Genetics of ANCA-Associated Vasculitis

ANCA-associated vasculitis (AAV) is a group of disorders that is caused by inflammation affecting small blood vessels. AAV includes microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) renamed from Wegener’s granulomatosis, and eosinophilic granulomatosis with polyangiitis (EGPA), renamed from Churg-Strauss syndrome. AAV can be considered a complex disease; in fact, both genetic and environmental factors are involved in its susceptibility. To improve the understanding of the disease, the genetic component has been extensively studied by candidate association studies and genome-wide association studies. Most of the identified genetic AAV risk factors are common variants, which still needs further investigation to clarify their importance. In this chapter, we discuss the results of genetic studies in AAV. We also present novel approaches to identifying the causal variants in complex susceptibility loci and disease mechanisms. Finally, we discuss the limitations of current methods and the challenges that we still have to approach in order to translate genomic and epigenomic data into clinical practice.