Population differences in the distribution of HLA-B27 allele in ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease affecting mainly the spine and the sacroiliac joints. This disorder has a genetic background and is strongly associated with HLA-B27 gene which occurs in about 90 % of patients. The prevalence of ankylosing spondylitis usually correlates with the frequency of HLA-B27. The strength of association HLA-B27 with AS varies between different populations and is also distinct for individual alleles of HLA-B27 gene. Some alleles can increase a risk of ankylosing spondylitis while others may have a protective effect. This work deals with the population differences in the occurrence of HLA-B27 alleles and their relation to development of ankylosing spondylitis. Key words: ankylosing spondylitis, HLA-B27, allele, subtype, population difference