Identification and clinical transfusion of B (A) subgroup / 中国输血杂志

【Objective】 To carry out serological and molecular biological identification of B (A) subtype, and discuss the rational blood transfusion strategy. 【Methods】 Serological and direct sequencing methods were used to detect serotype and genotype of 7 cases of B (A) subtype, and cross matching was performed by saline medium and anti human globulin card to analyze the red blood cells(RBCs) transfusion strategy. 【Results】 The serology results of blood type of 7 samples were similar, with B(A)04/O01 in 3 cases, B(A)04/O02 in 2 cases and B(A)02/O01 in 2 cases. 7 cases of B (A) subtypes were matched with randomly selected blood donors of type O and B on the major side. 【Conclusion】 B(A) subtypes should be identified by genotyping techniques. Washed RBCs of type B and O can be used for B(A) blood type transfusion.

Identification for rare B(A) blood group / 临床检验杂志

Objective To investigate the serological and molecular identification of 2 rare B( A) blood groups. Methods The ABO blood groups of 2 samples from blood donors were detected by routine serological method. The genotype features was identified by PCR-sequence specific primer (PCR-SSP) and direct sequence analysis. Results The serological results for the 2 blood donors showed the characteristics of B(A) phenotype. The sample 1 was genotyped as BO2 subtype by PCR-SSP and direct sequencing showed B alleles in exon 7, presented nt640 A＞G mutation which was confirmed to be B(A)04/O02 genotype.The sample 2 was genotyped as BO1 sub-type by PCR-SSP and direct sequencing showed B alleles presented nt700 C＞G mutation in exon 7 which was confirmed to be B(A)02/O01 genotype. Conclusion The phenotype of the two samples should be B ( A ) and the genotypes should be rare B(A)04/O02 and B(A)02/O01.

Identification and molecular mechanism study of a case with B(A)02 allele / 天津医药

Objective To identify and investigate B(A)02 allele in a patient. Methods Serological tests were performed with standard serological methods in a patient with B(A)02 allele. DNA sequences of all seven exons and exon-intron boundaries of ABO gene were analyzed by polymerase chain reaction (PCR), direct DNA sequencing and sequencing after gene cloning. In order to analyze the allele, PyMOL software was used to establish 3D model of Glycosyltransferases B (GTB). Results The serological results showed the characteristics of B(A) phenotype. DNA analysis revealed that ABO gene of the individual was heterozygous of B(A)02/O01 allele. 700C>G mutation was identified in B101 allele, which resulted in the amino acid substitution P234A in GTB. Through the analysis of the 3D structure of GTB, it was speculated that the P234A replacement affected the intermolecular forces of the 234 amino acid and Met-266, thus changed the conformation of the donor-binding pocket of GTB,that made GTB capable of recognizing and tranferring the GalNac to the H antigen, which can lead to the formation of the weak A antigen on membrane of red blood cells. Conclusion The P234A replacement can affect the spatial conformation of the specific recognition region conformed by Met-266 and Ala-268 residues, which leads to the antigenicity change of the ABO blood group.

A Case of ABO*Ael02/O04 Genotype with Typical Phenotype O / 대한진단검사의학회지

Ael is a rare blood type which has the least amount of A antigen among A subgroups. It can be detected by special tests performed to resolve the discrepancy between red cell and serum typing in routine serological typing. The presence of A antigen on Ael red cell is demonstrable only by adsorption and elution tests. An Ael individual does not secret A substance in the saliva and may have anti-A antibody in the serum which is usually less reactive with the reagent red cells than anti-B antibody. In Korea, Ael02 has been reported more frequently than other Ael alleles. We report a case of Ael02/O04 who presented as typical phenotype O with strong anti-A and anti-B antibodies and no A antigen detected even by adsorption and elution tests. The case has been proved to be Ael02/O04 by direct sequencing analysis. In individuals with history of discrepancies in the results of ABO phenotyping, ABO genotyping is needed for an accurate evaluation of their blood type.

Molecular Characteristics of A Subgroups in Koreans / 대한수혈학회지

BACKGROUND: An exact ABO blood type is essential for transfusion therapy. Genetic structures of ABO blood group and subgroup have been investigated and about 100 ABO alleles have been reported worldwide. This study was performed to investigate the molecular characteristics of A subgroups in the Korean population. METHODS: Nine A and five AB subgroups were collected from patients and from blood donors of Korean Red Cross blood centers after serological ABO blood group typing. On these samples, allele-specific polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), direct sequencing of exon 6 and 7, and allele separation were performed for ABO gene analysis. RESULTS: The ABO PCR-RFLP genotyping results of 13 samples among the provisional 14 A subgroups were identical with their phenotypes. ABO*A205 allele was observed in an Aint subgroup. Two new A alleles that showed 784G>A base change and 990C>T of intron 6. And a polymorphism of 532C>T in A(pro) intron 5 were also discovered. Conclusion: Through the molecular analysis of this study, serologically unidentified A subgroups were obviously identified. And the new alleles only observed in the Korean A subgroups were recognized.

Study on B(A) phenotypes and identification of novel B(A)641 allele in chinese population / 中国输血杂志

C mutation. All 8 samples displayed the B(A) phenotype. Their real genotypes were B(A)/O. Conclusion Three B(A) alleles in the Chinese Han population were detected. Two alleles,B(A)700,B(A)640 were reported previously. One novel allele B(A)641, was first identified in this study.