The B*4602 was identified in a healthy Japanese donor. The B46 variant anti
gen differed serologically from B46. The nucleotide sequence of B*4602 diff
ered from that of B*4601 by a single base (from A to G) at position 293 in
exon 2. The substitution changed the amino acid Asp at position 74 to Gly.
The gene frequency of B*4602 in the Japanese population is extremely low, T
he presumed haplotype of B*4602 was HLA-A2-Cwl-B*4602-DRB1*09. This is the
first report of polymorphism of the B46 antigen.