MovieChat Forums > Necessary Roughness (2011) Discussion > Before people start to think their paren...

Before people start to think their parents are not their parents...

posted 11 years ago by P-K-One
9 replies | jump to latest

It is entirely possible to have bloodtype B if one of your parents is bloodtype A.

You have two genes (Yeah, I know, I am lying technically but you know it's true in a greater sense so shut up) determining your bloodtype and the combination determines the bloodtype:

00 = 0
0A = A
AA = A
AB = AB
BB = B
0B = B

So if your father is A0 he will be A but he can pass you the 0. If your mother is BB or B0 and passes you the B, your bloodtype will be B.

I usually do not correct science mistakes on TV shows or in movies but this is one where I thought that it could actually impact the live of people who see this and go "That cheating bastard/bitch!"

[–] maggieameanderings 11 years ago

Thanks for posting this because it saved me the trouble. What you explained is what I came on here to post.

It doesn't bother me so much that the athlete on the show made this mistake ---- I can excuse her ignorance. But, if it turns out that her father is her biological father, she deserves the 5 years of misery she put herself through for her inability to use Google. It's just a pity she's put the rest of her family through 5 years of misery too, especially her sister. If her father is her biological father, she's going to owe everyone one hell of an apology.

And Dani is a psychologist, not a psychiatrist so no medical degree. However, Dani does know how to use Google and will do lots of research for her clients, so let's hope she checks into this and realizes that her client could be wrong about her parentage. (I would have loved it if, after the athlete told her sister the bad news, the sister turned to her and explained the reality of blood type inheritance.)

Where I really got irritated was when they pulled this same nonsense on "Rizzoli & Isles" when Dr. Isles who's not just a medical doctor but is supposed to be a freaking genius who knows practically anything science related (she's an expert at chemistry, forensics, anthropology, anything they need her to be an expert at), but she says that a type B parent can't have a type O child. I actually wrote the show about that because it was so ridiculous for Dr. Isles not to have known that was incorrect

Here's the one additional detail I'd add. O is "recessive" as you showed, if you have O and anything else, your blood type is going to be the anything else. But O is the most common "gene" (actually an allele) in this country. The largest group of people are type O http://bloodcenter.stanford.edu/about_blood/blood_types.html. And most people who are type A or type B are actually OA or OB. So it's actually not unusual for someone with type B or type A to pass on the O allele. Two A and/or B parents can have a type O child. It's the same way two healthy carrier parents can have a child with a recessive disease like cystic fibrosis. The child inherited the recessive gene from both parents. The type O child inherited the recessive O alleles from both parents.

If you want to read more about blood typing and inheritance, read http://bioweb.wku.edu/courses/biol115/wyatt/genetics/blood_type.htm

http://maggieameanderings.com/Archive.htm

[–] mjwm44 11 years ago

Not so fast --
She said "my parents couldn't donate", not "my father couldn't donate".

So if her type A father was actually her father, he had to pass her the O of AO,
else she would be AB.

Her mother can't be Type B (BB or BO), giving her the B, or she would have been able to donate.

If her mother is AB and passed her the B, she surely would have heard that explanation for her mother not being able to donate, along with the explanation for her father not being able, and would know where the B came from.

That only leaves the possibility that her mother is Type O (or AO), and a third party contributing the B.

[The writers didn't touch on the lesser known blood incompatibilities, but if her mother was a Type B and only incompatible due to Rh factor +/-, or one of the rare complicating factors, she should have heard that explanation, and would still know where the B came from.]

[–] maggieameanderings 11 years ago

Now I can't recall which was A and which was B.

Let's go with the daughter was a B and the father was an A. We're never told the mother's blood type, but it's easy to figure out.......

If you're talking about only about A-B-O, the mother has to be blood type AB. The mother is where the daughter got the B from. From a type A father, the daughter gets his O allele.

Neither a type AB mother or a type A father can donate to a type B child.

(The scenario also works if the daughter was an A and the father was a B. The mother is still going to have to be an AB. The mother would be where the daughter gets the A from. And from the type B father, the daughter gets his O allele. Again, neither the type AB mother or the type B father could donate to a type A child.)

Everyone thought the daughter was unconscious, so no one was going to tell her anything. It was an emergency situation. The doctors probably just tested both the parents and told the parents they weren't a match. (Assuming the parents didn't already know their blood types.) Actually, I find it more likely that the parents asked if they could donate blood to help. The doctor then asked what their blood types were and they were told they couldn't donate to their daughter. Because normally you just go straight to the blood bank for blood in an emergency situation, not wait and get it from donors.

Once the emergency had past, I also don't see the doctors volunteering an explanation as to why they had to use blood from the blood bank instead of from her parents --- especially since it's possible that it was a different doctor than the ER doctor. The daughter should have just asked if she wanted an explanation. Or there's always Google.

