Genetics and epigenetics of rheumatoid arthritis

Rheumatoid arthritis (RA) is known to have a genetic component: the evidence comes from twin and family studies as well as genetic studies themselves. Family studies consistently confirm that first degree relatives of patients with RA are at increased risk of developing the condition, supporting a genetic component. The most robust data comes from the Icelandic genealogical database. This chapter covers the basics of genetic studies in RA, designing the genetic study, RA-specific results and insights that can be gained from these. Detailed analyses of selected genetic regions are discussed, alongside genes that may indicate severity. Genetic factors associated with treatment response are also considered. Finally, the role of epigenetics is covered.