HLA-DR AND HLA-DQ DNA GENOTYPING IN MULTIPLE-SCLEROSIS PATIENTS IN NORTHERN-IRELAND

DNA from multiple sclerosis (MS) patients and healthy control individuals from the Northern Ireland population, was assessed by restriction fragment length polymorphism (RFLP) analysis to look for disease-associated polymorphisms. HLA-DR and -DQ allogenotyping was performed using a single enzyme (TaqI)/Multiple probe system. The TaqI/DR-beta RFLPs correlate well with serologically defined specificities and in addition detect further subtypes of these associated with DQ or Dw specificities. The results confirm an association of MS with DR-beta-15 and show a decreased frequency of DR-beta-4 in the patients. An increased frequency of DR-beta-17 in patients negative for DR-beta-15 was also found. There is a decrease in the frequency of the TaqI/DQ-beta-3 (TA10 + ve) RFLP and the TaqI/DQ-alpha-2LL genotype in the MS patients, these not being associated with DR-beta-15. In addition RFLP analysis of the DPA1 and DPB1 genes reveals an MspI/DP-beta 3.0-kb fragment which occurs at a higher frequency in the patients than in the controls.