DADA2 is a monogenic disorder that affects multiple organs [7]. The syndrome is mainly characterized by medium vessel vasculitis, resembling polyarteritis nodosa, early stroke, recurrent fever, and slight immunodeciency. The phenotypic appear­ance varies considerably. The illness generally shows up in childhood. However, some people go unidentied until adulthood [8]. DADA2 should be suspected in the patient presenting with recurrent fever, rash, and strokes even in the absence of fam­ily history. The patients exhibit hematological problems, including pure red cell aplasia (PRCA), hypogammaglobulinemia, thrombocytopenia, and neutropenia [9]. Patients presenting with hematologic manifestations like PRCA and bone marrow failure present with severe disease and complete loss of function of ADA2. In con­trast, those who suffer from vasculitis presented late in the course of the disease and had missense mutation with roughly 3% residual enzyme function. The hemato­logic symptoms do not respond to treatment with tumor necrotic factor (TNF) inhib­itors. On the other hand, vasculitis symptoms usually respond well to TNF inhibitors [10]. The clinical manifestations of the DADA2 are shown in Fig.4.1.