Abstract
Cloning of the histo-blood group ABO genes has opened up a new era of ABO Typing. In addition to the orthodox immunological ABO phenotyping, it is now possible to determine the ABO genotypes of individuals. Progress has been made in elucidating the molecular genetic bases of three major alleles, subgroups, cis-AB and B (A). Mutational analysis of various alleles has provided clues for the structural basis of activity and specificity of A and B glycosyltransferases. Further advancement is expected in the study of regulatory mechanism of ABO gene expression as well as the functional analysis of ABO polymorphism in the near future.
