Characterization of 50 local anti-HLA-A9 (A23 and/or A24) sera against
the HLA-A2403 antigen allowed the retrospective assignment of A2403 a
nd the verification of A23 and A24 specificities in a panel of 9196 vo
lunteer bone marrow donors. The six A2403 positive subjects identified
were confirmed by PCR using four sequence-specific primer mixtures. P
opulation analysis showed the distribution and HLA-A/B linkage disequi
librium of HLA-A23 and A24 to be typical of a Northern European Caucas
oid population. HLA-A2403 has a phenotype frequency of 0.00065 (gene f
requency - 0.00033) and is in linkage disequilibrium with HLA-B63 and
possibly B35.