The diversity of extended gene haplotypes HLA-B*27 in Croatia

In the present study the extended haplotypes of HLA-B*27 gene were analysed in the sample of 42 Croatian families. Peripheral blood (2 ml) was collected from all the individuals and genomic DNA was extracted using a commercial kit. The HLA alleles were determined using the method PCR sequence specific primers (PCR-SSP) while the microsatellite alleles were amplified using the method PCR-STR. Analysis of HLA-A-B*27-D6S2927-STR MICA-TNFalpha-DRB1 extended haplotypes demonstrated the strongest linkage disequilibrium between HLA-B*27 alleles and microsatellite alleles D6S2927-1 and STR_MICA-A4. Analysis indicated that the rare allele B*2730 is always present in the extended haplotype HLA-A3-B*2730-D6S2927-1-STR MICA-A4-TNFalpha-9-DRB1*16. The results of the present study will be applied in future studies of association between microsatellite alleles and spondyloarthropathies and contribute to a better understanding of peptide binding to HLA class I molecules, as well as other aspects of immune response.