Renal manifestations including thrombotic microangiopathy (TMA), atypical hemolytic uremic syndrome (aHUS), and nephrotic syndrome have been described in cblC deficiency (2–4), and MMACHC variant c.271dupA was the most frequent damaged allele in patients with cblC defect and renal TMA (5, 6). The gene discussed is CBLC; the disease is hyperinsulinemic hypoglycemia, familial, 4.