Allele frequency of HLA-B39 in the Japanese population and identification of a novel B39 allele, B*3923

A new HLA-B39 allele, B*3923, was found in the Japanese population. Compared with B*39022, the new allele had a single point mutation at position 503 in exon 3 with an amino acid substitution, Gln144Arg. To determine B39 allele frequency in Japanese, 275 B39-positive samples from 3277 Japanese individuals were examined by polymerase chain reaction using microtitre plate hydribization (PCR-MPH) and single-strand conformation polymorphism (PCR-SSCP). The frequency of B*3923 was estimated to be 0.4% in B39 alleles of the Japanese population. B*3923 was found in samples from four Japanese individuals, all of whom have DRB1*1406.