HLA-B*4413 identified in a UK Caucasoid potential bone marrow donor

We describe a novel allele belonging to the B*44 allele group. HLA-B*4413 w as identified in a Caucasoid potential bone marrow donor from the Anthony N olan Bone Marrow Trust register. Initial HLA typing of this donor revealed unusual serological reactivity. Further investigation was carried out by re ference strand conformation analysis (RSCA) and sequence-based typing (SBT) using DNA extracted from an Epstein-Barr virus (EBV)-transformed B-cell li ne made from this donor (AMI005AN). In this individual, two B*44 alleles we re revealed upon initial investigation: B*4409 and a previously unseen alle le which has been named B*4413. B*4413 is identical to B*44031 except for a unique nucleotide substitution resulting in an amino acid difference at re sidue 61 in the alpha 1 helix.