HLA-B*8202 identified in a Caucasoid potential bone marrow donor.
Sequence analysis of HLA class I alleles has continued to reveal the true extent of polymorphism, particularly for B-locus alleles. This diversity can arise through reshuffling of polymorphic sequences generated by point mutation, resulting in interallelic recombination or intergenic recombination (1). Here we describe a new B-locus allele, B*8202, which is structurally most similar to B*8201, having only one nucleotide difference in exon 3 at nucleotide 557, resulting in an amino acid change of aspartic acid to glycine at residue 162. Glycine is the consensus amino acid for B-locus alleles, which suggests that B*8202 is older than B*8201 in evolutionary terms. B*8201 was found to be a hybrid of B*4501 and B*5602 that may have arisen through recombination events, explaining the serological patterns observed with these allotypes. The importance of high-resolution typing is emphasised here as routine typing suggested the presence of B*8201 and the new variant allele may have been missed had it not been typed further by sequence-based typing.
Cox
S T
ST
Anthony Nolan Research Institute, The Royal Free Hospital, London, United Kingdom.
Hossain
E
E
McWhinnie
A
A
Prokupek
B
B
Madrigal
J A
JA
Little
A M
AM
D000483:Alleles; D016026:Bone Marrow Transplantation / Q000276:immunology*; D004252:DNA Mutational Analysis; D015235:HLA-B Antigens / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000276:immunology; D012689:Sequence Homology, Nucleic Acid; D014019:Tissue Donors; D044465:White People / Q000235:genetics*
D015235:HLA-B Antigens