Deficiency of adenosine deaminase 2 (DADA2) with bilateral renal subcapsular hematoma: a case report and literature review.

Introduction and importance: Deficiency of adenosine deaminase 2 (DADA2) is a rare autosomal recessive genetic disorder caused by loss-of-function mutations in the adenosine deaminase 2 (ADA2) gene. This condition primarily manifests in pediatric cases before the age of 10 years, with sporadic cases reported in adults. ADA2 is a critical enzyme involved in macrophage differentiation and immune homeostasis. The clinical manifestations of DADA2 vary widely and can affect multiple organ systems. Our case uniquely highlights an infrequent DADA2 manifestation. Case presentation: An 18-year-old female presented with right flank pain, fever, and a history of joint pain, Raynaud's phenomenon, livedo-like rash, and chronic abdominal pain. Physical examination revealed subcapsular hematoma in the right kidney. Further evaluation showed positive serologic tests for rheumatoid factor and antinuclear antibody (ANA). Genetic testing confirmed DADA2 homozygosity. The patient was discharged on the appropriate medications. Clinical discussion: DADA2 is associated with vascular dysfunction and systemic vasculopathy. The clinical manifestations of DADA2 encompass a spectrum of organ involvement, including the skin, nervous system, gastrointestinal system, renal system, and the cardiovascular system. Early recognition and diagnosis are crucial for appropriate management. Conclusion: This case report highlights the diverse clinical presentations of ADA2 deficiency, specifically focusing on bilateral renal subcapsular hematoma. This finding emphasizes the importance of considering DADA2 as a differential diagnosis in patients presenting with unexplained renal manifestations. Increased awareness of the varied clinical presentations of DADA2 will contribute to earlier diagnosis, appropriate management, and improved outcomes in patients affected by this rare genetic disorder.