The RHD genotype of more than 96% of D- Japanese could be determined by conventional PCR-SSP. In addition, we identified a novel DEL allele having c.1252T>A mutation and a novel RHD silencing allele having c.761C>G nonsense mutation.

We first identified an ABCG2 null allele (provisional ISBT allele number ABCG2*01N.23) having a large deletion including the promoter region.

We identified three known and ten new silent KEL alleles from Japanese individuals with the K phenotype. The KEL allele with the c.299G>C (p.Cys100Ser) mutation was the most frequent.

Aim: The present study reports a single nucleotide polymorphism (SNP) of ATP-binding cassette, membrane G2 (ABCG2) gene may influence the expression of Jra antigen on red blood cells (RBCs). Methods: Genomic DNAs from 474 random donors were examined for SNPs, c.-262C/T, c.376C/T, and c.421C/A by polymerase chain reaction. The amount of Jra antigen of RBCs was assayed by flow cytometry using human monoclonal anti-Jra (HIRO-133). We classified them in three groups: Group I (wild type) with no variance of three loci (c.-262C, c.376C, and c.421C), Group II with SNP of c.376T and/or c.421A but with c.-262C, and Group III with SNP loci c.-262T. Results: Compared to Group I (n = 185), Group II (n = 263) showed decreased Jra expression on RBCs by 20–75%, whereas SNP c.-262T (Group III) increased Jra expression with more than 50%. The predicted open structure of 5′ untranslated region formed by c.-262T may recruit the initiation complex for translation or increase the rate of ribosomal scanning, thereby enhancing the frequency of protein synthesis. Conclusion: Among a healthy Japanese population, the SNPs c.376C>T and/or c.421C>A downregulated expression of Jra, whereas SNP c.-262C>T augmented Jra expression.

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