title: Serologic and molecular studies of two kindreds expressing recombinant HLA DR1/DR2 haplotypes.
abstract: We have recently identified two unrelated kindreds in which DR1 and DR2 co-segregate as a single haplotype spanning several generations. Serology, PCR-RFLP and sequence-specific oligonucleotide probes were used to characterize the presence and segregation of the DRB1 and DRB5 loci in these two kindreds. In both families, the recombination resulted in co-expression of a DRB1 locus that encoded a DR1 serologic phenotype and a DRB5 locus that encoded a "short" DR2 serologic phenotype. One of these kindreds co-expressed the DR1 and DR15 (DRB5*01). The other kindred co-expressed the DR1 and DR16 (DRB5*02). Our data indicate that the recombination event occurred in the region between the DRB1 locus and the DRB5 locus. This recombinant haplotype produces a DR2 phenotype which lacks the epitopes normally encoded by the DRB1 locus, resulting in a serologic "short" antigen. The clinical significance of such a recombinational event becomes evident when patients with such a genotype require allogeneic bone marrow transplantation.
authors.affiliation: Dept. of Pathology and Microbiology, University of Nebraska Medical Center, Omaha.
authors.forename: J
authors.initials: J
authors.lastname: Wisecarver
authors.forename: S
authors.initials: S
authors.lastname: Shepherd
authors.forename: K
authors.initials: K
authors.lastname: Beisel
authors.forename: R
authors.initials: R
authors.lastname: Rubocki
mesh_terms: D000483:Alleles; D001483:Base Sequence; D015343:DNA Probes, HLA; D000939:Epitopes / Q000235:genetics / Q000276:immunology; D005260:Female; D005802:Genes, MHC Class II; D006684:HLA-DR Antigens / Q000235:genetics*; D015798:HLA-DR1 Antigen / Q000235:genetics*; D015802:HLA-DR2 Antigen / Q000235:genetics*; D059811:HLA-DRB1 Chains; D059847:HLA-DRB5 Chains; D006239:Haplotypes / Q000235:genetics*; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010375:Pedigree; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic
chemical_list: D015343:DNA Probes, HLA; D000939:Epitopes; D006684:HLA-DR Antigens; D015798:HLA-DR1 Antigen; D015802:HLA-DR2 Antigen; D059811:HLA-DRB1 Chains; D059847:HLA-DRB5 Chains; D000949:Histocompatibility Antigens Class II