Quantifying the genetic risk for the development of axial spondyloarthropathy: could this become a diagnostic tool?

PURPOSE OF REVIEW: To assess the utility of recent genetic findings in ankylosing spondylitis (AS) and axial spondyloarthropathy (SpA) in relation to diagnostic testing, prognosis and responses to biologic treatment and the development of new therapies. RECENT FINDINGS: AS and other forms of SpA are polygenic with more than 100 genes contributing to disease susceptibility. The role of genes in determining the outcome of the disease and response to treatment is less clear. Here, we review some of the progress that has been made over the past decade in understanding the genetic contribution to these diseases and how this may be used to inform the development of new treatments. In those with a high pretest probability of SpA human leukocyte antigen (HLA)-B27 testing can increase the posttest predictive value to almost 100% in some cases. There are currently no reliable genetic predictors of disease severity or response to treatment. SUMMARY: The utility of HLA-B27 as a diagnostic tool when coupled with careful clinical assessment is well established but other genetic markers probably have relatively little to add. In contrast, novel drug targets are likely to be identified from genetic association studies.

Molecular genetics of rheumatoid arthritis.

Following the successful determination of the molecular genetics of single-gene disorders, attention has not surprisingly turned to complex genetic disorders. However, preliminary experience suggests that unravelling the genetic component of common inflammatory disorders, such as rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus, might be a harder nut to crack.