HLA-DRB1, DQA1, DQB1 DNA POLYMORPHISM IN THE BULGARIAN POPULATION

We describe for the first time the use of PCR based techniques to anal yze the MHC class II polymorphism of the Bulgarian population. The pre sent study provides the HLA-DRB, DQB1 allele frequencies in 116 Bulgar ian individuals and DQA1 alleles frequencies in 100 subjects. DNA from these individuals was typed for DRB and DQB1 typed by the PCR- Allele Specific Amplification (PCR-ASA) method and DQA1 by PCR followed by h ybridization using Sequence Specific Oligonucleotides (PCR-SSO). Allel e and haplotype frequencies and linkage disequilibria are computed by the standard methods used for the XIth International Histocompatibilit y Workshop. The highest frequencies are 0.159, 0.109 and 0.085 for DRB 11101, DRB1*1601 and DRB1*1301 respectively. Among the eight DQA1 all eles detected, DQA10501 (0.344) is found to be much more frequent tha n the two most frequent alleles DQA10102 (0.225) and DQA1*0101 (0.151 ). Twelve DQB1 alleles are found and three of them, DQB10301 (0.280), DQB10502 (0.153) and DQB1*0201 (0.133) showed the highest frequencie s. The haplotype DRB11101-DQA1*0501-DQB1*0301 (0.079) predominate cle arly, followed by DRB11601-DQA1*0102-DDQB1*0502 (0.055) and DRB1*0101 -DQA10101-DQB1*0501. These results indicate that the Bulgarian popula tion is characterized by features representative of the European anthr opological type with a substantial contribution from the Southern Belt of Europe.