Blood types- I'm A- my mom was O+ and my dad was B+ ?? Serious answers only.?

Question

My blood type is A- , my mother was O+ and my father was B+, I have heard that this is very unusual, very rare but can happen... Can anyone explain how this can be?

Answer 1

Your mother may have the bombay (hh) genotype.

Those individuals test as type O but can genotypically  be any other type. She may be a masked type A.

Thus if she really heterozygous A(h), and he is heterozygous B, that would give you a 25% chance of being O.  Any siblings?

Answer 2

Yes it is possible. Each person has two copies of the gene for blood type (one from mom, one from dad) and gives one of those two copies to the baby.

There are three possible genes for those two positions: A, B, O. If you have A and O, you will be A; if you have B and O, you will be B. So it is possible for Mom to have type A and really be genes A,O and give baby her O gene, while Dad has blood type B with genes B,O and also gives baby his O gene, making baby O,O or type O.

Just like you have two copies of the A, B or O alleles, you also have two copies of the Rh factor alleles. So for two parents who are both Rh positive, they could be either +/ - or +/+. If both of them are +/-, then they could have each passed the - allele to their child and have a negative (-/-) child.

Hope this helps answer your question

Answer 3

Type A blood has type A tranferase that bond  N-acetylgalactosamine to an antigen on the surface.

Type B blood has type B tranferase that bond Galactose instead.

Type O blood has NO ACTIVE tranferase and the gene code for defective A or B tranferases.

If your father was type B he could have both B and inactive A genes. and have given you one one either. I your mother was O, she should have both inactive A genes and given you one or the other.

IF your mother or your father had a gene for A type tranferase that was made inactive by a single point mutation, there is a 1 chance in 10,000 that the mutation could revert (mutate) back to the normal type A tranferase. Therfore there are 3 mutation  possibilities to yield a type A offspring.

Start here and follow the slides:http://www3.kumc.edu/jcalvet/bioc801l/ts...

Answer 4

The offspring normally generated from an "O" and from a "B" coupling can only be "O" or "B".  The possibility of either one of your parents having a extremely rare blood type like Bombay is less likely than somebody making a mistake and typing one of your parents wrong.  For you to be an "A" one of your parents had to have the "A" gene to pass onto you.  The "A" gene is dominate and it has to be expressed.

As for two positive people conceiving a negative child - that isn't uncommon at all.  The rhesus blood group is a little more complex and involves inheriting a group of three genes from each parent.  The most common phenotype without going into a lot of depth is one negative set and one positive set.  Both your parents gave you the negative set.