The overactivation of the complement system triggers a destructive cycle of endothelial damage and dysfunction which leads to thrombosis, destruction of erythrocytes and organ damage and dysfunction. aHUS is a life-threatening condition and can lead to stroke, heart attack, kidney failure and premature death.^1-2,4-6

In some patients, there may be no identified genetic variant; 30–50% of aHUS patients do not have an identified disease-causing genetic driver. Genetic testing is not required for a diagnosis of aHUS.^2,7-10

Some of the complement-triggering conditions linked to the development of aHUS include pregnancy/postpartum, hypertensive emergency, solid organ transplantation, autoimmune diseases, certain prescription medications or illicit drugs, infections, glomerulonephritis, surgery/trauma and malignancy.^1,11