Deduced probable HLA-C*07:359-associated human leukocyte antigen haplotypes found by case analysis of Taiwanese unrelated bone marrow hematopoietic stem cell donors.

OBJECTIVES

HLA-C07:359 is a low-incidence allele in the human leukocyte antigen (HLA)-C locus. The objective of this study is to report the ethnicity and haplotypes of HLA-C07:359 that were found during an analysis of Taiwanese unrelated bone marrow hematopoietic stem cell donors.

MATERIALS AND METHODS

A sequence-based typing method was employed to confirm low-incidence al-leles. Polymerase chain reaction was performed to amplify exon 2 and exon 3 of the HLA-A, HLA-B, and HLA-C loci, as well as exon 2 of the HLA-DRB1 locus, using group-specific primer sets. The amplicons were sequenced in both directions using BigDye Terminator Cycle Sequencing Ready Reaction kits, according to the manufacturer's protocols. The potential unrelated bone marrow stem cell donors investigated here are individuals with Taiwanese ethnicity who are participating in the Tzu Chi Bone Marrow Donor Registry.

RESULTS

The DNA sequence of C07:359 is identical to that of C07:02:01:01 in exons 2, 3, and 4 except at residue 862, where the G of C07:02:01:01 is substituted by the A of C07:359. The nucleotide exchange leads to an amino acid replacement at codon 264, where the glutamic acid of C07:02:01:01 is replaced by the lysine of C07:359. We deduced a probable HLA-B and HLA-C haplotype that is associated with C07:359 in Taiwanese, namely B39-C*07:359.

CONCLUSION

Information on the ethnicity of the C07:359 allele and its deduced probable HLA haplotypes that are associated with the low-incidence C07:359 allele reported here are of value to HLA testing laboratories for reference purposes. In addition, they can be used by stem cell transplantation donor search coordinators to determine a strategy for finding compatible donors using unrelated bone marrow donor registries when patients carry this uncommon HLA allele.