Hemolytic Syndrome [best] — Atypical

aHUS has an estimated incidence of 0.5–1 per million per year, accounting for approximately 5–10% of all pediatric HUS cases but a higher proportion of adult cases. Without treatment, up to 50% of patients progress to end-stage renal disease (ESRD) or die during the first acute episode. The advent of complement-blocking monoclonal antibodies has transformed aHUS from a disease with guarded prognosis to a manageable chronic condition, yet challenges in diagnosis, cost, and long-term monitoring persist.