NOVEL HLA-DPB1 ALLELES DETECTED IN THE ETHIOPIAN POPULATION

The number of identified HLA-DPB1 alleles increased rapidly by applica tion of DNA-based typing techniques. PCR-SSO typing indicated the pres ence of possible new HLA-DPB1 variants in the Ethiopian population. Th e use of the SET technique, which considers polymorphic as well as con stant regions in the second exon of HLA genes, allowed direct identifi cation of two new allelic variants. Moreover, a recently identified HL A-DPA1 variant was also present in this population. The newly defined allelic HLA-DPB1 sequences found in five individuals of the Ethiopian population were confirmed by cloning and subsequent sequencing of the cloned DNA. One of the new alleles was shown to segregate in a family and was also present in unrelated individuals. Both new DPB1 alleles r epresent new combinations of existing polymorphism in the hypervariabl e regions. In different populations the frequency of these new HLA-DP variants remains to be determined.