The role of genetics and epigenetics in rheumatic diseases: are they really a target to be aimed at?

To date, numerous genetic and epigenetic studies have been performed and provided a crucial step forward in our understanding of the pathogenesis of rheumatic diseases. However, most of the recent advances in the treatment of rheumatic diseases including biological therapies are not based on or even discrepant from these genetic and epigenetic findings. For example, tumor necrosis factor inhibitors are quite successful in the treatment of rheumatoid arthritis (RA), Behçet's disease (BD), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) but not in that of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), Sjögren's syndrome (SS) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV), conversely, RA shares genetic backgrounds more with SLE, SSc, SS and AAV than BD, AS and PsA. In this review, we briefly highlight the findings from recent genetic and epigenetic studies and discuss what needs to be studied to provide a novel, more efficacious management of rheumatic diseases.