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 C*07:359 is identical to that of C*07:02:01:01 in exons 2, 3, and 4 except at residue 862, where the G of C*07:02:01:01 is substituted by the A of C*07:359. The nucleotide exchange leads to an amino acid replacement at codon 264, where the glutamic acid of C*07:02:01:01 is replaced by the lysine of C*07:359. We deduced a probable HLA-B and HLA-C haplotype that is associated with C*07:359 in Taiwanese, namely B*39-C*07:359.
CONCLUSIONS: Information on the ethnicity of the C*07:359 allele and its deduced probable HLA haplotypes that are associated with the low-incidence C*07:359 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.