Deficiency of Adenosine Deaminase 2 (DADA2) is a rare monogenic autoinflammatory and vasculopathic disorder caused by mutations in the ADA2 gene (previously known as CECR1). This gene encodes the adenosine deaminase 2 enzyme, which plays a role in immune regulation and the integrity of blood vessels. DADA2 is inherited in an autosomal recessive manner. However, there is marked clinical variability for the same genetic mutations, including among siblings.
The disease typically presents in early childhood, with clinical features including recurrent strokes (especially lacunar infarcts), systemic inflammation, livedo racemosa or other skin manifestations, cytopenias (especially anemia or neutropenia), and immune dysregulation that may mimic autoimmune diseases. There is no cure, but TNF inhibitors (such as etanercept or adalimumab) have shown significant effectiveness in controlling vasculitis and preventing strokes. In severe hematologic forms, hematopoietic stem cell transplantation may be considered.