Identification of the novel HLA-B*40:221 allele in a Taiwanese hematopoietic stem cell donor using a sequence-based

K L Yang1, S K Lee, P Y Lin

  • 1Laboratory of Immunogenetics and Cord Blood Bank, Buddhist Tzu Chi Stem Cells Centre and Marrow Donor Registry, Buddhist Tzu Chi General Hospital, Buddhist Compassion Relief Tzu Chi Foundation, Hualien, Taiwan. edward@tzuchi.com.tw

Using DNA sequence-based typing method, we found a new HLA-B*40 variant, B*40:221, in a Taiwanese hematopoietic stem cell donor. The allele sequence of B*40:221 is identical to the sequence of B*40:01:01 in exons 2, 3 and 4 except the nucleotides at codon 265 (GGG→AGG). The sequence variation caused one amino acid exchange at residue 265 where Gly was replaced by Arg. The probable HLA-A, -B, -C, -DRB1 and -DQB1 haplotype in association with B*40:221 may be deduced as HLA-A*11:01-B*40:221-C*03:04-DRB1*14:54-DQB1*05:02. The generation of B*40:221 is thought as a result of a nucleotide point mutation involving B*40:01:01. Our discovery of B*40:221 increases the polymorphism of B*40 in Taiwanese.

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