Update on the genetics of psoriatic arthritis

Abstract

Psoriatic arthritis (PsA) is a common disease arising from a complex interplay between genetic, environmental and immune related factors. PsA exhibits one of the largest known recurrence risks among fi rst degree relatives in a complex rheumatic disease. While there is substantive evidence supporting a strong genetic component of PsA, it has been diffi cult to elucidate genes specifi c to PsA pathogenesis. Investigating the genetic etiology of PsA is inherently challenging given the existence of gene-gene interactions, gene-environment interactions as well as a potential contribution of copy number variants (CNVs) and epigenetic factors. This chapter will provide an overview of the genetics basis of PsA focusing on candidate gene studies, genome-wide linkage and association-based studies, in addition to highlighting the genetics related to PsA pharmacotherapy (i.e., pharmacogenetics).