title: Presence of the DRB4*0103102N null allele in different DRB1*04-positive individuals.
abstract: The DRB4 gene encoding the DR53 antigen is present in DRB1*04-, DRB1*07- and DRB1*09-positive individuals. Eight allelic variants of DRB4 have been recognized, 5 resulting in an expressed DR53 antigen and 3 belonging to the null alleles. So far the DRB4*0103102N null allele had been found exclusively in individuals carrying the haplotype DR7,-DQ9. High-resolution typing of HLA class II by polymerase chain reaction using sequence-specific primers (PCR-SSP) and/or sequence-based typing of kidney patients and their families revealed the presence of the DRB4*0103102N null allele segregating with DRB1*04 and DQB1*03 in 4 different families. Three different haplotypes on which the null allele was located, were recognized by family studies: DRB1*0401, DQB1*0301; DRB1*0402, DQB1*0302 and DRB1*0404, DQB1*0302. Determination of the DR53 specificity of antisera reacting with DR53-positive individuals has always been difficult due to the simultaneous presence of DR4, 7 or 9. Identification of DR4-positive DR53-negative individuals as described here, provided the serological reactions with DR53-antisera and revealed the antibody specificities in the antisera used.
authors.affiliation: Tissue Typing Laboratory, University Hospital Maastricht, The Netherlands.
authors.forename: C E
authors.initials: CE
authors.lastname: Voorter
authors.forename: N M
authors.initials: NM
authors.lastname: Lardy
authors.forename: E M
authors.initials: EM
authors.lastname: van den Berg-Loonen
mesh_terms: D000483:Alleles; D004247:DNA / Q000032:analysis; D017931:DNA Primers / Q000737:chemistry; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D059845:HLA-DRB4 Chains; D006239:Haplotypes; D006801:Humans; D008215:Lymphocytes, Null; D010375:Pedigree
chemical_list: D017931:DNA Primers; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C553505:HLA-DRB1*04:01 antigen; C553506:HLA-DRB1*04:02 antigen; D059845:HLA-DRB4 Chains; D004247:DNA