poster: I thought it could be something related to blood types. (The charts Betelgeuze linked to are super useful.) But yeah, it couldn't be only about donating blood, because AFAIK hospitals don't use relatives for that.
Just to be sure: are matching blood types necessary for organ or bone marrow donation? So e.g. Jim with type O couldn't receive a donation from his kid with AB?
posted by sively at 1:02 PM on February 22, 2016
Just to be sure: are matching blood types necessary for organ or bone marrow donation? So e.g. Jim with type O couldn't receive a donation from his kid with AB?
posted by sively at 1:02 PM on February 22, 2016
Best answer: Transplant matching is complicated as hell, and there's a difference between a match and compatibility versus incompatibility (which, if you look at that link, isn't quite as case-closed as it used to be).
Match vs compatibility would come up in any conversation about risks, though. There would be no way to not talk about it.
posted by Lyn Never at 1:10 PM on February 22, 2016 [2 favorites]
Match vs compatibility would come up in any conversation about risks, though. There would be no way to not talk about it.
posted by Lyn Never at 1:10 PM on February 22, 2016 [2 favorites]
Anecdata regarding bone marrow transplant compatibility: My mother had leukaemia and one of the therapies they looked into was a bone marrow transplant. However, only my mother's siblings were tested, not me or my sisters. We were told that because the patient's children only share half their DNA they're unlikely to be a match.
posted by escapepod at 1:41 PM on February 22, 2016 [1 favorite]
posted by escapepod at 1:41 PM on February 22, 2016 [1 favorite]
However, only my mother's siblings were tested, not me or my sisters. We were told that because the patient's children only share half their DNA they're unlikely to be a match.
Siblings also share only half DNA. There's probably some other reason siblings are better than kids.
posted by If only I had a penguin... at 2:07 PM on February 22, 2016
Siblings also share only half DNA. There's probably some other reason siblings are better than kids.
posted by If only I had a penguin... at 2:07 PM on February 22, 2016
Best answer: Yeah, leukemia. When my dad was being prepped for a bone-marrow transplant my brother and I both had to give like 10 vials of blood for testing - not testing to see if we were matches, but testing to help with chromosome mapping as his had been damaged by chemotherapy (at least that is my fuzzy memory of the explanation 6 years ago).
I think they already knew from our blood types that we weren't donor matches, but they needed our DNA to help find a match. If we weren't really his children I'm pretty sure that would have been revealed at that point.
posted by DuckGirl at 2:23 PM on February 22, 2016 [3 favorites]
I think they already knew from our blood types that we weren't donor matches, but they needed our DNA to help find a match. If we weren't really his children I'm pretty sure that would have been revealed at that point.
posted by DuckGirl at 2:23 PM on February 22, 2016 [3 favorites]
Best answer: An organ or stem cell transplant would certainly reveal nonpaternity during HLA typing-- see this article.
How to handle this is an issue that is still being debated in the medical community. In most cases the consent form specifies that "incidental findings" like nonpaternity will not be conveyed to the donor or recipient because it's not information that is relevant to the reason for the testing (beyond "you are not a match" or "you are a match"). So Jim might refuse an organ based on his belief that the workup would show nonpaternity, but in fact probably the doctors would not tell either of them whether it did or did not.
posted by The Elusive Architeuthis at 3:07 PM on February 22, 2016 [1 favorite]
How to handle this is an issue that is still being debated in the medical community. In most cases the consent form specifies that "incidental findings" like nonpaternity will not be conveyed to the donor or recipient because it's not information that is relevant to the reason for the testing (beyond "you are not a match" or "you are a match"). So Jim might refuse an organ based on his belief that the workup would show nonpaternity, but in fact probably the doctors would not tell either of them whether it did or did not.
posted by The Elusive Architeuthis at 3:07 PM on February 22, 2016 [1 favorite]
Best answer: If only I had a penguin... misunderstands how the inheritance works. There are 8 alleles that must be matched in bone marrow transplants. The 8 alleles are actually in 2 sets of 4 - each set consists of "linked" genes which almost always segregate together because they are very close to each other on the DNA. You get one set of 4 from your Mom and the other from your Dad. Therefore, a quarter of your siblings will be 8/8 matches with you, half will be 4/8 matches and a quarter will not be matches at all. All of your children will be 4/8 matches*.
