[A Bw12 blood type caused by 278C>T mutation of ABO gene].

OBJECTIVE:To determine the serotype and genotype of a sample with ABO blood group discrepancies. METHODS:Serotype was determined with serological method. Sequence specific primer polymerase chain reaction (SSP-PCR) was carried out based on the serotype. Sequences of exons 6 and 7 of ABO gene was analyzed by sequence-based testing (SBT). RESULTS:Completely agglutinated A antigen, half agglutinated B antigen and weak agglutinated anti-B antibody were detected in both erythrocytes and serum, which suggested presence of a ABw serotype. An A/Bw12 genotype was revealed by B subgroup detection. Sequences of exons 6 and 7 were 278CT, 297GA and 467CT, 526CG, 657CT, 703GA, 796CA, 803GC, 930GA, respectively. The genotype fit with A102/B101 except for a nt278 C>T mutation. Blood group antigen gene mutation database (BGMUT) search has confirmed the mutant allele to be Bw12. CONCLUSION:An A102/Bw12 genotype has been found in the Chinese population.