Negative testing both for ADAMTS13 deficiency or presence of anti-ADAMTS13 autoantibodies, with a negative assessment for STEC-HUS trough Shiga-like toxin testing and STEC stool culture, supports the diagnosis of aHUS, for which further secondary causes must be ruled out in order to verify the diagnosis of primary aHUS. Here, ADAMTS13 is linked to hemolytic-uremic syndrome.