Evaluation of the Genotypes of the Lewis Blood Group in a Korean Population Using Direct Sequencing

ABSTRACT

BACKGROUND: The FUT2 and FUT3 genes determine the Lewis phenotype of red blood cells (RBCs). Recently, the Lewis genes, the secretor genes, and several mutations that cause Lewis negative and nonsecretor phenotypes have been identified. The purpose of this study was to analyze the gene frequency of FUT2 and FUT3 in a Korean population by comparing the use of the direct sequencing method to the use of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for mutation detection in the FUT2 and FUT3 genes. METHODS: RBCs and peripheral blood leukocytes were obtained from 225 apparently healthy volunteers to determine the phenotype and genotype of the FUT2 and FUT3 genes. Lewis phenotypes were determined on K3EDTA-stablized fresh blood samples using the column agglutination method. Lewis blood group genotyping was performed by use of the direct sequencing method. For the detection of T59G, C357T, and A385T mutations, the PCR-RFLP method was performed. RESULTS: The frequencies of the Lewis blood group phenotype were 12.4% for Le(a+b-), 70.7% for Le(a-b+), 11.1% for Le(a-b-) and 5.8% for Le(a+b+), respectively. Direct Sequencing of the FUT2 gene identified 92.2% C357T, 56.9% A385T, 0.4% G244A mutations and 1.8% del396. Direct Sequencing of the FUT3 gene identified 46.9% T59G, 30.4% G508A, 1.1% T202C, 1.1% C314T, 0.7% A1029G, 3.0% T1067A and 13.3% G1242A mutations. The PCR-RFLP method results were discordant in nine cases (1 case for C357T, 4 cases for A385T and 2 cases for T59G) as compared to the direct sequencing method results. CONCLUSION: We have determined the frequencies of FUT2 and FUT3 gene mutations in a Korean population. The use of the direct sequencing method was more accurate than the use of the PCR-RFLP method for the determination of the genotype of the FUT2 and FUT3 genes.