Blood type discussion. Anyone familiar with blood types ?

amberrmariee20

So growing up my mother always told me my blood type was O negative, so I've always told everyone that's what it was. Today I mentioned to my dr that I was O negative, and she goes and pulls my chart and it says O positive, after calling down to the lab and looking at my charts from 1995 and even 2007, I was of course always O positive and I never ever knew the difference.

Which got me thinking... My son is now almost 4 and his blood type is O negative. I'm O positive and his father is A positive.. It was to my understanding that if both parents were positive the child would be positive as well or if both parents were negative then the child would be negative too... Any one have any other insight on this ?

Edit due to words being hard.

DeeGreer

https://www.acog.org/Patients/FAQs/The-Rh-Factor-How-It-Can-Affect-Your-Pregnancy

My mom was RH positive and my sister was negative. She almost died and they did an emergency c-section.

amberrmariee20

@DeeGreer wouldn't that be the opposite ? Your mother being rh negative and sister being rh positive ?

casserole27

Im sure experts will correct me if Im wrong. From what I understand blood type is not totally hereditary. While most families will share a type some will vary from child to child.

My mother's blood type is different than both of her parents. And my husbands siblings are all different and they all have the same parents.

glerro

Here is a genetic table that should better explain. Its all genetics just like eye and hair color.
Im O- and DH is A+. Our DD is O+.

danixbanani24

casserole27 said:

Im sure experts will correct me if Im wrong. From what I understand blood type is not totally hereditary. While most families will share a type some will vary from child to child. My mother's blood type is different than both of her parents. And my husbands siblings are all different and they all have the same parents.

This.  I'm the only negative blood type in my (immediate) family.

glerro

Rh negative is a recessive gene. Although u and ur husband are postive ur genes could be (+ -). It is possible for u and ur husband to have a negative rh child. It just means ur both (+ -) with the positive being dominant. U each gave ur child the negative recessive gene. I hope this helps. See the pic above i posted

DeeGreer

@amberrmariee20 errrm...yes...excuse me. I slept 3 hours. I tried to find that chart and I failed at google. I'M SO SLEEPY I'M GOING TO CRY.

casserole27

I got curious and looked it up. So I'm gonna correct myself a little bit.

So it is genetic but not hereditary. Theres a bit of a difference. The chart previously posted is correct. There are 4 different maternal blood types and 4 different paternal blood types possible, so there are 16 different combinations of possible blood types. Yay genetics. Haha.

amberrmariee20

glerro said:

Rh negative is a recessive gene. Although u and ur husband are postive ur genes could be (+ -). It is possible for u and ur husband to have a negative rh child. It just means ur both (+ -) with the positive being dominant. U each gave ur child the negative recessive gene. I hope this helps. See the pic above i posted

Okay that makes much more sense. I was always under the impression that if both parents were positive then the child would have to be and if both were negative then the child would be. I confused the heck out of myself today !

SarahAnne1101

Haha. I'm telling you, in nursing school so so many people couldn't wrap their heads around this. My professors said that the exam over it was when they usually knew who was going to graduate and who wasn't/  Basically it all has to do with recessive and dominant genes and alleles. It's a little complicated, and that chart is the easiest way to see how it can happen in parents and child... 

leessshhh

my mother is A+ and my father is B+ and out of my siblings im the only AB- . but like PP said Rh- is a recessive gene , the chart they provided breaks it down the best way possible . lol 

margies2010

@leessshhh - You are almost the universal receiver! If you were Rh (+) you would be able to accept packed RBC from any donor.

I spent quite a bit of time studying Immunohematology in school, as well as working in a blood bank, and studied genetics before all that. The answers above regarding the recessive genes are completely accurate. Just because a phenotype (expressed) gene is present, that doesn't give an immediate indication of the genotype (genes present).

I am homozygous for the MTHFR677 mutation, which puts me at a clot risk. My husband has no copies of the mutation, so my sons will both be carriers of the mutation and could possibly pass it on to their kids.

Sorry, I love genetics!

Edit: passionate typos

hammy_711

I have a master's in molecular genetics, so I hope I can explain this  First, I'm not sure what "genetic but hereditary" means as these things are synonomous.  It was explained correctly above that both the mother and father could exhibit the rh+ blood type and still pass only the rh- gene to their kid making the kid have an an rh- blood type.  It just means both parents had a + and - rh gene and each happened to provide the - copy to their child.  Therefore, the child must have 2 negative copies.  It's less common, but certainly possible.  

leessshhh

@margies2010 - well then my siblings are all quite lucky , they are all AB+ . I will be sure to tell them the good news ! lol 

choyandjill

Just a minor correction on some of the information above. Those with O- blood types are considered universal DONORS. Whereas AB+ are universal RECIPIENTS. Individuals with Blood Type O may only receive transfusions from the same blood type. The reason being that O persons have antibodies against the A and B proteins. So any blood specimen with A and/or B antigens, will hemolyse when transfused to an O patient.

kaza512

Just to add more confusion to the mix.. Blood type is different than Rh factor (although they are listed together).  Blood  type is A, B, O or AB.  Rh is  - or +.  The Rh factor is what you are referring to and that previous chart is accurate.  Every individual carries two genes.  If you are Rh- , both of those genes are negative because it is recessive.  If you are positive, you can either have two positive genes, or one positive and one negative+.  In OPs case, you and your partner must both have one of each, so your son got negative.  A mother doesn't need to be concerned if she is positive, it is only dangerous if she is negative.

What is mildly annoying is that regardless of whether I KNOW for certain that my husband is indeed the father and that he is definitely Rh negative, (and I am negative too) is that I still have to get a Rhogam shot.  Working in this field, I know why they do it, because not everyone is honest or knows who the father is, so as a precaution, every Rh negative woman gets it, but still, it's one more shot I don't need

VioletandRose

Ok, just want to make sure I have this straight...out of curiosity.

I have A- blood type. At first I thought this meant that both of my parents were neg. It turns out that my mom is neg and my dad is pos. What you're saying is that both of my parents have the recessive - gene, and that is how I got the negative blood?

margies2010

Yes. Your father had one copy of Rh+ and one copy of Rh-. He is "Rh+" because that "overrides" the Rh- as it is dominant. He passed the Rh- to you along with your mom's Rh-.