Four new DP alleles identified in a study of 500 unrelated bone marrow donor-recipient pairs

HLA-DP genotyping of 500 donor recipient pairs in a retrospective analysis sponsored by the National Marrow Donor Program (NMDP) identified four new D P alleles, two DPB1 and two DPA1. DNA sequencing confirmed that DPB1*8001 a nd *8101, each found in a single individual, are novel combinations of prev iously described sequence motifs in the six variable regions of DPB1. DPA1* 02014, found in two individuals, is identical tu DPA1*02011 except for a no vel silent substitution, a G to A transition at the third position oi codon 14. DPA1*01032, found in one individual, is identical to DPB1*01031 except for a silent G to A transition at the third position of codon 20. The iden tification of these novel alleles brings the total number of reported DPB1 alleles to 85 and DPA1 alleles to 15.