A novel a subtype allele that demonstrates allelic competition

Ann Clin Lab Sci. 2011 Summer;41(3):282-4.


A 68-year-old man with an ABO discrepancy discovered during a routine check up and 3 members of his family were referred for ABO analysis. A novel allele (A(w)14; 699 C>A, H233Q) was found by sequence analysis of exons 6&7 and in those with the A(w)14 allele, complete ABO analysis was performed. The propositus and his son had an A(w) phenotype with the A(w)14/O01 genotype. His daughter had an A(w)14/B101 genotype with a normal B phenotype. Three-dimensional molecular modelling was used to predict the effect of the H233Q amino acid change on the resulting A glycosyltransferase. The A(w)14 produced a weak A phenotype, and its ability to produce A antigens was further reduced when it was co-inherited with a B101 enzyme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / genetics*
  • Aged
  • Alleles
  • Amino Acid Sequence
  • Base Sequence
  • DNA Mutational Analysis
  • Female
  • Glycosyltransferases / genetics
  • Humans
  • Male
  • Molecular Sequence Data
  • Nuclear Family
  • Sequence Analysis, DNA


  • ABO Blood-Group System
  • Glycosyltransferases