title: Identification of the novel allele HLA-B*0809 in a Caucasian individual: estimation of allogeneic potential between B*08 variants.
abstract: The identification of the new allele HLA-B*0809, which was found in a Caucasian individual, is described. In the sequence analysis the new allele differs from B*0801 by six nucleotides located in exon 3. As the structure is identical to a variety of other HLA-B alleles, it is likely that the new allele originated by gene conversion. At the protein level, the new allele has two amino acid differences compared to B*0801. Comparing the residues of the alpha1 and alpha2 domains of the B*08 variants to each other, a high degree of polymorphism was found. Three alleles differ from B*0801 by only one amino acid residue whereas the other comparisons revealed at least two disparities. B*0809 differs from the other B*08 variants by at least two amino acid residues, suggesting that mismatching may provoke alloreactivity and thus impair clinical outcome of bone marrow transplantation. Among the B*08 alleles with a single amino acid difference, the mismatch combinations B*0801 vs. B*0805 and B*0801 vs. B*0807 appear to be the most compatible based on structural data.
authors.affiliation: Department of Transfusion Medicine, Hannover Medical School, Germany.
authors.forename: H A
authors.initials: HA
authors.lastname: Elsner
authors.forename: R
authors.initials: R
authors.lastname: Blasczyk
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D016026:Bone Marrow Transplantation; D017931:DNA Primers / Q000737:chemistry; D015795:HLA-B8 Antigen / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA; D014184:Transplantation, Homologous; D044465:White People / Q000235:genetics*
chemical_list: D017931:DNA Primers; D015795:HLA-B8 Antigen