Atypical Hemolytic Uremic Syndrome (aHUS)
Complement-mediated ‘atypical’ hemolytic uremic syndrome (aHUS) is a chronic and life-threatening ultra-rare genetic disease with an estimated prevalence of seven per one million individuals in which uncontrolled complement activation causes blood clots in small blood vessels throughout the body, or thrombotic microangiopathy (TMA), leading to kidney failure, stroke, heart attack and death.

The prognosis for patients with aHUS is generally poor. Approximately 70% of patients with the most common mutation experience chronic renal insufficiency, chronic dialysis, or death by one year after the first clinical symptoms. aHUS commonly recurs in patients who undergo renal transplantation for the kidney injury and kidney failure suffered due to the uncontrolled complement activity. Approximately 50% of patients with aHUS have been identified to have genetic mutations in at least one of the complement control proteins or neutralizing autoantibodies to complement regulatory factors, which can lead to uncontrolled complement activation.