Long-term kidney function stabilization with fludrocortisone in autosomal recessive renal tubular dysgenesis: a case report.

Renal tubular dysgenesis (RTD) is a rare disorder characterized by impaired development of the proximal tubules and kidney dysfunction due to decreased fetal renal plasma flow and renin-angiotensin system (RAS) inhibition. Fetal anuria causes severe oligohydramnios and Potter sequence, and most patients die within days after birth due to refractory hypotension, anuria, and respiratory distress. While vasopressin and fludrocortisone therapy have been reported, the long-term efficacy remains unclear due to the rarity of survivors. We report a 10-year-old girl with autosomal recessive renal tubular dysgenesis (ARRTD), a genetic form of RTD caused by mutations in RAS-related genes. She initially experienced recurrent dehydration, electrolyte abnormalities, and kidney dysfunction due to polyuria but showed long-term improvement following fludrocortisone therapy.