David J. Sas, D.O.

David J. Sas, D.O., is a pediatric nephrologist at Mayo Clinic in Rochester, Minnesota, where he serves as Chair of the Division of Pediatric Nephrology in the Department of Pediatrics. Dr. Sas provides care for children and families throughout Minnesota and surrounding areas who are affected by conditions involving the kidneys and urinary system. His practice focuses on helping children with kidney stone disease — including rare, inherited forms — restore kidney function and quality of life through accurate diagnosis, individualized prevention strategies, and evidence-based management. He is also an Associate Professor of Pediatrics at Mayo Clinic College of Medicine and Science.

Dr. Sas takes a practical, patient-focused approach to care. "I meet patients where they are and make sure everyone has a clear understanding of the goals of our treatment strategy," he says.

Areas of expertise

Dr. Sas provides comprehensive evaluation and treatment for children with kidney and metabolic disorders, using both clinical and research insights to guide care.

• Kidney stone disease: Specialized expertise in diagnosing and managing pediatric stone disease, including rare and genetic causes such as primary hyperoxaluria and Dent disease.
• Electrolyte disorders: Evaluation and treatment of chronic and acute imbalances in sodium, potassium, calcium, and other electrolytes.
• Acid-base disorders: Accurate diagnosis and management of conditions affecting the body's acid-base balance, including metabolic acidosis and alkalosis.
• Inherited and rare kidney diseases: Multidisciplinary care for children with nephrocalcinosis, cystinuria, and tubular disorders.

Research and expertise

Dr. Sas is internationally recognized for his clinical and research leadership in pediatric urinary stone disease. He contributes extensively to the Rare Kidney Stone Consortium and has been involved in major clinical trials that helped establish new therapies for genetic stone disorders such as primary hyperoxaluria type 1. His academic work bridges the laboratory and clinic, emphasizing translational research and precision medicine approaches to children's kidney care. Board-certified in pediatrics and pediatric nephrology, Dr. Sas also teaches and mentors learners through Mayo Clinic College of Medicine and Science.