The A312 Allele (c.280A>T) Is Responsible for the Weak A Phenotype

Ann Clin Lab Sci. 2017 Jan;47(1):99-102.

Abstract

The ABO*A312 allele was found in a 71-year-old Korean male with ABO discrepancy and in his two sons. Although the ABO*A312 allele (c.280A>T, I94F) in an AwB case was registered in GenBank, the impact of the I94F mutation of the ABO gene on the activity of A transferase has not been studied. Transient transfection experiments were performed in HeLa cells using A101, A102, and A312 alleles synthesized by site-directed mutagenesis, and the functional expression level of A antigen was assessed by flow cytometry. The results showed that the A102 and A312 alleles expressed A antigen levels that were 80.28% and 19.32%, respectively, of that of the A101 allele. Our study results demonstrate that the c.280A>T variant is responsible for the weakened expression of A antigen.

Keywords: ABO subgroup; expression study; weak A.

MeSH terms

  • ABO Blood-Group System / genetics*
  • Aged
  • Alleles*
  • Antigens / metabolism*
  • Female
  • Flow Cytometry
  • Genotype
  • Genotyping Techniques
  • Green Fluorescent Proteins / metabolism
  • HeLa Cells
  • Humans
  • Male
  • Pedigree
  • Phenotype

Substances

  • ABO Blood-Group System
  • Antigens
  • Green Fluorescent Proteins