Rare subgroup of A phenotype—a case series
Nur Ilyia Syazwani Saidin, Nurul Anis Che Anuar, Mohd Nazri Hassan, Noor Haslina Mohd Noor, Zefarina Zulkafli, Hisham Atan EdinurAbstract
Testing for ABO incompatibility between a potential blood donor and recipient is the cornerstone of pretransfusion testing. Occasionally, weak agglutination reactions occur due to low expression of A and B antigens on the surface of red blood cells. This can lead to inconsistencies in blood group typing, as seen in a case where a patient’s forward and reverse typing showed discrepancies. Following a comprehensive analytical assessment, the patient was identified as having a distinctive variant of blood group A, belonging to the less common subgroups—A 3 , A end , A x , A m , A y , and A el . Herein, we present 3 case series of ABO subgroups identified through extended ABO blood grouping procedures.