Hyperinsulinemic Hypoglycemia in a Neonate

A 25-day-old girl born from consanguineous parents presented with seizures. She was apyretic, and, except for axial hypotonia, her neurological examination was normal. A cerebral scan and cardiac and abdominal ultrasonography did not detect any abnormality. First-line biological investigations showed hypoketotic hyperinsulinemic hypoglycemia [glucose, 1 mmol/L (18 mg/dL); reference, 4–6 mmol/L (70–110 mg/dL); insulin, 19.32 mUI/L; reference, 2.00–12.00 mUI/L] and a constant hyperlactatemia (5.7 mmol/L; reference, 0.5–2.2 mmol/L). Cortisol (258 nmol/L; reference, 250–800 nmol/L), ammonia (34 μmol/L; reference