Regarding the ABO blood group system in humans if an individ

Regarding the ABO blood group system in humans, if an individual is genetically I^B i and yet expresses the O blood type, which genotype is he or she likely to have? Hh HH hh i^A i i^B i none of the above are correct.

Solution

Option C is the correct answer. This hh is also known as Bombay blood group. These individuals do not express H antigen. Thus these individuals are unable to form either of A or B antigen on their RBCs. Usual test of these individuals for blood group shows them as having O blood group.