HLA and Non-HLA Genes in Ankylosing Spondylitis and Seronegative Spondyloarthritis in Asia

Genetic susceptibility to ankylosing spondylitis, the prototype of the seronegative spondyloarthropathies is strongly associated with the major histocompatibility antigen HLA-B27. However besides HLA-B27, there are other genes, both MHC and non-MHC, that predispose to susceptibility and severity of disease. Studies on the genetic epidemiology of these diseases in Asia have shown similar findings to those elsewhere; with most showing strong association of HLA-B27 with ankylosing spondylitis, no difference in HLA B27 subtypes between patients and controls, some association of IL-1 gene cluster, TNF and LMP polymorphisms with ankylosing spondylitis, association of HLADR8 with acute anterior uveitis, and no association with TAP and TGF polymorphisms. Genetic predisposition to disease severity has not been reported from Asian studies. As most studies from the region have been of small sample size, future studies should be designed to obtain adequate levels of significance, and the results of genome wide linkage scans may be useful in guiding future studies into the genetic background of these diseases.