strains, mainly O157, and has a good prognosis (2, 3). Atypical HUS or diarrhea (-) HUS may be idiopathic, familial or due to a variety of conditions such as therapeutic drug usage (ovulation inhibitors, immunosuppressive agents), various diseases (malignancies, systemic lupus erythematosus), pregnancy and infections (4, 5). It can occur at any age including newborns and it has a frequently recurrent course and poor renal prognosis (1, 4, 5).