Deficiency of adenosine deaminase type 2 (DADA2) is a rare multisystem vasculopathic syndrome. It is an autosomal recessive disorder caused by loss-of-function mutations in the Cat Eye Syndrome Chromosome Region Candidate 1 (CECR1) gene on chromosome 22q11, which encodes the adenosine deaminase type 2 (ADA2) enzyme. While some carriers are asymptomatic, many develop significant clinical disease affecting multiple systems, including immunodeficiency with recurrent infections, intermittent fevers, livedo racemosa, childhood-onset polyarteritis nodosa (PAN), and systemic vasculopathy, including early-onset recurrent strokes and Sneddon syndrome. DADA2 syndrome is a rare condition, with an estimated prevalence of 4 per 1 million per year in the general population.