Development of PCR-SSOP for HLA-A typing of bone marrow registry donors

A medium resolution PCR-SSOP typing method, using 26 digoxigenin labelled probes, has been established for the identification of HLA-A alleles. The system is capable of discriminating all of the serologically defined specificities except for eight heterozygous combinations which are however rare in Caucasians. The method has been applied to 1,838 individuals on the local bone marrow registry who either had only one detectable HLA-A antigen, or a HLA-A antigen whose presence had been queried using the serological technique or a broad HLA-A specificity assigned by the serological technique. In all but one case the serologically assigned antigens were detected with the PCR-SSOP method. In addition, PCR-SSOP detected the presence of a second HLA-A allele in over 10% of individuals who had been previously homozygous. Frequency information, based on a population of 5,000 individuals, has been established using a combination of molecular and serological typing data.