Two conserved HLA haplotypes (HLA-A∗11:127N-B∗54:01-DRB1∗04:05 and HLA-A∗11:01-B∗40:221-C∗03:04-DRB1∗14:54-DQB1∗05:02) observed in the Taiwanese population

Abstract

ObjectiveHLA-A∗11:127N and HLA-B∗40:221 are two rarely observed alleles in the HLA-A locus and in HLA-B locus, respectively. The objective of this study is to report the two plausible deduced HLA haplotypes in association with HLA-A∗11:127N and HLA-B∗40:221 in unrelated Taiwanese bone marrow stem cell donors. Materials and MethodsA sequence-based typing method was used to confirm the low incidence alleles observed. Polymerase chain reaction was carried out to amplify exons 2, 3, and 4 of the HLA-A, -B, and -C loci with group-specific primer sets. Amplicons were sequenced using the BigDye Terminator Cycle Sequencing Ready Reaction Kit in both directions according to the manufacturer's protocol. ResultsWe deduced the two probable HLA haplotypes in association with A∗11:127N and B∗40:221 as HLA-A∗11:127N-B∗54:01-DRB1∗04:05 and HLA-A∗11:01-B∗40:221-C∗03:04-DRB1∗14:54-DQB1∗05:02, respectively. ConclusionInformation on the two deduced HLA haplotypes associated with the rare A∗11:127N and B∗40:221 alleles that we report here is valuable for HLA tissue typing laboratories for reference purposes and for stem cell transplantation donor search coordinators to determine the likelihood of finding compatible donors in unrelated bone marrow donor registries for patients bearing these two uncommon HLA alleles. Because A∗11:127N and B∗40:221 have so far been found only in the Taiwanese population, we think the haplotypes that we report here are most likely conserved in Taiwanese.