HLA haplotype in association with the low incidence C*07:66 allele found by case analysis of Taiwanese and mainland Chinese individuals.

OBJECTIVES

HLA-C07:66 is a low-incidence HLA-C allele. The aim of the study is to report the Taiwanese and mainland Chinese ethnicities of individuals with C07:66, together with its uniqueness and polymorphism.

MATERIALS AND METHODS

A sequence-based typing method was employed to confirm this low-incidence allele. Polymerase chain reaction was performed to amplify exons 2, 3, and 4 of the HLA-A, HLA-B, and HLA-C loci and exon 2 of the HLA-DRB1 and HLA-DQB1 loci using group-specific primer sets. The amplicons were sequenced in both directions using BigDye Terminator Cycle Sequencing Ready Reaction kit. The blood donors in this study consisted of randomized Taiwanese and mainland Chinese individuals and family members with the C*07:66 allele.

RESULTS

The DNA sequence of C07:66 is identical to that of C07:02:01:01 for exons 2, 3, and 4, except for residue 688 in exon 4. This nucleotide substitution causes a single amino acid alteration to the protein sequence of C07:02:01:01. Confirmation of the DNA and protein sequences of C07:66 and the Taiwanese and mainland Chinese ethnicities of individuals with this allele were established in this study. One probable HLA C*07:66-associated HLA haplotype may be deduced from these individuals.

CONCLUSION

The information on the ethnicity of the C07:66 allele and the deduced probable HLA haplotype associated with the low-incidence C07:66 allele reported in this study may aid in HLA testing laboratories for reference purposes. In addition, they can be used by stem cell transplant donor search coordinators to help create, for patients bearing this uncommon HLA allele, strategies for finding compatible donors using bone marrow donor registries comprising unrelated individuals.