The distribution of glycophorin GYP(B‐A‐B) hybrids among blood donors in north‐eastern Thailand

Background and Objectives Glycophorin GYP(B‐A‐B) hybrid alleles encode a set of low‐frequency antigens, including Mi a . Such hybrids are predominantly found in East and Southeast Asians and demonstrate variation in frequency within that region. These antigens and their corresponding antibodies are clinically significant. We aimed to characterize the GYP(B‐A‐B) hybrid alleles among north‐eastern Thai blood donors. Materials and Methods Altogether, 1377 DNA samples from north‐eastern Thai blood donors were genotyped for GYP(B‐A‐B) using high‐resolution melting (HRM) assay. Samples exhibiting aberrant melting profiles were investigated by Sanger sequencing. The immunogenic potential of the Mi a antigen across diverse populations was also assessed using the Giblett equation. Results Among the 1377 donors, 249 (18.08%) were identified as carrying GYP(B‐A‐B) hybrids. Of these, 17 samples (1.24%) were GYP*Mur homozygotes, 219 (15.90%) were GYP*Mur/GYPB heterozygotes, 12 (0.87%) were GYP*Thai/GYPB heterozygotes and one sample (0.07%) was a compound GYP*Mur/GYP*Thai heterozygote. Additionally, six single‐nucleotide polymorphisms (SNPs) were identified in five donors with the wild‐type GYPB/GYPB genotype. Furthermore, one sample carried two variants at positions c.136+743C>G and c.136+746C>T within intron 2. The Giblett equation calculation predicted a high immunogenic potential of Mi a antigen with substantial variation across populations (1.269–10.468). Conclusion In this study, GYP*Mur was the predominant hybrid allele with a frequency of 254/2754 (9.22%). GYP(B‐A‐B) hybrid alleles show considerable heterogeneity and immunogenicity, with population‐dependent differences driven by variations in antigen distribution and antibody prevalence. The use of our molecular approach may help identify compatible blood products for transfusion and prevent alloimmunization.