Routine HLA sequence-specific-oligonucleotide typing and confirming sequence-based typing of a prospective bone marrow donor identified a novel B*27 allele, HLA-B*2734.

In this study, we report the identification of a new human leukocyte antigen-B allele in a sample that was tested in our routine typing for volunteer bone marrow donors. This novel allele officially named B*2734 was found in a female donor of Caucasoid origin (laboratory code 158567). The search for unrelated bone marrow donors was initiated by the Aktion Knochenmarkspende Bayern. In comparison with the closest related allele B*2707, B*2734 differs at two nucleotide positions, all located in exon 3, at position 412, 'A' in B*2707 is replaced by 'G' and at position 486, 'G' is replaced by 'A' in the novel allele. The single nucleotide polymorphism at position 412 results in an amino acid substitution at codon 138. The amino acid asparagine is changed to aspartic acid in B*2734 allele. The second nucleotide exchange is a silent mutation and codon 163 remains unaffected as ACG-->ACA, still codes for alanine.