Atypical haemolytic uraemic syndrome associated with a mutation triggered by .

We present a case of haemolytic uraemic syndrome (HUS) triggered by . Of the species, only type 1 is said to produce Shiga toxin and consequently cause HUS. Investigation of the complement system in this patient revealed a mutation. In individuals with mutations in complement genes incomplete penetrance of atypical HUS (aHUS) is seen, suggesting that a trigger, such as infection, is required for disease to manifest. In an era of complement modulatory therapy for aHUS it is important to be alert to unusual presentations of diarrhoeal-associated disease.