Are siblings expected to be of same blood group?

Philippines
March 23, 2008 3:39am CST
This is in relation to my other discussion. http://www.mylot.com/w/discussions/1443497.aspx My friend already asked one of her father's 6 siblings of her blood type. The answer was A+ and she was the youngest of them. It somehow relieved her a little bit. So, is it conclusive that her father is probably having a type A blood?
1 person likes this
4 responses
• India
23 Mar 08
Hi Piesmeralda! I am a student of Biotechnology and I can surely help you in this matter. I read your previous discussion too. You have mentioned that your friend has a blood group of type A and both her parents with type O (although she is not sure about it). Let me tell you that if both the parents are of O type, the child will definitely have a blood group of O. There is no other possibility. Ask your friend to confirm the blood groups of her siblings. If all the siblings have a blood type of O, then its confirmed that both her parents are of type O. As far as this discussion is concerned, the answer is no. Siblings may not have the same blood group. This results in various circumstances such as if both the parents are of type A (for instance), the the offspring will have a type of either A or AB. So, one of the siblings may have a blood type of A and the other with type AB. I hope you got it. Ask your friend to confirm her parent's blood type. Or let me suggest a better alternative: Ask her to confirm the blood types of all her siblings. I can make sure after that. All the best!! Do let me know about the situation. I believe I can help you further.
• Philippines
23 Mar 08
Hi amitaliasb2! Thanks for taking your time on this matter. I'll let her know of your suggestion, if she can do something about that. I perceived from her that she is very discreet about this towards her family. If she will ask them straight, she will sound suspicious. She doesn't want to hurt them with anything going on in her mind. We'll try to work on that. Thanks again.
@aneer72 (181)
• India
23 Mar 08
No siblings need not have the same blood group. The blood group is decided by either their father's or mother's. There are also instances that the blood group will be different from that of both the parents.
• Philippines
23 Mar 08
A lot of work ahead for my friend, thank you very much.
@nancygibson (3737)
• France
23 Mar 08
My parents are different blood groups and my brother and I are not the same as each other. Its usual to be the same as one of your parents but from what I remember being tod when I asked the nurse at blood doners, in some rare cases you can be a third group if the parental combination is just right- I don't think that happens very often though, usually a child will match the blood group of one of their parents.
• Philippines
23 Mar 08
I think there's still work to be done by my friend. Thanks.
@Modestah (11192)
• United States
28 Mar 08
a child must be one of the types of either parent or a combination there of... so if mom is A and Dad is B child can be A, B, or AB. I am not sure how it works when O is thrown into the mixture though as I do not believe there is A0 or BO (well, there is BO but that is not talking about blood type :) ) you have to watch out when you mix + and - factors, though.