Abstract

The transcription factor hepatocyte nuclear factor-4a plays a key role in insulin secretion and mutations in its encoding gene, HNF4A, have been associated with Monogenic diabetes (MODY 1) during adolescence or early adulthood and with transient hyperinsulinemic hypoglycemia during infancy. They are inherited as an autosomal dominant trait, therefore, HNF4A sequencing should be considered in every neonate presenting with macrosomia or persistent hypoglycemia after 24 hours from birth, especially when there is a family history of early-onset diabetes. Management of hyperinsulinism includes regular feeding, intravenous glucose and diazoxide, as first-line treatment. Blood glucose levels need regular monitoring to adjust treatment properly. Continuous glucose monitoring systems are not validated for neonates or patients with hyperinsulinism, so finger-prick blood tests are usually used before every meal. We present a case of diazoxide use in a female patient with neonatal hypoglycemia due to HNF4A mutation, where continuous glucose monitoring facilitated treatment decisions and detected hyperglycemia, as an adverse event early in the course. Notably, CGM use after hospital discharge contributed significantly to ongoing glucose monitoring and management. We recommend that further studies could establish CGM’s usefulness as an adjunct in clinical care.