RESUMEN
BACKGROUND: In the Duffy blood group system (Fy(a), Fy(b), Fy(x), and Fy antigens), Fy(x) antigen is associated with weak Fy(b) while Fy antigen means the null phenotype Fy (a-b-). Fyx antigen and Fy antigen result from the polymorphisms of Fy125 allele. This report assessed the allele frequency and genotype frequency of Fy(a), Fy(b), Fy(x), and Fy antigens in Koreans. METHODS: We performed a study of the followings on 253 visitors to the health promotion center of Seoul National University Bundang Hospital: PCR-RFLP and PCR-SSP for the detection of Duffy 125G > A and -33T > C; PCR-SSP for the detection of Duffy 265C > T and 298G > A. RESULTS: The results of PCR-RFLP and PCR-SSP were consistent with each other in a total of 253 subjects. Allele frequency was as follows: Fy 92.3%, Fy(125) 6.1%, and fy(125/265) 1.6%. The fy(125/265) allele was newly observed. Fy(125/298), fy(125/265/298), and fy(-33/125) alleles were not detected in Koreans. The distribution of Duffy phenotypes in Koreans was as follows: Fy (a+b-) 88.1%, Fy (a-b+) 0.4%, Fy (a+b+) 11.5%, and Fy (a-b-) 0.0%. Fy (a+) was 99.6% and Fy (b+) was 11.9%. CONCLUSION: In our study for Duffy polymorphisms, the frequency of Fy allele was very high. The frequency was similar to those of other Asian populations, but different from those of Caucasians. The fy(125/265) allele, which was associated with Fy(x) antigen, was newly detected in Koreans.