Sons blood type does not match?
The father could be A or AB, and he could be + or -. The ABO blood type is controlled by a gene with 3 possible alleles, A, B, or O. A and B are co-dominant (meaning they are both expressed), and O is recessive to both. Since we have 2 copies of each gene (one from mom and one from dad), a person can be AO (expressing O blood type), AB (showing AB type), BO (showing B type), or OO (showing O type). You are OO. Dad could be AA, AB, or AO (since he only passes on one copy, and you pass on the other). As for the Rh factor (the + or -), either you OR dad (or both) could have passed that on.
