23 replies to this topic

[xaetos]

I recently managed to bring myself to donate blood. Apparently, when you do this, they send you a donors card in the mail with your blood type on it.. which I got today. I am, apparently, O RH+ (which I discovered to be the most common type, after a bit of research).

Now, a few weeks ago, my mom went to see if she would be able to give blood. There are a couple reasons why she wouldn't be able to, they're still figuring out if she's eligible or not. But they tested her blood type while she was there, and discovered she was AB (I'm not sure if it was RH- or RH+). She told me this whenever she got home that day, because thats the rarest type..

In my bit of research today after I found out my blood type, I came across some stuff on the genetics of blood types.. what blood types you could potentially inherit based on both your parents blood types. I have no idea what type my dad is, but I know my mom is AB.. supposedly, anyways. The info that I found today (on more than one website) said that if either parent was blood type AB, it was impossible for their child to be type O.

Now, think about this. I'm definately blood type O. My mom has been told she's type AB.

My question here isn't about finding out you're adopted, or parent infidelity, or any of that stuff, because it seems pretty unlikely that thats what happened here. Instead, I was wondering if anyone here actually knew anything about genetics, and if my information is correct.

The other thing I was wondering was the chances of an on-the-spot blood type test being incorrect. This seems like the most likely possibility, but I'm wondering what the chances are. The test was done by someone from Canadian Blood Services, and apparently she was pretty excited when she had her first AB person of the day..

Anyways.. what I'd like to know:
-Some stuff on blood type genetics.. from a person, not a website :\
-Chances of that test being wrong

Thanks to anyone that might be able to help XD Also, I'm not sure if this is in the right place or not. Move it if its not..

[ankitunlimited]

Now whatever i write here is from my high school bio classes.

Our blood has antibodies and antigens, these antigens cause action from antibodies, antibodies will kill red blood cells with the same type of antigen and will form klumps. there are three basic antigens

O type

A type

B Type

If your blood type is A - you have A anitgen, and B antibodies, so giving you B blood will cause klumps and you will die.

Similarly if you have B, you have B antigen and A antibody, so giving A blood will kill you.

You have O type, it means you have both A and B antibodies nut neither antigen, that means you can basicallygive blood to anyone , but in the modern scenario such chances arent taken.

Rh factor is also very important for blood classification, if you have Rh factor antigen you are Rh positive, if you don't, you are Rh Negative. if a Rh- woman is pregnant with a Rh positive foetus, it can cause the death of the baby, as his/her mother's antibodies will attack his red blood corpuscles.

A blood test is done by applying your blood with antigens and then seeing if your blood reacts,the test is simple enough and i think the chances of the test being wrong are equal to your sample being exchanged.

[WindAndWater]

You should have two alleles (think A, B, O), one from your mother, and the other from your father. A and B are co-dominant, and O is recessive, which means that if you got an A from your mother and an O from your father, you'd be type A, because A is dominant over O. The same goes for recieving B from your mother. The only way to be type O is to recive it from both parents. So that means that theoretically you can't be type O, if your mother's AB, because you would've recieved either an A or a B from her. I think that your guess that one of the blood tests was inaccurate probably makes sense, although I think it is possible (although very unlikely) to recieve both alleles from a single parent. I hope that helps.

By the way, if you're type O+ that means that many people can use your blood, which means that you'll probably be hounded by the Red Cross for the rest of your life ;-)

Edited by WindAndWater, 05 April 2006 - 05:35 AM.

[terminal2k]

from what i remembered in high school you inherited two sets of genes, and could pass either of these on to your children, just because you have the dominant gene that gives you A or B blood doesn't mean you don't also have the O gene.

[xaetos]

Quote

I think it is possible (although very unlikely) to recieve both alleles from a single parent.

Hmm.. thats kind of interesting. I'll have to go look up some stuff on that.. thanks XD That would make sense, too, because my mom took a guess that my dad was type O, which has two O.. alleles? XP

This stuff is pretty much on par with what I found on random websites. I talked to the bio teacher today, and she said the test was probably wrong.. Thanks for the help XD Any more info on the accuracy of that test that showed my mom as type AB would be really helpful...

[iGuest]

parents with same blood group and different RH factorsBlood Type Genetics

Me and my wife have same blood group, but I'm A negative and my wife is A positive. Will there be any problem in pregnancy or in future for our baby? please suggest what are the medications for that.

-question by Munish

[iGuest]

A few possible answersBlood Type Genetics

The possibility that I will contribute is the idea of a rare mutation. Mutations happen all the time when a child is produced, and there is a chance that one of those mutations could possibly have affected your blood type. Specifically, if your father is type O, then you would only need one recessive O allele from your mother to get your blood type. If she, as AB, were going to pass on an allele there is a 50% chance that it would be an A allele. The importance of that is that there is actually only 1 base pair difference in the DNA segment that makes up the allele when A is compared to O. 

Mutations are sure to occur, the only thing that makes this specific mutation unlikely is that the chances that a mutation would randomly occure at that specific base pair are very small. Still, Something's going mutate, some base pairs are going to switch. With so many people on this earth, even something with a very very small percent chance will most probably occur, possibly more than one would think. Who's to say that you're not that one in a  million chance that mutates the A into an O?

 

Other than that, there is the possibility of incomplete penetrance of your blood type. I have not heard that blood types have anything less than complete penetrance, but I am not an expert on that. Penetance describes the relationship in a population between a genotype and the phenotype is usually represents. In this case, there may be a possibility that you have a type AO or BO blood, but do not exhibit the A or B antigens that are the mark of that blood type.

On the individual rather than population scale, it is possible that you personally have a very very low expressivity of a blood type that is actually not OO. For a quick basic review of blood type, blood type is determined by the antigens present on the surface of the blood cell. Type A blood cells have A antigens on their surface, type B cells have B antigens, AB blood has both, and O is determined by a lack of any antigens at all.  Expressivity is the degree that a given genotype is expressed as a phenotype in a single individual. It could be that you have a very very low expressivity for an A or B type blood. If that were the case, perhaps you do have A or B antigens, but you produce so few of them that they were simply not picked up in the test.

 This information comes from applying the principals learned in a college level genetics class applied to basic biological principals. (High school level, I hope. If not, then I will try to come back and explain properly, but I hope it was all understandable with only a high school level biology backing.)

Hope you find this at least interesting.

-reply by Sarah

[iGuest]

possible child blood type Blood Type Genetics

my blood group in B ( Rh-) , and my wife blood group is O ( Rh+) , and we get a child of A( Rh+) as blood group. I would like your opinion , is it possible.

thanks

- mhoudine

 

[iGuest]

I am b- and my son is O-. What could his father be? My mom is O+ and my dad is AB-. Does this have anything to do his bloot type also? 

[iGuest]

blood typeBlood Type Genetics

Quote

"I am b- and my son is O-. What could his father be? My mom is O+ and myDad is AB-. Does this have anything to do his blood type also?"

His father could be A (with a recessive O), B (with a recessive O), or O. And could be either Rh- or +.