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I know its late but i am 0- my parents ,my brother and sister are are all ab+ is this possible? I'm blond with blue eyes my parents and my brother and sister are dark haired and blue eyed . I'm starting to think I'm a bastard child even though i was loved the same as my siblings, I'm also the oldest. another factor i was born in October and my parents were married in march and my mother insists i wasn't premature and am my fathers offspring. one more note my siblings suffer from high blood pressure and other health concerns which by the blessing of God i have yet to encounter.

O- makes up 7% of the US population. My husband and I are both O- as are both our children. I know my father was O-, but I am not sure about my mother. I’ll ask her today after church. :)
The tricky thing about O- is that we can donate to everyone but can only recieve from another O-. Which means the Red Cross loves our family as they are always in need of our type.

My grandfather was red haired and blue eyed, my father had dark hair and brown eyes. My mother was blond as a child but darkened with age as did my brother. I have chestnut hair and brown eyes. My husband has very dark almost black hair and blue eyes. Our children are strawberry blond blue eyed daughter and dark haired brown eyed son.

I canp;t answer your question, I’m not a biologist, but here are a couple sites that might interest you.

http://www.classkids.org/library/classqa/bloodtyp.htm

http://www.biology.arizona.edu/Human_Bio/problem_sets/blood_types/inherited.html

I know its late but i am 0- my parents ,my brother and sister are are all ab+ is this possible?

Yes, this is possible. Your blood type neither proves nor disproves your parentage, but what you describe is possible with a single set of parents. Here's why:

First, a little genetics. Some traits are dominant and some are recessive. A given dominant traits is expressed whether you have two copies of the dominant gene (from both parents; called homozygous) or just one (from just one parent; called heterozygous). The recessive trait is only expressed if you are homozygous for it. You have two copies of everything, of course, one from each parent. Chromosomes come in pairs for the same reason.

Now, consider your ABO blood type, which has three alleles (A, B, and O) and is coded on the ninth chromosome. Both the blood group A allele and the B allele are dominant. So one could be AA or OA and still test as A. Same thing wih BB or OB. In your example, your parents may have been OA and OB. If so, their children could be AB, OA, OB, or OO.

Next, consider your Rh type, which is completely separate from your ABO type. There are actually many alleles in this blood group system, but normally we only care about the Rh(D) gene, located on the first chromosome. If it is present, homozygously or heterozygously, you are called Rh-positive. In its absence, you are Rh-negative. If both parents are heterozygous Rh(D) positive (i.e., one positive and one negative), they could have children that are homozygous ++, heterozygous +-, or homozygous --. In the first two cases, the child would be Rh-positive.

Hope that helps!