[Serologic and molecular biological detection of rare B(A) blood group].

This study was aimed to investigate one case with rare type B(A) in ABO blood group by using serological and molecular biological methods, and analyze the cause of inconsistency resulting from multiple detections. The serological method was used to identify the serum type of ABO blood group, at the same time the PCR sequencing method was used to detect the genotypes. The results indicated that the group typing and reverse typing for the blood donor were inconsistent, the group typing was AB, the reverse typing was B. The ABO genotype was B(A) 04 /001. This genotype was involved in nt640A > G point mutation which caused valine replacing methionine at 214. It is concluded that the sample inconsistent between the group typing and reverse typing could be typed by molecular biological method, and the molecular basis of weak expression of ABO blood group is elucidated too.