After only 6 hours since the test began, the patient experienced symptomatic hypoglycaemia with plasma glucose level went down to 1.6 mmol/L, and his concomitant serum insulin level was 53 mIU/L and C-peptide level was 0.23 nmol/L and pro-insulin level was 3.8 pmol/L. The gene discussed is INS; the disease is Hypoglycemia.