REN and congenital thrombotic thrombocytopenic purpura: A laboratory evaluation revealed the following: a blood urea nitrogen (BUN) level of 71 mg/dl (25.3 mmol/L), a serum creatinine level of 4.69 mg/dl (414.6 μmol/L) and a plasma renin activity above 20 ng/ml/hr (above 5.56 ng/L/s, normal range 0.9–2.9 ng/ml/hr) with microangiopathic hemolytic anemia.