[jengland14 (OP)]

Hello, I just need some clear information about the genetic process of blood types. My husband and I are both blood type A+ but our daughter is blood type B+. I was curious as to how this happened. I have read countless information that says two As=A or O. I have been trying to gather information on both of our families, looking for recessive Bs but it takes time contacting everyone especially when my husband's family lives in another country. When I gave birth the most shocking part was hearing that she had B+ blood because I was so sure she'd have A+ so it would be so helpful for an educated explanation because so far everything I have read has lead me no where. Thank you so much!

[Colin2B]

Hello, I just need some clear information about the genetic process of blood types. My husband and I are both blood type A+ but our daughter is blood type B+. I was curious as to how this happened. I have read countless information that says two As=A or O. I have been trying to gather information on both of our families, looking for recessive Bs but it takes time contacting everyone especially when my husband's family lives in another country. When I gave birth the most shocking part was hearing that she had B+ blood because I was so sure she'd have A+ so it would be so helpful for an educated explanation because so far everything I have read has lead me no where. Thank you so much!

It might be worth posting a question here http://genetics.thetech.org/ask/ask71

[evan_au]

Perhaps the most scientificaly interesting cause is chimerism, where organs of a single person can have different genetics. The blood is produced by the bone marrow, but the eggs or sperm could be genetically different, and carry a different blood type. There have been cases exactly as you describe.

Other events happen more than people like to admit, but:

• Sometimes the mother is not the one she thinks she is (babies can be switched in hospital)
  
• Sometimes the father is not the one he thinks he is. 

Some of these conditions can be distinguished with a modern paternity test (which also functions as a maternity test). Before you decide to have the test, make sure that you and your partner are willing to live with the findings, whatever they are. A talk to a genetic counselor may help clarify the range of possible outcomes.

Detecting chimerism in an individual is somewhat invasive, since it requires taking samples from various parts of a single body, in the hope that distinct genetic patterns can be recognized within a single individual.

In the case of chimerism arising from fusion of twins soon after fertilization, a baby girl may be as closely related to her uncles and aunts as she is to her mother (it can happen with boys too).

[jengland14 (OP)]

She is definitely our daughter. We were never separated at the hospital (she was born in my room and stayed in my room) and I have never cheated on my husband. Not to mention she looks too much like each of us in different ways to be someone else's child! This is why my question has driven me a little crazy. I do know that one of my husband's grandmothers was B+ and her son (my husband's father) is 0+. My husband's mother is A+ and one of his sibling's, his sister, is actually B+ too. Thank you for you information!

[syhprum]

I haves serious doubts as to whether I am my "sons" father I am B- what could my "sons"  group be that would exclude me from being his father ?

[evan_au]

I am B- what could my "sons"  group be?

Knowing that you are B- does not really constrain your son's blood group, because you could be BB (homozygous) or BO (heterozygous).

• If you are BO, your child could be A, B,O or AB (ie anything)
  
• The "-" means you are homozygous for the Rh factor (both copies of your genes are Rh-). Your child could be Rh+ or Rh- (ie anything).

Analysis of blood type really needs the mother's and child's blood type too, if you are going to have any confidence (and even then it may not be conclusive).

The table here gives the inheritance patterns: http://en.wikipedia.org/wiki/ABO_blood_group_system#Genetics
..But it may be easier to use a Blood Type Calculator, like the one here: http://www.endmemo.com/medical/bloodtype.php

Blood types are not conclusive about inheritance in all cases; a parental test provides far more information about the genetics.

[Rodin1880]

It's well documented that incest produces poor offspring... Diversity in breeding is what creates strong surviving individuals... This being the case, I believe that human beings are capable of great diversity in offspring, for the sake of survival of our species... Lust is a natural desire, causing males to have sex with many females and females having sex with many males, before we became "civilized"... While never proven and perhaps never even researched, I have to believe that human, if not other animal, female egg development changes with every opportune, varied, injection of DNA into her. Your children are 50% Father, and a mix of the Mother and every guy that she ever had unprotected sex with... Which is probably why it was probably never even researched...