0 Members and 1 Guest are viewing this topic.
The major types are A, B, AB, and O. We inherit our blood types from our biological parents. Each parent contributes 1 gene: an A, B, or O gene. So each of us have 2 genes for blood type, we could have AA, AB, AO etc. This is called our genotype. A and B will always be expressed, O is only expressed if there is no other gene present. That means that if your genotype is AA or AO, your blood type is A, but only if you have the genotype OO will you have blood type O. There are other kinds of blood typing, for example Rh + or Rh - , these are controlled by different genes. Basically, your blood type refers to what proteins are on your cells. Your immune system will recognize cells that have the wrong proteins on them and attack those cells. That is why it is so important that blood transfusions and organ donors have matching blood types. That way, your body, doesn't recognize the newly introduced cells as invaders.
But, if anti-D antibodies are transferred across the placenta to attack the "incompatible" blood of the newborn, why don't the anti-A and anti-B antibodies carried by people with A, B and O blood groups do the same thing?The answer is that these antibodies are referred to as IgM, rather than IgG. They are a different type of antibody which is not transferred across the placenta like anti-D.Chris