The paraclinical evaluation during an episode of hypoglycemia indicated a plasma glucose value of 44 mg/dL, serum insulin level 16.3 μU/mL (normal 2.2–24.9 μU/mL), C peptide level 3.72 ng/mL (normal 1.1–4.4 ng/mL), HbA1c 4.99% (normal 4–5.6%), the absence of urinary ketone bodies and anti-insulin antibodies <0.03 U/mL (normal <0.4 U/mL). The gene discussed is INS; the disease is Hypoglycemia.