Recognition of HLA-A*24: 137 allele in a Taiwanese unrelated bone marrow stem cell donor and the plausible HLA haplotype associated with A*24:137

We detected a rare HLA-A*24:137 allele in an unrelated Taiwanese haematopoietic stem cell donor during a routine SBT (sequence-based typing) HLA typing exercise. The DNA sequence of A*24:137 is identical to the sequence of A*24:02:01:01 in exons 2 and 3 except at codon 21 where CGC was replaced with CAA. The DNA variation caused an amino acid alteration at amino acid residue 21 (R->Q). The HLA haplotype in association with A*24:137 may be deduced as A*24:137-B*15-DRB1*14. The formation of A*24:137 was probably the result of a nucleotide point mutation involving A*24:02:01:01. It remains to be determined whether A*24:137 is restricted to Taiwanese/Chinese ethnicity.