Polymorphism at Codons 114, 116, 145, and 163 Muddle the Typing of HLA-B1304

• Published in: Human immunology 1997-06, Vol.55 (1), p.66-73
• Main Authors: Ellexson, Mary, Lai-Kwan, Pauline, Lau, Marie, Muto, Kathie, Terasaki, Paul, Cole, Jeff, Thompson, Caroline, Hildebrand, William
• Format: Article
• Language: English
• Subjects: Alleles; Amino Acid Sequence; Base Sequence; Codon; Cross Reactions; Genotype; Histocompatibility Testing; HLA-B Antigens - genetics; HLA-B Antigens - immunology; HLA-B13 Antigen; HLA-B15 Antigen; Humans; Molecular Sequence Data; Polymorphism, Genetic
• ISSN: 0198-8859; 1879-1166
• DOI: 10.1016/S0198-8859(97)00055-4

Genetic exchanges often muddle the typing of HLA class I molecules, this is also the case for HLA-B∗1304. Serologic and molecular DNA class I typing report a B15/B55 type for cell 847, whereas DNA sequencing finds B∗5501/B∗1304. HLA-B∗1304 differs by no more than four amino acids from other HLA-B13 molecules, a comparative analysis of the B13 and B15 families was therefore performed to determine why serologic and molecular DNA approaches report a B15 type for B∗1304. Comparisons demonstrate that limited differences individuate the B15 and B13 molecules such that the genetic recombination of codons 145 and 163 in the class I heavy chain’s α2 alpha helix prompt B∗1304 to exhibit a B15X21 pattern of serologic cross-reactivity. Molecular DNA class I typing approaches are also swayed by genetic recombinations to type B∗1304 as a B15 molecule: B15-like nucleotide sequences encoding residues 114, 116, and 145, lead B∗1304 to exhibit a B15 PCR amplification pattern. Thus, genetic exchanges encoding key amino acids in the class I heavy chain lead molecular and serologic typing approaches to categorize HLA-B∗1304 as a member of the B15 family.