It is defined as a metabolic disorder of multiple aetiologies, characterised by chronic hyperglycaemia with disturbance of carbohydrate, fat, protein, water and electrolyte metabolism which result from defects in insulin secretion, insulin action or both.2 Much of the morbidity and mortality burden of diabetes mellitus is due to the acute and chronic complications that often arise. The gene discussed is INS; the disease is Other metabolic disease.