Researchers have identified a new gene that is thought to be critical in the regulation of insulin -- the key hormone in diabetes -- from a family with both high and low blood sugar conditions. Besides Type 1 or Type 2 diabetes, nearly 1-2 per cent of cases of the blood sugar condition is due to impairment in a gene called MAFA, that can impair production of insulin and also cause insulinomas -- insulin-producing tumours in pancreas, the study showed.