In our case, ADAMTS13 activity and microbiological testing (BioFire GI panel) helped us to rule out the causes of TMA like thrombotic thrombocytopenic purpura (TTP), Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (STEC-HUS), and atypical HUS (aHUS). The gene discussed is ADAMTS13; the disease is atypical hemolytic-uremic syndrome.