Distribution and molecular basis of A2 subtype in Guangzhou blood donors

Abstract

Objective To investigate the distribution and molecular basis of A2 subtype among blood donors in Guangzhou. Methods Whole blood samples of 793 group A blood donors in Guangzhou Blood Center were randomly collected. A2 subtype was screened by anti-A1 lectin in 96-well plate, and ABO typing was confirmed by the tube test. Then, the genomic DNA of A2 subtype blood donors was extracted, and the exons 6-7 of ABO gene were sequenced to determine the genotype of A2 subtype. Results Among 793 group A blood donors, there were 13 cases of A2 subtype, and the frequency in group A was 1.64%(13/793). The sequencing results of exons 6-7 of ABO gene showed that 10 of the 13 A2 subtypes carried A2 alleles, which were ABO*A2.05/ ABO*O.01.01 (n=5), ABO*A2.05/ ABO*O.01.02(n=2), ABO*A2.01/ABO*O.01.01(n=1) and ABO*A2.01/ ABO*O.01.02(n=2), respectively. The other 3 cases only carried ABO*A1.02 alleles. Conclusion The main genotype of A2 subtype in Guangzhou is ABO*A2.05, followed by ABO*A2.01.

Keywords

• a2 subtype
• abo gene
• a2 allele