Fatal Breakthrough Invasive Fungal Infection due to Aspergillus flavus in a Pediatric Patient with Adenosine Deaminase Deficiency.

Adenosine deaminase 2 (ADA-2) deficiency is a rare autoinflammatory and immunodeficiency disorder that predisposes affected individuals to severe infections. We report the case of a 13-year-old boy with a homozygous CECR1 (c.11104 del) mutation who developed fatal breakthrough invasive aspergillosis caused by Aspergillus flavus. Despite combination antifungal therapy, multiple surgical interventions, and granulocyte transfusions, the infection progressed, leading to pulmonary dissemination. Fungal culture and polymerase chain reaction (PCR) confirmed A. flavus. This case underscores the aggressive course of fungal infections in ADA-2 deficiency and the limited efficacy of standard treatment strategies in the setting of profound immunosuppression and vascular invasion. Early recognition and novel therapeutic approaches are urgently needed to improve outcomes in this vulnerable population.