RESUMEN
PURPOSE: HLA (human leukocyte antigen)-class I genes are highly polymorphic, play many roles in organ and bone marrow transplantation. HLA-B is the most polymorphic class I locus with 414 alleles. HLA-class I typing, which is based on serologic method, has been used until recently. The development of molecular biological techniques make it possible to define the genotypes of HLA genes. METHODS: Analyses of HLA-B genotyping on 1,000 UCB (Umbilical Cord Blood) samples which were considered to be HLA-B homozygote or blank were performed by ARMS-PCR (Amplification Refractory Mutation System-PCR) method and direct sequencing. RESULTS: We could identify HLA-B*5001 which was known to be absent in Koreans. CONCLUSION: It is strongly suggested that HLA-B homozygote should be confirmed to the DNA level especially in cases of donor selection for the unrelated bone marrow transplantation.