In the study population, MHT was reported as occurring at the same time as aHUS symptoms in ~ 2/3 of patients presenting with comorbid aHUS and MHT, irrespective of treatment status, and more patients with aHUS and MHT possessed pathogenic genetic variants or anti-CFH antibodies than patients with aHUS alone (40 [56%] vs 382 [37%]). This evidence concerns the gene CFH and malignant hypertension.