A DNA-RFLP TYPING SYSTEM THAT POSITIVELY IDENTIFIES SEROLOGICALLY WELL-DEFINED AND ILL-DEFINED HLA-DR AND DQ ALLELES, INCLUDING DRw10

Abstract

A single enzyme/multiple probe system of HLA-DR and DQ typing using restriction fragment—length polymorphism (RFLP) analysis is presented. TaqI-digested genomic DNAs are hybridized sequentially with short DRβ, DQβ, and DQα cDNA probes. The DRβ probe discriminates between the DR allelic specificities DR1 to DRwl4, with the two exceptions of some DR3/DRwl3 and some DR7/DRw9 combinations. We describe the positive identification of a DRw10-specific RFLP and demonstrate its segregation in families. The DQβ probe defines an allelic system that identifies the alleles DQw1, DQw2, and DQw3. This permits the resolution of DR3/DRw13 and DR7/DRw9 alleles by defining the DR/DQ association caused by linkage disequilibrium. The DQα probe defines another allelic series interrelated with, but independent from, the DQβ series. Specific DQβ/DQα RFLP combinations correlate with known Dw splits of DR2, DRw6, and DR7. Combined use of the three probes permits the identification of HLA-DR, DQ, and certain Dw specificities and provides an effective and easily interpretable system for major histocompatibility complex class II allogenotyping.