Studies On The Molecular Mechanism Of Antigen Weak Expression In ABO Blood Group

ABO system was the first blood group system to be discovered,and it is the most important blood type system in the clinical.ABO antigens show strong immunogenicity,remains the vital significance in the transfusion and organ transplantation medicine.The formation process of ABO antigens is relatively complex and involved factors in it is quite a lot.There are more and more studies have found that the ABO antigens are likely to exhibit the phenomenon of antigen weakening by the influence of gene locus mutation?blood group substance?disease and chromosome recombination,which lead to difficult to determine the correct blood type and may endanger the transfusion safety of patient finally.The application of molecular biological techniques can avoid interference of external factors and clear the molecular mechanism of ABO antigen weak expression.This study applied the PCR-sequencing into the research of molecular mechanism of ABO antigen weak expression to type accurately by eliminating the interference.We explored the potential links between the blood group and lapse to of the disease and taken a further research into the mechanism of antigen weakening by methylation analysis?TA cloning and STR analysis.We found 4 cases of ABO antigen weak expression,the A_weakB individual was the rare B?A?04 subtype which was caused by the mutation in exon of ABO gene,the AB_weak individual whose genotype was A102/B101 may caused by a novel variant in regulatory region of B allele,the A_weak individual whose genotype was A102/O01 caused by the methylation in the promoter of ABO gene,the other A_weak individual was caused by the blood chimera with A102/O02/O01.In conclution,the studies on the molecular mechanism of antigen weak expression in ABO blood group can explain problems that serological identification may encounter to ensure the transfusion safety and open up new way to research the mutation mechanism of blood group.