The Genetic and Phenotypic Basis of Blood Group A Subtypes in Koreans

Transfus Med. 2005 Aug;15(4):329-34. doi: 10.1111/j.0958-7578.2005.00598.x.


A serological and genetic study of Korean blood donors with phenotypic group A subtypes was performed. There were 176 donors with phenotypic A subtypes identified. Exons 6 and 7 from 57 representative donors were sequenced. The A(var) allele (784 G > A) was cloned and sequenced, and a family study demonstrating its inheritance and unusual serological characteristics was performed. The A102 allele was the most frequently identified allele in phenotypically A2 (58%, 11/19) and A2B (68%, 17/25) donors. Anti-A1 was rarely present amongst A2 and A2B donors. The family study revealed that the A(var) allele was expressed as phenotype A(weak)B in A(var)/B heterozygote members, but as phenotype O in A(var)/O heterozygotes. The most frequent allele in Korean donors with the A2 phenotype differs from its Caucasian counterpart, as does the frequency of anti-A1. The A(var) allele demonstrates allelic enhancement in A(var)/B heterozygotes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / genetics*
  • Alleles
  • Blood Donors
  • Gene Frequency
  • Genotype
  • Humans
  • Inheritance Patterns*
  • Korea
  • Pedigree
  • Phenotype
  • Sequence Analysis, DNA


  • ABO Blood-Group System