Molecular approaches to transfusion medicine in P olynesians and M aori in N ew Z ealand

Summary In recent years, with the application of genotyping technology, there has been a substantial increase in the number of reported blood group alleles. This survey was designed to evaluate new molecular blood group genotyping methods and compile reference blood group data sets for P olynesian and M aori subjects. Subsequent analyses of these results were used to calculate probability of random match, to trace Polynesian ancestry and migration patterns and to reveal past and present episodes of genetic admixture. Genomic DNA samples from M aori and P olynesian subjects were drawn from the V ictoria U niversity of W ellington DNA Bank and genotyped using combination of commercial PCR ‐ SSP kits, hybridization SNP assay services or sequence‐based typing. This survey also involves compilation of serological ABO and R hesus blood group data from R akai P aaka Iwi tribal members for comparison with those generated during our molecular blood group study. We observed perfect consistency between results obtained from all molecular methods for blood group genotyping. The A, O, DC cEe, DCC ee, MN s, K−k+, Jk(a+b−), Jk(a+b+), Fy(a+b−), Fy(a+b+), Di(a+b−), Co(a+b−) and Do(a−b+) were predominant blood group phenotypes in both P olynesians and M aori. Overall, our survey data show only small differences in distributions of blood group phenotypes between P olynesian and Maori groups and their subgroups. These differences might be associated with selection, population history and gene flow from E uropeans. In each case, we estimate that patients with certain blood groups have a very low probability of an exact phenotypic match, even if the patients were randomly transfused with blood from donors of their own ethnicity. The best way to avoid haemolytic transfusion reaction in such cases is to perform a pretransfusion cross‐match and recruit increased numbers of donors with rare phenotype profiles. The conclusion of this study is that application of molecular method covering as many known variants as possible may help to improve the accuracy blood group genotyping and potentially conserve the routine requirements of transfusion centres.