Prediction of Duffy blood group phenotypes through genotypic analysis among Southern Thai blood donors

Abstract

Abstract: 

Background and Objectives: The Duffy (FY) blood group system is important in transfusion medicine due to the risk of alloimmunization from Fy^a and Fy^b antigens after transfusion or pregnancy. Serological testing can misinterpret Fy^a, Fy^b, and Fy^x antigens; therefore, genotyping of FY*A and FY*B alleles is applied to accurately predict FY phenotypes. This study aimed to determine FY*A and FY*B allele frequencies, predict FY phenotypes, and assess the presence of the FY*X allele in Southern Thai blood donors. Materials and methods: Altogether, 427 DNA samples of blood donors in Southern Thailand were genotyped using in-house PCR with sequence-specific primers (PCR-SSP) to detect FY*A and FY*B alleles. Samples with FY*A/B and FY*B/B genotypes were confirmed and used to determine the FY*X allele by DNA sequencing. Results: The FY*A, FY*B and FY*B^ES allele frequencies were 0.854, 0.145 and 0.001, respectively. Although the Fy(a–b–) phenotype was not observed, one donor was identified as possessing the FY*A/B^ES genotype. Genotype frequencies were FY*A/A (72.83%), FY*A/B (24.82%), FY*B/B (2.11%) and FY*A/B^ES (0.23%). Those 115 samples with FY*A/B and FY*B/B genotypes, FY*X allele screening revealed variation only at c.298G>A, which did not affect Fy^b antigen expression. Fy^a and Fy^b alloimmunization risks were significantly higher in Southern Thais compared to Central and Northern Thais and other Asian populations (p < 0.05). Conclusion: The high frequency of the FY*A and FY*B alleles among Southern Thais contributes to transfusion-induced alloimmunization risks. Consequently, FY genotyping is suggested to minimize transfusion reactions and improve blood transfusion safety.