Case Report: The tree that hides the forest, a case of renal ANCA vasculitis concurrent with Fabry nephropathy. [version 1; peer review: awaiting peer review]

This case report presents a complex case of a 65-year-old female with a history of hypertension and a family history of polycystic kidney disease and Fabry disease presented with acute pancreatitis and subsequent renal insufficiency. Despite initial corticosteroid therapy for immuno-allergic nephropathy, the patient's condition deteriorated with the development of a skin rash, uremic syndrome, and neurological symptoms. A renal biopsy revealed cellular crescents and cytoplasmic vacuolization in podocytes and tubular cells. Genetic testing confirmed a GLA gene mutation, consistent with Fabry disease. While undergoing treatment with cyclophosphamide, the patient experienced severe allergic reactions, ultimately leading to acute respiratory distress syndrome and fatal outcome. Despite the Fabry disease variant being primarily associated with cardiac involvement, renal involvement was evident. This case highlights the rarity of this co-occurrence, the diagnostic challenges, the importance of genetic factors in autoimmune kidney diseases, and the impact of drug allergies on patient management.