Molecular genetic mechanism analysis and pedigree investigation of rare B_weak subgroup

To analyze the molecular mechanism of rare B_weak subgroup in the ABO blood group system and conduct pedigree investigations.

The blood group was detected by conventional serological method, and ABO gene of proband and her family was amplified and sequenced by polymerase chain reaction method.

The study showed that the proband was a B_weak phenotype by conventional serological method. Her family's serological results were as follows, her father and eldest brother were B_weak subgroup while her mother and second eldest brother were O group. The proband's ABO gene sequencing result was ABO*BW.27/ABO*O.01.02. Her father, mother and two elder brothers were ABO*BW.27/ABO*O.01.01, ABO*O.01.01/ABO*O.01.02, ABO*BW.27/ABO*O.01.02, ABO*O.01.01/ABO*O.01.02.

Conventional blood group serology combined with molecular diagnostic technology can accurately identify the B_weak subgroup, and the pedigree investigation analysis showed that the proband's allelic mutation came from her father. She has gained a point mutation of c.905A>G on the basis of ABO*B.01.