A blood donor with genotype hh and AB has which red blood cell phenotype?

To determine the red blood cell phenotype of a donor with genotype hh and AB, it’s essential to understand the meaning of the genotype and how blood types are classified. The ABO blood group system is based on the presence or absence of antigens on the surface of red blood cells.

In this case, the donor's genotype is AB, indicating that they have both A and B antigens present on their red blood cells. The hh genotype refers to the lack of the H antigen, which is necessary for the expression of A and B antigens. Therefore, even though the person has the genotype indicating AB blood type, the presence of “hh” means that the H antigen, which is a precursor to the A and B antigens, is not produced.

Individuals with the hh genotype typically have the Bombay phenotype, which means they can have the genetic makeup for various ABO blood types, such as A, B, AB, but do not express these blood groups due to the absence of the H antigen. As a result, their red blood cells will not show the typical A or B antigens, and thus they will phenotypically appear as type O blood, which does not express the A or B antigens.

This unique situation confirms that the