Neonatal hyperinsulinaemic hypoglycaemia and monogenic diabetes due to a heterozygous mutation of the HNF4A gene.

Recent research has demonstrated that mutations of the hepatocyte nuclear factor 4-alpha (HNF4A) gene are associated with neonatal hyperinsulinaemic hypoglycaemia. Mutations of this gene also cause one of the subtypes of monogenic diabetes, a form of diabetes formerly known as maturity-onset diabetes of the young. This article describes a family discovered to have a novel frame-shift mutation of the HNF4A gene in the setting of early-onset maternal diabetes and severe neonatal hyperinsulinaemic hypoglycaemia. The implications of a diagnosis of HNF4A gene mutation for obstetric and paediatric practice are discussed.