There are other reasons besides A-B-O that blood can be incompatible. All we can go by is what we're told in the show and the show mentioned only A-B-O factor, not any of the other factors.

http://maggieameanderings.com/Archive.htm

[–] GailinParis 11 years ago

Is there a possibility the twins were adopted and never told?

[–] maggieameanderings 11 years ago

It's a TV show. There's a possibility of anything.

But the most likely thing is the writers did not understand how blood types are inherited. It's a common misconception. People think they have to have the same blood type as their parents. Just like on this show, I've heard of someone in real life who thought he couldn't be the child of his parents because his blood type didn't match. IIRC, the parents were both Bs while he was an O.

Personally, my blood type doesn't match anyone else in my immediate family --- not my parents and not any of my siblings. But I didn't freak out when I found that out and start thinking one of my parents cheated or I was adopted. Because I was taught about blood types in high school biology. So I knew that just because my blood type was unique in my family didn't mean my parents weren't my parents. It just meant I was a product of a 1 in 4 inheritance.

http://maggieameanderings.com/Archive.htm

[–] aftermidnite 11 years ago

On one show recently, a character was stuck by a car and in serious condition. The hospital asked his daughter for blood. When they tested her blood, they discovered it didn't match. So, the hospital ALWAYS performs DNA testing if relative's blood doesn't match. When they did, they found out that the daughter wasn't his. The doctor told the next relative they needed more blood because the daughter wasn't related to the patient. Not only the most stupid scene, but against the law too.

So it isn't uncommon for TV shows can make up any ridiculous story.

It is actually a little offensive to me. They think we are all so stupid they can just spout nonsense. I realize these shows aren't documentaries but shouldn't the major science be somewhat true? It isn't an obscurity, it is easy to fact check.

[–] maggieameanderings 11 years ago

I can't tell what it is you think is a ridiculous story. The other show you watched recently or Necessary Roughness? Or both?

For this DNA testing scenario do you have any actual evidence or just what you saw off a TV show? Because it's extremely common and quite normal for relatives to not have matching blood types. To do DNA testing for that reason would be like doing DNA testing because the parents have dark hair and the kid has red hair.

And hospitals don't just take blood out of one person and stick it directly into someone else. Blood donated for someone else has to be screened before it can be used. According to the FDA, it's screened for seven different infectious agents http://www.fda.gov/BiologicsBloodVaccines/BloodBloodProducts/ApprovedP roducts/LicensedProductsBLAs/BloodDonorScreening/default.htm. What the Red Cross does http://www.redcrossblood.org/learn-about-blood/what-happens-donated-bl ood/blood-testing. That takes time. In an emergency situation, hospitals get the blood from their blood bank where all the blood has already been screened. In fact, in emergency situations they don't even wait for the patient's blood to be typed. They use O- blood as that's the only type that can be safely donated to anyone under normal circumstances. (Some people have a rare medical condition where the blood needs to be an exact match to them not just an A-B-O & Rh match.) Then while they're putting the O- blood in the patient, then they have the patient's blood typed and then they use a matching blood type from the blood bank.

In the scenario you're describing from the TV show you watched, it sounds like the patient would be dead before he'd get any blood. First, the daughter has to donate the blood. That takes time. Then they have to type the blood. That takes more time. So then they do a DNA test, that takes even more time. Then they tell the next relative that the daughter wasn't related and have the next relative donate ---- more time. Then the next relative's blood must be typed --- time. The blood must be screened ---- more time. All the while the car accident victim is lying there without getting any blood. Probably dead by now if the condition is that serious.

No, what's going to happen is that patient's going to come into the hospital, get O- blood immediately, have his blood typed and start getting matching blood from the blood bank. In the meantime, any family that wants to can donate blood for the patient (it's called a directed donation), but the blood will have to go through all the usual screening. A hospital would never just take blood out of one person and stick it in another ---- IT'S ILLEGAL. The blood would have to be screened and that takes time.

So when you said "So it isn't uncommon for TV shows can make up any ridiculous story" I agree. And it sounds like the show you watched did make up a ridiculous story. So I hope that is the ridiculous story you're referring to.

http://maggieameanderings.com/Archive.htm

[–] aftermidnite 11 years ago

So when you said "So it isn't uncommon for TV shows can make up any ridiculous story" I agree. And it sounds like the show you watched did make up a ridiculous story. So I hope that is the ridiculous story you're referring to.

Yes that's it exactly. I was just using another show as an example of equally questionable writing. It was so ridiculous that I wrote to the network about it.

[–] sunneyone 11 years ago

Back in the day they'd take donations from the family on the spot. My dad was a universal donor and I remember when I was a kid him giving blood at the hospital when my grandmother had surgery.
But that was early 80s, before the AIDs crisis. :/