title: HLA-B*4431: a new HLA-B variant with a complex ancestral history involving HLA-B*44, B*40 and B*07 alleles.
abstract: We here describe the identification of the new allele HLA-B*4431, which was found in three members of a Turkish family. Sequencing of the new allele following haplotype-specific PCR amplification revealed that exon 2 is identical to HLA-B*4402, whereas exon 3 resembles a HLA-B*40 variant with the exception of position 572, where a single nucleotide transversion (C > G) leads to an amino acid exchange (Trp162Ser). The generation of the 3' part of B*4431 may be best explained by a separate recombination between B*40 and B*07. Although B*4431 consists of B44 in its alpha1 domain and of B60(40) in its alpha2 domain; the new allele only displayed B44 seroreactivity, which demonstrates that epitopes crucial for B60(40) specificity must be located in the alpha1 domain.
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D016026:Bone Marrow Transplantation; D003601:Cytotoxicity Tests, Immunologic; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D015235:HLA-B Antigens / Q000235:genetics*; D059947:HLA-B40 Antigen; D059948:HLA-B44 Antigen; D015793:HLA-B7 Antigen / Q000235:genetics*; D006239:Haplotypes; D006650:Histocompatibility Testing; D006801:Humans; D008969:Molecular Sequence Data; D009190:Myelodysplastic Syndromes / Q000175:diagnosis / Q000235:genetics / Q000628:therapy; D020641:Polymorphism, Single Nucleotide / Q000235:genetics
chemical_list: D005819:Genetic Markers; D015235:HLA-B Antigens; D059947:HLA-B40 Antigen; D059948:HLA-B44 Antigen; D015793:HLA-B7 Antigen