INS and Hypoglycemia: During hypoglycemia, insulin was 16.72 μIU/ml (<2 μIU/ml), C-peptide was 3.8 ng/ml (normal range 0.9-1.8 ng/ml), blood ketone level was 0 mmol/l and plasma ammonia was elevated at 253 μmol/l (normal range 16-60 μmol/l), indicating hypoketotic hypoglycemia consistent with hyperinsulinism with hyperammonemia.