Blood Group Discrepancy in a Whole Blood Donor With Weak AB.

The ABO blood group system was the first to be discovered; still, there is an enigma in ABO subgroups. The A1 and A2 phenotypes account for about 99% of all A or AB blood group individuals, and the rest are the weaker subgroups. They usually are suspected in cases of blood group discrepancies. Meticulous serological testing with technical expertise will help to differentiate these subgroups. We describe a case of a healthy blood donor with blood group discrepancy due to a weak subgroup of 'A' in the AB blood group.