Haplotypes in the 5'-upstream region, exons 3 and 4, and introns 2 and 3 of the ABO blood group gene.

We previously described two haplotypes named the ABORR*L-associated and ABORR*S-associated haplotypes in the 5'-upstream region of the ABO blood group gene. Here we studied polymorphisms in exons (Exs) 3 and 4 and introns (Ints) 2 and 3 of the ABO gene, and analyzed the haplotypes in those Exs, Ints, and the 5'-upstream region. Two haplotypes (at Int2nt108-Int2nt362-Int2nt369-Int2nt539-Ex3nt106-Int3nt1178-Int3nt1357-Ex4nt188-Ex4nt189) were deduced to be (1) A-C-C-C-T-C-T-A-T, which was linked with ABORR*L and ABO*O(A), and (2) A-C-C-C-G-T-C-G-C, G-C-C-C-G-T-C-G-C, and A-T-G-A-G-T-C-G-C, which were linked with ABORR*S and the other common ABO alleles. This finding also shows the existence of two major lineages of the Japanese ABO alleles.