A 12-year-old girl presented with hemolytic uremic syndrome (HUS) characterized by gastrointestinal symptoms, thrombocytopenia, elevated lactate dehydrogenase (LDH), undetectable haptoglobin, moderate anemia, mildly decreased C3 levels, and acute kidney injury (AKI), requiring temporary hemodialysis for 5 days. This evidence concerns the gene C3 and hemolytic-uremic syndrome.