Brief communication A novel HLA-B*420502 allele identified by PCR-SSO/SSP routine typing and confirmed by Sequencing-based typing* F. Mrazek I. Fae Z. Ambruzova L. Raida K. Indrak M. Petrek G.F. Fischer Authors’ affiliation: F. Mrazek 1 , I. Fae 3 , Z. Ambruzova 1 , L. Raida 2 , K. Indrak 2 , M. Petrek 1 , G.F. Fischer 3 1 Department of Immunology,Tissue Typing Laboratory, Medical Faculty, Palacky University Olomouc, Czech Republic 2 Department of Haemato- oncology, Medical Faculty, Palacky University Olomouc, Czech Republic 3 Institute for Blood Group Serology, University of Vienna, Austria Correspondence to: Dr Frantisek Mrazek Department of Immunology Medical Faculty Palacky University I.P. Pavlova 6 CZ-775 20 Olomouc Czech Republic Tel.: þ420 58 5415116 Fax: þ420 58 5415116 e-mail: mrazekf@fnol.cz Abstract: A novel human leukocyte antigen-B (HLA-B) allele, B*420502, was identified in a patient with leukemia (Caucasoid, Czech ancestry) and his mother during intrafamily search for the hematopoietic stem cell donor. The novel allele was initially detected by HLA typing at low resolution using both sequence specific primers and sequence specific oligonucleotides techniques that resulted in unique reaction patterns. The alleles of the HLA-B locus were separated by the haplotype-specific extraction technique. Sequencing of those alleles revealed a novel allele, B*420502, that is identical with B*420501 except a T!G exchange (synonymous mutation) at position 618. A novel human leukocyte antigen-B (HLA-B) allele, B*420502, is reported. The allele was detected during an intrafamilial donor search for hematopoietic stem cell transplantation in a male patient and his mother. The results from HLA-B locus low-resolution typing by two independent techniques, polymerase chain reaction (PCR) with sequence specific primers (PCR-SSP) and PCR with sequence- specific oligonucleotides (PCR-SSO) not matching to any known genotype, proposed the presence of a new allele. After heterozygous sequencing-based typing (SBT) was performed, further ‘allele- specific’ SBT on the particular alleles separated using haplotype-specific extraction confirmed a novel HLA-B allele officially designed B*420502 (1). Key words: haplotype-specific extraction; HLA-B; polymerase chain reaction; sequencing-based typing Acknowledgments: Technical assistance of M. Lukesova and S. Camachova is gratefully acknowledged. Supported in part by the Czech govt. funding (Research programmes MSMT J14/98: 151100004 and 151100002). Received 19 October 2004, revised 7 December 2004, accepted for publication 14 December 2004 Copyright ß Blackwell Munksgaard 2005 doi: 10.1111/j.1399-0039.2005.00376.x Tissue Antigens 2005: 65: 275–277 Printed in Singapore. All rights reserved *The nucleotide sequence of the allele B*420502 reported in this article has been submitted to the EMBL database. Accession numbers AJ716156 (exon 1 and joint CDS), AJ716157 (exon 2), and AJ716158 (exon 3) have been assigned to the particular sequence data. The name B*420502 has been officially assigned by the WHO Nomenclature Committee in June 2004. This follows the agreed policy that, subject to the conditions stated in the most recent Nomenclature Report (1), names will be assigned to new sequences as they are identified. List of such new names will be published in the following WHO Nomenclature Report. 275