The girl presented normal glucose metabolism (fasting glycaemia: 79 mg/dL, HbA1c: 5.4%) with insulin resistance (fasting insulin: 51 mU/mL, HOMA-IR index: 9.9), normal lipid profile (total Cholesterol: 197 mg/dL, HDL: 23 mg/dL, LDL Cholesterol: 137 g/dL, Triglycerides: 185 g/L) and hepatic steatosis with mildly increased transaminases levels (AST: 62 U/L, ALT: 122 U/L). The gene discussed is INS; the disease is fatty liver disease.