title: Complete coding sequence of HLA-B*2712: a serologic B27-negative antigen associated to Bw6.
abstract: We report the complete coding sequence of a new HLA-B27 subtype, B*2712, which was found in a Caucasian Spanish family within the chromosome A2-Cw2-B*2712-DR15-DQ6. B*2712 was first detected as a segregating B blank Bw6-associated antigen. Extensive serologic analysis demonstrated that this new B27 subtype was not recognised by any of the B27-monospecific antibodies, giving positive reactions only with some monoclonal reagents against B40 or B27,40. Sequencing analysis showed a high similarity with B*2708, only differing in three clustered amino acid residues at positions 69 to 71 located in the alpha helix of the alpha1 domain. Residues 69 and 71 point towards the T-cell receptor, while amino acid 70 points to the antigen binding site. Loss of the conserved structure of pocket B as well as the differentiated pocket F configuration suggests that B*2712 does not confer ankylosing spondylitis susceptibility. Misleading serologic definition supports the usefulness of DNA-typing methods to complement HLA class I typing.
authors.affiliation: Centro de Transfusión de Madrid, Menendez Pelayo, Spain. ctm@bitmailer.net
authors.forename: A
authors.initials: A
authors.lastname: Balas
authors.forename: S
authors.initials: S
authors.lastname: Santos
authors.forename: F
authors.initials: F
authors.lastname: García-Sánchez
authors.forename: R
authors.initials: R
authors.lastname: Lillo
authors.forename: J L
authors.initials: JL
authors.lastname: Merino
authors.forename: J L
authors.initials: JL
authors.lastname: Vicario
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018076:DNA, Complementary; D015235:HLA-B Antigens / Q000235:genetics*; D015796:HLA-B27 Antigen / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data
chemical_list: D018076:DNA, Complementary; D015235:HLA-B Antigens; D015796:HLA-B27 Antigen; C038652:HLA-Bw6 antigen