title: Immunogenetics of a new HLA-B null allele, HLA-B*4423N.
abstract: The second example of an HLA-B*44 null allele (B*4423N) was identified by discrepancies between serological and polymerase chain reaction-sequence-specific primer (PCR-SSP) typing in two north-western European Caucasoid unrelated stem cell donor volunteers. HLA-B*4423N was identical to B*440201 except for a single nucleotide substitution at position 493 in exon 3, resulting in a premature stop codon at bases 493-495 (TAG rather than CAG at codon 141). As expected, comprehensive serological testing using 54 antisera, directed towards B44 or Bw4, failed to identify the HLA-B44 (Bw4) specificity. The B*4423N-bearing haplotype was identified as A*0201, Cw*0501, DRB1*0408, DRB4*01, DQA1*03, DQB1*0304 and the frequency of B*4423N estimated as 0.00006 (carriage frequency 0.0121%) in 16 533 subjects resident in Wales.
authors.affiliation: Welsh Transplantation and Immunogenetics Laboratory, Welsh Blood Service, Pontyclun, UK.
authors.forename: L
authors.initials: L
authors.lastname: Hammond
authors.forename: J
authors.initials: J
authors.lastname: Street
authors.forename: J
authors.initials: J
authors.lastname: Downing
authors.forename: J
authors.initials: J
authors.lastname: Thompson
authors.forename: C
authors.initials: C
authors.lastname: Darke
mesh_terms: D005060:Europe; D005787:Gene Frequency; D005828:Genetics, Population; D015235:HLA-B Antigens / Q000235:genetics* / Q000276:immunology; D059948:HLA-B44 Antigen; D006801:Humans; D007125:Immunogenetics; D017422:Sequence Analysis, DNA; D014852:Wales; D044465:White People / Q000235:genetics
chemical_list: D015235:HLA-B Antigens; D059948:HLA-B44 Antigen