This could be your plot point - Haploidentical bone marrow transplant (meaning 4/8 of the alleles match) is an option - all of your children and both of your parents should be haploidentical. This might be the most perfect match for your story line - patient needs transplant, is not matched with siblings, parents are too frail to donate, the kids would be the perfect candidates for haploidentical transplant, but uh-oh, no one is a match.
It is possible to find unrelated matches (much easier if you are white vs a minority) - you can often get an 8/8 or 7/8 match, but coordinating donation is complicated and there are very good reasons to prefer someone who is already committed to the process.
You might get 5/8 or 6/8 if their mother shares some alleles but 7/8 would be incredibly rare to find in someone related to you.
posted by fermezporte at 3:26 PM on February 22, 2016 [4 favorites]
This could be your plot point - Haploidentical bone marrow transplant (meaning 4/8 of the alleles match) is an option - all of your children and both of your parents should be haploidentical. This might be the most perfect match for your story line - patient needs transplant, is not matched with siblings, parents are too frail to donate, the kids would be the perfect candidates for haploidentical transplant, but uh-oh, no one is a match.
It is possible to find unrelated matches (much easier if you are white vs a minority) - you can often get an 8/8 or 7/8 match, but coordinating donation is complicated and there are very good reasons to prefer someone who is already committed to the process.
You might get 5/8 or 6/8 if their mother shares some alleles but 7/8 would be incredibly rare to find in someone related to you.
posted by fermezporte at 3:26 PM on February 22, 2016 [4 favorites]
I think organ donation is a better bet than blood donation, mostly because I think it's pretty unusual for people to donate blood SPECIFICALLY for a relative.
If your story happens to be set in the 1980s or 1990s (a time period many in this thread seem to have forgotten), there would be nothing unusual about relatives donating blood specifically for their kin. During this era there was a particularly widespread distrust of the public blood supply and it was very common for relatives of compatible blood types to donate blood prior to a surgery specifically for their loved one to receive. This is still done today (at the patient or family's request) although it's less common in the US -- in other countries, especially those where blood supply is inadequate or refrigeration can be unreliable, it's still fairly common for family members to donate blood specifically for their relative who is undergoing surgery.
posted by telegraph at 4:42 PM on February 22, 2016 [3 favorites]
If your story happens to be set in the 1980s or 1990s (a time period many in this thread seem to have forgotten), there would be nothing unusual about relatives donating blood specifically for their kin. During this era there was a particularly widespread distrust of the public blood supply and it was very common for relatives of compatible blood types to donate blood prior to a surgery specifically for their loved one to receive. This is still done today (at the patient or family's request) although it's less common in the US -- in other countries, especially those where blood supply is inadequate or refrigeration can be unreliable, it's still fairly common for family members to donate blood specifically for their relative who is undergoing surgery.
posted by telegraph at 4:42 PM on February 22, 2016 [3 favorites]
Best answer: If Jim was going to have any DNA mutation analysis testing run and comes back positive for a known variant, his adult children would have an interest in being tested. Paternity would come into question if Jim were a homozygote of a variant (2 copies) and his adult children tested negative for the variant (2 copies of typical gene aka wild type). These types of tests are used in determining the cause of a variety of illnesses, cancer, hereditary hemochromatosis, clotting disorders, drug metabolizer status, etc etc.
posted by txtwinkletoes at 6:47 PM on February 22, 2016
posted by txtwinkletoes at 6:47 PM on February 22, 2016
This thread is closed to new comments.
posted by GilvearSt at 10:00 AM on February 22, 2016 [5 favorites]