title: Identification of HLA-A*0224: implications for PCR-SSP HLA typing.
abstract: We describe a novel HLA-A*02 allele, A*0224, that was identified after a comparison of DNA and serological typing revealed a discrepancy in the HLA-A types: HLA-A2 was defined by serology but was not detected by the polymerase chain reaction using sequence-specific primers (PCR-SSP). DNA sequencing indicated the presence of a variant HLA-A*02 allele that differed from A*0201 by a single base (C/A) at position 453. This base substitution corresponded to the annealing site of a primer common to the two A*02-amplifying PCR-SSP mixtures used in the method. This provides an explanation for the results and highlights a limitation of PCR-SSP methods even where two PCR mixtures are used to detect alleles. Serological titration studies suggested that A*0201, A*0205 and A*0224 are unlikely to be differentiated during routine serological typing.
authors: Regional Tissue Typing Laboratory, Welsh Blood Service, Cardiff, UK. mguttridge@wbmdr.demon.co.uk
authors: M G
authors: MG
authors: Guttridge
authors: J
authors: J
authors: Street
authors: M
authors: M
authors: Thomas
authors: C
authors: C
authors: Darke
mesh_terms: D001483:Base Sequence; D018076:DNA, Complementary; D015789:HLA-A2 Antigen / Q000145:classification / Q000235:genetics*; D006650:Histocompatibility Testing; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction
chemical_list: D018076:DNA, Complementary; D015789:HLA-A2 Antigen