 1. Hemolytic Uremic Syndrome, HUS, is a condition characterized by three symptoms, mechanical hemolytic anemia, thrombocytopenia, and renal impairment. 2. Atypical HUS. A HUS refers to non-chegotoxin HUS and can be caused by secondary factors, such as streptococcus pneumonia or other causes. However, A HUS is considered a primary disease due to a disorder in complement alternative pathway regulation. 3. Atypical HUS accounts for 5-10% of HUS cases in children, but the majority of HUS cases in adults. The incidence of complement A HUS is not known precisely, but more than 1,000 A HUS patients have been reported. 4. Onset of A HUS can occur from the neonatal period to adulthood, and most patients present with hemolytic anemia, thrombocytopenia, renal failure, and extra-renal manifestations. 5. Diagon. This article was authored by Fremos Barquiveronique and Lorex Gentile. We are article.tv, links in the description below.