Scientists have recently identified a genetic mutation that gives rise to blood sugar variation. It is estimated that in the U.S. 30 million people are living with diabetes, with type 2 being the most common. However, there are rarer forms that account for just 1-4 percent of the cases in the U.S. Known as monogenic diabetes, this type arises from a single mutation in a gene that is passed down from one or both parents. These mutations impair the function of beta cells, which secrete insulin. In the study done by Professor Marta Korbonits of the William Harvey Research Institute at QMUL in the UK, the researchers studied a family in which some members had diabetes, while others had insulin-producing tumors in the pancreas known as insulinomas. How can both high-blood sugar and low-blood sugar conditions run in the same family? Professor Korbonits says a single gene – the MAFA gene – is to blame. The MAFA gene normally regulates production of beta cells, and the mutation causes either diabetes or insulinomas. While the cause of the conditions remain unclear, studying these rare conditions can help researchers explore new ways to trigger regeneration of beta cells and treat more common forms of diabetes.