LARGE-SCALE DRB AND DQB1 OLIGONUCLEOTIDE TYPING FOR THE NMDP REGISTRY- PROGRESS REPORT FROM YEAR 2

DNA typing of HLA class II alleles of the DRB1/3/4/5 and DQB1 loci usi ng sequence-specific oligonucleotide probes and polymerase chain react ion amplified DNA has been used for the large-scale typing of donors f or the National Marrow Donor Program unrelated donor registry. The res ults of quality control analysis for the second year of the project (1 0/1/939/ 30/94) show the typing continues to be highly accurate, speci fic, and reliable. The average percent of correctly classified HLA oli gotypes (groups of alleles defined by a hybridization pattern with a p anel of sequence-specific oligonucleotide probes) based on 9,244 DRB1 and 7,244 DQB1 assignments was 99.8% (range 99.4%100.0%) for DRB1/DRB3 /DRB4/DRB5 and 99.8% (range 99.6%100.0%) for DQB1. This level of accur acy is particularly remarkable because the 4,636 DRB quality control s amples were tested blindly and could not be distinguished from 57,580 donor samples tested at the same time by the laboratories.