My parents blood type is A+ and im A-??????

Question

I am just about 3 months pregnant and just had my blood work done. My mom went to the apt. with me and thought that i was A+ Since she and my dad and brother and sister are. The doctor called back and said that i am A- and need a shot so that my body wont develop antibodies. How is it that i am the only one?

Answer 1

This is a difficult thing to understand, I don't really understand it. But for some reason,

The A, B, AB, O, and all that is genetic.

the - and + isn't direct.

It's possible for negatives to have a postive baby, and positive parents to have a negative baby.

Answer 2

This will be easy...basic genetics.  

Both your parents are A+

You are A-

Each person has two alleles for each type of blood type, whether it be ABO blood-typing or Rh factor.

You have at least one A from one of your parents, making you also A.

But you may also have an "O" allele and one "A" allele.  But because A is "dominant", you will be considered "A"

For instance, your Dad could be AO (his genotype), but his phenotype will be simply "A" because A is dominant and O is recessive...your Mom could be AA (genotype) and the phenotype will also be "A"

Ok, hopefully you are alright there.

Now onto your Rh (Rhesus) factor...this one is easy since there is only one possibility as to why you are negative and both your parents positive:

Each of your parents has one Rh+ allele on one chromosome and NO Rh allele on the other chromosome...and because you only need one Rh+ allele to be Rh+, they are both Rh+

Mom is + -     Dad is also + -

You are - -

You got the one chromosome from each parent that did not have Rhesus factor on it...

SO RELAX!!!  Yes, you are still their child ;-)  Some people ask me that sometimes...as it is just as possible to have a kid with O blood even if both parents were A. (both parents had a genotype of AO, and each gave the chromosome for O blood to the child, so the child is O)

And you will need the shot if your child is Rh+ as you are Rh-

It is not "extremely" dangerous for this child, but is exceptionally dangerous is you have another child that is Rh+ in the future...that is the real problem.  Because by then after your first preganancy, your body will have created antibodies to the Rh antigen of your first pregancy which can kill subsequent fetuses with Rh+ blood!!!!  Take the shot!!!

Answer 3

genetics.

some chromosomes skip every generation.

your kid could be A+, no one knows.