MTHFR and hyperinsulinemic hypoglycemia, familial, 4: In addition to those detected by newborn screening, 14 patients (10%) were diagnosed in the first year (4 non-pyridoxine responsive CBS deficiency; 1 unsure regarding responsiveness; 3 cblC, 1 cblG, 1 cblE defect; 2 MTHFR deficiency; 2 could not name the diagnosis).