A rare, genetic thrombotic microangiopathy due to dysregulation of the alternative complement pathway and characterized by the triad of hemolytic anemia, thrombocytopenia, and acute renal dysfunction. The disease is MONDO_0016244 (atypical hemolytic-uremic syndrome). Also known as: Atypical Hemolytic Uremic Syndrome, D-HUS, aHUS, atypical HUS, atypical hemolytic uremic syndrome, hemolytic-uremic syndrome without diarrhea, hemolytic-uremic syndrome without diarrhoea, non-diarrhea-associated hemolytic uremic syndrome.