Deficiency of adenosine deaminase type 2 (DADA2): clinical picture, diagnosis and treatment

Deficiency of adenosine deaminase type 2 (DADA2) is a genetically determined multisystem auto inflammatory disease first described in 2014. It results from pathogenic variants in the ADA2 gene that lead to the reduction or complete loss of ADA2 enzyme activity. It presents with a highly variable phenotype as systemic or cerebral vasculitis, immunodeficiency and/or bone marrow failure, usually with early onset. More than 370 published cases of DADA2 can be found in international literature, however, statistical calculations estimate the prevalence to more than 35.000 individuals worldwide. The diversity of the phenotypic spectrum delays diagnosis and effective treatment of patients not infrequently until adulthood. By reviewing the clinical picture, diagnosis and therapy of DADA2. we aim to improve the awareness of this disease among professionals and thus shorten the patients' pathway to effective treatment, which is efficient and crucial in preventing some of the permanent sequelae of untreated disease. (author)